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Observational Implications of Axionic Isocurvature Fluctuations ; The axion is the most attractive candidate to solve the strong CP problem in QCD. If it exists, the inflationary universe produces axion fluctuations which are mixtures of isocurvature and adiabatic fluctuations in general. We investigate how large isocurvature fluctuations are allowed or favored in order to explain observations of the large scale structure of the present universe. Generic flat universe models with mixed isocurvature adiabatic density fluctuations are studied. It is found that the observations are consistent with the mixed fluctuation model if the ratio alpha of the power spectrum of isocurvature fluctuations to that of adiabatic fluctuations is less than sim 0.1. In particular, the mixed fluctuation model with alpha sim 0.05, total matter density Omega0 0.4, and Hubble parameter H070 kmsMpc gives a very good fit to the observational data. Since the height of the acoustic peak in the angular power spectrum of the cosmic microwave background CMB radiation decreases significantly when the isocurvature fluctuations are present, the mixed fluctuation model can be tested in future satellite experiments. Ratios of the amplitude at the peak location to that at the COBE normalization scale for various models are given. Furthermore, we also obtain the amplitude of isocurvature fluctuations as a function of axion parameters and the Hubble parameter during the inflation. We discuss the axion fluctuations in some realistic inflation models and find that a significant amount of the isocurvature fluctuations are naturally produced.

Positron Escape from Type Ia Supernovae ; We generate bolometric light curves for a variety of type Ia supernova models at late times, simulating gammaray and positron transport for various assumptions about the magnetic field and ionization of the ejecta. These calculated light curve shapes are compared with light curves of specific supernovae for which there have been adequate late observations. The selection of models is generally not based upon the ability to fit the late observations, but rather because the model has been demonstrated by other authors to approximate the spectra and early light curves of that specific SN. From these comparisons we draw two conclusions whether a suggested model is an acceptable approximation of a particular event, and, given that it is, the magnetic field characteristics and degree of ionization that are most consistent with the observed light curve shape. For the ten SNe included in this study, five strongly suggest 56Co positron escape as would be permitted by a weak or radiallycombed magnetic field. Of the remaining five SNe, none clearly show the upturned light curve expected for positron trapping in a strong, tangled magnetic field. Chandrasekhar mass models can explain normally, sub, and super luminous supernova light curves; subChandrasekhar mass models have difficulties with sub and potentially normally luminous SNe. An estimate of the galactic positron production rate from type Ia SNe is compared with gammaray observations of Galactic 511 keV annihilation radiation. Additionally, we emphasize the importance of correctly treating the positron transport for calculations of spectra, or any properties, of type Ia SNe at late epochs geq 200 d.

The Standard Cosmological Model and CMB Anisotropies ; This is a course on cosmic microwave background CMB anisotropies in the standard cosmological model, designed for beginning graduate students and advanced undergraduates. Standard cosmological model'' in this context means a Universe dominated by some form of cold dark matter CDM with adiabatic perturbations generated at some initial epoch, e.g., Inflation, and left to evolve under gravity alone which distinguishes it from defect models. The course is primarily theoretical and concerned with the physics of CMB anisotropies in this context and their relation to structure formation. Brief presentations of the uniform Big Bang model and of the observed largescale structure of the Universe are given. The bulk of the course then focuses on the evolution of small perturbations to the uniform model and on the generation of temperature anisotropies in the CMB. The theoretical development is performed in the pseudoNewtonian gauge because it aids intuitive understanding by providing a quick reference to classical Newtonian concepts. The fundamental goal of the course is not to arrive at a highly exact nor exhaustive calculation of the anisotropies, but rather to a good understanding of the basic physics that goes into such calculations.

B stars as a diagnostic of starformation at low and high redshift ; We have extended the evolutionary synthesis models by Leitherer et al. 1999b by including a new library of B stars generated from the IUE highdispersion spectra archive. We present the library and show how the stellar spectral properties vary according to luminosity classes and spectral types. We have generated synthetic UV spectra for prototypical young stellar populations varying the IMF and the star formation law. Clear signs of age effects are seen in all models. The contribution of B stars in the UV line spectrum is clearly detected, in particular for greater ages when O stars have evolved. With the addition of the new library we are able to investigate the fraction of stellar and interstellar contributions and the variation in the spectral shapes of intense lines. We have used our models to date the spectrum of the local super star cluster NGC17051. Photospheric lines of CIII1247, SiIII1417, and SV1502 were used as diagnostics to date the burst of NGC 17051 at 10 Myr. We have selected the starforming galaxy 1512cB58 as a first application of the new models to highz galaxies. This galaxy is at z2.723, it is gravitationally lensed, and its high signaltonoise Keck spectrum show features typical of local starburst galaxies, such as NGC 17051. Models with continuous star formation were found to be more adequate for 1512cB58 since there are spectral features typical of a composite stellar population of O and B stars. A model with Z 0.4Zsolar and an IMF with alpha2.8 reproduces the stellar features of the 1512cB58 spectrum.

Fomin's conception of quantum cosmogenesis ; The main aim of this paper is to extend the early approach to quantum cosmogenesis provided by Fomin. His approach was developed independently to the wellknown Tryon description of the creation of the closed universe as a process of quantum fluctuation of vacuum. We apply the Fomin concept to derive the cosmological observables. We argue that Fomin's idea from his 1973 work, in contrast to Tryon's one has impact on the current Universe models and the proposed extension of his theory now can be tested by distant supernovae SNIa. Fomin's idea of the creation of the Universe is based on the intersection of two fundamental theories general relativity and quantum field theory with the contemporary cosmological models with dark energy. As a result of comparison with contemporary approaches concerning dark energy, we found out that Fomin's idea appears in the context of the present acceleration of the Universe explanation cosmological models with decaying vacuum. Contemporary it appears in the form of Ricci scalar dark energy connected with the holographic principle. We show also that the Fomin model admits the bounce instead of the initial singularity. We demonstrate that the Fomin model of cosmogenesis can be falsified and using SNIa data the values of model parameters is in agreement with observations.

The Xray Halo of GX51 ; Using Chandra observations we have measured the energyresolved dustscattered Xray halo around the lowmass Xray binary GX51, which shows signs of both singly and multiplyscattered Xrays. We compared the observed Xray halo at various energies to predictions from a range of dust models. These fits used both smoothlydistributed dust as well as dust in clumped clouds, with CO and 21 cm observations helping to determine the position of the clouds along the line of sight. We found that the BAREGRB model of Zubko, Dwek Arendt 2004 generally led to the best results, although inadequacies in both the overall model and the data limit our conclusions. We also found that the composite dust models of Zubko, Dwek Arendt 2004, especially the no carbon'' models, gave uniformly poor results. Although models using cloud positions and densities derived naively from CO and 21 cm data gave generally poor results, plausible adjustments to the distance of the largest cloud and the mass of a cloud in the expanding 3 kpc Arm lead to significantly improved fits. We suggest that combining Xray halo, CO, and 21 cm observations will be a fruitful method to improve our understanding of both the gas and dust phases of the interstellar medium.

The Galactic WN stars Spectral analyses with lineblanketed model atmospheres versus stellar evolution models with and without rotation ; CONTEXT Very massive stars pass through the WolfRayet WR stage before they finally explode. Details of their evolution have not yet been safely established, and their physics are not well understood. Their spectral analysis requires adequate model atmospheres, which have been developed step by step during the past decades and account in their recent version for line blanketing by the millions of lines from iron and irongroup elements. However, only very few WN stars have been reanalyzed by means of lineblanketed models yet. AIMS The quantitative spectral analysis of a large sample of Galactic WN stars with the most advanced generation of model atmospheres should provide an empirical basis for various studies about the origin, evolution, and physics of the WolfRayet stars and their powerful winds. METHODS We analyze a large sample of Galactic WN stars by means of the Potsdam WolfRayet PoWR model atmospheres, which account for iron line blanketing and clumping. The results are compared with a synthetic population, generated from the Geneva tracks for massive star evolution. RESULTS We obtain a homogeneous set of stellar and atmospheric parameters for the Galactic WN stars, partly revising earlier results. CONCLUSIONS Comparing the results of our spectral analyses of the Galactic WN stars with the predictions of the Geneva evolutionary calculations, we conclude that there is rough qualitative agreement. However, the quantitative discrepancies are still severe, and there is no preference for the tracks that account for the effects of rotation. It seems that the evolution of massive stars is still not satisfactorily understood.

NonGaussianities in Multifield Inflation ; We compute the amplitude of the nonGaussianities in inflationary models with multiple, uncoupled scalar fields. This calculation thus applies to all models of assisted inflation, including Nflation, where inflation is driven by multiple axion fields arising from shift symmetries in a flux stabilized string vacuum. The nonGaussianities are associated with nonlinear evolution of the field and density perturbations, characterized by the parameter fNL. We derive a general expression for the nonlinear parameter, incorporating the evolution of perturbations after horizoncrossing. This is valid for arbitrary separable potentials during slow roll. To develop an intuitive understanding of this system and to demonstrate the applicability of the formalism we examine several cases with quadratic potentials twofield models with a wide range of mass ratios, and a general Nfield model with a narrow mass spectrum. We uncover that fNL is suppressed as the number of efoldings grows, and that this suppression is increased in models with a broad spectrum of masses. On the other hand, we find no enhancement to fNL that increases with the number of fields. We thus conclude that the production of a large nonGaussian signal in multifield models of inflation is very unlikely as long as fields are slowly rolling and potentials are of simple, quadratic form. Finally, we compute a spectrum for the scalar spectral index that incorporates the nonlinear corrections to the fields' evolution.

The exact numerical treatment of inflationary models ; The precision reached by the recent CMB measurements gives new insights into the shape of the primordial power spectra of the cosmological perturbations. In the context of inflationary cosmology, this implies that the CMB data are now sensitive to the form of the inflaton potential. Most of the current approaches devoted to the derivation of the inflationary primordial power spectra, or to the inflaton potential reconstruction problem, rely on approximate analytical treatments that may break down for exotic models. In this article, we numerically solve the inflationary evolution of both the background and all the perturbed quantities to extract the primordial power spectra exactly. Such a method solely relies on General Relativity and linear perturbation theory. More than providing a tool to test analytical approximations, one may consider, without complications, the treatment of nonstandard inflationary models as those involving several fields, eventually nonminimally coupled to gravity. The usefulness of the exact numerical approach to deal with CMB data is illustrated by analysing the WMAP third year data in the context of single field models. For this purpose, we introduce a new inflationary related parameter encoding the basic properties of the reheating era. This reheating parameter has significant observable effects and provides a selfconsistency test of inflationary models. As a working example, the marginalised probability distributions of the reheating and potential parameters associated with the small field models are presented.

A Viscoelastic model of phase separation ; We show here a general model of phase separation in isotropic condensed matter, namely, a viscoelastic model. We propose that the bulk mechanical relaxation modulus that has so far been ignored in previous theories plays an important role in viscoelastic phase separation in addition to the shear relaxation modulus. In polymer solutions, for example, attractive interactions between polymers under a poorsolvent condition likely cause the transient gellike behavior, which makes both bulk and shear modes active. Although such attractive interactions between molecules of the same component exist universally in the twophase region of a mixture, the stress arising from attractive interactions is asymmetrically divided between the components only in dynamically asymmetric mixtures such as polymer solutions and colloidal suspensions. Thus, the interaction network between the slower components, which can store the elastic energy against its deformation through bulk and shear moduli, is formed. It is the bulk relaxation modulus associated with this interaction network that is primarily responsible for the appearance of the sponge structure peculiar to viscoelastic phase separation and the phase inversion. We demonstrate that a viscoelastic model of phase separation including this new effect is a general model that can describe all types of isotropic phase separation including solid and fluid models as its special cases without any exception, if there is no coupling with additional order parameter. The physical origin of volume shrinking behavior during viscoelastic phase separation and the universality of the resulting spongelike structure are also discussed.

Universal amplitude ratios and Coxeter geometry in the dilute A model ; The leading excitations of the dilute AL model in regime 2 are considered using analytic arguments. The model can be identified with the integrable phi1,2 perturbation of the unitary minimal series ML,L1. It is demonstrated that the excitation spectrum of the transfer matrix satisfies the same functional equations in terms of elliptic functions as the exact Smatrices of the phi1,2 perturbation do in terms of trigonometric functions. In particular, the bootstrap equation corresponding to a selffusing process is recovered. For the special cases L3,4,6 corresponding to the Ising model in a magnetic field, and the leading thermal perturbations of the tricritical Ising and threestate Potts model, as well as for the unrestricted model, Linfty, we relate the structure of the Bethe roots to the Lie algebras E8,7,6 and D4 using Coxeter geometry. In these cases Coxeter geometry also allows for a single formula in generic Lie algebraic terms describing all four cases. For general L we calculate the spectral gaps associated with the leading excitation which allows us to compute universal amplitude ratios characteristic of the universality class. The ratios are of field theoretic importance as they enter the bulk vacuum expectation value of the energy momentum tensor associated with the corresponding integrable quantum field theories.

Theory of ddensity wave viewed from a vertex model and its implications ; The thermal disordering of the ddensity wave, proposed to be the origin of the pseudogap state of high temperature superconductors, is suggested to be the same as that of the statistical mechanical model known as the 6vertex model. The low temperature phase consists of a staggered order parameter of circulating currents, while the disordered high temperature phase is a powerlaw phase with no order. A special feature of this transition is the complete lack of an observable specific heat anomaly at the transition. There is also a transition at a even higher temperature at which the magnitude of the order parameter collapses. These results are due to classical thermal fluctuations and are entirely unrelated to a quantum critical point in the ground state. The quantum mechanical ground state can be explored by incorporating processes that causes transitions between the vertices, allowing us to discuss quantum phase transition in the ground state as well as the effect of quantum criticality at a finite temperature as distinct from the powerlaw fluctuations in the classical regime. A generalization of the model on a triangular lattice that leads to a 20vertex model may shed light on the Wigner glass picture of the metalinsulator transition in twodimensional electron gas. The powerlaw ordered high temperature phase may be generic to a class of constrained systems and its relation to recent advances in the quantum dimer models is noted.

The Social Architecture of Capitalism ; A dynamic model of the social relations between workers and capitalists is introduced. The model is deduced from the assumption that the law of value is an organising principle of modern economies. The model selforganises into a dynamic equilibrium with statistical properties that are in close qualitative and in many cases quantitative agreement with a broad range of known empirical distributions of developed capitalism, including the powerlaw distribution of firm size, the Laplace distribution of firm and GDP growth, the lognormal distribution of firm demises, the exponential distribution of the duration of recessions, the lognormalPareto distribution of income, and the gammalike distribution of the rateofprofit of firms. Normally these distributions are studied in isolation, but this model unifies and connects them within a single causal framework. In addition, the model generates business cycle phenomena, including fluctuating wage and profit shares in national income about values consistent with empirical studies. A testable consequence of the model is a conjecture that the rateofprofit distribution is consistent with a parametermix of a ratio of normal variates with means and variances that depend on a firm size parameter that is distributed according to a powerlaw.

Stochastic storage models and noiseinduced phase transitions ; The most frequently used in physical application diffusive based on the FokkerPlanck equation model leans upon the assumption of small jumps of a macroscopic variable for each given realization of the stochastic process. This imposes restrictions on the description of the phase transition problem where the system is to overcome some finite potential barrier, or systems with finite size where the fluctuations are comparable with the size of a system. We suggest a complementary stochastic description of physical systems based on the mathematical stochastic storage model with basic notions of random input and output into a system. It reproduces statistical distributions typical for noiseinduced phase transitions e.g. Verhulst model for the simplest up to linear forms of the escape function. We consider a generalization of the stochastic model based on the series development of the kinetic potential. On the contrast to Gaussian processes in which the development in series over a small parameter characterizing the jump value is assumed Stratonovich R.L., Nonlinear Nonequilibrium Thermodynamics, Springer Series in Synergetics, vol.59, Springer Verlag, 1994, we propose a series expansion directly suitable for storage models and introduce the kinetic potential generalizing them.

FAYE A Java Implement of the FrameStreamStop Analysis Model ; FAYE, The Frame AnalYsis Executable, is a Java based implementation of the FrameStreamStop model for analyzing data. Unlike traditional Event based analysis models, the FrameStreamStop model has no preference as to which part of any data is to be analyzed, and an Event get as equal treatment as a change in the high voltage. This model means that FAYE is a suitable analysis framework for many different type of data analysis, such as detector trends or as a visualization core. During the design of FAYE the emphasis has been on clearly delineating each of the executable's responsibilities and on keeping their implementations as completely independent as possible. This leads to the large part of FAYE being a generic core which is experiment independent, and smaller section that customizes this core to an experiments own data structures. This customization can even be done in C, using JNI, while the executable's control remains in Java. This paper reviews the FrameStreamStop model and then looks at how FAYE has approached its implementation, with an emphasis on which responsibilities are handled by the generic core, and which parts an experiment must provide as part of the customization portion of the executable.

Modelchecking Driven Blackbox Testing Algorithms for Systems with Unspecified Components ; Componentbased software development has posed a serious challenge to system verification since externallyobtained components could be a new source of system failures. This issue can not be completely solved by either modelchecking or traditional software testing techniques alone due to several reasons 1 externally obtained components are usually unspecifiedpartially specified; 2it is generally difficult to establish an adequacy criteria for testing a component; 3components may be used to dynamically upgrade a system. This paper introduces a new approach called em modelchecking driven blackbox testing that combines modelchecking with traditional blackbox software testing to tackle the problem in a complete, sound, and automatic way. The idea is to, with respect to some requirement expressed in CTL or LTL about the system, use modelchecking techniques to derive a condition expressed in communication graphs for an unspecified component such that the system satisfies the requirement iff the condition is satisfied by the component, and which can be established by testing the component with test cases generated from the condition onthefly. In this paper, we present modelchecking driven blackbox testing algorithms to handle both CTL and LTL requirements. We also illustrate the idea through some examples.

Interval Neutrosophic Sets and Logic Theory and Applications in Computing ; This book presents the advancements and applications of neutrosophics. Chapter 1 first introduces the interval neutrosophic sets which is an instance of neutrosophic sets. In this chapter, the definition of interval neutrosophic sets and settheoretic operators are given and various properties of interval neutrosophic set are proved. Chapter 2 defines the interval neutrosophic logic based on interval neutrosophic sets including the syntax and semantics of first order interval neutrosophic propositional logic and first order interval neutrosophic predicate logic. The interval neutrosophic logic can reason and model fuzzy, incomplete and inconsistent information. In this chapter, we also design an interval neutrosophic inference system based on first order interval neutrosophic predicate logic. The interval neutrosophic inference system can be applied to decision making. Chapter 3 gives one application of interval neutrosophic sets and logic in the field of relational databases. Neutrosophic data model is the generalization of fuzzy data model and paraconsistent data model. Here, we generalize various settheoretic and relationtheoretic operations of fuzzy data model to neutrosophic data model. Chapter 4 gives another application of interval neutrosophic logic. A soft semantic Web Services agent framework is proposed to faciliate the registration and discovery of high quality semantic Web Services agent. The intelligent inference engine module of soft Semantic Web Services agent is implemented using interval neutrosophic logic.

Binary inspiral, gravitational radiation, and cosmology ; Observations of binary inspiral in a single interferometric gravitational wave detector can be cataloged according to signaltonoise ratio rho and chirp mass cal M. The distribution of events in a catalog composed of observations with rho greater than a threshold rho0 depends on the Hubble expansion, deceleration parameter, and cosmological constant, as well as the distribution of component masses in binary systems and evolutionary effects. In this paper I find general expressions, valid in any homogeneous and isotropic cosmological model, for the distribution with rho and cal M of cataloged events; I also evaluate these distributions explicitly for relevant matterdominated FriedmannRobertsonWalker models and simple models of the neutron star mass distribution. In matter dominated FriedmannRobertsonWalker cosmological models advanced LIGO detectors will observe binary neutron star inspiral events with rho8 from distances not exceeding approximately 2,textGpc, corresponding to redshifts of 0.48 0.26 for h0.8 0.5, at an estimated rate of 1 per week. As the binary system mass increases so does the distance it can be seen, up to a limit in a matter dominated EinsteindeSitter cosmological model with h0.8 0.5 that limit is approximately z2.7 1.7 for binaries consisting of two 10,textModot black holes. Cosmological tests based on catalogs of the kind discussed here depend on the distribution of cataloged events with rho and cal M. The distributions found here will play a pivotal role in testing cosmological models against our own universe and in constructing templates for the detection of cosmological inspiraling binary neutron stars and black holes.

Extended particle models based on hollow singular hypersurfaces in general relativity Classical and quantum aspects of charged textures ; In present paper we construct classical and quantum models of an extended charged particle. One shows that consecutive modelling can be based on the hollow thinwall charged texture in the hydrodynamical approach of a perfect fluid which acquires gravitational mass due to EinsteinMaxwell interaction. We demonstrate that such a model has equilibrium states at the radius equal to the established classical radius of a charged particle. Also we consider quantum aspects of the theory and obtain the internal Dirac sea conception in a natural way. Besides, the phenomenological unification on the mass level of the two families of elementary particles, charged pions and electrons and positrons, evidently arises as the effect induced by classical and quantum gravity prior to Standard Model. Finally, in the cosmological connection our model proposes the answer on the important question, what are the real sources of texture matter. Besides, the texture hypothesis means that in the early Universe the topological texture foam phase existed before the leptonhadron one.

Classical Signature Change in the Black Hole Topology ; Investigations of classical signature change have generally envisaged applications to cosmological models, usually a FriedmannLemaitreRobertsonWalker model. The purpose has been to avoid the inevitable singularity of models with purely Lorentzian signature, replacing the neighbourhood of the big bang with an initial, singularity free region of Euclidean signture, and a signature change. We here show that signature change can also avoid the singularity of gravitational collapse. We investigate the process of rebirth of Schwarzschild type black holes, modelling it as a double signature change, joining two universes of Lorentzian signature through a Euclidean region which provides a bounce'. We show that this process is viable both with and without matter present, but realistic models which have the signature change surfaces hidden inside the horizons require nonzero density. In fact the most realistic models are those that start as a finite cloud of collapsing matter, surrounded by vacuum. We consider how geodesics may be matched across a signature change surface, and conclude that the particle masses' must jump in value. This scenario may be relevant to Smolin's recent proposal that a form of natural selection operates on the level of universes, which favours the type of universe we live in.

Reduced models for quantum gravity ; The preceding talks given at this conference have dealt mainly with general ideas for, main problems of and techniques for the task of quantizing gravity canonically. Since one of the major motivations to arrange for this meeting was that it should serve as a beginner's introduction to canonical quantum gravity, we regard it as important to demonstrate the usefulness of the formalism by means of applying it to simplified models of quantum gravity, here formulated in terms of Ashtekar's new variables. From the various, completely solvable, models that have been discussed in the literature we choose those that we consider as most suitable for our pedagogical reasons, namely 21 gravity and the spherically symmetric model. The former model arises from a dimensional, the latter from a Killing reduction of full 31 gravity. While 21 gravity is usually treated in terms of closed topologies without boundary of the initial data hypersurface, the toplogy for the spherically symmetric system is chosen to be asymptotically flat. Finally, 21 gravity is more suitably quantized using the loop representation while spherically symmetric gravity is easier to quantize via the selfdual representation. Accordingly, both types of reductions, both types of topologies and both types of representations that are mainly employed in the literature in the context of the new variables come into practice. What makes the discussion especially clear is the fact that for both models the reduced phase space turns out to be finitely dimensional.

The Dynamics of MultiScalar Field Cosmological Models and Assisted Inflation ; We investigate the dynamical properties of a class of spatially homogeneous and isotropic cosmological models containing a barotropic perfect fluid and multiple scalar fields with independent exponential potentials. We show that the assisted inflationary scaling solution is the global latetime attractor for the parameter values for which the model is inflationary, even when curvature and barotropic matter are included. For all other parameter values the multifield curvature scaling solution is the global latetime attractor in these solutions asymptotically the curvature is not dynamically negligible. Consequently, we find that in general all of the scalar fields in multifield models with exponential potentials are nonnegligible in latetime behaviour, contrary to what is commonly believed. The earlytime and intermediate behaviour of the models is also studied. In particular, nscalar field models are investigated and the structure of the saddle equilibrium points corresponding to inflationary mfield scaling solutions and noninflationary mfield matter scaling solutions are also studied where mn, leading to interesting transient dynamical behaviour with new physical scenarios of potential importance.

PostNewtonian SPH calculations of binary neutron star coalescence. I. Method and first results ; We present the first results from our PostNewtonian PN Smoothed Particle Hydrodynamics SPH code, which has been used to study the coalescence of binary neutron star NS systems. The Lagrangian particlebased code incorporates consistently all lowestorder 1PN relativistic effects, as well as gravitational radiation reaction, the lowestorder dissipative term in general relativity. We test our code on sequences of single NS models of varying compactness, and we discuss ways to make PN simulations more relevant to realistic NS models. We also present a PN SPH relaxation procedure for constructing equilibrium models of synchronized binaries, and we use these equilibrium models as initial conditions for our dynamical calculations of binary coalescence. Though unphysical, since tidal synchronization is not expected in NS binaries, these initial conditions allow us to compare our PN work with previous Newtonian results. We compare calculations with and without 1PN effects, for NS with stiff equations of state, modeled as polytropes with Gamma3. We find that 1PN effects can play a major role in the coalescence, accelerating the final inspiral and causing a significant misalignment in the binary just prior to final merging. In addition, the character of the gravitational wave signal is altered dramatically, showing strong modulation of the exponentially decaying waveform near the end of the merger. We also discuss briefly the implications of our results for models of gammaray bursts at cosmological distances.

Testing nonstandard cosmological models with supernovae ; In this work we study the magnituderedshift relation of a nonstandard cosmological model. The model under consideration was firstly investigated within a special case of metricaffine gravity MAG and was recently recovered via different approaches by two other groups. Apart from the usual cosmological parameters for pressureless matter Omegarm m, cosmological constantdark energy Omegalambda, and radiation Omegarm r a new density parameter Omegapsi emerges. The field equations of the model reduce to a system which is effectively given by the usual Friedmann equations of general relativity, supplied by a correction to the energy density and pressure in form of Omegapsi, which is related to the nonRiemannian structure of the underlying spacetime. We search for the bestfit parameters by using recent SN Ia data sets and constrain the possible contribution of a new darkenergy like component at low redshifts, thereby we put an upper limit on the presence of nonRiemannian quantities in the late stages of the universe. In addition the impact of placing the data in redshift bins of variable size is studied. The numerical results of this work also apply to several anisotropic cosmological models which, on the level of the field equations, exhibit a similar scaling behavior of the density parameters like our nonRiemannian model.

Modeling the spectrum of gravitational waves in the primordial Universe ; Recent observations from type Ia Supernovae and from cosmic microwave background CMB anisotropies have revealed that most of the matter of the Universe interacts in a repulsive manner, composing the socalled dark energy constituent of the Universe. The analysis of cosmic gravitational waves GW represents, besides the CMB temperature and polarization anisotropies, an additional approach in the determination of parameters that may constrain the dark energy models and their consistence. In recent work, a generalized Chaplygin gas model was considered in a flat universe and the corresponding spectrum of gravitational waves was obtained. The present work adds a massless gas component to that model and the new spectrum is compared to the previous one. The Chaplygin gas is also used to simulate a LambdaCDM model by means of a particular combination of parameters so that the Chaplygin gas and the LambdaCDM models can be easily distinguished in the theoretical scenarios here established. The lack of direct observational data is partialy solved when the signature of the GW on the CMB spectra is determined.

Higher Dimensional Dust Cosmological Implications of a Decay Law for Term Expressions for Some Observable Quantities ; In this paper we have considered the multidimensional cosmological implications of a decay law for Lambda term that is proportional to beta fracddot aa, where beta is a constant and a is the scale factor of RWspace time. We discuss the cosmological consequences of a model for the vanishing pressure for the case k0. It has been observed that such models are compatible with the result of recent observations and cosmological term Lambda gradually reduces as the universe expands. In this model Lambda varies as the inverse square of time, which matches its natural units. The proper distance, the luminosity distanceredshift, the angular diameter distanceredshift, and look back timeredshift for the model are presented in the frame work of higher dimensional space time. The model of the Freese it et al. it Nucl. Phys. B bf 287, 797 1987 for n2 is retrieved for the particular choice of A0 and also Einsteinde Sitter model is obtained for A0 23. This work has thus generalized to higher dimensions the wellknow result in four dimensional space time. It is found that there may be significant difference in principle at least, from the analogous situation in four dimensional space time.

A Model of CP Violation ; It is shown that a twoHiggs doublet model with Vacuum CP Violation and Approximate Global U1 Family Symmetries AGUFS may provide one of the simplest and attractive models in understanding origin and mechanisms of CP violation at the weak scale. The whole new interactions of the model are explicitly presented here. It is seen that CP violation can occur, after spontaneous symmetry breaking, everywhere it can from a single CPphase in the vacuum. It is also shown that the mechanism of spontaneous symmetry breaking provides not only a mechanism for giving mass to the bosons and the fermions, but also a mechanism for generating CPphase of the bosons and the fermions. Four types of CPviolating mechanism are classified. A new type of CPviolating mechanism is emphasized and can provide a consistent application to both the established and the reported CPviolating phenomena. The smallness of the CKM mixing angles and the induced KMtype CPviolating effects as well as the suppression of flavorchanging neutral scalar interactions can be attributed to the AGUFS and Partial Conservation of Neutral Flavor PCNF. This suggests that if one Higgs doublet is necessary for generation of mass, two Higgs doublets are then needed for origin and phenomenology of CP violation. Various interesting phenomenological features arising from this model are analyzed. Their experimental implications and importance are discussed and emphasized. Directly searching for the exotic Higgs bosons introduced in this model is worthwhile at both ee and hadron colliders.

The R Axion From Dynamical Supersymmetry Breaking ; All generic, calculable models of dynamical supersymmetry breaking have a spontaneously broken R symmetry and therefore contain an R axion. We show that the axion is massive in any model in which the cosmological constant is finetuned to zero through an explicit Rsymmetrybreaking constant. In visiblesector models, the axion mass is in the 100 MeV range and thus evades astrophysical bounds. In nonrenormalizable hiddensector models, the mass is of order of the weak scale and can have dangerous cosmological consequences similar to those already present from other fields. In renormalizable hidden sector models, the axion mass is generally quite large, of order 107 GeV. Typically, these axions are cosmologically safe. However, if the dominant decay mode is to gravitinos, the potentially large gravitino abundance that arises from axion decay after inflation might affect the successful predictions of bigbang nucleosynthesis. We show that the upper bound on the reheat temperature after standard inflation can be competitive with or stronger than bounds from thermal gravitino production, depending on the model and the gravitino mass.

Could the Supersymmetric Higgs Particles Naturally be PseudoGoldstone Bosons ; The doublettriplet splitting problem is perhaps the most problematic aspect of supersymmetric grand unified theories. It can be argued that the most natural reason for the Higgs doublets to be light is that they are pseudoGoldstone bosons associated with the spontaneous breakdown of an accidental global symmetry. In this paper we discuss the possibility of implementing this idea in the SU6 model of refs. citeZur,Bar2,Bar3,Bar4. We show that although it is simple to generate an accidental symmetry of the renormalizable terms of the potential, it is quite difficult to construct a model which allows for the preservation of the accidental symmetry in the nonrenormalizable terms. We summarize the constraints on such models and then give three different ways to construct a superpotential where the dangerous mixing terms are sufficiently suppressed even in the presence of nonrenormalizable operators. With these examples we demonstrate the existence of consistent models implementing the Higgs as pseudoGoldstone boson scheme. We extend one of the three examples to include fermion masses. We also show that when restricted to regular group embeddings the only possible models without light triplets are trivial generalizations of the SU6 model we consider.

Exotic leptoquarks from superstring derived models ; The H1 and ZEUS collaborations have recently reported a significant excess of events at high Q2 in positronproton collisions. While there exists insufficient data to conclusively determine the origin of this excess, one possibility is that it is due to a new leptoquark at mass scale around 200 GeV. We examine the type of leptoquark states that exist in superstring derived standardlike models, and show that, while these models may contain the standard leptoquark states which exist in Grand Unified Theories, they also generically contain new and exotic leptoquark states with fractional lepton number, pm12. In contrast to the traditional GUTtype leptoquark states, the couplings of the exotic leptoquarks to the Standard Model states are generated after the breaking of U1BL. This important feature of the exotic leptoquark states may result in local discrete symmetries which forbid some of the undesired leptoquark couplings. We examine these couplings in several models and study the phenomenological implications. The flavor symmetries of the superstring models are found to naturally suppress leptoquark flavor changing processes.

Bounds on Supersymmetry from Electroweak Precision Analysis ; The Standard Model global fit to precision data is excellent. The Minimal Supersymmetric Standard Model can also fit the data well, though not as well as the Standard Model. At best, supersymmetric contributions either decouple or only slightly decrease the total chi2, at the expense of decreasing the number of degrees of freedom. In general, regions of parameter space with large supersymmetric corrections from light superpartners are associated with poor fits to the data. We contrast results of a simple oblique approximation with full oneloop results, and show that for the most important observables the nonoblique corrections can be larger than the oblique corrections, and must be taken into account. We elucidate the regions of parameter space in both gravity and gaugemediated models which are excluded. Significant regions of parameter space are excluded, especially with positive supersymmetric mass parameter mu. We give a complete listing of the bounds on all the superpartner and Higgs boson masses. For either sign of mu, and for all supersymmetric models considered, we set a lower limit on the mass of the lightest CPeven Higgs scalar, mh 78 GeV. Also, the first and second generation squark masses are constrained to be above 280 325 GeV in the supergravity gaugemediated model.

The abundance of relativistic axions in a flaton model of PecceiQuinn symmetry ; Flaton models of PecceiQuinn symmetry have good particle physics motivation, and are likely to cause thermal inflation leading to a welldefined cosmology. They can solve the mu problem, and generate viable neutrino masses. Canonical flaton models predict an axion decay constant Fa of order 1010 GeV and generic flaton models give Fa of order 109 GeV as required by observation. The axion is a good candidate for cold dark matter in all cases, because its density is diluted by flaton decay if Fa is bigger than 1012 GeV. In addition to the dark matter axions, a population of relativistic axions is produced by flaton decay, which at nucleosynthesis is equivalent to some number delta Nnu of extra neutrino species. Focussing on the canonical model, containing three flaton particles and two flatinos, we evaluate all of the flatonflatinoaxion interactions and the corresponding axionic decay rates. They are compared with the dominant hadronic decay rates, for both DFSZ and KSVZ models. These formulas provide the basis for a precise calculation of the equivalent delta Nnu in terms of the parameters masses and couplings. The KSVZ case is probably already ruled out by the existing bound delta Nnulsim 1. The DFSZ case is allowed in a significant region of parameter space, and will provide a possible explanation for any future detection of nonzero delta Nnu.

Phenomenology of a New Minimal Supersymmetric Extension of the Standard Model ; We study the phenomenology of a new Minimallyextended Supersymmetric Standard Model nMSSM where a gauge singlet superfield is added to the MSSM spectrum. The superpotential of this model contains no dimensionful parameters, thus solving the muproblem of the MSSM. A global discrete Rsymmetry, forbidding the cubic singlet selfinteraction, imposed on the complete theory, guarantees its stability with respect to generated higherorder tadpoles of the singlet and solves both the domain wall and PecceiQuinn axion problems. We give the free parameters of the model and display some general constraints on them. A particular attention is devoted to the neutralino sector where a quasipure singlino appears to be always the LSP of the model, leading to additional cascades, involving the NLSP LSP transition, compared with the MSSM. We then present the upper bounds on the masses of the lightest and nexttolightest when the lightest is an invisible singlet CPeven Higgs bosons, including the full oneloop and dominant twoloop corrections. These bounds are found to be much higher than the equivalent ones in the MSSM. Finally, we discuss some phenomenological implications for the Higgs sector of the nMSSM in Higgs production at future hadron colliders.

One Loop Soft Supersymmetry Breaking Terms in Superstring Effective Theories ; We perform a systematic analysis of soft supersymmetry breaking terms at the one loop level in a large class of string effective field theories. This includes the socalled anomaly mediated contributions. We illustrate our results for several classes of orbifold models. In particular, we discuss a class of models where soft supersymmetry breaking terms are determined by quasi model independent anomaly mediated contributions, with possibly nonvanishing scalar masses at the one loop level. We show that the latter contribution depends on the detailed prescription of the regularization process which is assumed to represent the Planck scale physics of the underlying fundamental theory. The usual anomaly mediation case with vanishing scalar masses at one loop is not found to be generic. However gaugino masses and Aterms always vanish at tree level if supersymmetry breaking is moduli dominated with the moduli stabilized at selfdual points, whereas the vanishing of the Bterm depends on the origin of the muterm in the underlying theory. We also discuss the supersymmetric spectrum of OI and OII models, as well as a model of gaugino condensation. For reference, explicit spectra corresponding to a Higgs mass of 114 GeV are given. Finally, we address general strategies for distinguishing among these models.

Unitarized pseudoscalar meson scattering amplitudes in three flavor linear sigma models ; The three flavor linear sigma model is studied as a toy model'' for understanding the role of possible light scalar mesons in the pi pi, pi K and pi eta scattering channels. The approach involves computing the tree level partial wave amplitude for each channel and unitarizing by a simple Kmatrix prescription which does not introduce any new parameters. If the renormalizable version of the model is used there is only one free parameter. While this highly constrained version has the right general structure to explain pi pi scatteirng, it is not quite'' right. A reasonable fit can be made if the renormalizability for the it effective Lagrangian is relaxed while chiral symmetry is maintained. The occurence of a Ramsauer Townsend mechanism for the f0980 region naturally emerges. The effect of unitarization is very important and leads to physical'' masses for the scalar nonet all less than about 1 GeV. The a01450 and K01430 appear to be outsiders'' in this picture and to require additional fields. Comparison is made with a scattering treatment using a more general nonlinear sigma model approach. In addition some speculative remarks and a highly simplified larger toy model are devoted to the question of the quark substructure of the light scalar mesons.

Dynamics of coupled bosonic systems with applications to preheating ; Coupled, multifield models of inflation can provide several attractive features unavailable in the case of a single inflaton field. These models have a rich dynamical structure resulting from the interaction of the fields and their associated fluctuations. We present a formalism to study the nonequilibrium dynamics of coupled scalar fields. This formalism solves the problem of renormalizing interacting models in a transparent way using dimensional regularization. The evolution is generated by a renormalized effective Lagrangian which incorporates the dynamics of the mean fields and their associated fluctuations at oneloop order. We apply our method to two problems of physical interest i a simple twofield model which exemplifies applications to reheating in inflation, and ii a supersymmetric hybrid inflation model. This second case is interesting because inflation terminates via a smooth phase transition which gives rise to a spinodal instability in one of the fields. We study the evolution of the zero mode of the fields and the energy density transfer to the fluctuations from the mean fields. We conclude that back reaction effects can be significant over a wide parameter range. In particular for the supersymmetric hybrid model we find that particle production can be suppressed due to these effects.

Soft Color Interactions and Diffractive Hard Scattering at the Fermilab Tevatron ; An improved understanding of nonperturbative QCD can be obtained by the recently developed soft color interaction models. Their essence is the variation of color stringfield topologies, giving a unified description of final states in high energy interactions, e.g., diffractive and nondiffractive events in ep and ppbar. Here we present a detailed study of such models the soft color interaction model and the generalized area law model applied to ppbar, considering also the general problem of the underlying event including beam particle remnants. With models tuned to HERA ep data, we find a good description also of Tevatron data on production of W, beauty and jets in diffractive events defined either by leading antiprotons or by one or two rapidity gaps in the forward or backward regions. We also give predictions for diffractive Jpsi production where the soft exchange mechanism produces both a gap and a color singlet ccbar state in the same event. This soft color interaction approach is also compared with Pomeronbased models for diffraction, and some possibilities to experimentally discriminate between these different approaches are discussed.

Ubiquitous CP violation in a topinspired leftright model ; We explore CP violation in a LeftRight Model that reproduces the quark mass and CKM rotation angle hierarchies in a relatively natural way by fixing the bidoublet Higgs VEVs to be in the ratio mbmt. Our model is quite general and allows for CP to be broken by both the Higgs VEVs and the Yukawa couplings. Despite this generality, CP violation may be parameterized in terms of two basic phases. A very interesting feature of the model is that the mixing angles in the righthanded sector are found to be equal to their lefthanded counterparts to a very good approximation. Furthermore, the righthanded analogue of the usual CKM phase deltaL is found to satisfy the relation deltaR approx deltaL. The parameter space of the model is explored by using an adaptive Monte Carlo algorithm and the allowed regions in parameter space are determined by enforcing experimental constraints from the K and B systems. This method of solution allows us to evaluate the left and righthanded CKM matrices numerically for various combinations of the two fundamental CPodd phases in the model. We find that all experimental constraints may be satisfied with righthanded W and Flavour Changing Neutral Higgs masses as low as about 2 TeV and 7 TeV, respectively.

Type II Leptogenesis and the Neutrino Mass Scale ; We discuss the effect of the neutrino mass scale on baryogenesis via the outofequilibrium decay of the lightest righthanded sneutrinos in type II seesaw models. We calculate the type II contributions to the decay asymmetries for minimal scenarios based on the Standard Model and on the Minimal Supersymmetric Standard Model, where the additional direct mass term for the neutrinos arises from a Higgs triplet vacuum expectation value. The result in the supersymmetric case is new and we correct the previous result in the scenario based on the Standard Model. We confirm and generalize our results by calculating the decay asymmetries in an effective approach, which is independent of the realization of the type II contribution. We derive a general upper bound on the decay asymmetry in type II seesaw models and find that it increases with the neutrino mass scale, in sharp contrast to the type I case which leads to an upper bound of about 0.1 eV on the neutrino mass scale. We find a lower bound on the mass of the lightest righthanded neutrino, significantly below the corresponding type I bound for partially degenerate neutrinos. This lower bound decreases with increasing neutrino mass scale, making leptogenesis more consistent with the gravitino constraints in supersymmetric models.

Relaxing the Upper Bound on the Mass of the Lightest Supersymmetric Higgs Boson ; We present a class of supersymmetric models in which the lightest Higgsboson mass can be as large as a few hundred GeV 200 300 GeV while the successful MSSM prediction for gauge coupling unification is preserved. The theories are formulated on a 5D warped space truncated by two branes, and a part of the Higgs sector is localized on the infrared brane. The structure of the Higgs sector in the four dimensional effective theory below the KaluzaKlein mass scale is essentially that of the nexttominimal supersymmetric standard model NMSSM, or related theories. However, large values of the NMSSM couplings at the weak scale are now possible as these couplings are required to be perturbative only up to the infrared cutoff scale, which can in general be much lower than the unification scale. This allows the possibility of generating a large quartic coupling in the Higgs potential, and thereby significantly raising the Higgsboson mass bound. We present two particularly simple models. In the first model, the quark and lepton fields are localized on the ultraviolet brane, where the grand unified symmetry is broken. In the second model, the quark and lepton fields are localized on the infrared brane, and the unified symmetry is broken both on the ultraviolet and infrared branes. Our theories potentially allow the possibility of a significant reduction in the finetuning needed for correct electroweak symmetry breaking, although this is somewhat model dependent.

Neutrino Masses in the Supersymmetric SU3C X SU3L X U1X Model with righthanded neutrinos ; The Rsymmetry formalism is applied for the supersymmetric SU3C X SU3L X U1X 331 model with righthanded neutrinos. For this kind of models, we study generalization of the MSSM relation among Rparity, spin and matterparity. Discrete symmetries for the proton stable in this model are imposed, and we show that in such a case it is able to give leptons masses at only the tree level contributions required. A simple mechanism for the mass generation of the neutrinos is explored. We show that at the lowenergy effective theory, neutrino spectrum contains three Dirac fermions, one massless and two degenerate in mass. At the energylevel where the mixing among them with neutralinos turned on, neutrinos obtain Majorana masses and correct the lowenergy effective result which naturally gives rise to an inverted hierarchy mass pattern. This mass spectrum can fit the current data with minor finetuning. Consistent values for masses of the charged leptons are also given. In this model, the MSSM neutralinos and charginos can be explicitly identified in terms of the new constraints on masses which is not as in a supersymmetric version of the minimal 331 model.

Topological SigmaModels in Four Dimensions and Triholomorphic Maps ; It is wellknown that topological sigmamodels in 2 dimensions constitute a pathintegral approach to the study of holomorphic maps from a Riemann surface S to an almost complex manifold K, the most interesting case being that where K is a Kahler manifold. We show that, in the same way, topological sigmamodels in 4 dimensions introduce a path integral approach to the study of triholomorphic maps qMN from a 4dimensional Riemannian manifold M to an almost quaternionic manifold N. The most interesting cases are those where M, N are hyperKahler or quaternionic Kahler. BRSTcohomology translates into intersection theory in the modulispace of this new class of instantonic maps, named by us hyperinstantons. The definition of triholomorphicity that we propose is expressed by the equation qJu q ju 0, u1,2,3, where ju is an almost quaternionic structure on M and Ju is an almost quaternionic structure on N. This is a generalization of the CauchyFueter equations. For M, N hyperKahler, this generalization naturally arises by obtaining the topological sigmamodel as a twisted version of the N2 globally supersymmetric sigmamodel. We discuss various examples of hyperinstantons, in particular on the torus and the K3 surface. We also analyse the coupling of the topological sigmamodel to topological gravity. The study of

Matrix Models and Geometry of Moduli Spaces ; We give the description of discretized moduli spaces d.m.s. Mcdisc introduced in citeCh1 in terms of discrete de Rham cohomologies for moduli spaces Mgn. The generating function for intersection indices cohomological classes of d.m.s. is found. Classes of highest degree coincide with the ones for the continuum moduli space Mc. To show it we use a matrix model technique. The Kontsevich matrix model is the generating function in the continuum case, and the matrix model with the potential Nalpha tr bigl fr 14 L XL X fr12log 1Xfr12Xbigr is the one for d.m.s. In the latest case the effects of DeligneMumford reductions become relevant, and we use the stratification procedure in order to express integrals over open spaces Mdisc in terms of intersection indices, which are to be calculated on compactified spaces Mcdisc. We find and solve constraint equations on partition function cal Z of our matrix model expressed in times for d.m.s. tpmmtr frdmdlmfr1el1. It appears that cal Z depends only on even times and cal ZtpmcdotCaa N ecal AeFt2n Ft2n, where Ftpm2n is a logarithm of the partition function of the Kontsevich model, cal A being a quadratic differential operator in ddtpm2n.

4D Chiral N1 Type I Vacua With And Without D5Branes ; In this paper we consider compactifications of type I strings on Abelian orbifolds. We discuss the tadpole cancellation conditions for the general case with D9branes only. Such compactifications have perturbative heterotic duals which are also realized as orbifolds with nonstandard embedding of the gauge connection. The latter have extra twisted states that become massive once orbifold singularities are blownup. This is due to the presence of perturbative heterotic superpotential with couplings between the extra twisted states, the orbifold blowup modes, and sometimes untwisted matter fields. Anomalous U1 generically present in such models also plays an important role in type Iheterotic treelevel duality matching. We illustrate these issues on a particular example of Z3 otimes Z3 orbifold type I model and its heterotic dual. The model has N1 supersymmetry, U43 otimes SO8 gauge group, and chiral matter. We also consider compactifications of type I strings on Abelian orbifolds with both D9 and D5branes. We discuss tadpole cancellation conditions for a certain class of such models. We illustrate the model building by considering a particular example of type I theory compactified on Z6 orbifold. The model has N1 supersymmetry, U6otimes U6otimes U42 gauge group, and chiral matter. This would correspond to a nonperturbative chiral vacuum from the heterotic point of view.

Exactly solvable models of twodimensional dilaton gravity and quantum eternal black holes ; New approach to exact solvability of dilaton gravity theories is suggested which appeals directly to structure of field equations. It is shown that black holes regular at the horizon are static and their metric is found explicitly. If a metric possesses singularities the whole spacetime can be divided into different sheets with one horizon on each sheet between neighboring singularities with a finite value of dilaton field addition horizons may arise at infinite value of it, neighboring sheets being glued along the singularity. The position of singularities coincide with the values of dilaton in solutions with a constant dilaton field. Quantum corrections to the Hawking temperature vanish. For a wide subset of these models the relationship between the total energy and the total entropy of the quantum finite size system is the same as in the classical limit. For another subset the metric itself does not acquire quantum corrections. The present paper generalizes Solodukhin's results on the RST model in that instead of a particular model we deal with whole classes of them. Apart from this, the found models exhibit some qualitatively new properties which are absent in the RST model. The most important one is that there exist quantum black holes with geometry regular everywhere including infinity.

Spin Foam Models and the Classical Action Principle ; We propose a new systematic approach that allows one to derive the spin foam state sum model of a theory starting from the corresponding classical action functional. It can be applied to any theory whose action can be written as that of the BF theory plus a functional of the B field. Examples of such theories include BF theories with or without cosmological term, YangMills theories and gravity in various spacetime dimensions. Our main idea is twofold. First, we propose to take into account in the path integral certain distributional configurations of the B field in which it is concentrated along lower dimensional hypersurfaces in spacetime. Second, using the notion of generating functional we develop perturbation expansion techniques, with the role of the free theory played by the BF theory. We test our approach on various theories for which the corresponding spin foam state sum models are known. We find that it exactly reproduces the known models for BF and 2D YangMills theories. For the BF theory with cosmological term in 3 and 4 dimensions we calculate the terms of the transition amplitude that are of the first order in the cosmological constant, and find an agreement with the corresponding first order terms of the known state sum models. We discuss implications of our results for existing quantum gravity models.

Graded PoissonSigma Models and DilatonDeformed 2D Supergravity Algebra ; Fermionic extensions of generic 2d gravity theories obtained from the graded PoissonSigma model gPSM approach show a large degree of ambiguity. In addition, obstructions may reduce the allowed range of fields as given by the bosonic theory, or even prohibit any extension in certain cases. In our present work we relate the finite Walgebras inherent in the gPSM algebra of constraints to algebras which can be interpreted as supergravities in the usual sense NeuveuSchwarz or Ramond algebras resp., deformed by the presence of the dilaton field. With very straightforward and natural assumptions on them like demanding rigid supersymmetry in a certain flat limit, or linking the anticommutator of certain fermionic charges to the Hamiltonian constraint in the genuine'' supergravity obtained in this way the ambiguities disappear, as well as the obstructions referred to above. Thus all especially interesting bosonic models spherically reduced gravity, the JackiwTeitelboim model etc. under these conditions possess a unique fermionic extension and are free from new singularities. The superspace supergravity model of Howe is found as a special case of this supergravity action. For this class of models the relation between bosonic potential and prepotential does not introduce obstructions as well.

Exactly solvable models of twodimensional dilaton cosmology with quantum backreaction ; We consider general approach to exactly solvable 2D dilaton cosmology with oneloop backreaction from conformal fields taken into account. It includes as particular cases previous models discussed in literature. We list different types of solutions and investigate their properties for simple models, typical for string theory. We find a rather rich class of everywhere regular solutions which exist practically in every type of analyzed solutions. They exhibit different kinds of asymptotic behavior in past and future, including inflation, superinflation, deflation, power expansion or contraction. In particular, for some models the dS spacetime with a timedependent dilaton field is the exact solution of field equations. For some kinds of solutions the weak energy condition is violated independent of a specific model. We find also the solutions with a singularity which is situated in an infinite past or future, so at any finite moment of a comoving time the universe is singularityfree. It is pointed out that for some models the spacetime may be everywhere regular even in spite of infinitely large quantum backreaction in an infinite past.

Type IIA PatiSalam Flux Vacua ; We show that for supersymmetric AdS vacua on Type IIA orientifolds with flux compactifications, the RR tadpole cancellation conditions can be completely relaxed, and then the fourdimensional N1 supersymmetry conditions are the main constraints on consistent intersecting D6brane model building. We construct two kinds of threefamily PatiSalam models. In the first kind of models, the suitable threefamily SM fermion masses and mixings can be generated at the stringy tree level, and then the rank one problem for the SM fermion Yukawa matrices can be solved. In the second kind of models, only the third family of the SM fermions can obtain masses at tree level. In these models, the complex structure parameters can be determined by supersymmetric D6brane configurations, and all the moduli may be stabilized. The initial gauge symmetries U4C times U2L times U2R and U4C times USp2L times U2R can be broken down to the SU3C times SU2L times U1BL times U1I3R due to the GreenSchwarz mechanism and D6brane splittings, and further down to the SM gauge symmetry around the string scale via the supersymmetry preserving Higgs mechanism. Comparing to the previous model building, we have less bidoublet Higgs fields. However, there generically exist some exotic particles.

Critical twopoint functions and the lace expansion for spreadout highdimensional percolation and related models ; We consider spreadout models of selfavoiding walk, bond percolation, lattice trees and bond lattice animals on the ddimensional hyper cubic lattice having long finiterange connections, above their upper critical dimensions d4 selfavoiding walk, d6 percolation and d8 trees and animals. The twopoint functions for these models are respectively the generating function for selfavoiding walks from the origin to x, the probability of a connection from 0 to x, and the generating function for lattice trees or lattice animals containing 0 and x. We use the lace expansion to prove that for sufficiently spreadout models above the upper critical dimension, the twopoint function of each model decays, at the critical point, as a multiple of x2d as x goes to infinity. We use a new unified method to prove convergence of the lace expansion. The method is based on xspace methods rather than the Fourier transform. Our results also yield unified and simplified proofs of the bubble condition for selfavoiding walk, the triangle condition for percolation, and the square condition for lattice trees and lattice animals, for sufficiently spreadout models above the upper critical dimension.

Boson mappings and fourparticle correlations in algebraic neutronproton pairing models ; Neutronproton pairing correlations are studied within the context of two solvable models, one based on the algebra SO5 and the other on the algebra SO8. Bosonmapping techniques are applied to these models and shown to provide a convenient methodological tool both for solving such problems and for gaining useful insight into general features of pairing. We first focus on the SO5 model, which involves generalized T1 pairing. Neither boson meanfield methods nor fermionpair approximations are able to describe in detail neutronproton pairing in this model. The analysis suggests, however, that the boson Hamiltonian obtained from a mapping of the fermion Hamiltonian contains a pairing force between bosons, pointing to the importance of bosonboson or equivalently fourfermion correlations with isospin T0 and spin S0. These correlations are investigated by carrying out a second boson mapping. Closed forms for the fermion wave functions are given in terms of the fermionpair operators. Similar techniques are applied albeit in less detail to the SO8 model, involving a competition between T1 and T0 pairing. Conclusions similar to those of the SO5 analysis are reached regarding the importance of fourparticle correlations in systems involving neutronproton pairing.

KermanKleinDonauFrauendorf model for oddodd nuclei formal theory ; The KermanKleinDonauFrauendorf KKDF model is a linearized version of the KermanKlein equations of motion formulation of the nuclear manybody problem. In practice, it is a generalization of the standard coreparticle coupling model that, like the latter, provides a description of the spectroscopy of odd nuclei in terms of the properties of neighboring even nuclei and of singleparticle properties, that are the input parameters of the model. A divers sample of recent applications attest to the usefulness of the model. In this paper, we first present a concise general review of the fundamental equations and properties of the KKDF model. We then derive a corresponding formalism for oddodd nuclei that relates their properties to those of four neighboring even nuclei, all of which enter if one is to include both multipole and pairing forces. We treat these equations in two ways. In the first we make essential use of the solutions of the neighboring odd nucleus problem, as obtained by the KKDF method. In the second, we relate the properties of the oddodd nuclei directly to those of the even nuclei. For both choices, we derive equations of motion, normalization conditions, and an expression for transition amplitudes. We also solve the problem of choosing the subspace of physical solutions that arises in an equations of motion approach that includes pairing interactions.

Hierarchical noise in large systems of independent agents ; A generalization of the coherentnoise models M. E. J. Newman and K. Sneppen, Phys. Rev. Ebf54, 6226 1996 is presented where the agents in the model are subjected to a multitude of stresses, generated in a hierarchy of different contexts. The hierarchy is realized as a Cayleytree. Two different ways of stress propagation in the tree are considered. In both cases, coherence arises in large subsystems of the tree. Clear similarities between the behavior of the tree model and of the coherentnoise model can be observed. For one of the two methods of stress propagation, the behavior of the tree model can be approximated very well by an ensemble of coherentnoise models, where the sizes k of the systems in the ensemble scale as k2. The results are found to be independent of the tree's structure for a large class of reasonable choices. Additionally, it is found that powerlaw distributed lifetimes of agents arise even under the complete absence of correlations between the stresses the agents feel.

Renormalization of the ETAS branching model of triggered seismicity from total to observable seismicity ; Several recent works point out that the crowd of small unobservable earthquakes with magnitudes below the detection threshold md may play a significant and perhaps dominant role in triggering future seismicity. Using the ETAS branching model of triggered seismicity, we apply the formalism of generating probability functions to investigate how the statistical properties of observable earthquakes differ from the statistics of all events. The ETAS epidemictype aftershock sequence model assumes that each earthquake can trigger other earthquakes aftershocks''. An aftershock sequence results in this model from the cascade of aftershocks of each past earthquake. The triggering efficiency of earthquakes is assumed to vanish below a lower magnitude limit m0, in order to ensure the convergence of the theory and may reflect the physics of stateandvelocity frictional rupture. We show that, to a good approximation, the ETAS model is renormalized onto itself under what amounts to a decimation procedure m0 to md, with just a renormalization of the branching ratio from n to an effective value nmd. Our present analysis thus confirms, for the full statistical properties, the results obtained previously by one of us and Werner, based solely on the average seismic rates the firstorder moment of the statistics. However, our analysis also demonstrates that this renormalization is not exact, as there are small corrections which can be systematically calculated, in terms of additional contributions that can be mapped onto a different branching model a new relevant direction in the language of the renormalization group.

Prospects for Money Transfer Models ; Recently, in order to explore the mechanism behind wealth or income distribution, several models have been proposed by applying principles of statistical mechanics. These models share some characteristics, such as consisting of a group of individual agents, a pile of money and a specific trading rule. Whatever the trading rule is, the most noteworthy fact is that money is always transferred from one agent to another in the transferring process. So we call them money transfer models. Besides explaining income and wealth distributions, money transfer models can also be applied to other disciplines. In this paper we summarize these areas as statistical distribution, economic mobility, transfer rate and money creation. First, money distribution or income distribution can be exhibited by recording the money stock flow. Second, the economic mobility can be shown by tracing the change in wealth or income over time for each agent. Third, the transfer rate of money and its determinants can be analyzed by tracing the transferring process of each one unit of money. Finally, money creation process can also be investigated by permitting agents go into debts. Some future extensions to these models are anticipated to be structural improvement and generalized mathematical analysis.

Quantitative patterns in the structure of model and empirical food webs ; We analyze the properties of model food webs and of fifteen community food webs from a variety of environments. We first perform a theoretical analysis of the niche model of Williams and Martinez. We derive analytical expressions for the distributions of species' number of prey, number of predators, and total number of trophic links and find that they follow universal functional forms. We also derive expressions for a number of other biologically relevant parameters, including the fraction of top, intermediate, basal, and cannibal species, the standard deviations of generality and vulnerability, the correlation coefficient between species' number of prey and number of predators, and assortativity. We show that our findings are robust under rather general conditions. We then use our analytical predictions as a guide to the analysis of fifteen of the most complete empirical food webs available. We uncover quantitative unifying patterns that describe the properties of the model food webs and most of the trophic webs considered. Our results support a strong new hypothesis that the empirical distributions of number of prey and number of predators follow universal functional forms that, without free parameters, match our analytical predictions. Further, we find that the empirically observed correlation coefficient, assortativity, and fraction of cannibal species are consistent with our analytical expressions and simulations of the niche model. Finally, we show that the average distance between nodes and the average clustering coefficient show a high degree of regularity for both the empirical data and simulations of the niche model. Our findings suggest that statistical physics concepts such as scaling and universality may be useful in the description of natural ecosystems.

Matter density perturbations and effective gravitational constant in modified gravity models of dark energy ; We derive the equation of matter density perturbations on subhorizon scales for a general Lagrangian density fR, phi, X that is a function of a Ricci scalar R, a scalar field phi and a kinetic term Xnabla phi22. This is useful to constrain modified gravity dark energy models from observations of largescale structure and weak lensing. We obtain the solutions for the matter perturbation deltam as well as the gravitational potential Phi for some analytically solvable models. In a fR dark energy model with the Lagrangian density fRalpha R1mLambda, the growth rates of perturbations exhibit notable differences from those in the standard Einstein gravity unless m is very close to 0. In scalartensor models with the Lagrangian density fFphiR2pphi,X we relate the models with coupled dark energy scenarios in the Einstein frame and reproduce the equations of perturbations known in the current literature by making a conformal transformation. We also estimate the evolution of perturbations in both Jordan and Einstein frames when the energy fraction of dark energy is constant during the matterdominated epoch.

The Structure of the Homunculus. III. Forming a Disk and Bipolar Lobes in a Rotating Surface Explosion ; We present a semianalytic model for shaping the nebula around eta Carinae that accounts for the simultaneous production of bipolar lobes and an equatorial disk through a rotating surface explosion. Material is launched normal to the surface of an oblate rotating star with an initial kick velocity that scales approximately with the local escape speed. Thereafter, ejecta follow ballistic orbital trajectories, feeling only a central force corresponding to a radiatively reduced gravity. Our model is conceptually similar to the windcompressed disk model of Bjorkman Cassinelli, but we modify it to an explosion instead of a steady linedriven wind, we include a rotationallydistorted star, and we treat the dynamics somewhat differently. Continuumdriving avoids the disk inhibition that normally operates in linedriven winds. Our model provides a simple method by which rotating hot stars can simultaneously produce intrinsically bipolar and equatorial mass ejections, without an aspherical environment or magnetic fields. Although motivated by eta Carinae, the model may have generic application to other LBVs, Be stars, or SN1987A's nebula. When nearEddington radiative driving is less influential, our model generalizes to produce bipolar morphologies without disks, as seen in many PNe.

Fusion Algebras of Logarithmic Minimal Models ; We present explicit conjectures for the chiral fusion algebras of the logarithmic minimal models LMp,p' considering Virasoro representations with no enlarged or extended symmetry algebra. The generators of fusion are countably infinite in number but the ensuing fusion rules are quasirational in the sense that the fusion of a finite number of representations decomposes into a finite direct sum of representations. The fusion rules are commutative, associative and exhibit an sl2 structure but require socalled Kac representations which are reducible yet indecomposable representations of rank 1. In particular, the identity of the fundamental fusion algebra is in general a reducible yet indecomposable Kac representation of rank 1. We make detailed comparisons of our fusion rules with the results of Gaberdiel and Kausch for p1 and with Eberle and Flohr for p,p'2,5 corresponding to the logarithmic YangLee model. In the latter case, we confirm the appearance of indecomposable representations of rank 3. We also find that closure of a fundamental fusion algebra is achieved without the introduction of indecomposable representations of rank higher than 3. The conjectured fusion rules are supported, within our lattice approach, by extensive numerical studies of the associated integrable lattice models. Details of our lattice findings and numerical results will be presented elsewhere. The agreement of our fusion rules with the previous fusion rules lends considerable support for the identification of the logarithmic minimal models LMp,p' with the augmented cp,p' minimal models defined algebraically.

Systems level circuit model of C. elegans undulatory locomotion mathematical modeling and molecular genetics ; To establish the relationship between locomotory behavior and dynamics of neural circuits in the nematode C. elegans we combined molecular and theoretical approaches. In particular, we quantitatively analyzed the motion of C. elegans with defective synaptic GABA and acetylcholine transmission, defective muscle calcium signaling, and defective muscles and cuticle structures, and compared the data with our systems level circuit model. The major experimental findings are i anteriortoposterior gradients of body bending flex for almost all strains both for forward and backward motion, and for neuronal mutants, also analogous weak gradients of undulatory frequency, ii existence of some form of neuromuscular stretch receptor feedback, iii invariance of neuromuscular wavelength, iv biphasic dependence of frequency on synaptic signaling, and v decrease of frequency with increase of the muscle time constant. Based on i we hypothesize that the Central Pattern Generator CPG is located in the head both for forward and backward motion. Points i and ii are the starting assumptions for our theoretical model, whose dynamical patterns are qualitatively insensitive to the details of the CPG design if stretch receptor feedback is sufficiently strong and slow. The model reveals that stretch receptor coupling in the body wall is critical for generation of the neuromuscular wave. Our model agrees with our behavioral dataiii, iv, and v, and with other pertinent published data, e.g., that frequency is an increasing function of muscle gapjunction coupling.

Why Does the Rouse Model Works at Least Satisfactorily at Polymer Molecular Masses MMc ; Generalization of the Rouse model without any use of the postulates concerning the Gaussian distribution of the vector connecting the ends of segments is advanced. In the initial in general, nonlinear Langevin equations, selfaveraging over continuous fragments of a macromolecule naturally defines a linear term for the tagged chain, and this term differs from the entropy term of the classical Rouse model only by the numerical coefficient. According to the inertiafree approximation, the initial decay rates of correlation functions for the normal modes are described by the Rouse model independently of the character of fluctuations of the vector connecting the ends of the Kuhn segment. This statement is valid for any moment if the initial Langevin equations are treated in terms of the approximation of dynamic selfconsistency. Simulation of the Fraenkel chains by the method of Brownian dynamics shows that decay of autocorrelation functions of shortwave normal modes is fairly described by the linearized equations for a given model of a chain and that the Rouse equation can be used for the longwave modes. The results of this study make it possible to explain a marked difference between the lengths of the Kuhn and Rouse segments that is estimated from static and dynamic experiments.

Electronic Correlations within Fermionic Lattice Models ; We investigate twosite electronic correlations within generalized Hubbard model, which incorporates the conventional Hubbard model parameters t hopping between nearest neighbours, U Coulomb repulsion attraction supplemented by the intersite Coulomb interactions parameters J1parallel spins, J2 antiparellel spins and the hopping of the intrasite Cooper pairs parameter V. As a first step we find the eigenvalues Ealpha and eigenvectors Ealpha of the dimer and we represent each partial Hamiltonian Ealpha Ealpha Ealpha alpha 1,2,..,16 in the second quantization with the use of the Hubbard and spin operators. Each dimer energy level possesses its own Hamiltonian describing different twosite interactions which can be active only in the case when the level will be occupied by the electrons. A typical feature is the appearence of two generalized tJ interactions ascribed to two different energy levels which do not vanish even for UJ1J2V0 and their coupling constants are equal to pm t in this case. The competition between ferromagnetism, antiferromagnetism and superconductivity intrasite and intersite pairings is also a typical feature of the model because it persists in the case UJ1J2V0 and tneq 0. The same types of the electronic, competitive interactions are scattered between different energy levels and therefore their thermodynamical activities are dependent on the occupation of these levels. It qualitatively explains the origin of the phase diagram of the model. We consider also a real lattice as a set of interacting dimers to show that the competition between magnetism and superconductivity seems to be universal for fermonic lattice models.

Hadron Loops General Theorems and Application to Charmonium ; In this paper we develop a formalism for incorporating hadron loops in the quark model. We derive expressions for mass shifts, continuum components and mixing amplitudes of quenched quark model states due to hadron loops, as perturbation series in the valencecontinuum coupling Hamiltonian. We prove three general theorems regarding the effects of hadron loops, which show that given certain constraints on the external bare quark model states, the valencecontinuum coupling, and the hadrons summed in the loops, the following results hold 1 The loop mass shifts are identical for all states within a given N,L multiplet. 2 These states have the same total openflavor decay widths. 3 Loopinduced valence configuration mixing vanishes provided that Li neq Lf or Si neq Sf. The charmonium system is used as a numerical case study, with the 3P0 decay model providing the valencecontinuum coupling. We evaluate the mass shifts and continuum mixing numerically for all 1S, 1P and 2S charmonium valence states due to loops of D, D, Ds and Ds meson pairs. We find that the mass shifts are quite large, but are numerically similar for all the lowlying charmonium states, as suggested by the first theorem. Thus, loop mass shifts may have been hidden in the valence quark model by a change of parameters. The twomeson continuum components of the physical charmonium states are also found to be large, creating challenges for the interpretation of the constituent quark model.

Modeling magnetohydrodynamics and non equilibrium SoHOUVCS line emission of CME shocks ; We provide a guideline to interpret the UVCS emission lines in particular O VI and Si XII during shock wave propagation in the outer solar corona. We use a numerical MHD model performing a set of simulations of shock waves generated in the corona and from the result we compute the plasma emission for the O VI and Si XII including the effects of NEI. We analyze the radiative and spectral properties of our model with the support of a detailed radiation model including Doppler dimming and an analytical model for shocks, and, finally, we synthesize the expected O VI 1032A line profile. We explain several spectral features of the observations like the absence of discontinuities in the O VI emission during the shock passage, the brightening of Si XII emission and the width of the lines. We use our model also to give very simple and general predictions for the strength of the line wings due to the ions shock heating and on the line shape for Limb CMEs or Halo CMEs. The emission coming from postshock region in the solar corona roughly agrees with the emission from a simple planar and adiabatic shock, but the effect of thermal conduction and the magnetic field may be important depending on the event parameters. Doppler dimming significantly influences the O VI emission while Si XII line brightens mainly because of the shock compression. Significant shock heating is responsible for the wide and faint component of the O VI line usually observed which may be taken as a shock signature in the solar corona.

Unitarity Bounds for Gauged Axionic Interactions and the GreenSchwarz Mechanism ; We analyze the effective actions of anomalous models in which a fourdimensional version of the GreenSchwarz mechanism is invoked for the cancellation of the anomalies, and we compare it with those models in which gauge invariance is restored by the presence of a WessZumino term. Some issues concerning an apparent violation of unitarity of the mechanism, which requires DolgovZakharov poles, are carefully examined, using a class of amplitudes studied in the past by BouchiatIliopoulosMeyer BIM, and elaborating on previous studies. In the WessZumino case we determine explicitly the unitarity bound using a realistic model of intersecting branes the Madrid model by studying the corresponding BIM amplitudes. This is shown to depend significantly on the Stuckelberg mass and on the coupling of the extra anomalous gauge bosons and allows one to identify StandardModellike regions which are anomalyfree from regions where the growth of certain amplitudes is dominated by the anomaly, separated by an inflection point which could be studied at the LHC. The bound can even be around 510 TeV's for a Z' mass around 1 TeV and varies sensitively with the anomalous coupling. The results for the WZ case are quite general and apply to all the models in which an axionlike interaction is introduced as a generalization of the PecceiQuinn mechanism, with a gauged axion.

Anatomy of TopMode Extended Technicolor Model ; We analyze two versions of the extended technicolor ETC incorporating the top quark condensate via the flavoruniversal coloron type topcolor SU31 times SU32 A straightforward topmode ETC having quarks and techniquarks assigned to a single strong SU31, and a twisted model'' with techniquarks carrying the weak SU32 while quarks the strong SU31. The straightforward model has the same ETC structure as that of Appelquist et al. without topcolor which we first analyze to find that it yields only too small ETCinduced mass for the third generation. In contrast, our model having topcolor takes the form of a version of the topcolorassisted technicolor TC2 after ETC breakings, which triggers the top quark condensate giving rise to a realistic top mass. However, techniquarks have the strong topcolor SU31 in addition to the already strong walkingconformal technicolor, which triggers the techniquark condensate at scale much higher than the weak scale, a disaster. We then consider a twisted model'' of TC2, though not an explicit ETC. We find a new feature that ETC''induced quark mass is enhanced to the realistic value by the large anomalous dimension gammam simeq 2 of NambuJonaLasiniotype topcolor interactions. The result roughly reproduces the realistic quark masses. We further find a novel effect of the above large anomalous dimension gammam simeq 2 The toppion mass has a universal upper bound, mpit 70 GeV, in the generic TC2 model.

Asymptotic inference in some heteroscedastic regression models with long memory design and errors ; This paper discusses asymptotic distributions of various estimators of the underlying parameters in some regression models with long memory LM Gaussian design and nonparametric heteroscedastic LM moving average errors. In the simple linear regression model, the firstorder asymptotic distribution of the least square estimator of the slope parameter is observed to be degenerate. However, in the second order, this estimator is n12consistent and asymptotically normal for hH32; nonnormal otherwise, where h and H are LM parameters of design and error processes, respectively. The finitedimensional asymptotic distributions of a class of kernel type estimators of the conditional variance function sigma2x in a more general heteroscedastic regression model are found to be normal whenever H1h2, and nonnormal otherwise. In addition, in this general model, lognconsistency of the local Whittle estimator of H based on pseudo residuals and consistency of a cross validation type estimator of sigma2x are established. All of these findings are then used to propose a lackoffit test of a parametric regression model, with an application to some currency exchange rate data which exhibit LM.

A Local Mean Field Analysis of Security Investments in Networks ; Getting agents in the Internet, and in networks in general, to invest in and deploy security features and protocols is a challenge, in particular because of economic reasons arising from the presence of network externalities. Our goal in this paper is to carefully model and quantify the impact of such externalities on the investment in, and deployment of, security features and protocols in a network. Specifically, we study a network of interconnected agents, which are subject to epidemic risks such as those caused by propagating viruses and worms, and which can decide whether or not to invest some amount to selfprotect and deploy security solutions. We make three contributions in the paper. First, we introduce a general model which combines an epidemic propagation model with an economic model for agents which captures network effects and externalities. Second, borrowing ideas and techniques used in statistical physics, we introduce a Local Mean Field LMF model, which extends the standard meanfield approximation to take into account the correlation structure on local neighborhoods. Third, we solve the LMF model in a network with externalities, and we derive analytic solutions for sparse random graphs, for which we obtain asymptotic results. We explicitly identify the impact of network externalities on the decision to invest in and deploy security features. In other words, we identify both the economic and network properties that determine the adoption of security technologies.

A generalized voter model on complex networks ; We study a generalization of the voter model on complex networks, focusing on the scaling of mean exit time. Previous work has defined the voter model in terms of an initially chosen node and a randomly chosen neighbor, which makes it difficult to disentangle the effects of the stochastic process itself relative to the network structure. We introduce a process with two steps, one that selects a pair of interacting nodes and one that determines the direction of interaction as a function of the degrees of the two nodes and a parameter alpha which sets the likelihood of the higher degree node giving its state. Traditional voter model behavior can be recovered within the model. We find that on a complete bipartite network, the traditional voter model is the fastest process. On a random network with power law degree distribution, we observe two regimes. For modest values of alpha, exit time is dominated by diffusive drift of the system state, but as the high nodes become more influential, the exit time becomes becomes dominated by frustration effects. For certain selection processes, a short intermediate regime occurs where exit occurs after exponential mixing.

Kinetic Energy Approach to Dissolving Axisymmetric Multiphase Plumes ; A phenomenological kinetic energy theory of buoyant multiphase plumes is constructed, being general enough to incorporate the dissolution of the dispersive phase. We consider an axisymmetric plume, and model the dissolution by means of the RanzMarshall equation in which there occurs a mass transfer coefficient dependent on the plume properties. Our kinetic energy approach is moreover generalized so as to take into account variable slip velocities. The theoretical model is compared with various experiments, and satisfactory agreement is found. One central ingredient in the model is the turbulent correlation parameter, called I, playing a role analogous to the conventional entrainment coefficient alpha in the more traditional plume theories. We use experimental data to suggest a relationship between I, the initial gas flux at the source, and the depth of the gas release. This relationship is used to make predictions for five distinct case studies. Comparison with various experimental data shows that the kinetic energy approach built upon use of the parameter I in practice has the order of predictive power as the conventional entrainmentcoefficient models. Moreover, an advantage of the present model is that its predictions are very quickly worked out numerically. Finally, we give a sensitivity analysis of the kinetic energy approach. It turns out that the model is relatively stable with respect to most of the input parameters. It is shown that the dissolution is of little influence on the dynamics of the dispersed phase as long as the dissolution is moderate.

Large nonGaussianity from multibrid inflation ; A model of multicomponent hybrid inflation, dubbed multibrid inflation, in which various observable quantities including the nonGaussianity parameter fNL can be analytically calculated was proposed recently. In particular, for a twobrid inflation model with an exponential potential and the condition that the end of inflation is an ellipse in the field space, it was found that, while keeping the other observational quantities within the range consistent with observations, large nonGaussianity is possible for certain inflationary trajectories, provided that the ratio of the two masses is large. One might question whether the resulting large nonGaussianity is specific to this particular form of the potential and the condition for the end of inflation. In this paper, we consider a model of multibrid inflation with a potential given by an exponential function of terms quadratic in the scalar field components. We also consider a more general class of ellipses for the end of inflation than those studied previously. Then, focusing on the case of twobrid inflation, we find that large nonGaussianity is possible in the present model even for the equalmass case. Then by tuning the model parameters, we find that there exist models for which both the nonGaussianity and the tensortoscalar ratio are large enough to be detected in the very near future.

On the path integral representation for quantum spin models and its application to the quantum cavity method and to Monte Carlo simulations ; The cavity method is a well established technique for solving classical spin models on sparse random graphs meanfield models with finite connectivity. Laumann et al. arXiv0706.4391 proposed recently an extension of this method to quantum spin12 models in a transverse field, using a discretized SuzukiTrotter imaginary time formalism. Here we show how to take analytically the continuous imaginary time limit. Our main technical contribution is an explicit procedure to generate the spin trajectories in a path integral representation of the imaginary time dynamics. As a side result we also show how this procedure can be used in simple heatbath like Monte Carlo simulations of generic quantum spin models. The replica symmetric continuous time quantum cavity method is formulated for a wide class of models, and applied as a simple example on the Bethe lattice ferromagnet in a transverse field. The results of the methods are confronted with various approximation schemes in this particular case. On this system we performed quantum Monte Carlo simulations that confirm the exactness of the cavity method in the thermodynamic limit.

Minimal Agent Based Model for Financial Markets II Statistical Properties of the Linear and Multiplicative Dynamics ; We present a detailed study of the statistical properties of an Agent Based Model and of its generalization to the multiplicative dynamics. The aim of the model is to consider the minimal elements for the understanding of the origin of the Stylized Facts and their SelfOrganization. The key elements are fundamentalist agents, chartist agents, herding dynamics and price behavior. The first two elements correspond to the competition between stability and instability tendencies in the market. The herding behavior governs the possibility of the agents to change strategy and it is a crucial element of this class of models. The linear approximation permits a simple interpretation of the model dynamics and, for many properties, it is possible to derive analytical results. The generalized non linear dynamics results to be extremely more sensible to the parameter space and much more difficult to analyze and control. The main results for the nature and SelfOrganization of the Stylized Facts are, however, very similar in the two cases. The main peculiarity of the non linear dynamics is an enhancement of the fluctuations and a more marked evidence of the Stylized Facts. We will also discuss some modifications of the model to introduce more realistic elements with respect to the real markets.

Bayesian analysis of the backreaction models ; We present the Bayesian analysis of four different types of backreation models, which are based on the Buchert equations. In this approach, one considers a solution to the Einstein equations for a general matter distribution and then an average of various observable quantities is taken. Such an approach became of considerable interest when it was shown that it could lead to agreement with observations without resorting to dark energy. In this paper we compare the LambdaCDM model and the backreation models with SNIa, BAO, and CMB data, and find that the former is favoured. However, the tested models were based on some particular assumptions about the relation between the average spatial curvature and the backreaction, as well as the relation between the curvature and curvature index. In this paper we modified the latter assumption, leaving the former unchanged. We find that, by varying the relation between the curvature and curvature index, we can obtain a better fit. Therefore, some further work is still needed in particular the relation between the backreaction and the curvature should be revisited in order to fully determine the feasibility of the backreaction models to mimic dark energy.

Common Origin for CP Violation in Cosmology and in Neutrino Oscillations ; We suggest predictive scenarios for neutrino masses which provide a common origin for CP violation in early universe cosmology and in neutrino oscillations. Our setup is the seesaw mechanism in the context of MSSM with two quasidegenerate righthanded neutrinos, with baryon asymmetry generated via resonant leptogenesis. Three different models are found with specific textures in the Yukawa coupling matrices, each with a single phase which controls leptogenesis and neutrino CP violation. One model leads to normal hierarchy of light neutrino masses and the prediction tan theta13 sin theta12 sqrtm2m3, resulting in a value of the reactor mixing angle theta13 very close to the current experimental lower limit. The other two models predict inverted hierarchical neutrino mass spectrum with the sum rules sin2 theta12 12tan theta23 sin theta 13 cos delta and sin2 theta12 12cot theta23 sin theta13 cos delta respectively. We obtain a lower bound for the phase delta in the normal hierarchical model, and a narrow range for delta for the inverted hierarchical model from cosmology. In our scenario, the masssplitting between the quasidegenerate righthanded neutrinos arise via renormalization group flow, which provides a lower limit on the MSSM parameter tan beta 12. The righthanded neutrino masses can be as low as TeV, which would avoid the gravitino problem generic to supersymmetric models.

NonFermi liquid properties of 2d symplectic fermions the role of a dynamically generated pseudogap ; The interacting symplectic fermion model in two spatial dimensions is further analyzed. As an effective low energy theory, the model is unitary. We show that a relativistic mass m is dynamically generated and derive a gap equation for it. By incorporating a finite temperature we study some fundamental properties of the model, such as the specific heat and spin response, which clearly show nonFermi liquid properties. We find that various physical properties are suppressed at temperatures T T where the crossover scale is T m. As a simplified, toy model of high Tc superconductivity, we thus identify the pseudogap energy scale with the zero temperature relativistic mass m, and show that this reproduces some qualitative aspects of the observed phenomenology of the pseudogap. The effects of the pseudogap and finite temperature on the dwave gap equation are analyzed. In this model, the pseudogap is a distinct phenomenon from superconductivity and in fact competes with it. Our analysis of Tc suggests that the quantum critical point of our model, where the pseudogap vanishes, occurs inside the superconducting dome near optimal doping. For an antiferromagnetic exchange energy of JkB 1350K, solutions of the dwave gap equation give a maximum Tc of about 110K.

Decomposition and Model Selection for Large Contingency Tables ; Large contingency tables summarizing categorical variables arise in many areas. For example in biology when a large number of biomarkers are crosstabulated according to their discrete expression level. Interactions of the variables are generally studied with loglinear models and the structure of a loglinear model can be visually represented by a graph from which the conditional independence structure can then be read off. However, since the number of parameters in a saturated model grows exponentially in the number of variables, this generally comes with a heavy burden as far as computational power is concerned. If we restrict ourselves to models of lower order interactions or other sparse structures we face similar problems as the number of cells remains unchanged. We therefore present a divideandconquer approach, where we first divide the problem into several lowerdimensional problems and then combine these to form a global solution. Our methodology is computationally feasible for loglinear interaction modeling with many categorical variables each or some of them having many categories. We demonstrate the proposed method on simulated data and apply it to a biomedical problem in cancer research.

A phenomenological model of the muon density profile on the ground of very inclined air showers ; Ultrahigh energy cosmic rays generate extensive air showers in Earth's atmosphere. A standard approach to reconstruct the energy of an ultrahigh energy cosmic rays is to sample the lateral profile of the particle density on the ground of the air shower with an array of surface detectors. For cosmic rays with large inclinations, this reconstruction is based on a model of the lateral profile of the muon density observed on the ground, which is fitted to the observed muon densities in individual surface detectors. The best models for this task are derived from detailed MonteCarlo simulations of the air shower development. We present a phenomenological parametrization scheme which allows to derive a model of the average lateral profile of the muon density directly from a fit to a set of individual MonteCarlo simulated air showers. The model reproduces the detailed simulations with a high precision. As an example, we generate a muon density model which is valid in the energy range 1e18 eV E 1e20 eV and the zenith angle range 60 deg theta 90 deg. We will further demonstrate a way to speed up the simulation of such muon profiles by three orders of magnitude, if only the muons in the shower are of interest.

Hydrocarbons Heterogeneous Pyrolysis Experiments and Modeling for Scramjet Thermal Management ; The last years saw a renewal of interest for hypersonic research in general and regenerative cooling specifically, with a large increase of the number of dedicated facilities and technical studies. In order to quantify the heat transfer in the cooled structures and the composition of the cracked fuel entering the combustor, an accurate model of the thermal decomposition of the fuel is required. This model should be able to predict the fuel chemical composition and physical properties for a broad range of pressures, temperatures and cooling geometries. For this purpose, an experimental and modeling study of the thermal decomposition of generic molecules longchain or polycyclic alkanes that could be good surrogates of real fuels, has been started at the DCPR laboratory located in Nancy France. This successful effort leads to several versions of a complete kinetic model. These models do not assume any effect from the material that constitutes the cooling channel. A specific experimental study was performed with two different types of steel regular E37, stainless 316L. Some results are given in the present paper.

Effective dynamics of the closed loop quantum cosmology ; In this paper we study dynamics of the closed FRW model with holonomy corrections coming from loop quantum cosmology. We consider models with a scalar field and cosmological constant. In case of the models with cosmological constant and free scalar field, dynamics reduce to 2D system and analysis of solutions simplify. If only free scalar field is included then universe undergoes nonsingular oscillations. For the model with cosmological constant, different behaviours are obtained depending on the value of Lambda. If the value of Lambda is sufficiently small, bouncing solutions with asymptotic de Sitter stages are obtained. However if the value of Lambda exceeds critical value Lambdatextc fracsqrt3m2textPl2pigamma3 simeq 21 m2textPl then solutions become oscillatory. Subsequently we study models with a massive scalar field. We find that this model possess generic inflationary attractors. In particular field, initially situated in the bottom of the potential, is driven up during the phase of quantum bounce. This subsequently leads to the phase of inflation. Finally we find that, comparing with the flat case, effects of curvature do not change qualitatively dynamics close to the phase of bounce. Possible effects of inverse volume corrections are also briefly discussed.

Maximum Error Modeling for FaultTolerant Computation using Maximum a posteriori MAP Hypothesis ; The application of current generation computing machines in safetycentric applications like implantable biomedical chips and automobile safety has immensely increased the need for reviewing the worstcase error behavior of computing devices for faulttolerant computation. In this work, we propose an exact probabilistic error model that can compute the maximum error over all possible input space in a circuit specific manner and can handle various types of structural dependencies in the circuit. We also provide the worstcase input vector, which has the highest probability to generate an erroneous output, for any given logic circuit. We also present a study of circuitspecific error bounds for faulttolerant computation in heterogeneous circuits using the maximum error computed for each circuit. We model the error estimation problem as a maximum a posteriori MAP estimate, over the joint error probability function of the entire circuit, calculated efficiently through an intelligent search of the entire input space using probabilistic traversal of a binary join tree using ShenoyShafer algorithm. We demonstrate this model using MCNC and ISCAS benchmark circuits and validate it using an equivalent HSpice model. Both results yield the same worstcase input vectors and the highest difference of our error model over HSpice is just 1.23. We observe that the maximum error probabilities are significantly larger than the average error probabilities, and provides a much tighter error bounds for faulttolerant computation. We also find that the error estimates depend on the specific circuit structure and the maximum error probabilities are sensitive to the individual gate failure probabilities.

Strongcoupling limit in coldmolecule formation via photoassociation or Feshbach resonance through Nikitin exponential resonance crossing ; The strongcoupling limit of molecule formation in an atomic BoseEinstein condensate via twomode onecolor photoassociation or sweep across a Feshbach resonance is examined using a basic nonlinear timedependent twostate model. For the general class of termcrossing models with constant coupling, a common strategy for attacking the problem is developed based on the reduction of the initial system of semiclassical equations for atommolecule amplitudes to a third order nonlinear differential equation for the molecular state probability. This equation provides deriving exact solution for a class of periodic levelcrossing models. These models reveal much in common with the Rabi problem. Discussing the strongcoupling limit for the general case of variable detuning, the equation is further truncated to a limit firstorder nonlinear equation. Using this equation, the strong nonlinearity regime for the first Nikitin exponentialcrossing model is analyzed and accurate asymptotic expressions for the nonlinear transition probability to the molecular state are derived. It is shown that, because of a finite final detuning involved, this model displays essential deviations from the LandauZener behavior. In particular, it is shown that in the limit of strong coupling the final conversion probability tends to 16. Thus, in this case the strong interaction limit is not optimal for molecule formation. We have found that if optimal field intensity is applied the molecular probability is increased up to 14 i.e., the half of the initial atomic population.

Analyzing the BoerMulders function within different quark models ; A general formalism for the evaluation of time reversal odd parton distributions is applied here to calculate the BoerMulders function. The same formalism when applied to evaluate the Sivers function led to results which fulfill the Burkardt sum rule quite well. The calculation here has been performed for two different models of proton structure a constituent quark model and the MIT bag model. In the latter case, important differences are found with respect to a previous evaluation in the same framework, a feature already encountered in the calculation of the Sivers function. The results obtained are consistent with the present wisdom, i.e., the contributions for the u and d flavors turn out to have the same sign, following the pattern suggested analyzing the model independent features of the impact parameter dependent generalized parton distributions. It is therefore confirmed that the present approach is suitable for the analysis of time reversal odd distribution functions. A critical comparison between the outcomes of the two models, as well as between the results of the calculations for the Sivers and BoerMulders functions, is also carried out.

Modelling Inhomogeneity in the Universe ; An overview of some recent developments in inhomogeneous models is presented. As the volume and precision of cosmological data improves, it will become more and more essential to understand the nonlinear behaviour of the Einstein field equations. This requires the study of exact inhomogeneous solutions, including their density distributions, their evolution, their geometry, and their causal structure. Observations are strongly affected by the detailed geometry and evolution of a model, and therefore interpretation of observations depends on understanding them. It is generally assumed the universe is homogeneous if averaged over large enough scales, but to actually prove this is so, will require the assumption to be relaxed, and a rigorous inhomogeneous approach to be applied. Though the LT metric has long been used for models of spherical inhomogeneities, there have been a number of new results, including a variety of methods for creating models with specific properties, and their application to cosmic structures on several different scales. Interest in the Szekeres metrics is on the increase, and the quasispherical metric was recently used to model specific cosmic structures for the first time. The quasiplanar and quasihyperspherical metrics have been hardly studied until recent work invesigated their physical and geometric properties. There is enormous scope for work with these metrics.

Symmetries and geometrically implied nonlinearities in mechanics and field theory ; Discussed is relationship between nonlinearity and symmetry of dynamical models. The special stress is laid on essential, nonperturbative nonlinearity, when none linear background does exist. This is nonlinearity essentially different from ones given by nonlinear corrections imposed onto some linear background. In a sense our ideas follow and develop those underlying BornInfeld electrodynamics and general relativity. We are particularly interested in affine symmetry of degrees of freedom and dynamical models. Discussed are mechanical geodetic models where the elastic dynamics of the body is not encoded in potential energy but rather in affinelyinvariant kinetic energy, i.e., in affinelyinvariant metric tensors on the configuration space. In a sense this resembles the idea of Maupertuis variational principle. We discuss also the dynamics of the field of linear frames, invariant under the action of linear group of internal symmetries. It turns out that such models have automatically the generalized BornInfeld structure. This is some new justification of BornInfeld ideas. The suggested models may be applied in nonlinear elasticity and in mechanics of relativistic continua with microstructure. They provide also some alternative models of gravitation theory. There exists also some interesting relationship with the theory of nonlinear integrable lattices.

A continuum model for alignment of selfpropelled particles with anisotropy and densitydependent parameters ; We consider the macroscopic model derived by Degond and Motsch from a timecontinuous version of the Vicsek model, describing the interaction orientation in a large number of selfpropelled particles. In this article, we study the influence of a slight modification at the individual level, letting the relaxation parameter depend on the local density and taking in account some anisotropy in the observation kernel which can model an angle of vision. The main result is a certain robustness of this macroscopic limit and of the methodology used to derive it. With some adaptations to the concept of generalized collisional invariants, we are able to derive the same system of partial differential equations, the only difference being in the definition of the coefficients, which depend on the density. This new feature may lead to the loss of hyperbolicity in some regimes. We provide then a general method which enables us to get asymptotic expansions of these coefficients. These expansions shows, in some effective situations, that the system is not hyperbolic. This asymptotic study is also useful to measure the influence of the angle of vision in the final macroscopic model, when the noise is small.

Efficient Parallel Statistical Model Checking of Biochemical Networks ; We consider the problem of verifying stochastic models of biochemical networks against behavioral properties expressed in temporal logic terms. Exact probabilistic verification approaches such as, for example, CSLPCTL model checking, are undermined by a huge computational demand which rule them out for most real case studies. Less demanding approaches, such as statistical model checking, estimate the likelihood that a property is satisfied by sampling executions out of the stochastic model. We propose a methodology for efficiently estimating the likelihood that a LTL property P holds of a stochastic model of a biochemical network. As with other statistical verification techniques, the methodology we propose uses a stochastic simulation algorithm for generating execution samples, however there are three key aspects that improve the efficiency first, the sample generation is driven by onthefly verification of P which results in optimal overall simulation time. Second, the confidence interval estimation for the probability of P to hold is based on an efficient variant of the Wilson method which ensures a faster convergence. Third, the whole methodology is designed according to a parallel fashion and a prototype software tool has been implemented that performs the samplingverification process in parallel over an HPC architecture.

NonGaussianity from Axion Monodromy Inflation ; We study the primordial nonGaussinity predicted from simple models of inflation with a linear potential and superimposed oscillations. This generic form of the potential is predicted by the axion monodromy inflation model, that has recently been proposed as a possible realization of chaotic inflation in string theory, where the monodromy from wrapped branes extends the range of the closed string axions to beyond the Planck scale. The superimposed oscillations in the potential can lead to new signatures in the CMB spectrum and bispectrum. In particular the bispectrum will have a new distinct shape. We calculate the power spectrum and bispectrum of curvature perturbations in the model, as well as make analytic estimates in various limiting cases. From the numerical analysis we find that for a wide range of allowed parameters the model produces a feature in the bispectrum with fnl 50 or larger while the power spectrum is almost featureless. This model is therefore an example of a stringinspired inflationary model which is testable mainly through its nonGaussian features. Finally we provide a simple analytic fitting formula for the bispectrum which is accurate to approximately 5 in all cases, and easily implementable in codes designed to provide nonGaussian templates for CMB analyses.

Particle physics models of inflation and curvaton scenarios ; We review the particle theory origin of inflation and curvaton mechanisms for generating large scale structures and the observed temperature anisotropy in the cosmic microwave background CMB radiation. Since inflaton or curvaton energy density creates all matter, it is important to understand the process of reheating and preheating into the relevant degrees of freedom required for the success of Big Bang Nucleosynthesis. We discuss two distinct classes of models, one where inflaton and curvaton belong to the hidden sector, which are coupled to the Standard Model gauge sector very weakly. There is another class of models of inflaton and curvaton, which are embedded within Minimal Supersymmetric Standard Model MSSM gauge group and beyond, and whose origins lie within gauge invariant combinations of supersymmetric quarks and leptons. Their masses and couplings are all well motivated from low energy physics, therefore such models provide us with a unique opportunity that they can be verifiedfalsified by the CMB data and also by the future collider and noncollider based experiments. We then briefly discuss stringy origin of inflation, alternative cosmological scenarios, and bouncing universes.

Enhancing hyperspectral image unmixing with spatial correlations ; This paper describes a new algorithm for hyperspectral image unmixing. Most of the unmixing algorithms proposed in the literature do not take into account the possible spatial correlations between the pixels. In this work, a Bayesian model is introduced to exploit these correlations. The image to be unmixed is assumed to be partitioned into regions or classes where the statistical properties of the abundance coefficients are homogeneous. A Markov random field is then proposed to model the spatial dependency of the pixels within any class. Conditionally upon a given class, each pixel is modeled by using the classical linear mixing model with additive white Gaussian noise. This strategy is investigated the well known linear mixing model. For this model, the posterior distributions of the unknown parameters and hyperparameters allow ones to infer the parameters of interest. These parameters include the abundances for each pixel, the means and variances of the abundances for each class, as well as a classification map indicating the classes of all pixels in the image. To overcome the complexity of the posterior distribution of interest, we consider Markov chain Monte Carlo methods that generate samples distributed according to the posterior of interest. The generated samples are then used for parameter and hyperparameter estimation. The accuracy of the proposed algorithms is illustrated on synthetic and real data.

From Matrix Models and quantum fields to Hurwitz space and the absolute Galois group ; We show that correlators of the hermitian oneMatrix model with a general potential can be mapped to the counting of certain triples of permutations and hence to counting of holomorphic maps from worldsheet to sphere target with three branch points on the target. This allows the use of old matrix model results to derive new explicit formulae for a class of Hurwitz numbers. Holomorphic maps with three branch points are related, by Belyi's theorem, to curves and maps defined over algebraic numbers bmQ. This shows that the string theory dual of the onematrix model at generic couplings has worldsheets defined over the algebraic numbers and a target space mP1 bmQ. The absolute Galois group Gal bmQ mQ acts on the Feynman diagrams of the 1matrix model, which are related to Grothendieck's Dessins d'Enfants. Correlators of multimatrix models are mapped to the counting of triples of permutations subject to equivalences defined by subgroups of the permutation groups. This is related to colorings of the edges of the Grothendieck Dessins. The colorededge Dessins are useful as a tool for describing some known invariants of the Gal bmQ mQ action on Grothendieck Dessins and for defining new invariants.

Covariant Description of Flavor Conversion in the LHC Era ; A simple covariant formalism to describe flavor and CP violation in the lefthanded quark sector in a model independent way is provided. The introduction of a covariant basis, which makes the standard model approximate symmetry structure manifest, leads to a physical and transparent picture of flavor conversion processes. Our method is particularly useful to derive robust bounds on models with arbitrary mechanisms of alignment. Known constraints on flavor violation in the K and D systems are reproduced in a straightforward manner. Assumptionsfree limits, based on top flavor violation at the LHC, are then obtained. In the absence of signal, with 100 fb1 of data, the LHC will exclude weakly coupled strongly coupled new physics up to a scale of 0.6 TeV 7.6 TeV, while at present no general constraint can be set related to Delta t1 processes. LHC data will constrain Delta F2 contributions via samesign tops signal, with a model independent exclusion region of 0.08 TeV 1.0 TeV. However, in this case, stronger bounds are found from the study of CP violation in Dbar D mixing with a scale of 0.57 TeV 7.2 TeV. In addition, we apply our analysis to models of supersymmetry and warped extra dimension. The minimal flavor violation framework is also discussed, where the formalism allows to distinguish between the linear and generic nonlinear limits within this class of models.

The dynamics of the flat anisotropic models in the Lovelock gravity. I The evendimensional case ; In this article we give a full description of the dynamics of the flat anisotropic 41dimensional cosmological model in the presence of both GaussBonnet and Einstein contributions. This is the first complete description of this model with both terms taken into account. Our data is obtained using the numerical analysis, though, we use analytics to explain some features of the results obtained, and the same analytics could be applied to higherdimensional models in higherorder Lovelock corrections. Firstly, we investigate the vacuum model and give a description of all regimes; then, we add a matter source in the form of perfect fluid and study the influence the matter exerts upon the dynamics. Thus, we give a description of matter regimes as well. Additionally, we demonstrate that the presence of matter not only improves the situation with a smooth transition between the standard singularity and the Kasner regime, but also brings additional regimes and even partially erases the boundaries between different regimes inside the same triplet. Finally, we discuss the numerical and analytical results obtained and their generalization to the higherorder models.

Generalized individualbased epidemic model for vulnerability assessment of correlated scalefree complex networks ; Many complex networks exhibit vulnerability to spreading of epidemics, and such vulnerability relates to the viral strain as well as to the network characteristics. For instance, the structure of the network plays an important role in spreading of epidemics. Additionally, properties of previous epidemic models require prior knowledge of the complex network structure, which means the models are limited to only wellknown network structures. In this paper, we propose a new epidemiological SIR model based on the continuous time Markov chain, which is generalized to any type of network. The new model is capable of evaluating the states of every individual in the network. Through mathematical analysis, we prove an epidemic threshold exists below which an epidemic does not propagate in the network. We also show that the new epidemic threshold is inversely proportional to the spectral radius of the network. In particular, we employ the new epidemic model as a novel measure to assess the vulnerability of networks to the spread of epidemics. The new measure considers all possible effective infection rates that an epidemic might possess. Next, we apply the measure to correlated networks to evaluate the vulnerability of disassortative and assortative scalefree networks. Ultimately, we verify the accuracy of the theoretical epidemic threshold through extensive numerical simulations. Within the set of tested networks, the numerical results show that disassortative scalefree networks are more vulnerable to spreading of epidemics than assortative scalefree networks.

The spherical collapse model in time varying vacuum cosmologies ; We investigate the virialization of cosmic structures in the framework of flat FLRW cosmological models, in which the vacuum energy density evolves with time. In particular, our analysis focuses on the study of spherical matter perturbations, as they decouple from the background expansion, turn around and finally collapse. We generalize the spherical collapse model in the case when the vacuum energy is a running function of the Hubble rate, LambdaLambdaH. A particularly well motivated model of this type is the socalled quantum field vacuum, in which LambdaH is a quadratic function, LambdaHn0n2,H2, with n0neq 0. This model was previously studied by our team using the latest high quality cosmological data to constrain its free parameters, as well as the predicted cluster formation rate. It turns out that the corresponding Hubble expansion history resembles that of the traditional LambdaCDM cosmology. We use this LambdatCDM framework to illustrate the fact that the properties of the spherical collapse model virial density, collapse factor, etc. depend on the choice of the considered vacuum energy homogeneous or clustered. In particular, if the distribution of the vacuum energy is clustered, then, under specific conditions, we can produce more concentrated structures with respect to the homogeneous vacuum energy case.

Matrix models and stochastic growth in DonaldsonThomas theory ; We show that the partition functions which enumerate DonaldsonThomas invariants of local toric CalabiYau threefolds without compact divisors can be expressed in terms of specializations of the Schur measure. We also discuss the relevance of the HallLittlewood and Jack measures in the context of BPS state counting and study the partition functions at arbitrary points of the Kaehler moduli space. This rewriting in terms of symmetric functions leads to a unitary onematrix model representation for DonaldsonThomas theory. We describe explicitly how this result is related to the unitary matrix model description of ChernSimons gauge theory. This representation is used to show that the generating functions for DonaldsonThomas invariants are related to taufunctions of the integrable Toda and Toeplitz lattice hierarchies. The matrix model also leads to an interpretation of DonaldsonThomas theory in terms of nonintersecting paths in the lockstep model of vicious walkers. We further show that these generating functions can be interpreted as normalization constants of a corner growthlastpassage stochastic model.

Alice String as Source of the Kerr Spinning Particle ; Kerr geometry has twofoldedness which can be cured by a truncation of the negative' sheet of metric. It leads to the models of disklike sources of the Kerr solution and to a class of disklike or baglike models of the Kerr spinning particle. There is an alternative way to retain the negative' sheet as the sheet of advanced fields. In this case the source of spinning particle is the Kerr singular ring which can be considered as a twofold Alice string. This string can have electromagnetic excitations in the form of traveling waves generating spin and mass of the particle. Model of this sort was suggested in 1974 as a microgeon with spin. Recent progress in the obtaining of the nonstationary and radiating Kerr solutions enforces us to return to this model and to consider it as a model for the light spinning particles. We discuss here the real and complex Kerr geometry and some unusual properties of the oscillating solutions in the model of Alice string source.

The Crossing Statistic Dealing with Unknown Errors in the Dispersion of Type Ia Supernovae ; We propose a new statistic that has been designed to be used in situations where the intrinsic dispersion of a data set is not well known The Crossing Statistic. This statistic is in general less sensitive than chi2' to the intrinsic dispersion of the data, and hence allows us to make progress in distinguishing between different models using goodness of fit to the data even when the errors involved are poorly understood. The proposed statistic makes use of the shape and trends of a model's predictions in a quantifiable manner. It is applicable to a variety of circumstances, although we consider it to be especially well suited to the task of distinguishing between different cosmological models using type Ia supernovae. We show that this statistic can easily distinguish between different models in cases where the chi2' statistic fails. We also show that the last mode of the Crossing Statistic is identical to chi2', so that it can be considered as a generalization of chi2'.

Ultra Visible Warped Model From Flavor Triviality Improved Naturalness ; A warped extradimensional model, where the Standard Model Yukawa hierarchy is set by UV physics, is shown to have a sweet spot of parameters with improved experimental visibility and possibly naturalness. Upon marginalizing over all the model parameters, a KaluzaKlein scale of 2.1 TeV can be obtained at 2 sigma 95.4 CL without conflicting with electroweak precision measurements. Fitting all relevant parameters simultaneously can relax this bound to 1.7 TeV. In this bulk version of the RattazziZaffaroni shining model, flavor violation is also highly suppressed, yielding a bound of 2.4 TeV. Nontrivial flavor physics at the LHC in the form of flavor gauge bosons is predicted. The model is also characterized by a depletion of the third generation couplings as predicted by the general minimal flavor violation framework which can be tested via flavor precision measurements. In particular, sizable CP violation in Delta B2 transitions can be obtained, and there is a natural region where Bs mixing is predicted to be larger than Bd mixing, as favored by recent Tevatron data. Unlike other proposals, the new contributions are not linked to Higgs or any scalar exchange processes.

Imperfect Dark Energy from Kinetic Gravity Braiding ; We introduce a large class of scalartensor models with interactions containing the second derivatives of the scalar field but not leading to additional degrees of freedom. These models exhibit peculiar features, such as an essential mixing of scalar and tensor kinetic terms, which we have named kinetic braiding. This braiding causes the scalar stress tensor to deviate from the perfectfluid form. Cosmology in these models possesses a rich phenomenology, even in the limit where the scalar is an exact Goldstone boson. Generically, there are attractor solutions where the scalar monitors the behaviour of external matter. Because of the kinetic braiding, the position of the attractor depends both on the form of the Lagrangian and on the external energy density. The latetime asymptotic of these cosmologies is a de Sitter state. The scalar can exhibit phantom behaviour and is able to cross the phantom divide with neither ghosts nor gradient instabilities. These features provide a new class of models for Dark Energy. As an example, we study in detail a simple oneparameter model. The possible observational signatures of this model include a sizeable Early Dark Energy and a specific equation of state evolving into the final deSitter state from a healthy phantom regime.