August 2005 arXiv papers — page 3

J. Barranco, O. G. Miranda, T. I. Rashba

The possibility off measuring for the first time neutrino-nuclei coherent scattering has been recently discussed by several experimental collaborations. It is shown that such a measurement may be very sensitive to non-standard interactions of neutrinos with quarks and might set better constraints than those coming from future neutrino factory experiments. We

R. Wijnands, J. J. M. in 't Zand, M. Rupen, T. Maccarone

We present the first results of our X-ray monitoring campaign on a 1.7 square degree region centered on Sgr A* using the satellites XMM-Newton and Chandra. The purpose of this campaign is to monitor the behavior (below 10 keV) of X-ray sources (both persistent and transient) which are too faint to be detected by monitoring instruments aboard other satellites

R. P. Malik

The derivation of the exact and unique nilpotent Becchi-Rouet-Stora-Tyutin (BRST)- and anti-BRST symmetries for the matter fields, present in any arbitrary interacting gauge theory, has been a long-standing problem in the framework of superfield approach to BRST formalism. These nilpotent symmetry transformations are deduced for the four (3 + 1)-dimensional

N. N. Nikolaev, W. Schäfer, B. G. Zakharov

The origin of the breaking of conventional linear k_\perp-factorization for hard processes in a nuclear environment is by now well established. The realization of the nonlinear nuclear k_\perp-factorization which emerges instead was found to change from one jet observable to another. Here we report on an important technical progress, the evaluation of the fo

Marcelo Fiore, Tom Leinster

We show that Thompson's group F is the symmetry group of the "generic idempotent". That is, take the monoidal category freely generated by an object A and an isomorphism A \otimes A --> A; then F is the group of automorphisms of A.

Andreas Bredthauer, Ulf Lindstrom, Jonas Persson

We study the conditions under which N=(1,1) generalized sigma models support an extension to N=(2,2). The enhanced supersymmetry is related to the target space complex geometry. Concentrating on a simple situation, related to Poisson sigma models, we develop a language that may help us analyze more complicated models in the future. In particular, we uncover

R. K. Ellis, W. T. Giele, G. Zanderighi

We present a semi-numerical algorithm to calculate one-loop virtual corrections to scattering amplitudes. The divergences of the loop amplitudes are regulated using dimensional regularization. We treat in detail the case of amplitudes with up to five external legs and massless internal lines, although the method is more generally applicable. Tensor integrals

C. Tarantino

$B_d$ and $B_s$ meson systems play a fundamental role to test and improve our understanding of Standard Model flavor dynamics. The mixing parameters $Δm_{d,s}$ represent important constraints in the unitarity triangle analysis. Their theoretical estimates require non-perturbative calculations of B-meson decay constants and B-parameters; accurate results, rec

M. Gustafsson, D. Field, J. L. Lemaire, F. P. Pijpers

A statistical analysis is presented of the turbulent velocity structure in the Orion Molecular Cloud at scales ranging from 70 AU to 30000 AU. Results are based on IR Fabry-Perot interferometric observations of shock and photon-excited H2 in the K-band S(1) v=1-0 line at 2.121micron and refer to the dynamical characteristics of warm perturbed gas. Observatio

J. Berges, I. -O. Stamatescu

We present lattice simulations of nonequilibrium quantum fields in Minkowskian space-time. Starting from a non-thermal initial state, the real-time quantum ensemble in 3+1 dimensions is constructed by a stochastic process in an additional (5th) ``Langevin-time''. For the example of a self-interacting scalar field we show how to resolve apparent unsta

F. X. Wei, G. J. Mao, C. M. Ko, L. S. Kisslinger

We study the effects of isovector-scalar meson $δ$ on the equation of state (EOS) of neutron star matter in strong magnetic fields. The EOS of neutron-star matter and nucleon effective masses are calculated in the framework of Lagrangian field theory, which is solved within the mean-field approximation. From the numerical results one can find that the $δ$-fi

A. Fajarudin, A. Sulaiman, T. P. Djun, L. T. Handoko

The Yang-Mills magnetofluid unification is constructed using lagrangian approach by imposing certain gauge symmetry to the matter inside the fluid. The model provides a general description for relativistic fluid interacting with Abelian or non-Abelian gauge field. The differences with the hybrid magnetofluid model are discussed, and few physical consequences

B. Borasoy, P. C. Bruns, U. -G. Meißner, R. Nißler

It is shown how gauge invariance is obtained for the coupling of a photon to a two-body state described by the solution of the Bethe-Salpeter equation. This is illustrated both for a complex scalar field theory and for interaction kernels derived from chiral effective Lagrangians.

Steven Lansel, Mason A. Porter, Leonid A. Bunimovich

We study the dynamics of one-particle and few-particle billiard systems in containers of various shapes. In few-particle systems, the particles collide elastically both against the boundary and against each other. In the one-particle case, we investigate the formation and destruction of resonance islands in (generalized) mushroom billiards, which are a recen

M. Artuso, CLEO Collaboration

We extract a relatively precise value for the decay constant of the D+ meson by measuring B(D+ -> mu+ nu)=(4.40 +/- 0.66 {+0.09}{-0.12}) x 10^{-4}, using 281 inverse-pb of data taken on the psi(3770) resonance with the CLEO-c detector. We find fD+=(222.6 +/- 16.7 {+2.8}{-3.4}) MeV, and compare with current theoretical calculations. We also set a 90% confiden

V. Vittorini, F. Shankar, A. Cavaliere

We investigate how accretion episodes onto massive black holes power quasars and AGN while they accumulate mass into the holes. We compute both the trend and the stochastic component to the trigger of the accretion events, as provided by structure buildup after the hierarchical paradigm. We base on host galaxy evolution proceeding from the protogalactic era

Rabin Banerjee

We construct the deformed generators of Schroedinger symmetry consistent with noncommutative space. The examples of the free particle and the harmonic oscillator, both of which admit Schroedinger symmetry, are discussed in detail. We construct a generalised Galilean algebra where the second central extension exists in all dimensions. This algebra also follow

Abraham I. Harte

In this paper, we study the bulk motion of a classical extended charge in flat spacetime. A formalism developed by W. G. Dixon is used to determine how the details of such a particle's internal structure influence its equations of motion. We place essentially no restrictions (other than boundedness) on the shape of the charge, and allow for inhomogeneity

Francisco Correa, Mariano A. del Olmo, Mikhail S. Plyushchay

We show that for positive integer values $l$ of the parameter in the conformal mechanics model the system possesses a hidden nonlinear superconformal symmetry, in which reflection plays a role of the grading operator. In addition to the even $so(1,2)\oplus u(1)$-generators, the superalgebra includes $2l+1$ odd integrals, which form the pair of spin-$(l+{1/2}

Yoshio Koide

In a seesaw mass matrix model M_f = m_L M_F^{-1} m_R^\dagger with a universal structure of m_L \propto m_R, as the origin of m_L (m_R) for quarks and eptons, flavor-triplet Higgs scalars whose vacuum expectation values v_i are proportional to the square roots of the charged lepton masses m_{ei}, i.e. v_i \propto \sqrt{m_{ei}}, are assumed. Then, it is invest

Cai-Dian Lu, M. Matsumori, A. I. Sanda, Mao-Zhi Yang

The radiative B-> rho gamma, B-> omega gamma decay modes are caused by the FCNC process, so they give us good insight towards probing the standard model in order to search for new physics. In this paper, we compute the branching ratio, direct CP asymmetry, and isospin breaking effects using the perturbative QCD approach within the standard model.

Pavel Exner, Pavel Hejcik, Petr Seba

We study approximations of billiard systems by lattice graphs. It is demonstrated that under natural assumptions the graph wavefunctions approximate solutions of the Schroedinger equation with energy rescaled by the billiard dimension. As an example, we analyze a Sinai billiard with attached leads. The results illustrate emergence of global structures in lar

C. J. Isham

A preliminary investigation is made of possible applications in quantum theory of the topos formed by the collection of all $M$-sets, where $M$ is a monoid. Earlier results on topos aspects of quantum theory can be rederived in this way. However, the formalism also suggests a new way of constructing a `neo-realist' interpretation of quantum theory in whi

S. A. Haine, J. J. Hope

We examine the properties of an atom laser produced by outcoupling from a Bose-Einstein condensate with squeezed light. We introduce a method which allows us to model the full multimode dynamics of the squeezed optical field and the outcoupled atoms. We show that for experimentally reasonable parameters that the quantum statistics of the optical field are al

Eijiro Sakai

We propose six principles as the fundamental principles of quantum mechanics: principle of space and time, Galilean principle of relativity, Hamilton's principle, wave principle, probability principle, and principle of indestructibility and increatiblity of particles. We deductively develop the formalism of quantum mechanics on the basis of them: we dete

G. Baxter, R. A. Blythe, A. J. McKane

We give an exact solution to the Kolmogorov equation describing genetic drift for an arbitrary number of alleles at a given locus. This is achieved by finding a change of variable which makes the equation separable, and therefore reduces the problem with an arbitrary number of alleles to the solution of a set of equations that are essentially no more complic

William Bialek

Faced with a sequence of N binary events, such as coin flips (or Ising spins), it is natural to ask whether these events reflect some underlying dynamic signals or are just random. Plausible models for the dynamics of hidden biases lead to surprisingly high probabilities of misidentifying random sequences as biased. In particular, this probability decays as

Antony C. Searle, Craig M. Savage, Paul A. Altin, Francis H. Bennet

We have developed a relativistically-accurate computer graphics code and have used it to produce photo-realistic images and videos of scenes where special relativistic effects dominate, either in astrophysical contexts or in imaginary worlds where the speed of light is only a few metres per second. The videos have been integrated into our under-graduate teac

J. R. Mureika

A numerical model of 100 m and 200 m world class sprinting performances is modified using standard hydrodynamic principles to include effects of air temperature, pressure, and humidity levels on aerodynamic drag. The magnitude of the effects are found to be dependent on wind speed. This implies that differing atmospheric conditions can yield slightly differe

Martin Treiber, Arne Kesting, Dirk Helbing

We investigate the adaptation of the time headways in car-following models as a function of the local velocity variance, which is a measure of the inhomogeneity of traffic flow. We apply this mechanism to several car-following models and simulate traffic breakdowns in open systems with an on-ramp as bottleneck. Single-vehicle data generated by several 'v

Gordon Chalmers

All of the known fermions fit a simple formula which is presented here. The simple formula appears to indicate a topological origin to mass generation, and it is globally accurate to an approximate percent. Instantons or a quantized two Higgs mechanism, as in the MSSM model, could give a simple origin to the masses.

Jae Woo Lee, Kyoung Eun Lee, Per Arne Rikvold

We investigate the waiting-time distribution of the absolute return in the Korean stock-market index KOSPI. We define the waiting time as a time interval during which the normalized absolute return remains continuously below a threshold $r_c$. Through an exponential bin plot, we observe that the waiting-time distribution shows power-law behavior, $p_f (t) \s

E. A. Cummings, J. E. Daily, D. S. Durfee, S. D. Bergeson

We extend an isothermal thermal model of ultracold neutral plasma expansion to systems without spherical symmetry, and use this model to interpret new fluorescence measurements on these plasmas. By assuming a self-similar expansion, it is possible to solve the fluid equations analytically and to include velocity effects to predict the fluorescence signals. I

S. C. Tiwari

In this short note we amplify our comments on the paper PRL 95,010405 (2005).

A. G. Afonin, V. T. Baranov, V. M. Biryukov, I. M. Ivanov

This paper presents the physical background for particle extraction from IHEP accelerator using short bent silicon crystals, analyses the results of the studies, considers in detail the regime of simultaneous work of crystal extraction and several internal targets. It is experimentally shown that the use of short crystals allows the extraction of beams with

M. Bonitz, D. Block, O. Arp, V. Golubnychiy

Small three-dimensional strongly coupled charged particles in a spherical confinement potential arrange themselves in a nested shell structure. By means of experiments, computer simulations and theoretical analysis, it is shown that their structural properties depend on the type of interparticle forces. Using an isotropic Yukawa interaction, quantitative agr

Roman Ya. Kezerashvili

We are using a laser pointer as a light source, and metersticks as an optical branch and the screen for wave optics experiments. It is shown the setup for measurements of wavelength of laser light and rating radial spacing of the CD, diffraction on a wire and a slit, observation of a polarization of light and observation of a hologram.

Arturo Berrones

The effect caused by the presence of a number of distinct time scales in a simple stochastic model for the Earth's atmosphere temperature fluctuations is studied. The model is described by a dissipative dynamics consisting of a set of coupled stochastic evolution equations. The system shows features that resemble recent observations. In contrast to other

Thomas Kim Kjeldsen, Lars Bojer Madsen

A model based on the strong-field and Born-Oppenheimer approximations qualitatively describes the distribution over vibrational states formed in a diatomic molecular ion following ionization of the neutral molecule by intense laser pulses. Good agreement is found with a recent experiment [X. Urbain et al., Phys. Rev. Lett. 92, 163004 (2004)]. In particular,

Barbara Jacak

Recent Results from the PHENIX Collaboration on Au+Au and d+Au collisions at the Relativistic Heavy Ion Collider.

Gino Biondini, Yuji Kodama

The behavior of solutions of the finite-genus Whitham equations for the weak dispersion limit of the defocusing nonlinear Schrodinger equation is investigated analytically and numerically for piecewise-constant initial data. In particular, the dynamics of constant-amplitude initial conditions with one or more frequency jumps (i.e., piecewise linear phase) ar

Aarti Sawant, Amit Acharya

A method for model reduction in nonlinear ODE systems is demonstrated through computational examples. The method does not require an implicit separation of time-scales in the fine dynamics to be effective. From the computational standpoint, the method has the potential of serving as a subgrid modeling tool. From the physical standpoint, it provides a model f

David Ploog

The familiar Fourier-Mukai technique can be extended to an equivariant setting where a finite group $G$ acts on a smooth projective variety $X$. In this paper we compare the group of invariant autoequivalences $\Aut(D(X))^G$ with the group of autoequivalences of $D^G(X)$. We apply this method in three cases: Hilbert schemes on K3 surfaces, Kummer surfaces an

Galyna Tsyaputa

Pairwise non isomorphic semigroups obtained from the semigroup PT_n of all partial transformations by the deformed multiplication proposed by Ljapin are classified.

Uli Walther

We study $A$-hypergeometric systems $H_A(β)$ in the sense of Gelfand, Kapranov and Zelevinsky under two aspects: the structure of their holonomically dual system, and reducibility of their rank module. We prove first that rank-jumping parameters always correspond to reducible systems, and we show that the property of being reducible is ``invariant modulo the

A Aalam

Two single parameter families of polyhedra $P(ψ)$ are constructed in three dimensional spaces of constant curvature $C(ψ)$. Identification of the faces of the polyhedra via isometries results in cone manifolds $M(ψ)$ which are topologically $S^1\timesS^2$, $S^3$ or singular $S^2$. The singular set of $M(ψ)$ can have self intersections for some values of $ψ$

Richard F. Bass, Takashi Kumagai

We consider symmetric Markov chains on $\Bbb Z^d$ where we do {\bf not} assume that the conductance between two points must be zero if the points are far apart. Under a uniform second moment condition on the conductances, we obtain upper bounds on the transition probabilities, estimates for exit time probabilities, and certain lower bounds on the transition

Nigel Hitchin

In the context of generalized geometry we first show how the Courant bracket helps to define connections with skew torsion and then investigate a five-dimensional invariant functional and its associated geometry. A Hamiltonian flow arising from this corresponds to a version of the Nahm equations using the Courant bracket, and we investigate the six-dimension

Bénédicte Haas

We consider a family of fragmentation processes where the rate at which a particle splits is proportional to a function of its mass. Let $F\_{1}^{(m)}(t),F\_{2}^{(m)}(t),...$ denote the decreasing rearrangement of the masses present at time $t$ in a such process, starting from an initial mass $m$. Let then $m\to \infty $. Under an assumption of regular varia

Terence Gaffney, David Trotman, Leslie Wilson

This paper uses the theory of integral closure of modules to study the sections of both real and complex analytic spaces. The stratification conditions used are the (t^) conditions introduced by Thom and Trotman. Our results include a new simple proof showing how the (t^r) conditions improve under Grassman modification, and a characterization of the (t^r) co

David M. J. Calderbank, Michael A. Singer

We present a construction of complete self-dual Einstein metrics of negative scalar curvature on an uncountable family of manifolds of infinite topological type, which are enumerated by continued fraction expansions of irrational numbers. These manifolds may be regarded as limits of the resolutions of cyclic quotient singularities (governed by continued frac

Sonia Fourati

We give an interpretation of the bilateral exit problem for Lévy processes via the study of an elementary Markov chain. We exhibit a strong connection between this problem and Krein's theory on strings. For instance, for symmetric Lévy processes with bounded variations, the Lévy exponent is the correspondant spectral density and the Wiener-Hopf factoriza

Xia Chen

Let S_1(n),...,S_p(n) be independent symmetric random walks in Z^d. We establish moderate deviations and law of the iterated logarithm for the intersection of the ranges #{S_1[0,n]\cap... \cap S_p[0,n]} in the case d=2, p\ge 2 and the case d=3, p=2.

Richard Bass, Xia Chen, Jay Rosen

We study large deviations for the renormalized self-intersection local time of d-dimensional stable processes of index β\in (2d/3,d]. We find a difference between the upper and lower tail. In addition, we find that the behavior of the lower tail depends critically on whether β<d or β=d.

Robert Pollack, Tom Weston

We prove a formula (analogous to that of Kida in classical Iwasawa theory and generalizing that of Hachimori-Matsuno for elliptic curves) giving the analytic and algebraic p-adic Iwasawa invariants of a modular eigenform over an abelian p-extension of Q to its p-adic Iwasawa invariants over Q. On the algebraic side our methods, which make use of congruences

Dinah Rosenberg, Eilon Solan, Nicolas Vieille

Given an arbitrary long but finite sequence of observations from a finite set, we construct a simple process that approximates the sequence, in the sense that with high probability the empirical frequency, as well as the empirical one-step transitions along a realization from the approximating process, are close to that of the given sequence. We generalize t

Andrew Carter, David Pollard

Tusnady&#39;s inequality is the key ingredient in the KMT/Hungarian coupling of the empirical distribution function with a Brownian bridge. We present an elementary proof of a result that sharpens the Tusnady inequality, modulo constants. Our method uses the beta integral representation of Binomial tails, simple Taylor expansion and some novel bounds for the

Ronald W. Butler, Andrew T. A. Wood

We consider the problem of approximating the moment generating function (MGF) of a truncated random variable in terms of the MGF of the underlying (i.e., untruncated) random variable. The purpose of approximating the MGF is to enable the application of saddlepoint approximations to certain distributions determined by truncated random variables. Two important

Bing-Yi Jing, Qi-Man Shao, Wang Zhou

A saddlepoint approximation of the Student&#39;s t-statistic was derived by Daniels and Young [Biometrika 78 (1991) 169-179] under the very stringent exponential moment condition that requires that the underlying density function go down at least as fast as a Normal density in the tails. This is a severe restriction on the approximation&#39;s applicability.

Marc Hallin, Davy Paindaveine

We are deriving optimal rank-based tests for the adequacy of a vector autoregressive-moving average (VARMA) model with elliptically contoured innovation density. These tests are based on the ranks of pseudo-Mahalanobis distances and on normed residuals computed from Tyler&#39;s [Ann. Statist. 15 (1987) 234-251] scatter matrix; they generalize the univariate

Hidetoshi Shimodaira

Approximately unbiased tests based on bootstrap probabilities are considered for the exponential family of distributions with unknown expectation parameter vector, where the null hypothesis is represented as an arbitrary-shaped region with smooth boundaries. This problem has been discussed previously in Efron and Tibshirani [Ann. Statist. 26 (1998) 1687-1718

Marc Aerts, Gerda Claeskens, Jeffrey D. Hart

We propose and analyze nonparametric tests of the null hypothesis that a function belongs to a specified parametric family. The tests are based on BIC approximations, π_{BIC}, to the posterior probability of the null model, and may be carried out in either Bayesian or frequentist fashion. We obtain results on the asymptotic distribution of π_{BIC} under both

Liqun Wang

This paper is concerned with general nonlinear regression models where the predictor variables are subject to Berkson-type measurement errors. The measurement errors are assumed to have a general parametric distribution, which is not necessarily normal. In addition, the distribution of the random error in the regression equation is nonparametric. A minimum d

Rudolf Beran

This paper constructs improved estimators of the means in the Gaussian saturated one-way layout with an ordinal factor. The least squares estimator for the mean vector in this saturated model is usually inadmissible. The hybrid shrinkage estimators of this paper exploit the possibility of slow variation in the dependence of the means on the ordered factor le

R. Dennis Cook, Bing Li

The central mean subspace (CMS) and iterative Hessian transformation (IHT) have been introduced recently for dimension reduction when the conditional mean is of interest. Suppose that X is a vector-valued predictor and Y is a scalar response. The basic problem is to find a lower-dimensional predictor η^TX such that E(Y|X)=E(Y|η^TX). The CMS defines the infer

Marc Hallin, Zudi Lu, Lanh T. Tran

A local linear kernel estimator of the regression function x\mapsto g(x):=E[Y_i|X_i=x], x\in R^d, of a stationary (d+1)-dimensional spatial process {(Y_i,X_i),i\in Z^N} observed over a rectangular domain of the form I_n:={i=(i_1,...,i_N)\in Z^N| 1\leq i_k\leq n_k,k=1,...,N}, n=(n_1,...,n_N)\in Z^N, is proposed and investigated. Under mild regularity assumpti

S. C. Kou

This paper studies, under the setting of spline regression, the connection between finite-sample properties of selection criteria and their asymptotic counterparts, focusing on bridging the gap between the two. We introduce a bias-variance decomposition of the prediction error, using which it is shown that in the asymptotics the bias term dominates the varia

Joel L. Horowitz, Enno Mammen

This paper describes an estimator of the additive components of a nonparametric additive model with a known link function. When the additive components are twice continuously differentiable, the estimator is asymptotically normally distributed with a rate of convergence in probability of n^{-2/5}. This is true regardless of the (finite) dimension of the expl

Nicolas Chopin

The term ``sequential Monte Carlo methods&#39;&#39; or, equivalently, ``particle filters,&#39;&#39; refers to a general class of iterative algorithms that performs Monte Carlo approximations of a given sequence of distributions of interest (π_t). We establish in this paper a central limit theorem for the Monte Carlo estimates produced by these computational

Valen E. Johnson

This article describes an extension of classical χ^2 goodness-of-fit tests to Bayesian model assessment. The extension, which essentially involves evaluating Pearson&#39;s goodness-of-fit statistic at a parameter value drawn from its posterior distribution, has the important property that it is asymptotically distributed as a χ^2 random variable on K-1 degre

Luis E. Nieto-Barajas, Igor Prunster, Stephen G. Walker

This paper introduces and studies a new class of nonparametric prior distributions. Random probability distribution functions are constructed via normalization of random measures driven by increasing additive processes. In particular, we present results for the distribution of means under both prior and posterior conditions and, via the use of strategic late

Luis Dieulefait

This brief note only contains a modest contribution: we just fix some inaccuracies in the proof of the prime level weight 2 case of Serre&#39;s conjecture given in Khare&#39;s preprint &#34;On Serre&#39;s modularity conjecture for 2-dimensional mod p representations of G_Q unramified outside p&#34;, for the case of trivial character. More precisely, the modu

Yvette Kosmann-Schwarzbach, Camille Laurent-Gengoux

We study the geometric and algebraic properties of the twisted Poisson structures on Lie algebroids, leading to a definition of their modular class and to an explicit determination of a representative of the modular class, in particular in the case of a twisted Poisson manifold.

Emina Alibegovic, Mladen Bestvina

We prove that every limit group acts geometrically on a CAT(0) space with the isolated flats property.

Friedrich Wehrung

A (v,0)-semilattice is ultraboolean, if it is a directed union of finite Boolean (v,0)-semilattices. We prove that every distributive (v,0)-semilattice is a retract of some ultraboolean (v,0)-semilattices. This is established by proving that every finite distributive (v,0)-semilattice is a retract of some finite Boolean (v,0)-semilattice, and this in a funct

Philippe Flajolet, Joaquim Gabarro, Helmut Pekari

This article describes a purely analytic approach to urn models of the generalized or extended Pólya-Eggenberger type, in the case of two types of balls and constant ``balance,&#39;&#39; that is, constant row sum. The treatment starts from a quasilinear first-order partial differential equation associated with a combinatorial renormalization of the model and

Florent Benaych-Georges

We construct a random matrix model for the bijection Ψbetween clas- sical and free infinitely divisible distributions: for every d\geq1, we associate in a quite natural way to each *-infinitely divisible distribution μa distribution P_d^μ on the space of d\times d Hermitian matrices such that P_d^μP_d^ν=P_d^{μ*ν}. The spectral distribution of a random matrix

Christina Goldschmidt

We consider a model for random hypergraphs with identifiability, an analogue of connectedness. This model has a phase transition in the proportion of identifiable vertices when the underlying random graph becomes critical. The phase transition takes various forms, depending on the values of the parameters controlling the different types of hyperedges. It may

M. B. Sedra

The Moyal momentum algebra is, once again, used to discuss some important aspects of NC integrable models and 2d conformal field theories. Among the results presented, we setup algebraic structures and makes useful convention notations leading to extract non trivial properties of the Moyal momentum algebra. We study also the Lax pair building mechanism for p

Adel M. Awad

We present a class of higher dimensional solutions to Einstein-Maxwell equations in d-dimensions. These solutions are asymptotically locally flat, de-Sitter, or anti-de Sitter space-times. The solutions we obtained depend on two extra parameters other than the mass and the nut charge. These two parameters are the electric charge, q and the electric potential

F. Chishtie, M. Gagné-Portelance, T. Hanif, S. Homayouni

In a recently proposed model in which a vector non-Abelian gauge field interacts with an antisymmetric tensor field, it has been shown that the tensor field possesses no physical degrees of freedom. This formal demonstration is tested by computing the one-loop contributions of the tensor field to the self-energy of the vector field. It is shown that despite

Ian G Moss

This paper considers anomaly cancellation for eleven-dimensional supergravity on a manifold with boundary and theories related to heterotic $M$-theory. The Green-Schwarz mechanism is implemented without introducing distributions. The importance of the supersymmetry anomaly in constructing the low energy action is discussed and it is argued that a recently pr

Harald Grosse, Karl-Georg Schlesinger

We study an algebraic deformation problem which captures the data of the general deformation problem for a quantum vertex algebra. We derive a system of coupled equations which is the counterpart of the Maurer-Cartan equation on the usual Hochschild complex of an assocative algebra. We show that this system of equations results from an action principle. This

M R Setare

Motivated by the recent interest in quantization of black hole area spectrum, we consider the area spectrum of Schwarzschild, BTZ, extremal Reissner-Nordström, near extremal Schwarzschild-de Sitter, and Kerr black holes. Based on the proposal by Bekenstein and others that the black hole area spectrum is discrete and equally spaced, we implement Kunstatter&#3

Yujun Chen, Maxim Kontsevich, Albert Schwarz

We say that a function F(tau) obeys WDVV equations, if for a given invertible symmetric matrix eta^{alpha beta} and all tau \in T \subset R^n, the expressions c^{alpha}_{beta gamma}(tau) = eta^{alpha lambda} c_{lambda beta gamma}(tau) = eta^{alpha lambda} \partial_{lambda} \partial_{beta} \partial_{gamma} F can be considered as structure constants of commuta

Toshiaki Tanaka

We make a new multivariate generalization of the type A monomial space of a single variable. It is different from the previously introduced type A space of several variables which is an sl(M+1) module, and we thus call it type A&#39;. We construct the most general quasi-solvable operator of (at most) second-order which preserves the type A&#39; space. Invest

Qing-Hong Cao, Daisuke Nomura, Kazuhiro Tobe, C. -P. Yuan

We calculate the production cross section of the ``CP-odd&#39;&#39; Higgs boson via gluon fusion in the minimal supersymmetric standard model with explicit CP violation in the stop sector. We show that there is a parameter region in which the cross section is enhanced by a factor of about 1000, as compared to the case without CP violation in the stop sector.

A. A. Kochanov, K. S. Lokhtin, S. I. Sinegovsky

A hybrid model is used to describe the energy loss of very high-energy taus and muons in matter due to inelastic scattering on nuclei. The model involves soft and semihard photonuclear interactions as well as the deep inelastic scattering including the weak neutral current processes. For the lepton scattering on nuclei all important nuclear effects, the shad

Michael H. Seymour

In a recent paper, Dokshitzer and Marchesini rederived the anomalous dimension matrix for colour evolution of $gg \to gg$ scattering, first derived by Kidonakis, Oderda and Sterman. They noted a weird symmetry that it possesses under interchange of internal (colour group) and external (scattering angle) degrees of freedom and speculated that this may be rela

A. Cooper-Sarkar, C. Gwenlan

The H1 and ZEUS published PDF analyses are compared, including a discussion of the different treatments of correlated systematic uncertainties. Differences in the data sets and the analyses are investigated by putting the H1 data set through both PDF analyses and by putting the ZEUS and H1 data sets through the same (ZEUS) analysis, separately. Finally the H

Kenzo Ishikawa, Takashi Shimomura

A generalized scattering amplitude where momenta of incoming-particles and outgoing-particles as well as positions of incoming-particles and outgoing-particles are specified is formulated. Idealistic beams and idealistic measuring instruments where momenta and positions satisfy minimum uncertainty are studied with a use of minimum wave packets, coherent stat

F. Darabi

A new idea of quantum gravity is developed based on {\it Gravitational Complementary Principle}. This principle states that gravity has dual complement features: The quantum and classical aspects of gravity are complement and absolutely separated by the planck length into planckian and over-planckian domains, respectively. The classical Einstein equations ar

P. H. Damgaard, Urs M. Heller, K. Splittorff, B. Svetitsky

We derive the two-point spectral correlation function of the Dirac operator with a specific external source in the $ε$-regime of QCD. This correlation function has a unique and strong dependence on $F_π$, and thus provides an novel way to extract $F_π$ from lattice simulations. We test the method in a quenched lattice simulation with staggered fermions.

Simon Hands, Seyong Kim, Jon-Ivar Skullerud

We present results of simulations of Two Color QCD using two flavors of Wilson quark in the fundamental representation, at non-zero quark chemical potential mu, on an 8^3x16 lattice. Results for the quark number density, quark and gluon energy densities, and superfluid condensate are qualitatively distinct from the behaviour expected on the assumption that t

L. G. Landsberg

In the experiment with the SPHINX spectrometer in 1995-99 a new baryon state X(2000) -> Sigma^0K^+ was observed in the proton diffractive reactions p + N(C) -> Sigma^0K^+ + N(C). The main parameters of X(2000)^+ baryon are M = 1986 +- 6 MeV, Gamma = 98 +- 21 MeV. Unusual features of massive X(2000) state (narrow decay width Gamma/M simeq 0.05, anomalously la

Belle Collaboration

We report a measurement of the inclusive electron energy spectrum for charmed semileptonic decays of B mesons in a 140 fb^-1 data sample collected on the Upsilon(4S) resonance, with the Belle detector at the KEKB asymmetric energy e^+ e^- collider. We determine the first, second and third moments of the electron energy spectrum for threshold values of the el

Euro Spallucci, Michele Fontanini

In this paper, we are going to put in a single consistent framework apparently unrelated pieces of information, i.e. zero-point length, extra-dimensions, string T-duality. More in details we are going to introduce a modified Kaluza-Klein theory interpolating between (high-energy) string theory and (low-energy) quantum field theory. In our model zero-point le

A. V. Minkevich

Field theoretical scheme of regular Big Bang in 4-dimensional physical space-time, built in the framework of gauge approach to gravitation, is discussed. Regular bouncing character of homogeneous isotropic cosmological models is ensured by gravitational repulsion effect at extreme conditions without quantum gravitational corrections. The most general propert

Esra Erdem, Vladimir Lifschitz, Don Ringe

The concept of a temporal phylogenetic network is a mathematical model of evolution of a family of natural languages. It takes into account the fact that languages can trade their characteristics with each other when linguistic communities are in contact, and also that a contact is only possible when the languages are spoken at the same time. We show how com

Dmitry Zinoviev

Discrete event simulation specification (DEVS) is a formalism designed to describe both discrete state and continuous state systems. It is a powerful abstract mathematical notation. However, until recently it lacked proper graphical representation, which made computer simulation of DEVS models a challenging issue. Unified modeling language (UML) is a multipu