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A logBirnbaumSaunders Regression Model with Asymmetric Errors ; The paper by Leiva et al. 2010 introduced a skewed version of the sinhnormal distribution, discussed some of its properties and characterized an extension of the BirnbaumSaunders distribution associated with this distribution. In this paper, we introduce a skewed logBirnbaumSaunders regression model based on the skewed sinhnormal distribution. Some influence methods, such as the local influence and generalized leverage are presented. Additionally, we derived the normal curvatures of local influence under some perturbation schemes. An empirical application to a real data set is presented in order to illustrate the usefulness of the proposed model. |
Lattice models of nontrivial optical spaces based on metamaterial waveguides ; Metamaterials are being used to model various exotic optical spaces for such applications as novel lenses and cloaking. While most effort is directed towards engineering of continuously changing dielectric permittivity and magnetic permeability tensors, an alternative approach may be based on lattices of metamaterial waveguides. Here we demonstrate the power of the latter technique by presenting metamaterial lattice models of various 4D spaces. |
A contribution to the systematics of stochastic volatility models ; We compare systematically several classes of stochastic volatility models of stock market fluctuations. We show that the longtime return distribution is either Gaussian or develops a powerlaw tail, while the shorttime return distribution has generically a stretchedexponential form, but can assume also an algebraic decay, in the family of models which we call GARCH''type. The intermediate regime is found in the exponential OrnsteinUhlenbeck process. We calculate also the decay of the autocorrelation function of volatility. |
Applicability of Anderson and Hubbard model for Ce metal and cerium heavy fermion compounds ; The importance of taking into account intersite ff hybridization in electron structure calculations for Ce metal and cerium heavy fermion compounds was studied. We demonstrate that for heavyfermion systems such as cerium compound CeCu2Si2 ff hybridization can be neglected and Anderson model application is well justified. On another hand for cerium metal ff hybridization is strong enough to provide the contribution to hybridization function comparable to hybridization between 4f and itinerant electrons. We argue that in the case of Ce only the most general Hamiltonian combining Hubbard and Anderson models should be used. |
Bridging Model and Observed Stellar Spectra ; Accurate model stellar fluxes are key for the analysis of observations of individual stars or stellar populations. Model spectra differ from real stellar spectra due to limitations of the input physical data and adopted simplifications, but can be empirically calibrated to maximise their resemblance to actual stellar spectra. I describe a leastsquares procedure of general use and test it on the MILES library. |
Identifying Quantum Topological Phases Through Statistical Correlation ; We theoretically examine the use of a statistical distance measure, the indistinguishability, as a generic tool for the identification of topological order. We apply this measure to the toric code and two fractional quantum Hall models. We find that topologically ordered states can be identified with the indistinguishability for both models. Calculations with the indistinguishability also underscore a key distinction between symmetries that underlie topological order in the toric code and quantum Hall models. |
Cauchy problem for the BoltzmannBGK model near a global Maxwellian ; In this paper, we are interested in the Cauchy problem for the BoltzmannBGK model for a general class of collision frequencies. We prove that the BoltzmannBGK model linearized around a global Maxwellian admits a unique global smooth solution if the initial perturbation is sufficiently small in a high order energy norm. We also establish an asymptotic decay estimate and uniform L2stability for nonlinear perturbations. |
Holographic Dark Energy with Curvature ; In this paper we consider an holographic model of dark energy, where the length scale is the Hubble radius, in a non flat geometry. The model contains the possibility to alleviate the cosmic coincidence problem, and also incorporate a mechanism to obtain the transition from decelerated to an accelerated expansion regime. We derive an analytic form for the Hubble parameter in a non flat universe, and using it, we perform a Bayesian analysis of this model using SNIa, BAO and CMB data. We find from this analysis that the data favored a small value for Omegak, however high enough to still produce cosmological consequences. |
Stable fixed points in the Kuramoto model ; We develop a necessary condition for the existence of stable fixed points for the general network Kuramoto model, and use it to show that for the complete network the homogeneous model has no nonzero stable fixed point solution. This result provides further evidence that in the homogeneous case the zero fixed point has an attractor set consisting of the entire space minus a set of measure zero, a conjecture of Verwoerd and Mason 2007. |
Flavour constraints on the Aligned TwoHiggsDoublet Model and CP violation ; The Aligned TwoHiggsDoublet Model A2HDM describes a particular way of enlarging the scalar sector of the Standard Model, with a second Higgs doublet which is aligned to first the one in flavour space. This implies the absence of flavourchanging neutral currents at tree level and the presence of three complex parameters. Within this general approach, we analyze the charged Higgs phenomenology, including CP asymmetries in the K and B systems. |
On the Convergence of Bayesian Regression Models ; We consider heteroscedastic nonparametric regression models, when both the mean function and variance function are unknown and to be estimated with nonparametric approaches. We derive convergence rates of posterior distributions for this model with different priors, including splines and Gaussian process priors. The results are based on the general ones on the rates of convergence of posterior distributions for independent, nonidentically distributed observations, and are established for both of the cases with random covariates, and deterministic covariates. We also illustrate that the results can be achieved for all levels of regularity, which means they are adaptive. |
Time correlations for the parabolic Anderson model ; We derive exact asymptotics of time correlation functions for the parabolic Anderson model with homogeneous initial condition and timeindependent tails that decay more slowly than those of a double exponential distribution and have a finite cumulant generating function. We use these results to give precise asymptotics for statistical moments of positive order. Furthermore, we show what the potential peaks that contribute to the intermittency picture look like and how they are distributed in space. We also investigate for how long intermittency peaks remain relevant in terms of ageing properties of the model. |
Oscillations in the bispectrum ; There exist several models of inflation that produce primordial bispectra that contain a large number of oscillations. In this paper we discuss these models, and aim at finding a method of detecting such bispectra in the data. We explain how the recently proposed method of mode expansion of bispectra might be able to reconstruct these spectra from separable basis functions. Extracting these basis functions from the data might then lead to observational constraints on these models. |
On Urn Models, Noncommutativity and Operator Normal Forms ; Noncommutativity is ubiquitous in mathematical modeling of reality and in many cases same algebraic structures are implemented in different situations. Here we consider the canonical commutation relation of quantum theory and discuss a simple urn model of the latter. It is shown that enumeration of urn histories provides a faithful realization of the HeisenbergWeyl algebra. Drawing on this analogy we demonstrate how the operator normal forms facilitate counting of histories via generating functions, which in turn yields an intuitive combinatorial picture of the ordering procedure itself. |
An A4 model for neutrinos ; The study of an extension of the standard model based on the flavor symmetry A4 is presented. Neutrino Majorana mass terms arise from dimension five operator and charged lepton masses from renormalizable Yukawa couplings. We introduce three Higgs doublets that belong to one triplet irreducible representation of A4. We study the most general A4invariant scalar potential and the phenomenological consequences of the model. We find that the reactor angle could be as large as 0.03, while the atmospheric mixing angle is close to maximal. |
Canonical transformation for stiff matter models in quantum cosmology ; In the present work we consider FriedmannRobertsonWalker models in the presence of a stiff matter perfect fluid and a cosmological constant. We write the superhamiltonian of these models using the Schutz's variational formalism. We notice that the resulting superhamiltonians have terms that will lead to factor ordering ambiguities when they are written as operators. In order to remove these ambiguities, we introduce appropriate coordinate transformations and prove that these transformations are canonical using the symplectic method. |
TimeChanged Fast MeanReverting Stochastic Volatility Models ; We introduce a class of randomly timechanged fast meanreverting stochastic volatility models and, using spectral theory and singular perturbation techniques, we derive an approximation for the prices of European options in this setting. Three examples of random timechanges are provided and the implied volatility surfaces induced by these timechanges are examined as a function of the model parameters. Three key features of our framework are that we are able to incorporate jumps into the price process of the underlying asset, allow for the leverage effect, and accommodate multiple factors of volatility, which operate on different timescales. |
Bulk metric of brane world models and submanifolds in 6D pseudoEuclidean spacetime ; In this short note, fivedimensional brane world models with dS4 metric on the branes are discussed. The explicit coordinate transformations, which show the equivalence between the bulk metric of these brane world models and the metric induced on an appropriate submanifolds in the flat sixdimensional pseudoEuclidean spacetime, are presented. The cases of the zero and nonzero cosmological constant in the bulk are discussed in detail. |
On some models of geometric noncommutative general relativity ; Using Fedosov theory of deformation quantization of endomorphism bundle we construct several models of pure geometric, deformed vacuum gravity, corresponding to arbitrary symplectic noncommutativity tensor. Deformations of EinsteinHilbert and Palatini actions are investigated. Coordinate covariant field equations are derived up to the second order of the deformation parameter. For some models they are solved and explicit corrections to an arbitrary Ricciflat metric are pointed out. The relation to the theory of SeibergWitten map is also studied and the correspondence to the spacetime noncommutativity described by Fedosov product of functions is explained. |
The virial relation for compact Qballs in the complex signumGordon model ; In this work the properties of Qballs in the complex signumGordon model in d spatial dimensions is studied. We obtain a general virial relation for this kind of Qball in the higherdimensional spacetime. We compute the energy and radii of Qball with Vshaped field potential as a function of spatial dimensionality and a parameter defining the model potential energy density. |
Kinetic models with randomly perturbed binary collisions ; We introduce a class of Kaclike kinetic equations on the real line, with general random collisional rules, which include as particular cases models for wealth redistribution in an agentbased market or models for granular gases with a background heat bath. Conditions on these collisional rules which guarantee both the existence and uniqueness of equilibrium profiles and their main properties are found. We show that the characterization of these stationary solutions is of independent interest, since the same profiles are shown to be solutions of different evolution problems, both in the econophysics context and in the kinetic theory of rarefied gases. |
Probabilistic Model Checking for Propositional Projection Temporal Logic ; Propositional Projection Temporal Logic PPTL is a useful formalism for reasoning about period of time in hardware and software systems and can handle both sequential and parallel compositions. In this paper, based on discrete time Markov chains, we investigate the probabilistic model checking approach for PPTL towards verifying arbitrary lineartime properties. We first define a normal form graph, denoted by NFGinf, to capture the infinite paths of PPTL formulas. Then we present an algorithm to generate the NFGinf. Since discretetime Markov chains are the deterministic probabilistic models, we further give an algorithm to determinize and minimize the nondeterministic NFGinf following the Safra's construction. |
Chiral model for barKN interactions and its pole content ; We use chirally motivated effective mesonbaryon potentials to describe the low energy barKN data including the characteristics of kaonic hydrogen. Our results are examined in comparison with other approaches based on the unitarity and dispersion relation for the inverse of the Tmatrix. We demonstrate that the movements of the poles generated by the model upon varying the model parameters can serve as a tool to get additional insights on the dynamics of the strongly coupled piSigmabarKN system. |
Interstellar Turbulence and Star Formation ; We provide a brief overview of recent advances and outstanding issues in simulations of interstellar turbulence, including isothermal models for interior structure of molecular clouds and largerscale multiphase models designed to simulate the formation of molecular clouds. We show how selforganization in highly compressible magnetized turbulence in the multiphase ISM can be exploited in simple numerical models to generate realistic initial conditions for star formation. |
The 1N expansion of colored tensor models ; In this paper we perform the 1N expansion of the colored three dimensional Boulatov tensor model. As in matrix models, we obtain a systematic topological expansion, with more and more complicated topologies suppressed by higher and higher powers of N. We compute the first orders of the expansion and prove that only graphs corresponding to three spheres S3 contribute to the leading order in the large N limit. |
Extra dimensions as a source of the electroweak model ; The Higgs boson of the Standard model is described by a set of offdiagonal components of the multidimensional metric tensor, as well as the gauge fields. In the lowenergy limit, the basic properties of the Higgs boson are reproduced, including the shape of the potential and interactions with the gauge fields of the electroweak part of the Standard model. |
A Fuzzy Clustering Model for Fuzzy Data with Outliers ; In this paper a fuzzy clustering model for fuzzy data with outliers is proposed. The model is based on Wasserstein distance between interval valued data which is generalized to fuzzy data. In addition, Keller's approach is used to identify outliers and reduce their influences. We have also defined a transformation to change our distance to the Euclidean distance. With the help of this approach, the problem of fuzzy clustering of fuzzy data is reduced to fuzzy clustering of crisp data. In order to show the performance of the proposed clustering algorithm, two simulation experiments are discussed. |
Strong direct product theorems for quantum communication and query complexity ; A strong direct product theorem SDPT states that solving n instances of a problem requires Omegan times the resources for a single instance, even to achieve success probability expOmegan. We prove that quantum communication complexity obeys an SDPT whenever the communication lower bound for a single instance is proved by the generalized discrepancy method, the strongest technique in that model. We prove that quantum query complexity obeys an SDPT whenever the query lower bound for a single instance is proved by the polynomial method, one of the two main techniques in that model. In both models, we prove the corresponding XOR lemmas and threshold direct product theorems. |
The effect of limiting resources in aging populations ; The concept of a carrying capacity is essential in most models to prevent unlimited growth. Despite the large amount of deaths it introduces, the actual influence of the Verhulst term in simulations is often times not accounted for. Generally, it is treated merely as a scaling parameter that functions to keep simulated populations within computer limits. Here, we compare two different implementations of the concept in the Penna model Vehulst applied to all individuals VA and to newborns only VB. We observe variations in certain model features when random Verhulst deaths are restricted to a single age group. |
Backreaction as an alternative to dark energy and modified gravity ; The predictions of homogeneous and isotropic cosmological models with ordinary matter and gravity are off by a factor of two in the late universe. One possible explanation is the known breakdown of homogeneity and isotropy due to the formation of nonlinear structures. We review how inhomogeneities affect the average expansion rate and can lead to acceleration, and consider a semirealistic model where the observed timescale of ten billion years emerges from structure formation. We also discuss the relation between the average expansion rate and observed quantities. |
Local electrical characterization of resonant magnetization motion in a single ferromagnetic submicrometer particle in lateral geometry ; In this article a detailed characterization of a magnetization motion in a single submicrometer and multiterminal ferromagnetic structure in lateral geometry is performed in a GHz regime using direct DC characterization technique. We have shown applicability of the StonerWohlfarth model to the magnetic nanostructure with large length to with ratio. Applying the model to experimental data we are able to extract relevant magnetization motion parameters and show a correlation between high frequency inductive currents and local magnetization. Additionally, DC voltage generated over the structure at the resonance, with external magnetic field under an angle to the shape anisotropy axis, is explained by the model. |
The growth factor of matter perturbations in an fR gravity ; The growth of matter perturbations in the fR model proposed by Starobinsky is studied in this paper. Three different parametric forms of the growth index are considered respectively and constraints on the model are obtained at both the 1sigma and 2sigma confidence levels, by using the current observational data for the growth factor. It is found, for all the three parametric forms of the growth index examined, that the Starobinsky model is consistent with the observations only at the 2sigma confidence level. |
The KleinGordon equation in Machian model ; The nonlocal Machian model is regarded as an alternative theory of gravitation which states that all particles in the Universe as a 'gravitationally entangled' statistical ensemble. It is shown that the KleinGordon equation can be derived within this Machian model of the universe. The crucial point of the derivation is the activity of the Machian energy background field which causing a fluctuation about the average momentum of a particle, the nonlocality problem in quantum theory is addressed in this framework. |
Comment on Delayed luminescence of biological systems in terms of coherent states Phys. Lett. A 293 2002 93 ; Popp and Yan F. A. Popp, Y. Yan, Phys. Lett. A 293 2002 93 proposed a model for delayed luminescence based on a single timedependent coherent state. We show that the general solution of their model corresponds to a luminescence that is a linear function of time. Therefore, their model is not compatible with any measured delayed luminescence. Moreover, the functions that they use to describe the oscillatory behaviour of delayed luminescence are not solutions of the coupling equations to be solved. |
The Stability of some stochastic processes ; We formulate and prove a new criterion for stability of eprocesses. It says that any eprocess which is averagely bounded and concentrating is asymptotically stable. In the second part, we show how this general result applies to some shell models the Goy and the Sabra model. Indeed, we manage to prove that the processes corresponding to these models satisfy the eprocess property. They are also averagely bounded and concentrating. Consequently, their stability follows. |
Cosmological Consequences of Exponential Gravity in Palatini Formalism ; We investigate cosmological consequences of a class of exponential fR gravity in the Palatini formalism. By using the current largest type Ia Supernova sample along with determinations of the cosmic expansion at intermediary and highz we impose tight constraints on the model parameters. Differently from other fR models, we find solutions of transient acceleration, in which the largescale modification of gravity will drive the Universe to a new decelerated era in the future. We also show that a viable cosmological history with the usual matterdominated era followed by an accelerating phase is predicted for some intervals of model parameters. |
On light propagation in SwissCheese cosmologies ; We study the effect of inhomogeneities on light propagation. The Sachs equations are solved numerically in the SwissCheese models with inhomogeneities modelled by the LemaitreTolman solutions. Our results imply that, within the models we study, inhomogeneities may partially mimic the accelerated expansion of the Universe provided the light propagates through regions with lower than the average density. The effect of inhomogeneities is small and full randomization of the photons' trajectories reduces it to an insignificant level. |
An extended hybrid magnetohydrodynamics gyrokinetic model for numerical simulation of shear Alfven waves in burning plasmas ; Adopting the theoretical framework for the generalized fishbonelike dispersion relation, an extended hybrid magnetohydrodynamics gyrokinetic simulation model has been derived analytically by taking into account both thermal ion compressibility and diamagnetic effects in addition to energetic particle kinetic behaviors. The extended model has been used for implementing an eXtended version of Hybrid Magnetohydrodynamics Gyrokinetic Code XHMGC to study thermal ion kinetic effects on Alfv'enic modes driven by energetic particles, such as kinetic beta induced Alfv'en eigenmodes in tokamak fusion plasmas. |
ModelChecking LinearTime Properties of Quantum Systems ; We define a formal framework for reasoning about lineartime properties of quantum systems in which quantum automata are employed in the modeling of systems and certain closed subspaces of state Hilbert spaces are used as the atomic propositions about the behavior of systems. We provide an algorithm for verifying invariants of quantum automata. Then automatabased modelchecking technique is generalized for the verification of safety properties recognizable by reversible automata and omegaproperties recognizable by reversible Buechi automata. |
Fluid and Magnetofluid Modeling of Relativistic Magnetic Reconnection ; The fluidscale evolution of relativistic magnetic reconnection is investigated by using twofluid and magnetofluid simulation models. Relativistic twofluid simulations demonstrate the mesoscale evolution beyond the kinetic scales, and exhibit quasisteady Petschektype reconnection. Resistive relativistic MHD simulations further show new shock structures in and around the downstream magnetic island plasmoid. General discussions on these models are presented. |
A Finite State Model for Time Travel ; A time machine that sends information back to the past may, in principle, be built using closed timelike curves. However, the realization of a time machine must be congruent with apparent paradoxes that arise from traveling back in time. Using a simple model to analyze the consequences of time travel, we show that several paradoxes, including the grandfather paradox and Deutsch's unproven theorem paradox, are precluded by basic axioms of probability. However, our model does not prohibit traveling back in time to affect past events in a selfconsistent manner. |
New Physics effects on decay Bs to in Technicolor Model ; In this paper we calculate the contributions to the branching ratio of Bs to gammagamma from the charged PseudoGoldstone bosons appeared in one generation Technicolor model. We find that the theoretical values of the branching ratio, BRBstogammagamma, including the contributions of PGBs, Ppm and Ppm8, are much different from the SM prediction. The new physics effects can be enhance 23 levels to SM result. It is shown that the decay Bsto gammagamma can give the test the new physics signals from the technicolor model. |
Supergravity based inflation models a review ; In this review, we discuss inflation models based on supergravity. After explaining the difficulties in realizing inflation in the context of supergravity, we show how to evade such difficulties. Depending on types of inflation, we give concrete examples, particularly paying attention to chaotic inflation because the ongoing experiments like Planck might detect the tensor perturbations in near future. We also discuss inflation models in Jordan frame supergravity, motivated by Higgs inflation. |
Modeling galactic halos with predominantly quintessential matter ; This paper discusses a new model for galactic dark matter by combining an anisotropic pressure field corresponding to normal matter and a quintessence dark energy field having a characteristic parameter omegaq such that 1omegaq frac13. Stable stellar orbits together with an attractive gravity exist only if omegaq is extremely close to frac13, a result consistent with the special case studied by Guzman et al. 2003. Less exceptional forms of quintessence dark energy do not yield the desired stable orbits and are therefore unsuitable for modeling dark matter. |
Anisotropic Fluid and Bianchi Type III Model in fR Gravity ; This paper is devoted to study the Bianchi type III model in the presence of anisotropic fluid in fR gravity. Exponential and powerlaw volumetric expansions are used to obtain exact solutions of the field equations. We discuss the physical behavior of the solutions and anisotropy behavior of the fluid, the expansion parameter and the model in future evolution of the universe. |
An Econophysics Model for the StockMarkets' Analysis and Diagnosis ; In this paper we present an econophysic model for the description of shares transactions in a capital market. For introducing the fundamentals of this model we used an analogy between the electrical field produced by a system of charges and the overall of economic and financial information of the shares transactions from the stockmarkets. An energetic approach of the rate variation for the shares traded on the financial markets was proposed and studied. |
Special Geometries Emerging from YangMills Type Matrix Models ; I review some recent results which demonstrate how various geometries, such as Schwarzschild and ReissnerNordstroem, can emerge from YangMills type matrix models with branes. Furthermore, explicit embeddings of these branes as well as appropriate Poisson structures and starproducts which determine the noncommutativity of spacetime are provided. These structures are motivated by higher order terms in the effective matrix model action which semiclassically lead to an EinsteinHilbert type action. |
Anisotropy in BornInfeld brane cosmology ; The accelerated expansion of the universe together with its present day isotropy has posed an interesting challenge to the numerous model theories presented over the years to describe them. In this paper, we address the above questions in the context of a braneworld model where the universe is filled with a BornInfeld matter. We show that in such a model, the universe evolves from a highly anisotropic state to its present isotropic form which has entered an accelerated expanding phase. |
Gravitational potential evolution in Unified Dark Matter Scalar Field Cosmologies an analytical approach ; We investigate the time evolution of the gravitational potential Phi for a special class of nonadiabatic Unified Dark matter Models described by scalar field lagrangians. These models predict the same background evolution as in the LambdaCDM and possess a nonvanishing speed of sound. We provide a very accurate approximation of Phi, valid after the recombination epoch, in the form of a Bessel function of the first kind. This approximation may be useful for a future deeper analysis of Unified Dark Matter scalar field models. |
Arbitrage and Hedging in a non probabilistic framework ; The paper studies the concepts of hedging and arbitrage in a non probabilistic framework. It provides conditions for non probabilistic arbitrage based on the topological structure of the trajectory space and makes connections with the usual notion of arbitrage. Several examples illustrate the non probabilistic arbitrage as well perfect replication of options under continuous and discontinuous trajectories, the results can then be applied in probabilistic models path by path. The approach is related to recent financial models that go beyond semimartingales, we remark on some of these connections and provide applications of our results to some of these models. |
Well posedness of a linearized fractional derivative fluid model ; The onedimensional fractional derivative Maxwell model e.g. Palade et al. Rheol. Acta 35, 265, 1996, of importance in modeling the linear viscoelastic response in the glass transition region, has been generalized in Palade et al. Int. J. NonLinear Mech. 37, 315, 1999, to objective threedimensional constitutive equations CEs for both fluids and solids. Regarding the rest state stability of the fluid CE, in Heibig and Palade J. Math. Phys. 49, 043101, 2008, we gave a proof for the existence of weak solutions to the corresponding boundary value problem. The aim of this work is to achieve the study of the existence and uniqueness of the aforementioned solutions and to present smoothness results. |
On the capabilities of grammars, automata, and transducers controlled by monoids ; During the last decades, classical models in language theory have been extended by control mechanisms defined by monoids. We study which monoids cause the extensions of contextfree grammars, finite automata, or finite state transducers to exceed the capacity of the original model. Furthermore, we investigate when, in the extended automata model, the nondeterministic variant differs from the deterministic one in capacity. We show that all these conditions are in fact equivalent and present an algebraic characterization. In particular, the open question of whether every language generated by a valence grammar over a finite monoid is contextfree is provided with a positive answer. |
Basic Vaccination Control Techniques for a General True Mass Action SEIR Model ; This paper presents several simple linear vaccinationbased control strategies for a SEIR susceptible plus infected plus infectious plus removed populations propagation disease model. The model takes into account the total population amounts as a refrain for the illness transmission since its increase makes more difficult contacts among susceptible and infected. The vaccination control objective is the asymptotically tracking of the removedbyimmunity population to the total population while achieving simultaneously that the remaining populations i.e. susceptible plus infected plus infectious tend asymptotically to zero. |
Spin foam models with finite groups ; Spin foam models, loop quantum gravity and group field theory are discussed as quantum gravity candidate theories and usually involve a continuous Lie group. We advocate here to consider quantum gravity inspired models with finite groups, firstly as a test bed for the full theory and secondly as a class of new lattice theories possibly featuring an analogue diffeomorphism symmetry. To make these notes accessible to readers outside the quantum gravity community we provide an introduction to some essential concepts in the loop quantum gravity, spin foam and group field theory approach and point out the many connections to lattice field theory and condensed matter systems. |
Modeling of Time with Metamaterials ; Metamaterials have been already used to model various exotic optical spaces. Here we demonstrate that mapping of monochromatic extraordinary light distribution in a hyperbolic metamaterial along some spatial direction may model the flow of time. This idea is illustrated in experiments performed with plasmonic hyperbolic metamaterials. Appearance of the statistical arrow of time is examined in an experimental scenario which emulates a Big Banglike event. |
A random model of publication activity ; We examine a random model consisting of objects with positive weights and evolving in discrete time steps, which generalizes certain random graph models. We prove almost sure convergence for the weight distribution and show scalefree asymptotic behaviour. Martingale theory and renewallike equations are used in the proofs. |
31TQFTs and Topological Insulators ; LevinWen models are microscopic spin models for topological phases of matter in 21dimension. We introduce a generalization of such models to 31dimension based on unitary braided fusion categories, also known as unitary premodular categories. We discuss the ground state degeneracy on 3manifolds and statistics of excitations which include both points and defect loops. Potential connections with recently proposed fractional topological insulators and projective ribbon permutation statistics are described. |
A Class of NonLocal Models for Pedestrian Traffic ; We present a new class of macroscopic models for pedestrian flows. Each individual is assumed to move towards a fixed target, deviating from the best path according to the instantaneous crowd distribution. The resulting equation is a conservation law with a nonlocal flux. Each equation in this class generates a Lipschitz semigroup of solutions and is stable with respect to the functions and parameters defining it. Moreover, key qualitative properties such as the boundedness of the crowd density are proved. Specific models are presented and their qualitative properties are shown through numerical integrations. |
The lepton flavor violating decays Zto li lj in the simplest little Higgs model ; In the simplest little Higgs model the new flavorchanging interactions between heavy neutrinos and the Standard Model leptons can generate contributions to some lepton flavor violating decays of Zboson at oneloop level, such as Z to taupmmump, Zto taupmemp, and Z to mupmemp. We examine the decay modes, and find that the branching ratios can reach 107 for the three decays, which should be accessible at the GigaZ option of the ILC. |
GeV Emission from Collisional Magnetized Gamma Ray Bursts ; Magnetic fields may play a dominant role in gammaray bursts, and recent observations by the Fermi satellite indicate that GeV radiation, when detected, arrives delayed by seconds from the onset of the MeV component. Motivated by this, we discuss a magnetically dominated jet model where both magnetic dissipation and nuclear collisions are important. We show that, for parameters typical of the observed bursts, such a model involving a realistic jet structure can reproduce the general features of the MeV and a separate GeV radiation component, including the time delay between the two. The model also predicts a multiGeV neutrino component. |
Top quark pair production via ee collision in the littlest Higgs model with Tparity at the ILC ; In the littlest Higgs model with Tparity, we studied the contributions of the new particles to the topquark pair production via ee collision at the International Linear Collider. We calculated the topquark pair production cross section and found this process can generate significantly relative correction. The result may be a sensitive probe of the littlest Higgs model with Tparity. |
EntropyCorrected New Agegraphic Dark Energy Model in HoravaLifshitz Gravity ; In this work, we have considered the entropycorrected new agegraphic dark energy ECNADE model in HoravaLifshitz gravity in FRW universe. We have discussed the correspondence between ECNADE and other dark energy models such as DBIessence,YangMills dark energy, Chameleon field, Nonlinear electrodynamics field and hessence dark energy in the context of HoravaLifshitz gravity and reconstructed the potentials and the dynamics of the scalar field theory which describe the ECNADE. |
A Consistent Bootstrap Procedure for the Maximum Score Estimator ; In this paper we study the applicability of the bootstrap to do inference on Manski's maximum score estimator under the full generality of the model. We propose three new, modelbased bootstrap procedures for this problem and show their consistency. Simulation experiments are carried out to evaluate their performance and to compare them with subsampling methods. Additionally, we prove a uniform convergence theorem for triangular arrays of random variables coming from binary choice models, which may be of independent interest. |
Matrix model from N 2 orbifold partition function ; The orbifold generalization of the partition function, which would describe the gauge theory on the ALE space, is investigated from the combinatorial perspective. It is shown that the root of unity limit of the qdeformed partition function plays a crucial role on the orbifold projection. Then starting from the combinatorial representation of the partition function, a new type of multimatrix model is derived by considering its asymptotic behavior. It is also shown that SeibergWitten curve for the corresponding gauge theory arises from the spectral curve of this multimatrix model. |
Role of delay in the stochastic creation process ; We develop an approximate theoretical method to study discrete stochastic birth and death models that include a delay time. We analyze the effect of the delay in the fluctuations of the system and obtain that it can qualitatively alter them. We also study the effect of distributed delay. We apply the method to a proteindynamics model that explicitly includes transcription and translation delays. The theoretical model allows us to understand in a general way the interplay between stochasticity and delay. |
Closed Timelike Curves in the Galileon Model ; It has long been known that generic solutions to the nonlinear DGP and Galileon models admit superluminal propagation. In this note we present a solution of these models which also admits closed timelike curves CTCs. We observe that these CTCs only arise when, according to each observer, there exists some region in which the higher derivative terms are larger than the 2derivative kinetic term. |
Large N expansions and Painleve hierarchies in the Hermitian matrix model ; We present a method to characterize and compute the large N formal asymptotics of regular and critical Hermitian matrix models with general even potentials in the onecut and twocut cases. Our analysis is based on a method to solve continuum limits of the discrete string equation which uses the resolvent of the Lax operator of the underlying Toda hierarchy. This method also leads to an explicit formulation, in terms of coupling constants and critical parameters, of the members of the Painlev'e I and Painlev'e II hierarchies associated with onecut and twocut critical models respectively. |
Duality and Convergence for Binomial Markets with Friction ; We prove limit theorems for the superreplication cost of European options in a Binomial model with friction. The examples covered are markets with proportional transaction costs and the illiquid markets. The dual representation for the superreplication cost in these models are obtained and used to prove the limit theorems. In particular, the existence of the liquidity premium for the continuous time limit of the model proposed in 6 is proved. Hence, this paper extends the previous convergence result of 13 to the general nonMarkovian case. Moreover, the special case of small transaction costs yields, in the continuous limit, the Gexpectation of Peng as earlier proved by Kusuoka in 14. |
Quantum Finite Automata and Probabilistic Reversible Automata Rtrivial Idempotent Languages ; We study the recognition of Rtrivial idempotent R1 languages by various models of decideandhalt quantum finite automata QFA and probabilistic reversible automata DHPRA. We introduce bistochastic QFA MMBQFA, a model which generalizes both Nayak's enhanced QFA and DHPRA. We apply tools from algebraic automata theory and systems of linear inequalities to give a complete characterization of R1 languages recognized by all these models. We also find that forbidden constructions known so far do not include all of the languages that cannot be recognized by measuremany QFA. |
D term and gaugino masses in gauge mediation ; We systematically study supersymmetry breaking with nonvanishing F and D terms. We classify the models into two categories and find that a certain class of models necessarily has runaway behavior of scalar potential, while the other needs the FayetIliopoulos term to break supersymmetry. The latter class is useful to have a simple model of gauge mediation where the vacuum is stable everywhere and the gaugino mass is generated at the oneloop order. |
Extensional HigherOrder Logic Programming ; We propose a purely extensional semantics for higherorder logic programming. In this semantics program predicates denote sets of ordered tuples, and two predicates are equal iff they are equal as sets. Moreover, every program has a unique minimum Herbrand model which is the greatest lower bound of all Herbrand models of the program and the least fixedpoint of an immediate consequence operator. We also propose an SLDresolution proof procedure which is proven sound and complete with respect to the minimum model semantics. In other words, we provide a purely extensional theoretical framework for higherorder logic programming which generalizes the familiar theory of classical firstorder logic programming. |
A model of coopetitive game and the Greek crisis ; In the present work we propose an original analytical model of coopetitive game. We try to apply this analytical model of coopetition based on game theory and conceived at a macro level to the Greek crisis, suggesting feasible solutions in a cooperative perspective for the divergent interests which drive the economic policies in the euro area. |
A Gauge Invariant Dual Gonihedric 3D Ising Model ; We note that two formulations of dual gonihedric Ising models in 3d, one based on using Wegner's general framework for duality to construct a dual Hamiltonian for codimension one surfaces, the other on constructing a dual Hamiltonian for twodimensional surfaces, are related by a variant of the standard decorationiteration transformation. The dual Hamiltonian for twodimensional surfaces contains a mixture of link and vertex spins and as a consequence possesses a gauge invariance which is inherited by the codimension one surface Hamiltonian. This gauge invariance ensures the latter is equivalent to a third formulation, an anisotropic AshkinTeller model. We describe the equivalences in detail and discuss some MonteCarlo simulations which support these observations. |
A generalized BakSneppen model for Earth's magnetic field reversals ; We introduce a simple model for Earth's magnetic field reversals. The model consists in random nodes simulating vortices in the liquid part of the core which through a simple updating algorithm converge to a self organized critical state, with interreversal time probability distributions functions in the form of power laws as supposed to be in actual reversals. It should not be expected a detailed description of reversals. However, we hope to reach a profounder knowledge of reversals through some of the basic characteristic that are well reproduced. |
Holonomy observables in PonzanoRegge type state sum models ; We study observables on group elements in the PonzanoRegge model. We show that these observables have a natural interpretation in terms of Feynman diagrams on a sphere and contrast them to the well studied observables on the spin labels. We elucidate this interpretation by showing how they arise from the nogravity limit of the TuraevViro model and ChernSimons theory. |
Nonuniform autonomous onedimensional exclusion nearest neighbor reaction diffusion models, II ; In a recent article the most general nonuniform reactiondiffusion models on a onedimensional lattice with boundaries were considered, for which the time evolution equations of correlation functions are closed and the stationary profile can be obtained using a transfermatrix method. Here models are investigated for which also the equation of relaxation towards the stationary profile could be solved through a similar transfermatrix method. A classification is given, and dynamical phase transitions are studied. |
Plasmonic Nanoparticlebased Protein Detection by Optical Shift of a Resonant Microcavity ; We demonstrated a biosensing approach which, for the first time, combines the highsensitivity of whispering gallery modes WGM with a metallic nanoparticle based assay. We provided a computational model based on generalized Mie theory to explain the higher sensitivity of protein detection through Plasmonic enhancement. We quantitatively analyzed the binding of a model protein i.e., BSA to gold nanoparticles from highQ WGM resonance frequency shifts, and fit the results to an adsorption isotherm, which agrees with the theoretical predictions of a twocomponent adsorption model. |
Initial Enlargement in a Markov chain market model ; Enlargement of filtrations is a classical topic in the general theory of stochastic processes. This theory has been applied to stochastic finance in order to analyze models with insider information. In this paper we study initial enlargement in a Markov chain market model, introduced by R. Norberg. In the enlargened filtration several things can happen some of the jumps times can be accessible or predictable, but in the orginal filtration all the jumps times are totally inaccessible. But even if the jumps times change to accessible or predictable, the insider does not necessarily have arbitrage possibilities. |
GPD and PDF modeling in terms of effective lightcone wave functions ; We employ models from effective twobody lightcone wave functions LCWFs to provide a link between generalized parton distributions GPDs and unintegrated parton distribution functions uPDFs. Since we utilize the underlying Lorentz symmetry, GPDs can be entirely obtained from the parton number conserved LCWF overlaps. This also allows us to derive model constraints among GPDs. We illustrate that transversity distributions may be rather sizeable. |
Properties of some 31 dimensional vortex solutions of the CPN model ; We construct new classes of vortexlike solutions of the CPN model in 31 dimensions and discuss some of their properties. These solutions are obtained by generalizing to 31 dimensions the techniques well established for the two dimensional CPN models. We show that as the total energy of these solutions is infinite, they describe evolving vortices and antivortices with the energy density of some configurations varying in time. We also make some further observations about the dynamics of these vortices. |
Stochastic modeling of p53regulated apoptosis upon radiation damage ; We develop and study the evolution of a model of radiation induced apoptosis in cells using stochastic simulations, and identified key protein targets for effective mitigation of radiation damage. We identified several key proteins associated with cellular apoptosis using an extensive literature survey. In particular, we focus on the p53 transcription dependent and p53 transcription independent pathways for mitochondrial apoptosis. Our model reproduces known p53 oscillations following radiation damage. The key, experimentally testable hypotheses that we generate are inhibition of PUMA is an effective strategy for mitigation of radiation damage if the treatment is administered immediately, at later stages following radiation damage, inhibition of tBid is more effective. |
Knudsen gas provides nanobubble stability ; We provide a model for the remarkable stability of surface nanobubbles to bulk dissolution. The key to the solution is that the gas in a nanobubble is of Knudsen type. This leads to the generation of a bulk liquid flow which effectively forces the diffusive gas to remain local. Our model predicts the presence of a vertical water jet immediately above a nanobubble, with an estimated speed of sim3.3,mathrmms, in good agreement with our experimental atomic force microscopy measurement of sim2.7,mathrmms. In addition, our model also predicts an upper bound for the size of nanobubbles, which is consistent with the available experimental data. |
The Stability of The LongleyRice Irregular Terrain Model for Typical Problems ; In this paper, we analyze the numerical stability of the popular LongleyRice Irregular Terrain Model ITM. This model is widely used to plan wireless networks and in simulationvalidated research and hence its stability is of fundamental importance to the correctness of a large amount of work. We take a systematic approach by first porting the reference ITM implementation to a multiprecision framework and then generating loss predictions along many random paths using real terrain data. We find that the ITM is not unstable for common numerical precisions and practical prediction scenarios. |
B K2 l l decay beyond the Standard Model ; The exclusive B K2 l l decay is studied using the most general, model independent fourfermion interaction. The sensitivity of the ratio of the decay widths when K2 meson is longitudinally and transversally polarized, the forwardbackward asymmetry and longitudinal polarization of the final lepton on the new Wilson coefficients is studied. It is found that these quantities are very useful for establishing new physics beyond the Standard Model. |
A proof by graphical construction of the nopumping theorem of stochastic pumps ; A stochastic pump is a Markov model of a mesoscopic system evolving under the control of externally varied parameters. In the model, the system makes random transitions among a network of states. For such models, a nopumping theorem has been obtained, which identifies minimal conditions for generating directed motion or currents. We provide a derivation of this result using a simple graphical construction on the network of states. |
Hyperreactive model in dynamics of a variablemass point ; Basing on a new approach to the fundamental conception of the momentum of a variablemass point, the paper deals with the hyperreactive model of motion. The equations of motion are different in this model from the known MeshcherskyTsiolkovsky equations, which cannot be taken as a principle in the final analysis by reason of their conflicting behaviour. The suggested conception of hyperreactive motion allows to determine in what way the parameters of motion are dependent on the type of mass change, and thus to solve a basic problem how high absolute velocities may be reached in space. |
Stability analysis and Observational Measurement in Chameleonic Generalised BransDicke Cosmology ; We investigate the dynamics of the chameleonic Generalised BransDicke model in flat FRW cosmology. In a new approach, a framework to study stability and attractor solutions in the phase space is developed for the model by simultaneously best fitting the stability and model parameters with the observational data. The results show that for an accelerating universe the phantom crossing does not occur in the past and near future. |
New symmetries of the chiral Potts model ; In this paper a hithertho unknown symmetry of the threestate chiral Potts model is found consisting of two coupled TemperleyLieb algebras. From these we can construct new superintegrable models. One realisation is in terms of a staggered isotropic XY spin chain. Further we investigate the importance of the algebra for the existence of mutually commuting charges. This leads us to a natural generalisation of the boostoperator, which generates the charges. |
Achieving Fast Reconnection in Resistive MHD Models via Turbulent Means ; Astrophysical fluids are generally turbulent and this preexisting turbulence must be taken into account for the models of magnetic reconnection which are attepmted to be applied to astrophysical, solar or heliospheric environments. In addition, reconnection itself induces turbulence which provides an important feedback on the reconnection process. In this paper we discuss both theoretical model and numerical evidence that magnetic reconnection gets fast in the approximation of resistive MHD. We consider the relation between the Lazarian Vishniac turbulent reconnection theory and Lapenta's numerical experiments testifying of the spontaneous onset of turbulent reconnection in systems which are initially laminar. |
Emergent Models for Gravity an Overview of Microscopic Models ; We give a critical overview of various attempts to describe gravity as an emergent phenomenon, starting from examples of condensed matter physics, to arrive to more sophisticated pregeometric models. The common line of thought is to view the graviton as a composite particlecollective mode. However, we will describe many different ways in which this idea is realized in practice. |
The Coincidence Problem in Holographic fR Gravity ; It is wellknown that fR gravity models formulated in Einstein conformal frame are equivalent to Einstein gravity together with a minimally coupled scalar field. In this case, the scalar field couples with the matter sector and the coupling term is given by the conformal factor. We apply the holographic principle to such interacting models. In a spatially flat universe, we show that the Einstein frame representation of fR models leads to a constant ratio of energy densities of dark matter to dark energy. |
Comments on N 2 supersymmetric sigma models in projective superspace ; For the most general offshell N 2 supersymmetric sigma model in projective superspace, we elaborate on its formulation in terms of N 1 chiral superfields. A universal modelindependent expression is obtained for the holomorphic symplectic twoform, which determines the second supersymmetry transformation. This twoform is associated with the two complex structures of the hyperkahler target space, which are complimentary to the one used to realize the target space as a Kahler manifold. |
Holographic Dark Energy Model State Finder Parameters ; In this work, we have studied interacting holographic dark energy model in the background of FRW model of the universe. The interaction is chosen either in linear combination or in product form of the matter densities for dark matter and dark energy. The IR cut off for holographic dark energy is chosen as Ricci's length scale or radius of the future event horizon. The analysis is done using the state finder parameter and coincidence problem has been graphically presented. Finally, universal thermodynamics has been studied using state finder parameters. |
Random walk in random environment in a twodimensional stratified medium with orientations ; We consider a model of random walk in mathbb Z2 with fixed or random orientation of the horizontal lines layers and with non constant iid probability to stay on these lines. We prove the transience of the walk for any fixed orientations under general hypotheses. This contrasts with the model of Campanino and Petritis, in which probabilities to stay on these lines are all equal. We also establish a result of convergence in distribution for this walk with suitable normalizations under more precise assumptions. In particular, our model proves to be, in many cases, even more superdiffusive than the random walks introduced by Campanino and Petritis. |
Sheaves of metric structures ; We introduce and develop the theory of metric sheaves. A metric sheaf A is defined on a topological space X such that each fiber is a metric model. We describe the construction of the generic model as the quotient space of the sheaf through an appropriate filter. Semantics in this model is completely controlled and understood by the forcing rules in the sheaf. |
The Orbifolder A Tool to study the Low Energy Effective Theory of Heterotic Orbifolds ; The orbifolder is a program developed in C that computes and analyzes the lowenergy effective theory of heterotic orbifold compactifications. The program includes routines to compute the massless spectrum, to identify the allowed couplings in the superpotential, to automatically generate large sets of orbifold models, to identify phenomenologically interesting models e.g. MSSMlike models and to analyze their vacuumconfigurations. |
An analytic technique for the estimation of the light yield of a scintillation detector ; A simple model for the estimation of the light yield of a scintillation detector is developed under general assumptions and relying exclusively on the knowledge of its optical properties. The model allows to easily incorporate effects related to Rayleigh scattering and absorption of the photons.The predictions of the model are benchmarked with the outcomes of Monte Carlo simulations of specific scintillation detectors. An accuracy at the level of few percent is achieved. The case of a real liquid argon based detector is explicitly treated and the predicted light yield is compared with the measured value. |
Heat kernel expansion and induced action for matrix models ; In this proceeding note, I review some recent results concerning the quantum effective action of certain matrix models, i.e. the supersymmetric IKKT model, in the context of emergent gravity. The absence of pathological UVIR mixing is discussed, as well as dynamical SUSY breaking and some relations with string theory and supergravity. |
New results on twinlike models ; In this work we study the presence of kinks in models described by a single real scalar field in bidimensional spacetime. We work within the firstorder framework, and we show how to write firstorder differential equations that solve the equations of motion. The firstorder equations strongly simplify the study of linear stability, which is implemented on general grounds. They also lead to a direct investigation of twinlike theories, which is used to introduce a family of models that support the same defect structure, with the very same energy density and linear stability. |
On the rare Bs to two muons decay and noncontractibility of the physical space ; It is very well known that the rare electroweak processes could be very sensitive to the physics beyond the Standard Model. These processes are described with quantum loop diagrams containing also heavy particles. We show that the electroweak theory with the noncontractible space, as a symmetrybreaking mechanism without the Higgs scalar, essentially changes the Standard Model prediction of the branching ratio of the Bs meson decaying to two muons. The branching ratio is lower by more than 30 compared with the Standard Model result. Although the measurements are very challenging, the implications on the selection of the symmetrybreaking mechanism could be decisive. |