March 2005 arXiv papers — page 5

Gerardo Ortiz, Jorge Dukelsky

The BCS-to-BEC crossover, as well as the nature of Cooper pairs, in a superconducting and Fermi superfluid medium is studied from the exact ground state wavefunction of the reduced BCS Hamiltonian. As the strength of the interaction increases, the ground state continuously evolves from a mixed-system of quasifree fermions and pair resonances (BCS), to pair r

Lianyi He, Meng Jin, Pengfei Zhuang

We investigate pion superfluidity and its effect on meson properties and equation of state at finite temperature and isospin and baryon densities in the frame of standard flavor SU(2) NJL model. In mean field approximation to quarks and random phase approximation to mesons, the critical isospin chemical potential for pion superfluidity is exactly the pion ma

L. Audouin, L. Tassan-Got, P. Armbruster, J. Benlliure

The production cross sections of fragmentation-evaporation residues in the reaction Pb+p at 500A MeV have been measured using the inverse-kinematics method and the FRS spectrometer (GSI). Fragments were identified in nuclear charge using ionisation chambers. The mass identification was performed event-by-event using the B-rho - TOF - Delta-E technique. Altho

N. P. Konstantinidis

The $s_{i}={1/2}$ nearest neighbor antiferromagnetic Heisenberg model is considered for spins sitting on the vertices of clusters with the connectivity of fullerene molecules and a number of sites $n$ ranging from 24 to 32. Using the permutational and spin inversion symmetries of the Hamiltonian the low energy spectrum is calculated for all the irreducible r

Ramon van Handel, Hideo Mabuchi

Both in classical and quantum stochastic control theory a major role is played by the filtering equation, which recursively updates the information state of the system under observation. Unfortunately, the theory is plagued by infinite-dimensionality of the information state which severely limits its practical applicability, except in a few select cases (e.g

C. Olindo, M. A. Sagioro, C. H. Monken, S. Pádua

We study the number of coincidences in a Hong-Ou-Mandel interferometer exit whose arms have been supplemented with the addition of one or two optical cavities. The fourth-order correlation function at the beam-splitter exit is calculated. In the regime where the cavity length are larger than the one-photon coherence length, photon coalescence and anti-coales

D. Schmicker

We calculate the hydrogen molecule ion from the two particle Schr"odinger equation. Therefore a very simple two particle basis set is chosen. We suggest this ansatz to be used to solve the "two electron one phonon" three particle wave-function of a BCS superconductor. Possibly it can give hints for high temperature superconductors.

G. Badurek, P. Facchi, Y. Hasegawa, Z. Hradil

A tomographic technique is introduced in order to determine the quantum state of the center of mass motion of neutrons. An experiment is proposed and numerically analyzed.

G. Gonzalez

A general formalism for obtaining the Lagrangian and Hamiltonian for a one dimensional dissipative system is developed. The formalism is illustrated by applying it to the case of a relativistic particle with linear dissipation. The relativistic wave equation is solved for a free particle with linear dissipation.

R. Van Meter, K. M. Itoh

We present a detailed analysis of the impact on modular exponentiation of architectural features and possible concurrent gate execution. Various arithmetic algorithms are evaluated for execution time, potential concurrency, and space tradeoffs. We find that, to exponentiate an n-bit number, for storage space 100n (twenty times the minimum 5n), we can execute

Chikara Furusawa, Takao Suzuki, Akiko Kashiwagi, Tetsuya Yomo

The discovery of two fundamental laws concerning cellular dynamics with recursive growth is reported. First, the chemical abundances measured over many cells are found to obey a log-normal distribution and second, the relationship between the average and standard deviation of the abundances is found to be linear. The ubiquity of the laws is explored both the

Toshio Fukumi

Optimal structure of proteins is described by linear stochastic differential equation with mean decrease of free energy and volatility. Structure determining strategy is given by a twin of stochastic variables for which empirical conditions are not postulated. Optimal structure determination will be deformed to be adoptive to trading strategy employing marti

T. Karpiuk, M. Brewczyk, M. Gajda, K. Rzazewski

We consider the stability of a mixture of degenerate Bose and Fermi gases. Even though the bosons effectively repel each other the mixture can still collapse provided the Bose and Fermi gases attract each other strongly enough. For a given number of atoms and the strengths of the interactions between them we find the geometry of a maximally compact trap that

B. G. Sidharth

Newton's action at a distance gravitational law and Coulomb's action at a distance electrostatic law had to be reexamined in the light of field theories which originated from Maxwell's electrodynamics. These ideas were further modified with the advent of Quantum Theory, even though the differentiable spacetime manifold of Classical Physics was re

Nikolay M. Zubarev

The evolution of the interface between two ideal dielectric liquids in a strong vertical electric field is studied. It is found that a particular flow regime, for which the velocity potential and the electric field potential are linearly dependent functions, is possible if the ratio of the permittivities of liquids is inversely proportional to the ratio of t

Julien Toulouse, Francois Colonna, Andreas Savin

We study non-linear adiabatic connection paths in density-functional theory using modified electron-electron interactions that perform a long-range/short-range separation of the Coulomb interaction. These adiabatic connections allows to define short-range exchange-correlation potentials and short-range local exchange-correlation energies per particle that we

Reinhard Prix

In this work we extend our previously developed formalism of Newtonian multi-fluid hydrodynamics to allow for coupling between the fluids and the electromagnetic and gravitational field. This is achieved within the convective variational principle by using a standard minimal coupling prescription. In addition to the conservation of total energy and momentum,

Ari Sihvola

A geometric visualization is presented for the Brewster angle for a plane wave reflecting from an interface. The surface is assumed isotropic but it is allowed to display both dielectric and magnetic susceptibility, and hence the Brewster (polarizing) angle can attain any value between 0 and 90 degrees, and can exist for both parallel and perpendicular polar

Nobuyuki Sakai, Hisanori Kudoh

Sornette et al. claimed that the optimal supply does not agree with the average demand, by analyzing a bakery model where a daily demand fluctuates with a uniform distribution. In this note, we extend the model to general probability distributions, and obtain the formula of the optimal supply for Gaussian distribution, which is more realistic. Our result is

Gordon Chalmers

A route to the derivation of the numbers $s$ to the transcendental equation $ζ(s)=0$ is presented. The solutions to this equation require the solving of a geodesic flow in an infinite dimensional manifold. These solutions enable one approach to a formula generating the prime numbers.

Gordon Chalmers

A construction of polytopes is given based on integers. These geometries are constructed through a mapping to pure numbers and have multiple applications, including statistical mechanics and computer science. The number form is useful in topology and has a mapping to one-dimensional knot contours.

J. I. Kapusta, Y. Li

We derive a general formula for the correlation function of two identical particles with the inclusion of multiple elastic scatterings in the medium in which the two particles are produced. This formula involves the propagator of the particle in the medium. As illustration of the effect we apply the formula to the special case where the scatterers are static

Arnau Rios, Artur Polls, Angels Ramos, Isaac Vidaña

Bulk and single-particle properties of hot hyperonic matter are studied within the Brueckner-Hartree-Fock approximation extended to finite temperature. The bare interaction in the nucleon sector is the Argonne V18 potential supplemented with an effective three-body force to reproduce the saturating properties of nuclear matter. The modern Nijmegen NSC97e pot

Victor Velazquez, Jorge G. Hirsch, Alejandro Frank, Jose Barea

Statistical fluctuations of the nuclear ground state energies are estimated using shell model calculations in which particles in the valence shells interact through well defined forces, and are coupled to an upper shell governed by random 2-body interactions. Induced ground-state energy fluctuations are found to be one order of magnitude smaller than those p

Feng Pan, Yu Zhang, J. P. Draayer

The U(5)-O(6) transitional behavior of the Interacting Boson Model in the large N limit is revisited. Some low-lying energy levels, overlaps of the ground state wavefunctions, B(E2) transition rate for the decay of the first excited energy level to the ground state, and the order parameters are calculated for different total numbers of bosons. The results sh

Armando Barrañón, J. A. López

Evidence of a primitive spinodal decomposition has been obtained for central Ni+Ni Heavy Ion Collision, since higher order charge correlations show a peak when four fragments of size equal to 6 are produced with an excitation of 4.75 MeV. This can be considered as a signature of a primitive breakup in equal sized fragments with a privileged fragment size. Th

B. C. Liu, B. S. Zou

Using resonance isobar model and effective Lagrangian approach, from recent BES results on $J/ψ\to\bar ppη$ and $ψ\to\bar pK^+Λ$, we deduce the ratio between effective coupling constants of $N^*(1535)$ to $KΛ$ and $pη$ to be $R\equiv g_{N^*(1535)KΛ}/g_{N^*(1535)pη} =1.3\pm 0.3$. With previous known value of $g_{N^*(1535)pη}$, the obtained new value of $g_{N^

A. V. Borisov, S. L. Dudoladov

We consider generalizations of pairing relations for Kovalevskaya exponents in quasihomogeneous systems with quasihomogeneous tensor invariants. The case of presence of a Poisson structure in the system is investigated in more detail. We give some examples which illustrate general theorems.

Adilson E. Motter, Alessandro P. S. de Moura, Celso Grebogi, Holger Kantz

An adequate characterization of the dynamics of Hamiltonian systems at physically relevant scales has been largely lacking. Here we investigate this fundamental problem and we show that the finite-scale Hamiltonian dynamics is governed by effective dynamical invariants, which are significantly different from the dynamical invariants that describe the asympto

Lieselot Vandevenne, Andre Verbeure

The free Bose gas with attractive boundary conditions is an interesting toy model for the study of Bose-Einstein Condensation (BEC), because one has BEC already in one dimension. Here we study for the first time the imperfect Bose gas with these boundary conditions and prove rigorously the occurence of condensation.

V. Nazaikinskii, A. Savin, B. -W. Schulze, B. Sternin

We obtain a classification of elliptic operators modulo stable homotopy on manifolds with edges (this is in some sense the simplest class of manifolds with nonisolated singularities). We show that the operators are classified by the K-homology group of the manifold. To this end, we construct exact sequence in elliptic theory isomorphic to the K-homology exac

Ian Melbourne, Matthew Nicol

We prove an almost sure invariance principle that is valid for general classes of nonuniformly expanding and nonuniformly hyperbolic dynamical systems. Discrete time systems and flows are covered by this result. In particular, the result applies to the planar periodic Lorentz flow with finite horizon. Statistical limit laws such as the central limit theorem,

Stephen F. Sawin

For an arbitrary simple Lie algebra $\g$ and an arbitrary root of unity $q,$ the closed subsets of the Weyl alcove of the quantum group $U_q(\g)$ are classified. Here a closed subset is a set such that if any two weights in the Weyl alcove are in the set, so is any weight in the Weyl alcove which corresponds to an irreducible summand of the tensor product of

Andrew J. Sommese, Jan Verschelde, Charles W. Wampler

By a numerical continuation method called a diagonal homotopy we can compute the intersection of two positive dimensional solution sets of polynomial systems. This paper proposes to use this diagonal homotopy as the key step in a procedure to intersect general solution sets. Of particular interest is the special case where one of the sets is defined by a sin

Cheng-Der Fuh

Let ξ_0,ξ_1,...,ξ_{ω-1} be observations from the hidden Markov model with probability distribution P^{θ_0}, and let ξ_ω,ξ_{ω+1},... be observations from the hidden Markov model with probability distribution P^{θ_1}. The parameters θ_0 and θ_1 are given, while the change point ωis unknown. The problem is to raise an alarm as soon as possible after the distrib

Randal Douc, Eric Moulines, Tobias Ryden

An autoregressive process with Markov regime is an autoregressive process for which the regression function at each time point is given by a nonobservable Markov chain. In this paper we consider the asymptotic properties of the maximum likelihood estimator in a possibly nonstationary process of this kind for which the hidden state space is compact but not ne

Emmanuel Gobet, Marc Hoffmann, Markus Reiss

We study the problem of estimating the coefficients of a diffusion (X_t,t\geq 0); the estimation is based on discrete data X_{nΔ},n=0,1,...,N. The sampling frequency Δ^{-1} is constant, and asymptotics are taken as the number N of observations tends to infinity. We prove that the problem of estimating both the diffusion coefficient (the volatility) and the d

Yacine Ait-Sahalia, Per A. Mykland

We provide a general method to analyze the asymptotic properties of a variety of estimators of continuous time diffusion processes when the data are not only discretely sampled in time but the time separating successive observations may possibly be random. We introduce a new operator, the generalized infinitesimal generator, to obtain Taylor expansions of th

Shao-Wei Cheng, Kenny Q. Ye

Factorial designs have broad applications in agricultural, engineering and scientific studies. In constructing and studying properties of factorial designs, traditional design theory treats all factors as nominal. However, this is not appropriate for experiments that involve quantitative factors. For designs with quantitative factors, level permutation of on

Holger Dette, Viatcheslav B. Melas, Andrey Pepelyshev

For a broad class of nonlinear regression models we investigate the local E- and c-optimal design problem. It is demonstrated that in many cases the optimal designs with respect to these optimality criteria are supported at the Chebyshev points, which are the local extrema of the equi-oscillating best approximation of the function f_0\equiv 0 by a normalized

Peter Hall, Michael C. Minnotte, Chunming Zhang

It is well known that the number of modes of a kernel density estimator is monotone nonincreasing in the bandwidth if the kernel is a Gaussian density. There is numerical evidence of nonmonotonicity in the case of some non-Gaussian kernels, but little additional information is available. The present paper provides theoretical and numerical descriptions of th

Peter Hall, Hong Ooi

We discuss properties of two methods for ascribing probabilities to the shape of a probability distribution. One is based on the idea of counting the number of modes of a bootstrap version of a standard kernel density estimator. We argue that the simplest form of that method suffers from the same difficulties that inhibit level accuracy of Silverman's ba

Lawrence D. Brown, Andrew V. Carter, Mark G. Low, Cun-Hui Zhang

This paper establishes the global asymptotic equivalence between a Poisson process with variable intensity and white noise with drift under sharp smoothness conditions on the unknown function. This equivalence is also extended to density estimation models by Poissonization. The asymptotic equivalences are established by constructing explicit equivalence mapp

Agostino Nobile

The posterior distribution of the number of components k in a finite mixture satisfies a set of inequality constraints. The result holds irrespective of the parametric form of the mixture components and under assumptions on the prior distribution weaker than those routinely made in the literature on Bayesian analysis of finite mixtures. The inequality constr

Stephen Walker

We use martingales to study Bayesian consistency. We derive sufficient conditions for both Hellinger and Kullback-Leibler consistency, which do not rely on the use of a sieve. Alternative sufficient conditions for Hellinger consistency are also found and demonstrated on examples.

Daniel J. Nordman, Soumendra N. Lahiri

We consider the problem of determining the optimal block (or subsample) size for a spatial subsampling method for spatial processes observed on regular grids. We derive expansions for the mean square error of the subsampling variance estimator, which yields an expression for the theoretically optimal block size. The optimal block size is shown to depend in a

Peter Hall, Spiridon Penev

We suggest an adaptive sampling rule for obtaining information from noisy signals using wavelet methods. The technique involves increasing the sampling rate when relatively high-frequency terms are incorporated into the wavelet estimator, and decreasing it when, again using thresholded terms as an empirical guide, signal complexity is judged to have decrease

Alexander Goldenshluger, Assaf Zeevi

This article pursues a statistical study of the Hough transform, the celebrated computer vision algorithm used to detect the presence of lines in a noisy image. We first study asymptotic properties of the Hough transform estimator, whose objective is to find the line that ``best'' fits a set of planar points. In particular, we establish strong consis

Jianqing Fan, Jian Zhang

Generalized likelihood ratio statistics have been proposed in Fan, Zhang and Zhang [Ann. Statist. 29 (2001) 153-193] as a generally applicable method for testing nonparametric hypotheses about nonparametric functions. The likelihood ratio statistics are constructed based on the assumption that the distributions of stochastic errors are in a certain parametri

Hidefumi Ohsugi, Takayuki Hibi

Christos Athanasiadis studies an effective technique to show that Gorenstein sequences coming from compressed polytopes are unimodal. In the present paper we will use such the technique to find a rich class of Gorenstein toric rings with unimodal $h$-vectors arising from finite graphs.

Victor J. Yohai, Ruben H. Zamar

We consider the problem of constructing robust nonparametric confidence intervals and tests of hypothesis for the median when the data distribution is unknown and the data may contain a small fraction of contamination. We propose a modification of the sign test (and its associated confidence interval) which attains the nominal significance level (probability

Iain M. Johnstone, Marc Raimondo

We consider the nonparametric estimation of a periodic function that is observed in additive Gaussian white noise after convolution with a ``boxcar,'' the indicator function of an interval. This is an idealized model for the problem of recovery of noisy signals and images observed with ``motion blur.'' If the length of the boxcar is rational,

T. Tony Cai, Mark G. Low

A nonparametric adaptation theory is developed for the construction of confidence intervals for linear functionals. A between class modulus of continuity captures the expected length of adaptive confidence intervals. Sharp lower bounds are given for the expected length and an ordered modulus of continuity is used to construct adaptive confidence procedures w

Raluca M. Balan

In this paper we generalize Yu's [Ann. Probab. 24 (1996) 2079-2097] strong invariance principle for associated sequences to the multi-parameter case, under the assumption that the covariance coefficient u(n) decays exponentially as n\to \infty. The main tools that we use are the following: the Berkes and Morrow [Z. Wahrsch. Verw. Gebiete 57 (1981) 15-37]

Anda Gadidov

In this note we show that almost sure convergence to zero of symmetrized U-statistics indexed by a linear sector in Z^d_+ is equivalent to convergence along the diagonal of Z^d_+, as it is considered in Lata\la and Zinn [Ann. Probab. 28 (2000) 1908-1924]. Comparisons with similar results for sums of multi-indexed i.i.d. random variables are also made.

Didier Piau

We extend in two directions our previous results about the sampling and the empirical measures of immortal branching Markov processes. Direct applications to molecular biology are rigorous estimates of the mutation rates of polymerase chain reactions from uniform samples of the population after the reaction. First, we consider nonhomogeneous processes, which

Paolo Bellingeri, Eddy Godelle

We provide new group presentations for surface braid groups which are positive. We study some properties of such presentations and we solve the conjugacy problem in a particular case.

V. I. Afanasyev, J. Geiger, G. Kersting, V. A. Vatutin

We study branching processes in an i.i.d. random environment, where the associated random walk is of the oscillating type. This class of processes generalizes the classical notion of criticality. The main properties of such branching processes are developed under a general assumption, known as Spitzer's condition in fluctuation theory of random walks, an

Kacha Dzhaparidze, Harry van Zanten

In this paper we develop the spectral theory of the fractional Brownian motion (fBm) using the ideas of Krein's work on continuous analogous of orthogonal polynomials on the unit circle. We exhibit the functions which are orthogonal with respect to the spectral measure of the fBm and obtain an explicit reproducing kernel in the frequency domain. We use t

M. Kupsa, Y. Lacroix

In this paper we characterize possible asymptotics for hitting times in aperiodic ergodic dynamical systems: asymptotics are proved to be the distribution functions of subprobability measures on the line belonging to the functional class {6pt} {-3mm}(A){6mm}F={F:R\to [0,1]:\left\lbrack \matrixF is increasing, null on ]-\infty, 0]; \noalignF is continuous and

Erik I. Broman

Given a trigonometric polynomial f:[0,1]\to[0,1] of degree m, one can define a corresponding stationary process {X_i}_{i\in Z} via determinants of the Toeplitz matrix for f. We show that for m=1 this process, which is trivially one-dependent, is a two-block-factor.

Imre Csiszar, Frantisek Matus

The variation distance closure of an exponential family with a convex set of canonical parameters is described, assuming no regularity conditions. The tools are the concepts of convex core of a measure and extension of an exponential family, introduced previously by the authors, and a new concept of accessible faces of a convex set. Two other closures relate

Samy Tindel

In this note we show how to generalize the stochastic calculus method introduced by Comets and Neveu [Comm. Math. Phys. 166 (1995) 549-564] for two models of spin glasses, namely, the SK model with external field and the perceptron model. This method allows to derive quite easily some fluctuation results for the free energy in those two cases.

Stephane Boucheron, Olivier Bousquet, Gabor Lugosi, Pascal Massart

A general method for obtaining moment inequalities for functions of independent random variables is presented. It is a generalization of the entropy method which has been used to derive concentration inequalities for such functions [Boucheron, Lugosi and Massart Ann. Probab. 31 (2003) 1583-1614], and is based on a generalized tensorization inequality due to

Franck Barthe, Olivier Guedon, Shahar Mendelson, Assaf Naor

This article investigates, by probabilistic methods, various geometric questions on B_p^n, the unit ball of \ell_p^n. We propose realizations in terms of independent random variables of several distributions on B_p^n, including the normalized volume measure. These representations allow us to unify and extend the known results of the sub-independence of coord

Peter Howard, Mohammadreza Raoofi

We consider the asymptotic behavior of perturbations of Lax and overcompressive type viscous shock profiles arising in systems of regularized conservation laws with strictly parabolic viscosity, and also in systems of conservation laws with partially parabolic regularizations such as arise in the case of the compressible Navier--Stokes equations and in the e

Fabrizio Zanello

First, we construct a bijection between the set of $h$-vectors and the set of socle-vectors of artinian algebras. As a corollary, we find the minimum codimension that an artinian algebra with a given socle-vector can have. Then, we study the main problem in the paper: determining when there is a unique socle-vector for a given $h$-vector. We solve the proble

Fabrizio Zanello

In this paper we study standard graded artinian level algebras, in particular those whose socle-vector has type 2. Our main results are: the characterization of the level $h$-vectors of the form $(1,r,...,r,2)$ for $r\leq 4$; the characterization of the minimal free resolutions associated to each of the $h$-vectors above when $r=3$; a sharp upper-bound (unde

Y. Firat Celikler

We develop a dimension theory for D-semianalytic sets over an arbitrary non-Archimedean complete field. Our main results are the equivalence of several notions of dimension and a theorem on additivity of dimensions of projections and fibers in characteristic 0. We also prove a parameterized version of normalization for D-semianalytic sets.

Boris Chorny

We generalize the small object argument in order to allow for its application to proper classes of maps (as opposed to sets of maps in Quillen's small object argument). The necessity of such a generalization arose with appearance of several important examples of model categories which were proven to be non-cofibrantly generated. Our current approach allo

S. Caenepeel, E. De Groot, G. Militaru

A pair of adjoint functors $(F,G)$ is called a Frobenius pair of the second type if $G$ is a left adjoint of $βFα$ for some category equivalences $α$ and $β$. Frobenius ring extensions of the second kind provide examples of Frobenius pairs of the second kind. We study Frobenius pairs of the second kind between categories of modules, comodules, and comodules

E. K. Loginov

We consider the self-dual Yang-Mills equations in seven dimensions. Modifying the t'Hooft construction of instantons in $d=4$, we find $N$-instanton $7d$ solutions which depend on $8N$ effective parameters and are $E_{6}$-invariant.

J. -P. Derendinger, C. Kounnas, P. M. Petropoulos, F. Zwirner

We illustrate the correspondence between the N=1 superstring compactifications with fluxes, the N=4 gauged supergravities and the superpotential and Kähler potential of the effective N=1 supergravity in four dimensions. In particular we derive, in the presence of general fluxes, the effective N=1 supergravity theory associated to the type IIA orientifolds wi

A. R. Fazio

In the framework of the operator product expansion I provide a detailed evaluation of the contribution of the lowest photon condensate to the two-point photon Green function for four-dimensional spinor electrodynamics and three-dimensional scalar electrodynamics. Since the above mentioned condensate affects the part of the propagator contributing to physical

P. P. Avelino, J. C. R. E. Oliveira, C. J. A. P. Martins

We study the cosmological evolution of domain wall networks in two and three spatial dimensions in the radiation and matter eras using a large number of high-resolution field theory simulations with a large dynamical range. We investigate the dependence of the uncertainty in key parameters characterising the evolution of the network on the size, dynamical ra

Richard C. Brower, Chung-I Tan, Ethan Thompson

A salient feature of String/Gauge duality is an extra 5th dimension. Here we study the effect of confining deformations of AdS5 and compute the spectrum of a string stretched between infinitely massive quarks and compare it with the quantum states of the QCD flux as determined by Kuti, Juge and Morningstar in lattice simulations. In the long flux tube limit

Sunggeun Lee, Sang-Jin Sin

We consider $tt^*$ equations appearing in the study of localized tachyon condensations. They are described by various Toda system when we consider the condensation by the lowest tachyon corresponding to the monomial $xy$. The tachyon potential is calculated as a solution to these equations. The Toda system appearing in the deformation of $\C^2/\Z_n$ by $xy$

P. M. Lavrov, O. V. Radchenko

Higher order relations existing in normal coordinates between affine extensions of the curvature tensor and basic objects for any Fedosov supermanifolds are derived. Representation of these relations in general coordinates is discussed.

V. Dolotin, A. Morozov

We argue that discrete dynamics has natural links to the theory of analytic functions. Most important, bifurcations and chaotic dynamical properties are related to intersections of algebraic varieties. This paves the way to identification of boundaries of Mandelbrot sets with discriminant varieties in moduli spaces, which are the central objects in the world

Hiroshi Nunokawa, Stephen Parke, Renata Zukanovich Funchal

We show that by combining high precision measurements of the atmospheric delta m^2 in both the electron and muon neutrino (or anti-neutrino) disappearance channels one can determine the neutrino mass hierarchy. The required precision is a very challenging fraction of one per cent for both measurements. At even higher precision, sensitivity to the cosine of t

Andreas Schaelicke, Frank Krauss

The method to merge matrix elements for multi particle production and parton showers in electron-positron annihilations and hadronic collisions and its implementation into the new event generator SHERPA is described in detail. Examples highlighting different aspects of it are thoroughly discussed, some results for various cases are presented. In addition, a

Frank Krauss, Andreas Schaelicke, Steffen Schumann, Gerhard Soff

The merging procedure of tree-level matrix elements and the subsequent parton shower as implemented in the new event generator SHERPA will be validated for the example of single gauge boson production at the LHC. The validation includes consistency checks and comparisons to results obtained from other event generators. In particular, comparisons with full ne

Andreas Gerhold

This thesis is devoted to properties of quark matter at high density and (comparatively) low temperature, which might exist in the interior of compact stars. The specific heat and the quark self energy in normal quark matter are discussed in detail. In particular higher order corrections to the known leading order results are obtained. Also the phenomenon of

B. Klein, J. Braun, H. J. Pirner

We investigate finite volume effects on the pion mass and the pion decay constant with renormalization group (RG) methods in the framework of a phenomenological model for QCD. An understanding of such effects is important in order to interpret results from lattice QCD and extrapolate reliably from finite lattice volumes to infinite volume. We consider the qu

T. E. O. Ericson, A. N. Ivanov

We investigate the dispersive contribution by radiative processes such as (pi- proton to neutron gamma) and (pi- proton to Delta gamma) to the pion-nucleon scattering lengths of charged pions in the heavy baryon limit. They give a large isospin violating contribution in the corresponding isoscalar scattering length, but only a small violation in the isovecto

A. V. Kotikov, A. V. Lipatov, N. P. Zotov

The results for structure function $F_L$, obtained in the $k_T$-factorization and collinear approaches, are compared with recent H1 experimental data at fixed $W$ values.

ZEUS Collaboration

The ZEUS inclusive differential cross-section data from HERA, for charged and neutral current processes taken with e+ and e- beams, together with differential cross-section data on inclusive jet production in e+ p scattering and dijet production in γp scattering, have been used in a new NLO QCD analysis to extract the parton distribution functions of the pro

Yu. V. Dumin, L. M. Svirskaya

The experiments on verification of the Kibble-Zurek mechanism showed that topological defects are formed most efficiently in the systems of small size or low (quasi-)dimensionality, whereas in the macroscopic two- and three-dimensional samples a concentration of the defects, as a rule, is strongly suppressed. A reason for universality of such behavior can be

Abel Camacho

The possibilities that, in the realm of the detection of the so--called deformed dispersion relation, a light source with a continuous distribution of frequencies offers is discussed. It will be proved that the presence of finite coherence length entails the emergence of a new term in the interference pattern. This is a novel trait, which renders a new possi

Alan D. Rendall

Present knowledge about the nature of spacetime singularities in the context of classical general relativity is surveyed. The status of the BKL picture of cosmological singularities and its relevance to the cosmic censorship hypothesis are discussed. It is shown how insights on cosmic censorship also arise in connection with the idea of weak null singulariti

Yasusada Nambu

We investigate the backreaction of cosmological long wavelength perturbations on the evolution of the Universe. By applying the renormalization group method to a Friedmann-Robertson-Walker universe with long wavelength fluctuations, we demonstrate that the renormalized solution with the backreaction effect is equivalent to that of the separate universe. Then

Gabriel Istrate

We study threshold properties of random constraint satisfaction problems under a probabilistic model due to Molloy. We give a sufficient condition for the existence of a sharp threshold that leads (for boolean constraints) to a necessary and sufficient for the existence of a sharp threshold in the case where constraint templates are applied with equal probab

Gabriel Istrate, Stefan Boettcher, Allon G. Percus

We study the connection between the order of phase transitions in combinatorial problems and the complexity of decision algorithms for such problems. We rigorously show that, for a class of random constraint satisfaction problems, a limited connection between the two phenomena indeed exists. Specifically, we extend the definition of the spine order parameter

Zengyou He, Xiaofei Xu, Shengchun Deng

The task of outlier detection is to find small groups of data objects that are exceptional when compared with rest large amount of data. Detection of such outliers is important for many applications such as fraud detection and customer migration. Most existing methods are designed for numeric data. They will encounter problems with real-life applications tha

Uwe Hermann, Stefan Katzenbeisser, Christian Schallhart, Helmut Veith

During the last years, large-scale simulations of realistic physical environments which support the interaction of multiple participants over the Internet have become increasingly available and economically significant, most notably in the computer gaming industry. Such systems, commonly called networked virtual environments (NVEs), are usually based on a cl

A. A. Prikhod'ko, N. A. Prikhod'ko

This paper represents an approach to creating global knowledge systems, using new philosophy and infrastructure of global distributed semantic network (frame knowledge representation system) based on the space-time database construction. The main idea of the space-time database environment introduced in the paper is to bind a document (an information frame,

Angelo Luis Pagliosa, Claudio Cesar de Sa, Fernando D. Sasse

This article presents the Neo-Fuzzy-Neuron Modified by Kohonen Network (NFN-MK), an hybrid computational model that combines fuzzy system technique and artificial neural networks. Its main task consists in the automatic generation of membership functions, in particular, triangle forms, aiming a dynamic modeling of a system. The model is tested by simulating

Mehryar Mohri, Fernando Pereira, Michael Riley

Finite-state automata are a very effective tool in natural language processing. However, in a variety of applications and especially in speech precessing, it is necessary to consider more general machines in which arcs are assigned weights or costs. We briefly describe some of the main theoretical and algorithmic aspects of these machines. In particular, we

Marci Meingast, Christopher Geyer, Shankar Sastry

Cameras with rolling shutters are becoming more common as low-power, low-cost CMOS sensors are being used more frequently in cameras. The rolling shutter means that not all scanlines are exposed over the same time interval. The effects of a rolling shutter are noticeable when either the camera or objects in the scene are moving and can lead to systematic bia

Paolo Liberatore

We study the problem of deciding whether some PSPACE-complete problems have models of bounded size. Contrary to problems in NP, models of PSPACE-complete problems may be exponentially large. However, such models may take polynomial space in a succinct representation. For example, the models of a QBF are explicitely represented by and-or trees (which are alwa