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Lessons LearnedSharing the Experience of Developing a Metro System Case Study ; In this document we share the experiences gained throughout the development of a metro system case study. The model is constructed in EventB using its respective tool set, the Rodin platform. Starting from requirements, adding more details to the model in a stepwise manner through refinement, we identify some keys points and available plugins necessary for modelling large systems requirement engineering, decomposition, generic instantiation, among others, which ones are lacking plus strengths and weaknesses of the tool. |
Extremal behavior of pMAX processes ; The wellknown M4 processes of Smith and Weissman are very flexible models for asymptotically dependent multivariate data. Extended M4 of Heffernan emphet al. allows to also account for asymptotic independence. In this paper we introduce a more general multivariate model comprising asymptotic dependence and independence, which has the extended M4 class as a particular case. We study properties of the proposed model. In particular, we compute the multivariate extremal index, tail dependence and extremal coefficients. |
A class of smooth models satisfying marginal and context specific conditional independencies ; We study a class of conditional independence models for discrete data with the property that one or more loglinear interactions are defined within two different marginal distributions and then constrained to 0; all the conditional independence models which are known to be non smooth belong to this class. We introduce a new marginal loglinear parameterization and show that smoothness may be restored by restricting one or more independence statements to hold conditionally to a restricted subset of the configurations of the conditioning variables. Our results are based on a specific reconstruction algorithm from loglinear parameters to probabilities and fixed point theory. Several examples are examined and a general rule for determining the implied conditional independence restrictions is outlined. |
Aggregate Preferred Correspondence and the Existence of a MREE ; In this paper, a general model of a pure exchange differential information economy is studied. In this economic model, the space of states of nature is a complete probability measure space, the space of agents is a measure space with a finite measure, and the commodity space is the Euclidean space. Under appropriate and standard assumptions on agents' characteristics, results on continuity and measurability of the aggregate preferred correspondence in the sense of Aumann in 4 are established. These results together with other techniques are then employed to prove the existence of a maximin rational expectations equilibrium maximin REE of the economic model. |
Pseudoconformal Universe latetime contraction and generation of tensor modes ; We consider a bouncing Universe model which explains the flatness of the primordial scalar spectrum via complex scalar field that rolls down its negative quartic potential and dominates in the Universe. We show that in this model, there exists a rapid contraction regime of classical evolution. We calculate the power spectrum of tensor modes in this scenario. We find that it is blue and its amplitude is typically small, leading to mild constraints on the parameters of the model. |
Detectability of Lorentzviolating potentials in a unified model of fermions ; The detectability of the fermionpotentials appearing in a unified model of fermions is discussed from the viewpoint of an effective field theory. Although the fermionpotentials are effectively represented as terms similar to the acoefficients in the theory of standardmodel extension, their magnitudes are very large and their physical implications are different. A possibility is shown that the fermionpotentials are detectable by neither the deviations from conventional energymomentum conservations, the neutrinooscillations, the CPTviolation in neutral meson systems, nor the gravitational effects. |
Can we explain unexpected fluctuations of longterm real interest rate ; In this paper, we present own point of view how the unexpected fluctuations of the longterm real interest rate can be explained. We describe a macroeconomic environment by the modification of the fundamental macroeconomic equilibrium model called the ISLM model. Last but not least, we suggest a possible cooperation between the fiscal and monetary policy to reduce these fluctuations. Our modelling is demonstrated on an illustrative example. |
Modified Chaplygin Gas Cosmology ; Modified Chaplygin gas as an exotic fluid has been introduced in 34. Essential features of the modified Chaplygin gas as a cosmological model are discussed. Observational constraints on the parameters of the model have been included. The relationship between the modified Chaplygin gas and a homogeneous minimally coupled scalar field are reevaluated by constructing its selfinteracting potential. In addition, we study the role of the tachyonic field in the modified Chaplygin gas cosmological model and the mapping between scalar field and tachyonic field is also considered. |
NonGaussianity from Attractor Curvaton ; We propose a curvaton model in which the initial condition of the curvaton oscillation is determined by its attractor behavior during inflation. Assuming a chaotic inflation model, we find that the initial condition determined by the attractor behavior is appropriate to generate a sizable nonGaussianity contribution to the curvature perturbation, which will be tested in the foreseeable future. Implications on the thermal history of the universe and on particle physics models are also discussed. |
Anisotropic massive strings in scalartensor theory of gravitation ; We present the model of anisotropic universe with string fluid as source of matter within the framework of scalartensor theory of gravitation. Exact solution of field equations are obtained by applying Berman's law of variation of Hubble's parameter which yields a constant value of DP. The nature of classical potential is examined for the model under consideration. It has been also found that the massive strings dominate in early universe and at long last disappear from universe. This is in agreement with current astronomical observations. The physical and dynamical properties of model are also discussed. |
Stability of EinsteinAether Cosmological Models ; We use a dynamical systems analysis to investigate the future behaviour of EinsteinAether cosmological models with a scalar field coupling to the expansion of the aether and a noninteracting perfect fluid. The stability of the equilibrium solutions are analysed and the results are compared with the standard inflationary cosmological solutions and previously studied cosmological EinsteinAether models. |
Lectures on Screened Modified Gravity ; The acceleration of the expansion of the Universe has led to the construction of Dark Energy models where a light scalar field may have a range reaching up to cosmological scales. Screening mechanisms allow these models to evade the tight gravitational tests in the solar system and the laboratory. I will briefly review some of the salient features of screened modified gravity models of the chameleon, dilaton or symmetron types using fR gravity as a template. |
Correspondence between fG Gravity and Holographic Dark Energy via Powerlaw Solution ; In this paper, we discuss cosmological application of holographic Dark Energy HDE in the framework of fG modified gravity. For this purpose, we construct fG model with the inclusion of HDE and a wellknown power law form of the scale factor at. The reconstructed fG is found to satisfy a sufficient condition for a realistic modified gravity model. We find quintessence behavior of effective equation of state EoS parameter omegaDE through energy conditions in this context. Also, we observe that the squared speed of sound vs2 remains negative which shows the instability of HDE fG model. |
Molecular dynamics for longrange interacting systems on Graphic Processing Units ; We present implementations of a fourthorder symplectic integrator on graphic processing units for three Nbody models with longrange interactions of general interest the Hamiltonian Mean Field, Ring and twodimensional selfgravitating models. We discuss the algorithms, speedups and errors using one and two GPU units. Speedups can be as high as 140 compared to a serial code, and the overall relative error in the total energy is of the same order of magnitude as for the CPU code. The number of particles used in the tests range from 10,000 to 50,000,000 depending on the model. |
Wellposedness and stabilization of a model system for long waves posed on a quarter plane ; In this paper we are concerned with a initial boundaryvalue problem for a coupled system of two KdV equations, posed on the positive half line, under the effect of a localized damping term. The model arises when modeling the propagation of long waves generated by a wave maker in a channel. It is shown that the solutions of the system are exponential stable and globally wellposed in the weighted space L2e2bxdx for b0. The stabilization problem is studied using a Lyapunov approach while the wellposedness result is obtained combining fixed point arguments and energy type estimates. |
About the overlap distribution in mean field spin glass models ; We continue our presentation of mathematically rigorous results about the SherringtonKirkpatrick mean field spin glass model. Here we establish some properties of the distribution of overlaps between real replicas. They are in full agreement with the Parisi accepted picture of spontaneous replica symmetry breaking. As a byproduct, we show that the selfaveraging of the EdwardsAnderson fluctuating order parameter, with respect to the external quenched noise, implies that the overlap distribution is given by the SherringtonKirkpatrick replica symmetric Ansatz. This extends previous results of Pastur and Shcherbina. Finally, we show how to generalize our results to realistic short range spin glass models. |
Phase separation in strongly correlated electron systems with wide and narrow bands a comparison of the HubbardI and DMFT approximations ; The spinless FalicovKimball model on the simple cubic lattice is analyzed in the HubbardI and dynamical mean field DMFT approximations. The Matsubara and real frequency itinerant electron Green's functions, the evolution of the system with doping, and the range of phase separation are found in two approximations. At large values of the onsite Coulomb repulsion both approximations give similar results. The phase separation can be also favorable for a more general model, where heavy electrons have a finite bandwidth. This indicates that the phase separation phenomenon is an inherent feature of the systems described by the Hubbardlike models with wide and narrow bands. |
Canonical Ensemble Model for the Black Hole Quantum Tunneling Radiation ; In this paper, a canonical ensemble model for the black hole quantum tunneling radiation is introduced. With this model the probability distribution function corresponding to the emission shell is calculated. Comparing with this function, the statistical significance of the quantum tunneling radiation spectrum of black holes is investigated. Moreover, by calculating the entropy of the emission shell, a discussion about the mechanism of information flowing out from the black hole is given too. |
Emergent motion of condensates in masstransport models ; We examine the effect of spatial correlations on the phenomenon of realspace condensation in driven masstransport systems. We suggest that in a broad class of models with a spatially correlated steady state, the condensate drifts with a nonvanishing velocity. We present a robust mechanism leading to this condensate drift. This is done within the framework of a generalized zerorange process ZRP in which, unlike the usual ZRP, the steady state is not a product measure. The validity of the mechanism in other masstransport models is discussed. |
Radiative models for jets in Xray binaries ; In this work we develop a leptohadronic model for the electromagnetic radiation from jets in microquasars with lowmass companion stars. We present general results as well as applications to some specific systems, and carefully analyze the predictions of the model in the gammaray band. The results will be directly tested in the near future with the present and forthcoming spaceborne and terrestrial gammaray telescopes. |
A General Metric for Riemannian Manifold Hamiltonian Monte Carlo ; Markov Chain Monte Carlo MCMC is an invaluable means of inference with complicated models, and Hamiltonian Monte Carlo, in particular Riemannian Manifold Hamiltonian Monte Carlo RMHMC, has demonstrated impressive success in many challenging problems. Current RMHMC implementations, however, rely on a Riemannian metric that limits their application to analyticallyconvenient models. In this paper I propose a new metric for RMHMC without these limitations and verify its success on a distribution that emulates many hierarchical and latent models. |
Effective potential for a SUSY LeeWick model the WessZumino case ; Using a superfield generalization of the tadpole method, we study the oneloop effective potential for a Wess Zumino model modified by a higherderivative term, inspired by the LeeWick model. The oneloop Kahlerian potential is also obtained by other methods and compared with the effective potential. |
A solution to the evolutionrelated TruscottBrindley model for the generalized phytoplanktonzooplankton populations ; Phytoplankton are tiny floating plants algae living in oceans. In the process of photosynthesis, phytoplankton produces half of the world's oxygen. Moreover, by primary production, death and sinking, they transport carbon from the ocean's surface layer to marine sediments. There are many species of phytoplankton that can be distinguished according to morphology. In this paper, we investigate the generalised TruscottBrindley model of the dynamics of zoologically defined interacting populations which have spatial structure. Specifically, we consider conjointly marine phytoplankton and zooplankton populations, and model them as an excitable medium. The resolution using the Boubaker polynomials expansion scheme BPES along with stability analysis is carried out. |
A singlettriplet extension for the Higgs search at LEP and LHC ; We describe a simple extension of the standard model, containing a scalar singlet and a triplet fermion. The model can explain the possible enhancement in the decay H rightarrow gamma gamma at the LHC together with the excess found in the Higgs boson search at LEP2. The structure of the model is motivated by a recent argument, that was used to explain the number of fermion generations. For the sake of completenes we also considered the contributions from higher multiplets. |
A Missing Partner Model With 24plet Breaking SU5 ; We give a missing partner model using 24plet instead of 75plet to break the SU5 symmetry. Fermion masses and mixing are generated through the GeorgiJarlskog mechanism. The model is constructed at renormalizable level at very high energy. The perturbative region is extended for the unification gauge coupling. Constrains by proton decay is also satisfied. |
AdSMaxwell Bf Theory As A Model Of Gravity And BiGravity ; This article presents an extended model of gravity obtained by gauging the AdSMawell algebra. It involves additional fields that shift the spin connection, leading effectively to theory of two independent connections. Extension of algebraic structure by another tetrad gives rise to the model described by a pair of Einstein equations. |
Asymptotic Model Selection for Naive Bayesian Networks ; We develop a closed form asymptotic formula to compute the marginal likelihood of data given a naive Bayesian network model with two hidden states and binary features. This formula deviates from the standard BIC score. Our work provides a concrete example that the BIC score is generally not valid for statistical models that belong to a stratified exponential family. This stands in contrast to linear and curved exponential families, where the BIC score has been proven to provide a correct approximation for the marginal likelihood. |
The forest consensus theorem ; We show that the limiting state vector in the differential model of consensus seeking with an arbitrary communication digraph is obtained by multiplying the eigenprojection of the Laplacian matrix of the model by the vector of initial states. Furthermore, the eigenprojection coincides with the stochastic matrix of maximum outforests of the weighted communication digraph. These statements make the forests consensus theorem. A similar result for DeGroot's iterative pooling model requires the Cesaro timeaverage limit in the general case. The forests consensus theorem is useful for the analysis of consensus protocols. |
Nonparametric Reduced Rank Regression ; We propose an approach to multivariate nonparametric regression that generalizes reduced rank regression for linear models. An additive model is estimated for each dimension of a qdimensional response, with a shared pdimensional predictor variable. To control the complexity of the model, we employ a functional form of the KyFan or nuclear norm, resulting in a set of function estimates that have low rank. Backfitting algorithms are derived and justified using a nonparametric form of the nuclear norm subdifferential. Oracle inequalities on excess risk are derived that exhibit the scaling behavior of the procedure in the high dimensional setting. The methods are illustrated on gene expression data. |
Modified Associate Formalism without Entropy Paradox Part I. Model Description ; A Modified Associate Formalism is proposed for thermodynamic modelling of solution phases. The approach is free from the entropy paradox described by Luck et al. Z. Metallkd. 80 1989 pp. 270275. The model is considered in its general form for an arbitrary number of solution components and an arbitrary size of associates. Asymptotic behaviour of chemical activities of solution components in binary dilute solutions is also investigated. |
Spin12 Heisenberg antiferromanget on kagome a Z2 spin liquid with fermionic spinons ; Motivated by recent numerical and experimental studies of the spin12 Heisenberg antiferromagnet on kagome, we formulate a manybody model for fermionic spinons introduced by us earlier Phys. Rev. Lett. 103, 187203 2009. The spinons interact with an emergent U1 gauge field and experience strong shortrange attraction in the S0 channel. The ground state of the model is generically a Z2 liquid. We calculate the edge of the twospinon continuum and compare the theory to the slavefermion approach to the Heisenberg model. |
Exact model categories, approximation theory, and cohomology of quasicoherent sheaves ; Our aim is to give a fairly complete account on the construction of compatible model structures on exact categories and symmetric monoidal exact categories, in some cases generalizing previously known results. We describe the close connection of this theory to approximation theory and cotorsion pairs. We also discuss the motivating applications with the emphasis on constructing monoidal model structures for the derived category of quasicoherent sheaves of modules over a scheme. |
A continuation method for the efficient solution of parametric optimization problems in kinetic model reduction ; Model reduction methods often aim at an identification of slow invariant manifolds in the state space of dynamical systems modeled by ordinary differential equations. We present a predictor corrector method for a fast solution of an optimization problem the solution of which is supposed to approximate points on slow invariant manifolds. The corrector method is either an interior point method or a generalized GaussNewton method. The predictor is an Euler prediction based on the parameter sensitivities of the optimization problem. The benefit of a step size strategy in the predictor corrector scheme is shown for an example. |
Euclidean Relativistic Quantum Mechanics ; We discuss a formulation of exactly Poincar'e invariant quantum mechanics where the input is model Euclidean Green functions or their generating functional. We discuss the structure of the models, the construction of the Hilbert space, the construction and transformation properties of singleparticle states, and the construction of GeV scale transition matrix elements. A simple model is utilized to demonstrate the feasibility of this approach. |
The spectrum of gravitational waves in an fR model with a bounce ; We present an inflationary model preceded by a bounce in a metric fR theory. In this model, modified gravity affects only the early stages of the universe. We analyse the predicted spectrum of the gravitational waves in this scenario using the method of the Bogoliubov coefficients. We show that there are distinctive oscillatory signals on the spectrum for very low frequencies; i.e., corresponding to modes that are currently entering the horizon. |
Existence of Weak Solutions for a Diffuse Interface Model of NonNewtonian TwoPhase Flows ; We consider a phase field model for the flow of two partly miscible incompressible, viscous fluids of NonNewtonian power law type. In the model it is assumed that the densities of the fluids are equal. We prove existence of weak solutions for general initial data and arbitrarily large times with the aid of a parabolic Lipschitz truncation method, which preserves solenoidal velocity fields and was recently developed by Breit, Diening, and Schwarzacher. |
Toward a Market Model for Bayesian Inference ; We present a methodology for representing probabilistic relationships in a generalequilibrium economic model. Specifically, we define a precise mapping from a Bayesian network with binary nodes to a market price system where consumers and producers trade in uncertain propositions. We demonstrate the correspondence between the equilibrium prices of goods in this economy and the probabilities represented by the Bayesian network. A computational market model such as this may provide a useful framework for investigations of belief aggregation, distributed probabilistic inference, resource allocation under uncertainty, and other problems of decentralized uncertainty. |
A GraphTheoretic Analysis of Information Value ; We derive qualitative relationships about the informational relevance of variables in graphical decision models based on a consideration of the topology of the models. Specifically, we identify dominance relations for the expected value of information on chance variables in terms of their position and relationships in influence diagrams. The qualitative relationships can be harnessed to generate nonnumerical procedures for ordering uncertain variables in a decision model by their informational relevance. |
Bimodality in the firm size distributions a kinetic exchange model approach ; Firm growth process in the developing economies is known to produce divergence in their growth path giving rise to bimodality in the size distribution. Similar bimodality has been observed in wealth distribution as well. Here, we introduce a modified kinetic exchange model which can reproduce such features. In particular, we will show numerically that a nonlinear retention rate or savings propensity causes this bimodality. This model can accommodate binary trading as well as the whole systemside trading thus making it more suitable to explain the nonstandard features of wealth distribution as well as firm size distribution. |
On the Testability of Causal Models with Latent and Instrumental Variables ; Certain causal models involving unmeasured variables induce no independence constraints among the observed variables but imply, nevertheless, inequality contraints on the observed distribution. This paper derives a general formula for such instrumental variables, that is, exogenous variables that directly affect some variables but not all. With the help of this formula, it is possible to test whether a model involving instrumental variables may account for the data, or, conversely, whether a given variables can be deemed instrumental. |
New view on the diffraction discovered by Grimaldi and Gaussian beams ; In offered work short historical excursus to the classical theory of light is presented Grimaldi, Fermat, Newton, Huygens, Young, Fresnel, Fraunhofer, and Gauss. The ray analog of wave model of light and HuygensFresnel's elementary waves on the basis of consideration of geometrical model is offered. New geometrical properties of Gaussian beams are analyzed. The new, generalized interpretation of a corner of diffraction divergence of beams of light is given. Difference of geometrical properties of wave fronts of infinite and finite length is shown. Examples of possible application of our geometrical model in various areas are given. |
Model Prediction for the Transverse Single TargetSpin Asymmetry in inclusive DIS ; The singlespin asymmetry of unpolarized leptons scattering deepinelastically off transversely polarized nucleons is discussed. This observable is generated by a twophoton exchange between lepton and nucleon. In a partonic description of the asymmetry the nonperturbative part is given in terms of multiparton correlations quarkgluon correlation functions and quarkphoton correlation functions. Recently, a model for quarkgluon correlation functions was presented where these objects were expressed through nonvalence light cone wave functions. Using this model, estimates for the singlespin asymmetries for a proton and a neutron are presented. |
Discovery of Convoys in Network Proximity Log ; This paper describes an algorithm for discovery of convoys in database with proximity log. Traditionally, discovery of convoys covers trajectories databases. This paper presents a model for contextaware browsing application based on the network proximity. Our model uses mobile phone as proximity sensor and proximity data replaces location information. As per our concept, any existing or even especially created wireless network node could be used as presence sensor that can discover access to some dynamic or usergenerated content. Content revelation in this model depends on rules based on the proximity. Discovery of convoys in historical user's logs provides a new class of rules for delivering local content to mobile subscribers. |
Discriminating different models of luminosityredshift distribution ; The beginning of the cosmological phase bearing the direct kinematic imprints of supernovae dimming may significantly vary within different models of latetime cosmology, even if such models are able to fit present SNe data at a comparable level of statistical accuracy. This effect useful in principle to discriminate among different physical interpretations of the luminosityredshift relation is illustrated here with a pedagogical example based on the LTB geometry. |
Feedback models and stability analysis of three economic paradigms ; In this paper, simple mathematical models from Control Theory are applied to three very important economic paradigms, namely a minimum wages in selfregulating markets, b marketversustrue values and currency rates, and c government spending and taxation levels. Analytical solutions are provided in all three paradigms and some useful conclusions are drawn in terms of variable analysis. This short study can be used as an example of how feedback models and stability analysis can be applied as a guideline of 'proofs' in the context of economic policies. |
Cosmological perturbations in FR gravity ; The quasistatic solutions of the matter density perturbation in FR gravity models have been investigated in numerous papers. However, the oscillating solutions in FR gravity models have not been investigated enough so far. In this paper, the oscillating solutions are also examined by using appropriate approximations. And the behaviors of the matter density perturbation in FR gravity models with singular evolutions of the physical parameters are shortly investigated as applications of the approximated calculations. |
Information, noarbitrage and completeness for asset price models with a change point ; We consider a general class of continuous asset price models where the drift and the volatility functions, as well as the driving Brownian motions, change at a random time tau. Under minimal assumptions on the random time and on the driving Brownian motions, we study the behavior of the model in all the filtrations which naturally arise in this setting, establishing martingale representation results and characterizing the validity of the NA1 and NFLVR noarbitrage conditions. |
Protonrich nucleosynthesis and nuclear physics ; Although the detailed conditions for explosive nucleosynthesis are derived from astrophysical modeling, nuclear physics determines fundamental patterns in abundance yields, not only for equilibrium processes. Focussing on the nup and the gammaprocess, general nucleosynthesis features within the range of astrophysical models, but mostly independent of details in the modelling, are presented. Remaining uncertainties due to uncertain Qvalues and reaction rates are discussed. |
Markov degree of the Birkhoff model ; We prove the conjecture by Diaconis and Eriksson 2006 that the Markov degree of the Birkhoff model is three. In fact, we prove the conjecture in a generalization of the Birkhoff model, where each voter is asked to rank a fixed number, say r, of candidates among all candidates. We also give an exhaustive characterization of Markov bases for small r. |
Decision Under Uncertainty in Diagnosis ; This paper describes the incorporation of uncertainty in diagnostic reasoning based on the set covering model of Reggia et. al. extended to what in the Artificial Intelligence dichotomy between deep and compiled shallow, surface knowledge based diagnosis may be viewed as the generic form at the compiled end of the spectrum. A major undercurrent in this is advocating the need for a strong underlying model and an integrated set of support tools for carrying such a model in order to deal with uncertainty. |
Graceful exit from inflation for minimally coupled Bianchi A scalar field models ; We consider the dynamics of Bianchi A scalar field models which undergo inflation. The main question is under which conditions does inflation come to an end and is succeeded by a decelerated epoch. This socalled graceful exit from inflation is an important ingredient in the standard model of cosmology, but is, at this stage, only understood for restricted classes of solutions. We present new results obtained by a combination of analytical and numerical techniques. |
Mutation and Chaos in Nonlinear Models of Heredity ; In this short communication, we shall explore a nonlinear discrete dynamical system that naturally occurs in population systems to describe a transmission of a trait from parents to their offspring. We consider a Mendelian inheritance for a single gene with three alleles and assume that to form a new generation, each gene has a possibility to mutate, that is, to change into a gene of the other kind. We investigate the derived models. A numerical simulation assists us to get some clear picture about chaotic behaviors of such models. |
A Homogeneous Model of Spinfoam Cosmology ; We examine spinfoam cosmology by use of a simple graph adapted to homogeneous cosmological models. We calculate dynamics in the isotropic limit, and provide the framework for the aniostropic case. The dynamical behaviour is calculating transition amplitudes between holomorphic coherent states on a single node graph. The resultant dynamics is peaked on solutions which have no support on the zero volume state, indicating that big bang type singularities are avoided within such models. |
Towards a doublescaling limit for tensor models probing subdominant orders ; The definition of a doublescaling limit represents an important goal in the development of tensor models. We take the first steps towards this goal by extracting and analysing the nexttoleading order contributions, in the 1N expansion, for the IID tensor models. We show that the radius of convergence of the NLO series coincides with that of the leading order melonic sector. Meanwhile, the value of the susceptibility exponent at NLO is 32, signaling a departure from the leading order behaviour. Both pieces of information provide clues for a nontrivial doublescaling limit, for which we put forward some precise conjecture. |
Excitation spectra from angular momentum projection of HartreeFock states and the configurationinteraction shellmodel ; We make numerical comparison of spectra from angularmomentum projection on HartreeFock states with spectra from configurationinteraction nuclear shellmodel calculations, all carried out in the same model spaces in this case the sd, lower pf, and psd52 shells and using the same input Hamiltonians. We find, unsurprisingly, that the lowlying excitation spectra for rotational nuclides are well reproduced, but the spectra for vibrational nuclides, and more generally the complex specta for oddA and oddodd nuclides are less well reproduced in detail. |
Supersymmetry Breaking in Antide Sitter spacetime ; We study the questions of how supersymmetry is spontaneously broken in Anti deSitter spacetime. We verify that the wouldbe Rsymmetry in AdS4 plays a central role for the existence of metastable supersymmetry breaking. To illustrate, some wellknown models such as Poloyni models and O'Raifeartaigh models are investigated in detail. Our calculations are reliable in flat spacetime limit and confirm us that metastable vacua are generic even though quantum corrections are taken into account. |
Multivariate highfrequency financial data via semiMarkov processes ; In this paper we propose a bivariate generalization of a weighted indexed semiMarkov chains to study the high frequency price dynamics of traded stocks. We assume that financial returns are described by a weighted indexed semiMarkov chain model. We show, through Monte Carlo simulations, that the model is able to reproduce important stylized facts of financial time series like the persistence of volatility and at the same time it can reproduce the correlation between stocks. The model is applied to data from Italian stock market from 1 January 2007 until the end of December 2010. |
Inferring Team Strengths Using a Discrete Markov Random Field ; We propose an original model for inferring team strengths using a Markov Random Field, which can be used to generate historical estimates of the offensive and defensive strengths of a team over time. This model was designed to be applied to sports such as soccer or hockey, in which contest outcomes take value in a limited discrete space. We perform inference using a combination of Expectation Maximization and Loopy Belief Propagation. The challenges of working with a nonconvex optimization problem and a highdimensional parameter space are discussed. The performance of the model is demonstrated on professional soccer data from the English Premier League. |
Precursor of Inflation ; We investigate a nonsingular initial state of the Universe which leads to inflation naturally. The model is described by a scalar field with a quadratic potential in Eddingtoninspired BornInfeld gravity. The curvature of this initial state is given by the mass scale of the scalar field which is much smaller than the Planck scale. Therefore, in this model, quantum gravity is not necessary in understanding this preinflationary stage, no matter how large the energy density becomes. The initial state in this model evolves eventually to a long inflationary period which is similar to the usual chaotic inflation. |
pMSSM Benchmark Models for Snowmass 2013 ; We present several benchmark points in the phenomenological Minimal Supersymmetric Standard Model pMSSM. We select these models as experimentally wellmotivated examples of the MSSM which predict the observed Higgs mass and dark matter relic density while evading the current LHC searches. We also use benchmarks to generate spokes in parameter space by scaling the mass parameters in a manner which keeps the Higgs mass and relic density approximately constant. |
Calculus of functors and model categories II ; This is a continuation, completion, and generalization of our previous joint work with B. Chorny. We supply model structures and Quillen equivalences underlying Goodwillie's constructions on the homotopy level for functors between simplicial model categories satisfying mild hypotheses. |
Flavourful baryon and lepton number violation at the LHC ; We observe that the flavour symmetries of the Standard Model gauge sector, broken as they are in the Standard Model Yukawa Lagrangian, naturally suppress baryon and lepton number violation at low energies and, simultaneously, make it accessible at the LHC through resonant processes involving at least six fermions from all three generations. We establish a model independent classification of such transitions and identify two classes that give rise to particularly clean LHC signatures, namely bar t mu e and bar t bar t jets. |
Dark energy with rigid voids versus relativistic voids alone ; The standard model of cosmology is dominated at the present epoch by dark energy. Its voids are rigid and Newtonian within a relativistic background. The model prevents them from becoming hyperbolic. Observations of rapid velocity flows out of voids are normally interpreted within the standard model that is rigid in comoving coordinates, instead of allowing the voids' density parameter to drop below critical and their curvature to become negative. Isn't it time to advance beyond nineteenth century physics and relegate dark energy back to the no significant evidence box |
Prices and Asymptotics for Discrete Variance Swaps ; We study the fair strike of a discrete variance swap for a general timehomogeneous stochastic volatility model. In the special cases of Heston, HullWhite and SchobelZhu stochastic volatility models we give simple explicit expressions improving Broadie and Jain 2008a in the case of the Heston model. We give conditions on parameters under which the fair strike of a discrete variance swap is higher or lower than that of the continuous variance swap. The interest rate and the correlation between the underlying price and its volatility are key elements in this analysis. We derive asymptotics for the discrete variance swaps and compare our results with those of Broadie and Jain 2008a, Jarrow et al. 2013 and KellerRessel and Griessler 2012. |
BRST quantization of a sixthorder derivative scalar field theory ; We study a sixth order derivative scalar field model in Minkowski spacetime as a toy model of higherderivative critical gravity theories. This model is consistently quantized when using the BecchiRouetStoraTyutin BRST quantization scheme even though it does not show gauge symmetry manifestly. Imposing a BRST quartet generated by two scalars and ghosts, there remains a nontrivial subspace with positive norm. This might be interpreted as a Minkowskian dual version of the unitary truncation in the logarithmic conformal field theory. |
The 5D to 4D projection model applied as a Lepton to Galaxy Creation model ; The 5D to 4D projection is presented in a simple geometry giving the Perelman Theorem, resulting in a 3D doughnut structure for the space manifold of the Lorentz spacetime. It is shown that in the lowest quantum state, this Lorentz manifold confines and gives the de Broglie leptons from the massless 5D etrinos. On the scale of the universe, it allows for a model for the creation of galaxies. |
A CurieWeiss Model of SelfOrganized Criticality The Gaussian Case ; We try to design a simple model exhibiting selforganized criticality, which is amenable to a rigorous mathematical analysis. To this end, we modify the generalized Ising CurieWeiss model by implementing an automatic control of the inverse temperature. With the help of exact computations, we show that, in the case of a centered Gaussian measure with positive variance sigma2, the sum Sn of the random variables has fluctuations of order n34 and that Snn34 converges to the distribution C expx44sigma4,dx where C is a suitable positive constant. |
Modeling the dynamics of bivalent histone modifications ; Epigenetic modifications to histones may promote either activation or repression of the transcription of nearby genes. Recent experimental studies show that the promoters of many lineagecontrol genes in stem cells have bivalent domains in which the nucleosomes contain both active H3K4me3 and repressive H3K27me3 marks. It is generally agreed that bivalent domains play an important role in stem cell differentiation, but the underlying mechanisms remain unclear. Here we formulate a mathematical model to investigate the dynamic properties of histone modification patterns. We then illustrate that our modeling framework can be used to capture key features of experimentally observed combinatorial chromatin states. |
A Renormalization Group Approach to A YangMills Two Matrix Model ; A YangMills type two matrix model with mass terms is studied by use of a matrix renormalization group approach proposed by Brezin and ZinnJustin. The renormalization group method indicates that the model exhibits a critical behavior similar to that of two dimensional Euclidean gravity. A massless limit and the generation of quadratic terms along the renormalization group flow are discussed. |
A semiparametric scalemixture regression model and predictive recursion maximum likelihood ; To avoid specification of the error distribution in a regression model, we propose a general nonparametric scale mixture model for the error distribution. For fitting such mixtures, the predictive recursion method is a simple and computationally efficient alternative to existing methods. We define a predictive recursionbased marginal likelihood function, and estimation of the regression parameters proceeds by maximizing this function. A hybrid predictive recursionEM algorithm is proposed for this purpose. The method's performance is compared with that of existing methods in simulations and real data analyses. |
Unitary equivalence and similarity to Jordan models for weak contractions of class C0 ; We obtain results on the unitary equivalence of weak contractions of class C0 to their Jordan models under an assumption on their commutants. In particular, our work addresses the case of arbitrary finite multiplicity. The main tool is the theory of boundary representations due to Arveson. We also generalize and improve previously known results concerning unitary equivalence and similarity to Jordan models when the minimal function is a Blaschke product. |
The eigenpairs of a SylvesterKac type matrix associated with a simple model for onedimensional deposition and evaporation ; A straightforward model for deposition and evaporation on discrete cells of a finite array of any dimension leads to a matrix equation involving a SylvesterKac type matrix. The eigenvalues and eigenvectors of the general matrix are determined for an arbitrary number of cells. A variety of models to which this solution may be applied are discussed. |
A gauge theory generalization of the fermiondoubling theorem ; It is possible to characterize certain states of matter by properties of their edge states. This implies a notion of surfaceonly models' models which can only be regularized at the edge of a higherdimensional system. After incorporating the fermiondoubling results of Nielsen and Ninomiya into this framework, we employ this idea to identify new obstructions to symmetrypreserving regulators of quantum field theory. We focus on an example which forbids regulated models of Maxwell theory with manifest electromagnetic duality symmetry. |
TimeDependent HartreeFock Solution of GrossNeveu models Twisted Kink Constituents of Baryons and Breathers ; We find the general solution to the timedependent HartreeFock problem for the GrossNeveu models, with both discrete GN2 and continuous NJL2 chiral symmetry. We find new multibaryon, multibreather and twisted breather solutions, and show that all GN2 baryons and breathers are composed of constituent twisted kinks of the NJL2 model. |
Tripartite entangled pure states are tripartite nonlocal ; Nonlocal correlations as revealed by the violations to Bell inequalities are incompatible with local models without any nonlocal correlations. However some tripartite entangled states, e.g., symmetric pure states, exhibit a stronger nonlocality even incompatible with hybrid localnonlocal models allowing nonlocal correlations between any two parties. Here we propose a threeparticle Hardytype test without inequality, as illustrated by a gedanken experiment, that is failed by all nonsignaling local models while is passed by all tripartite entangled asymmetric pure states. Our result implies that every tripartite entangled state, regardless of the dimensions of the underlying Hilbert spaces, passes a Hardytype test and therefore is genuine tripartite nonlocal. Maximal success probability and a generalization to multipartite cases of our test are also presented. |
Explicit implied volatilities for multifactor localstochastic volatility models ; We consider an asset whose riskneutral dynamics are described by a general class of localstochastic volatility models and derive a family of asymptotic expansions for Europeanstyle option prices and implied volatilities. Our implied volatility expansions are explicit; they do not require any special functions nor do they require numerical integration. To illustrate the accuracy and versatility of our method, we implement it under five different model dynamics CEV local volatility, quadratic local volatility, Heston stochastic volatility, 32 stochastic volatility, and SABR localstochastic volatility. |
SUSY after LHC8 a brief overview ; With the 8 TeV LHC run now concluded, the first consequences of the experimental results on the supersymmetric parameter space can be drawn. On one hand, the negative direct searches place more and more stringent bounds on the mass of supersymmetric particles; on the other hand, the discovery of a 125 GeV Higgs boson points toward a quite heavy spectrum for the squarks of the third generation, at least in the minimal supersymmetric model. In this note I will briefly recap how this constitutes a problem for the naturalness of supersymmetric models, as well as the current experimental situation. Moreover, I will point out possible non minimal models in which the naturalness issue can be at least soften. |
Relativistic stellar model admitting a quadratic equation of state ; A class of solutions describing the interior of a static spherically symmetric compact anisotropic star is reported. The analytic solution has been obtained by utilizing the Finch and Skea it Class. Quant. Grav. bf 6 1989 467 ansatz for the metric potential grr which has a clear geometric interpretation for the associated background spacetime. Based on physical grounds appropriate bounds on the model parameters have been obtained and it has been shown that the model admits an equation of state EOS which is quadratic in nature. |
Cosmology with an Effective Term in Lyra Manifold ; A cosmological model in Lyra's geometry are studied under the assumption that an effective cosmological term is appeared in the field equations as the result of interaction between the displacement vector field and an auxiliary Lambda term. Some exact solutions of the model equations are obtained and preliminary studied for the simplest cases in order to illustrate how such a model works |
Rip Brane Cosmology from 4d Inhomogeneous Dark Fluid Universe ; Specific dark energy models with linear inhomogeneous timedependent equation of state, within the framework of 4d FriedmanRobertsonWalker FRW cosmology, are investigated. It is demonstrated that the choice of such 4d inhomogeneous fluid models may lead to a brane FRW cosmology without any explicit account of higher dimensions at all. Effectively, we thus obtain a brane dark energy universe without introducing the brane concept explicitly. Several examples of brane Rip cosmology arising from 4d inhomogeneous dark fluid models are given. |
BSM Higgs results from ATLAS and CMS ; Searches for Higgs bosons in different extensions of the Standard Model SM are presented. These include the Minimal Supersymmetric extension of the SM MSSM, the nexttoMSSM NMSSM, models with additional scalar singlets, doublets, or triplets, and generic searches for models with couplings modified with respect to the SM or for nonSM Higgs boson decay channels. Results are based on data collected by the ATLAS and CMS experiments in 2011 and 2012 at the LHC. No excess is found in any of the searches and thus the resulting exclusion limits are given. |
On the properties of the irrotational dust model ; In this note we analyze the model of the irrotational dust used recently to deparametrize gravitational action. We prove that the remarkable fact that the Hamiltonian is not a square root is a direct consequence of the timegauge choice in this model. No additional assumptions or sign choices are necessary to obtain this crucial feature. In this way we clarify a point recently debated in the literature. |
Hierarchical sparsity priors for regression models ; We focus on the increasingly important area of sparse regression problems where there are many variables and the effects of a large subset of these are negligible. This paper describes the construction of hierarchical prior distributions when the effects are considered related. These priors allow dependence between the regression coefficients and encourage related shrinkage towards zero of different regression coefficients. The properties of these priors are discussed and applications to linear models with interactions and generalized additive models are used as illustrations. Ideas of heredity relating different levels of interaction are encompassed. |
Hybrid conformal field theories ; We describe a class of 2,2 superconformal field theories obtained by fibering a LandauGinzburg orbifold CFT over a compact Kaehler base manifold. While such models are naturally obtained as phases in a gauged linear sigma model, our construction is independent of such an embedding. We discuss the general properties of such theories and present a technique to study the massless spectrum of the associated heterotic compactification. We test the validity of our method by applying it to hybrid phases of linear models and comparing spectra among the phases. |
Latetime acceleration in the coupled Cubic Galileon models ; We investigate the linearly and quadratically coupled cubic Galileon models that include linear potentials. These models may explain the latetime acceleration. In these cases, we need two equations of state parameter named the native and effective equations of state to test whether the universe is accelerating or not because there is coupling between the cold dark matter and Galileon. It turns out that there is no transition from accelerating phase to phantom phase in the future. |
Anisotropic Quintessence stars ; We propose a relativistic model for quintessence stars with the combination of an anisotropic pressure corresponding to normal matter and a quintessence dark energy having a characteristic parameter omegaq such that 1 omegaq 13. We discuss various physical features of the model and show that the model satisfies all the regularity conditions and can provide stable equilibrium configurations. |
Some Plane Symmetric Inhomogeneous Cosmological Models in the ScalarTensor Theory of Gravitation ; The present study deals with the inhomogeneous plane symmetric models in scalar tensor theory of gravitation. We used symmetry group analysis method to solve the field equations analytically. A new class of similarity solutions have been obtained by considering the inhomogeneous nature of metric potential. The physical behavior and geometrical aspects of the derived models are also discussed. |
Integrable lattice models from fourdimensional field theories ; This note gives a general construction of an integrable lattice model and a solution of the YangBaxter equation with spectral parameter from a fourdimensional field theory which is a mixture of topological and holomorphic. Spinchain models arise in this way from a twisted, deformed version of N1 gauge theory. |
Deriving Proper Uniform Priors for Regression Coefficients, Part II ; It is a relatively wellknown fact that in problems of Bayesian model selection improper priors should, in general, be avoided. In this paper we derive a proper and parsimonious uniform prior for regression coefficients. We then use this prior to derive the corresponding evidence values of the regression models under consideration. By way of these evidence values one may proceed to compute the posterior probabilities of the competing regression models. |
A toy model for the pseudogap state of cuprates ; A toy model is developed to capture dance of preformed pairs in the pseudogap state of high temperature cuprate superconductors. The model is a crude description of a hypothetical situation in which spindriven spatial organization of the preformed pairs is analyzed. Within a meanfield theory a slight generalization of BraggWilliams theory we examined the behaviour of heat capacity and an order parameter which captures the short range correlations between the preformed pairs. Below a transition temperature these short range correlations enhance and leads to a long range order spindensity wave. This is examined through the breakdown of statistical independence. |
Localization for a nonlinear sigma model in a strip related to vertex reinforced jump processes ; We study a lattice sigma model which is expected to reflect Anderson localization and delocalization transition for real symmetric band matrices in 3D, but describes the mixing measure for a vertex reinforced jump process too. For this model we prove exponential localization at any temperature in a strip, and more generally in any quasione dimensional graph, with pinning mass at only one site. The proof uses a MerminWagner type argument and a transfer operator approach. |
LAN property for families of distributions of solutions to Levy driven SDE's ; The LAN property is proved in the statistical model based on discretetime observations of a solution to a L'evy driven SDE. The proof is based on a general sufficient condition for a statistical model based on a discrete observations of a Markov process to possess the LAN property, and involves substantially the Malliavin calculusbased integral representations for derivatives of loglikelihood of the model. |
Modeling SelfSimilar Traffic for Network Simulation ; In order to closely simulate the real network scenario thereby verify the effectiveness of protocol designs, it is necessary to model the traffic flows carried over realistic networks. Extensive studies 1 showed that the actual traffic in access and local area networks e.g., those generated by ftp and video streams exhibits the property of selfsimilarity and longrange dependency LRD 2. In this appendix we briefly introduce the property of selfsimilarity and suggest a practical approach for modeling selfsimilar traces with specified traffic intensity. |
Geometric phase and phase diagram for nonHermitian quantum XY model ; We study the geometric phase for the ground state of a generalized onedimensional nonHermitian quantum XY model, which has transversefielddependent intrinsic rotationtime reversal symmetry. Based on the exact solution, this model is shown to have full real spectrum in multiple regions for the finite size system. The result indicates that the phase diagram or exceptional boundary, which separates the unbroken and broken symmetry regions corresponds to the divergence of the Berry curvature. The scaling behaviors of the groundstate energy and Berry curvature are obtained in an analytical manner for a concrete system. |
A regular version of Smilansky model ; We discuss a modification of Smilansky model in which a singular potential channel' is replaced by a regular, below unbounded potential which shrinks as it becomes deeper. We demonstrate that, similarly to the original model, such a system exhibits a spectral transition with respect to the coupling constant, and determine the critical value above which a new spectral branch opens. The result is generalized to situations with multiple potential channels'. |
Interacting Riccilike holographic dark energy ; In a flat FriedmannLemaitreRobertsonWalker background, a scheme of dark matterdark energy interaction is studied considering a holographic Riccilike model for the dark energy. Without giving a priori some specific model for the interaction function, we show that this function can experience a change of sign during the cosmic evolution. The parameters involved in the holographic model are adjusted with Supernova data and we obtained results compatible with the observable universe. |
Likelihood Adaptively Modified Penalties ; A new family of penalty functions, adaptive to likelihood, is introduced for model selection in general regression models. It arises naturally through assuming certain types of prior distribution on the regression parameters. To study stability properties of the penalized maximum likelihood estimator, two types of asymptotic stability are defined. Theoretical properties, including the parameter estimation consistency, model selection consistency, and asymptotic stability, are established under suitable regularity conditions. An efficient coordinatedescent algorithm is proposed. Simulation results and real data analysis show that the proposed method has competitive performance in comparison with existing ones. |
New Scotogenic Model of Neutrino Mass with U1D Gauge Interaction ; We propose a new realization of the oneloop radiative model of neutrino mass generated by dark matter scotogenic, where the particles in the loop have an additional U1D gauge symmetry, which may be exact or broken to Z2. This model is relevant to a number of astrophysical observations, including AMS02 and the dark matter distribution in dwarf galactic halos. |
Entanglement, Superselection Rules and Supersymmetric Quantum Mechanics ; In this paper we show that the energy eigenstates of supersymmetric quantum mechanics SUSYQM with non definite fermion number are entangled states. They are physical states of the model provided that observables with odd number of spin variables are allowed in the theory like it happens in the JaynesCummings model. Those states generalize the so called spin spring states of the JaynesCummings model which have played an important role in the study of entanglement. |
Proceedings Machines, Computations and Universality 2013 ; This volume contains the papers presented at the 6th conference on Machines, Computations and Universality MCU 2013. MCU 2013 was held in Zurich, Switzerland, September 911, 2013. The MCU series began in Paris in 1995 and has since been concerned with gaining a deeper understanding of computation through the study of models of general purpose computation. This volume continues in this tradition and includes new simple universal models of computation, and other results that clarify the relationships between models. |