December 2003 arXiv papers — page 6

H. Mkrtchyan, R. Mkrtchyan

We consider d=10 N=1 supersymmetry algebra with maximal number of tensor charges Z and introduce a class of orbits of Z, invariant w.r.t. the $T_8$ subgroup of massless particles' little group $T_8\ltimes SO(8)$. For that class of orbits we classify all possible orbits and little groups, which appear to be semidirect products of $T_8\ltimes SO(k_1)\times

Josep Gonzalez, Victor Rotger

We present explicit models for Shimura curves X_D and Atkin-Lehner quotients X_D/w_m of them of genus 2. We show that several equations conjectured by Kurihara are correct and compute for them the kernel of Ribet's isogeny J_0(D)^{new} --> J_D between the new part of the Jacobian of the modular curve X_0(D) and the Jacobian of X_D.

A. Bramon, R. Escribano, J. L. L. Martinez

A comparison of the linear sigma model (L$σ$M) and Chiral Perturbation Theory (ChPT) predictions for pion and kaon dynamics is presented. Lowest and next-to-leading order terms in the ChPT amplitudes are reproduced if one restricts to scalar resonance exchange. Some low energy constants of the order $p^4$ ChPT Lagrangian are fixed in terms of scalar meson ma

W. R. Gibbs

An algorithm is discussed for converting a class of recursive processes to a parallel system. It is argued that this algorithm can be superior to certain methods currently found in the literature for an important subset of problems. The cases of homogeneous and non-homogenous two term recursion are treated. Applications to three problems (finding the eigenva

Nikolai Brilliantov, Clara Saluena, Thomas Schwager, Thorsten Poeschel

A force-free granular gas is considered with impact-velocity dependent coefficient of restitution as it follows from the model of viscoelastic particles. We analyze structure formation in this system by means of three independent methods: Molecular Dynamics, numerical solution of the hydrodynamic equations and linear stability analysis of these equations. Al

Ignacio Garcia-Mata, Marcos Saraceno

We study the relationship between the spectral properties of diffusive open quantum maps and the classical spectrum of Ruelle-Pollicott resonances. The leading resonances determine the asymptotic time regime for several quantities of interest - the linear entropy, the Loschmidt echo and the correlations of the initial state. A numerical method that allow an

D. M. Asner, CLEO Collaboration

We report on the observation of the eta_{c}^{prime}(2^{1}S_{0}), the radial excitation of eta_{c}(1^{1}S_{0}) ground state of charmonium, in the two-photon fusion reaction gamma gamma rightarrow eta_{c}^{prime} rightarrow K_{S}^{0}K^{pm}pi^{mp} in 13.6 fb^{-1} of CLEO II/II.V data and 13.1 fb^{-1} of CLEO III data. We obtain M(eta_{c}^{prime})=3642.9 pm 3.1(

F. J. Botella, Joao P. Silva

We study the determination of gamma from CP-violating observables in B -> pi+ pi- and B -> psi K_S. This determination requires theoretical input to one combination of hadronic parameters. We show that a mild assumption about this quantity may allow bounds to be placed on gamma, but we stress the pernicious effects that an eightfold discrete ambiguity has on

Philip Phillips, Dimitrios Galanakis, Tudor D. Stanescu

We show that doped Mott insulators, such as the copper-oxide superconductors, are asymptotically slaved in that the quasiparticle weight, $Z$, near half-filling depends critically on the existence of the high energy scale set by the upper Hubbard band. In particular, near half filling, the following dichotomy arises: $Z\ne 0$ when the high energy scale is in

Donato Bini, Christian Cherubini, Gianluca Cruciani, Andrea Lunari

The behaviour of a massless Dirac field on a general spacetime background representing two colliding gravitational plane waves is discussed in the Newman-Penrose formalism. The geometrical properties of the neutrino current are analysed and explicit results are given for the special Ferrari-Ibanez solution.

John C. Collins

The theory of the on-shell Sudakov form factor to all order of logarithms is explained.

Zurab Berezhiani, Paolo Ciarcelluti, Denis Comelli, Francesco L. Villante

In the mirror world hypothesis the mirror baryonic component emerges as a possible dark matter candidate. An immediate question arises: how the mirror baryons behave and what are the differences from the more familiar dark matter candidates as e.g. cold dark matter? In this paper we answer quantitatively to this question. First we discuss the dependence of t

Jeremy S. Heyl, Lars Hernquist

We propose a model to account for the bursts from soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs) in which quantum electrodynamics (QED) plays a vital role. In our theory, that we term ``fast-mode breakdown,'' magnetohydrodynamic (MHD) waves that are generated near the surface of a neutron star and propagate outward through the magneto

T. Binoth, J. Ph. Guillet, F. Mahmoudi

A compact representation of the loop amplitude gamma gamma ggg -> 0 is presented. The result has been obtained by using helicity methods and sorting with respect to an irreducible function basis. We show how to convert spinor representations into a field strength representation of the amplitude. The amplitude defines a background contribution for Higgs boson

J. Garcia-Escudero, M. Lorente

The main purpose of this work is to review the results obtained recently concerning the unitarization of highest weight representations for affine Kac-Moody algebras following the work of Jakobsen and Kac.

J. Garcia-Escudero, M. Lorente

Using Jakobsen theorems, unitarizability in Hermitian Symmetric Spaces is discussed. The set of all missing highest weights is explicitly calculated and the construction of their corresponding highest weights vectors is studied.

D. G. Ireland, S. Janssen, J. Ryckebusch

The problem of extracting information on new and known $N^{*}$ resonances by fitting isobar models to photonuclear data is addressed. A new fitting strategy, incorporating a genetic algorithm, is outlined. As an example, the method is applied to a typical tree-level analysis of published $p(γ,K^{+})Λ$ data. It is shown that, within the limitations of this tr

O. Lisovyy

The goal of the present paper is to calculate the determinant of the Dirac operator with a mass in the cylindrical geometry. The domain of this operator consists of functions that realize a unitary one-dimensional representation of the fundamental group of the cylinder with $n$ marked points. The determinant represents a version of the isomonodromic $τ$-func

Luciano da Fontoura Costa, Gonzalo Travieso, Carlos Antonio Ruggiero

This article investigates the performance of grid computing systems whose interconnections are given by random and scale-free complex network models. Regular networks, which are common in parallel computing architectures, are also used as a standard for comparison. The processing load is assigned to the processing nodes on demand, and the efficiency of the o

H Chamati, M S Stoycheva, G A Evangelakis

We used molecular dynamics simulations based on a potential model in analogy to the Tight Binding scheme in the Second Moment Approximation to simulate the effects of aluminum icosahedral grains (dispersoids) on the structure and the mechanical properties of an aluminum matrix. First we validated our model by calculating several thermodynamic properties refe

S. Vaughan, R. Willingale, P. T. O'Brien, J. P. Osborne

We report the first detection of a time-dependent, dust-scattered X-ray halo around a gamma-ray burst. GRB 031203 was observed by XMM-Newton starting six hours after the burst. The halo appeared as concentric ring-like structures centered on the GRB location. The radii of these structures increased with time as t^{1/2}, consistent with small-angle X-ray scat

Robert A. Herrmann

This is a Research and Instructional Development Project from the U. S. Naval Academy. In this monograph, the basic methods of nonstandard analysis for n-dimensional Euclidean spaces are presented. Specific rules are deveoped and these methods and rules are applied to rigorous integral and differential modeling. The topics include Robinson infinitesimals, li

Tom J. T. Harper, Paul A. Thomas, Elizabeth Winstanley, Phil M. Young

We study the stability of new neutral and electrically charged four-dimensional black hole solutions of Einstein's equations with a positive cosmological constant and conformally coupled scalar field. The neutral black holes are always unstable. The charged black holes are also shown analytically to be unstable for the vast majority of the parameter spac

Ph. Boucaud, F. De Soto, A. Le Yaouanc, J. P. Leroy

We trace here instantons through the analysis of pure Yang-Mills gluon Green functions in the Landau gauge for a window of IR momenta (0.4 GeV $< k < 0.9$ GeV). We present lattice results that can be fitted only after substituting the BPST profile in the Instanton liquid model (ILM) by one based on the Diakonov and Petrov variational methods. This also leads

Clovis Hopman, Simon F. Portegies Zwart, Tal Alexander

The nature of ultraluminous X-ray sources (ULXs) is presently unknown. A possible explanation is that they are accreting intermediate mass black holes (IBHs) that are fed by Roche lobe overflow from a tidally captured stellar companion. We show that a star can circularize around an IBH without being destroyed by tidal heating (in contrast to the case of M_bh

C. A. Pastro

We present a process semantics for the purely additive fragment of linear logic in which formulas denote protocols and (equivalence classes of) proofs denote multi-channel concurrent processes. The polycategorical model induced by this process semantics is shown to be equivalent to the free polycategory based on the syntax (i.e., it is full and faithfully co

J. C. Lemm, J. Uhlig, A. Weiguny

The Feynman path integral representation of quantum theory is used in a non--parametric Bayesian approach to determine quantum potentials from measurements on a canonical ensemble. This representation allows to study explicitly the classical and semiclassical limits and provides a unified description in terms of functional integrals: the Feynman path integra

Aurelien Dantan, Michel Pinard

We show that a quasi-perfect quantum state transfer between an atomic ensemble and fields in an optical cavity can be achieved in Electromagnetically Induced Transparency (EIT). A squeezed vacuum field state can be mapped onto the long-lived atomic spin associated to the ground state sublevels of the Lambda-type atoms considered. The EIT on-resonance situati

Wolfgang Orthuber

We recommended consequent discrete combinatorial research in mathematical physics. Here we show an example how discretization of partial differential equations can be done and that quickly unexpected new findings can result from research in this up to now unexplored area. We transformed the vacuum Maxwell equations into finite-difference equations, provided

F. Zimmer, M. Fleischhauer

The advantages of light and matter-wave Sagnac interferometers -- large area on one hand and high rotational sensitivity per unit area on the other -- can be combined utilizing ultra-slow light in cold atomic gases. While a group-velocity reduction alone does not affect the Sagnac phase shift, the associated momentum transfer from light to atoms generates a

Sibasish Ghosh, Guruprasad Kar, Samir Kunkri, Anirban Roy

We give a proof of impossibility of probabilistic exact $1\to 2$ cloning of any three different states of a qubit. The simplicity of the proof is due to the use of a surprising result of remote state preparation [M.-Yong Ye, Y.-Sheng Zhang and G.-Can Guo, quant-ph/0307027 (2003)]. The result is extented to higher dimentional cases for special ensemble of sta

M. Hsieh, J. Kempe, S. Myrgren, K. B. Whaley

A single physical interaction might not be universal for quantum computation in general. It has been shown, however, that in some cases it can generate universal quantum computation over a subspace. For example, by encoding logical qubits into arrays of multiple physical qubits, a single isotropic or anisotropic exchange interaction can generate a universal

Alan Williams, Todd K. Leen, Patrick D. Roberts

Random walk methods are used to calculate the moments of negative image equilibrium distributions in synaptic weight dynamics governed by spike-timing dependent plasticity (STDP). The neural architecture of the model is based on the electrosensory lateral line lobe (ELL) of mormyrid electric fish, which forms a negative image of the reafferent signal from th

Dmitry Strekalov, Andrey B. Matsko, Nan Yu, Lute Maleki

We report on the experimental demonstration of light dragging effect due to atomic motion in a rubidium vapor cell. We found that the minimum group velocity is achieved for light red-shifted from the center of the atomic resonance, and that the value of this shift increases with decreasing group velocity, in agreement with the theoretical predictions by Koch

J. C. Berengut, V. A. Dzuba, V. V. Flambaum, M. G. Kozlov

We present an ab initio method of calculation of isotope shift in atoms with a few valence electrons, based on the configuration-interaction calculation of energy. The main motivation for developing the method comes from the need to analyze whether differences in isotope abundance in early universe can contribute to the observed anomalies in quasar absorptio

V. G. Nosov, A. M. Kamchatnov

A theory of nucleus-nucleus collisions has been developed for kinetic energies substantially in excess of the binding energy. The very high pressure produced in the compound system as a result of the fusion of the two colliding nuclei is the reason for the subsequent hydrodynamic expansion of the nuclear medium. The energy and angular distributions of the re

M. Frankel, V. Roytburd

Solutions of a 1-D free-interface problem modeling solid combustion front propagating in combustible mixture with periodically varying concentration of reactant exhibit classical phenomenon of mode locking. Numerical simulation shows a variety of locked periodic, quasi-periodic and chaotic solutions.

Eugene Bogomolny

The lectures are centered around three selected topics of quantum chaos: the Selberg trace formula, the two-point spectral correlation functions of Riemann zeta function zeros, and of the Laplace--Beltrami operator for the modular group. The lectures cover a wide range of quantum chaos applications and can serve as a non-formal introduction to mathematical m

N M J Woodhouse

The connections between Hitchin and Mason&#39;s twistor descriptions of the isomonodromy problem are explored.

J. Dittrich, V. I. Inozemtsev

Using the integral representation of the inverse of the logarithmic derivative of the elliptic theta function, the spectrum of the Lax matrix for the 1D system of particles interacting via inverse sinh-squared potential is shown to be given by the asymptotic Bethe ansatz in the thermodynamic limit.

Søren Fournais, Maria Hoffmann-Ostenhof, Thomas Hoffmann-Ostenhof, Thomas Østergaard Sørensen

We show that electronic wave functions Psi of atoms and molecules have a representation Psi=F*phi, where F is an explicit universal factor, locally Lipschitz, and independent of the eigenvalue and the solution Psi itself, and phi has locally bounded second derivatives. This representation turns out to be optimal as can already be demonstrated with the help o

Elliott H. Lieb, Michael Loss

We show that the Hamiltonian describing N nonrelativistic electrons with spin, interacting with the quantized radiation field and several fixed nuclei with total charge Z has a ground state when N <Z+1. The result holds for any value of the fine structure constant alpha and for any value of the ultraviolet cutoff Lambda on the radiation field. There is no in

A. N. Sergeev, A. P. Veselov

It is shown that the deformed Calogero-Moser-Sutherland (CMS) operators can be described as the restrictions on certain affine subvarieties (called generalised discriminants) of the usual CMS operators for infinite number of particles. The ideals of these varieties are shown to be generated by the Jack symmetric functions related to the Young diagrams with s

G. Gaeta, P. Morando

Let $M$ be smooth $n$-dimensional manifold, fibered over a $k$-dimensional submanifold $B$ as $π:M \to B$, and $\vartheta \in Λ^k (M)$; one can consider the functional on sections $ϕ$ of the bundle $π$ defined by $\int_D ϕ^* (\vartheta)$, with $D$ a domain in $B$. We show that for $k = n-2$ the variational principle based on this functional identifies a uniq

I. A. Taimanov

We describe two-dimensional potential Schrodinger and Dirac operators which are finite-gap at one energy level and have singular spectral curves. It appears that the singularities can be rather complicated. Such Dirac operators appear as the spectral curves of tori immersed into the three-space.

Victor Rotger

Let O be a maximal order in a totally indefinite quaternion algebra over a totally real number field. In this note we study the locus Q_O of quaternionic multiplication by O in the moduli space A_g of principally polarized abelian varieties of even dimension g with particular emphasis in the two-dimensional case. We describe Q_O as a union of Atkin-Lehner qu

Evgenia Soprunova

Gelfond and Khovanskii found a formula for the sum of the values of a Laurent polynomial over the zeros of a system of n Laurent polynomials in the algebraic n-torus. We expect that a similar formula holds in the case of exponential sums with real frequencies. Here we prove such a formula in dimension 1.

S. V. Ludkovsky

A non-Archimedean antiderivational line analog of the Cauchy-type line integration is defined and investigated over local fields. Classes of non-Archimedean holomorphic functions are defined and studied. Residues of functions are studied, Lorent series representations are described. Moreover, non-Archimedean antiderivational analogs of integral representatio

B. Plotkin, T. Plotkin

In this paper we study the notion of knowledge from the positions of universal algebra and algebraic logic. We consider first order knowledge which is based on first order logic. We define categories of knowledge and knowledge bases. These notions are defined for the fixed subject of knowledge. The key notion of informational equivalence of two knowledge bas

B. Plotkin

In the paper the main attention is paid to conditions on algebras from a given variety which provide coincidence of their algebraic geometries. The main part here play the notions mentioned in the title of the paper.

Aleksandar Ivić

This review article brings forth some recent results in the theory of the Riemann zeta-function $qzeta(s)$.

G. Labelle, C. Lamathe, P. Leroux

In this paper, we generalize 2-trees by replacing triangles by quadrilaterals, pentagons or $k$-sided polygons ($k$-gons), where $k\geq 3$ is fixed. This generalization, to $k$-gonal 2-trees, is natural and is closely related, in the planar case, to some specializations of the cell-growth problem. Our goal is the labelled and unlabelled enumeration of $k$-go

K. Leschke, F. Pedit, U. Pinkall

We characterize Willmore tori in the 4-sphere with nontrivial normal bundle as Twistor projections of elliptic curves in complex projective space or as inverted minimal tori (with planar ends) in Euclidean 4-space.

B. Plotkin

The aim of the paper is to discuss the relations between the three kinds of objects named in the title. In a sense, this is a survey of such relations; however, some new directions are also considered. This relates, especially, to sections 3, 4 and 5, where we consider the universal algebraic geometry. This geometry is parallel to universal algebra.

Hiroshi Goda, Andrei V. Pajitnov

The Morse-Novikov number MN(L) of a smooth link L in the three-dimensional sphere is by definition the minimal possible number of critical points of a regular circle-valued Morse function on the link complement (the term regular means that the Morse function must have nice behaviour in a tubular neighbourhood of L). Novikov homology provides lower bounds for

Lucia Caporaso

This paper surveys some applications of moduli theory to issues concerning the distribution of rational points on algebraic varieties. It will appear on the proceedings of the Fano Conference.

Marius Crainic, Rui Loja Fernandes

We show that various notions of integrability for Poisson brackets are all equivalent, and we give the precise obstructions to integrating Poisson manifolds. We describe the integration as a symplectic quotient, in the spirit of the Poisson sigma-model of Cattaneo and Felder. For regular Poisson manifolds we express the obstructions in terms of variations of

F. P. Boca, R. N. Gologan, A. Zaharescu

We prove some asymptotic formulae concerning the distribution of the index of Farey fractions of order Q as $Q\to \infty$.

Florin P. Boca, Radu N. Gologan, Alexandru Zaharescu

We remove a small disc from the flat two-dimensional torus and consider a point-like particle that starts moving from the center of the disc with linear trajectory. We provide asymptotic estimates for the moments of the first exit time, with respect to the velocity, when the radius of the disc tends to zero.

John H. Schwarz

The three string vertex for Type IIB superstrings in a maximally supersymmetric plane-wave background can be constructed in a light-cone gauge string field theory formalism. The detailed formula contains certain Neumann coefficients, which are functions of a momentum fraction y and a mass parameter μ. This paper reviews the derivation of useful explicit expr

Alexandr Yelnikov

In this paper the hamiltonian analysis of the pure Chern-Simons theory on the noncommutative plane is performed. We use the techniques of geometric quantization to show that the classical reduced phase space of the theory has nontrivial topology and that quantization of the symplectic structure on this space is possible only if the Chern-Simons coefficient i

Al. Zamolodchikov

An infinite set of operator-valued relations in Liouville field theory is established. These relations are enumerated by a pair of positive integers $(m,n)$, the first $(1,1)$ representative being the usual Liouville equation of motion. The relations are proven in the framework of conformal field theory on the basis of exact structure constants in the Liouvi

Vladimir V. Kassandrov

In the field theories with twistor structure particles can be identified with (spacially bounded) caustics of null geodesic congruences defined by the twistor field. As a realization, we consider the ``algebrodynamical&#39;&#39; approach based on the field equations which originate from noncommutative analysis (over the algebra of biquaternions) and lead to

Bruno Iochum, Thomas Schucker, Christoph Stephan

We classify all irreducible, almost commutative geometries whose spectral action is dynamically non-degenerate. Heavy use is made of Krajewski&#39;s diagrammatic language. The motivation for our definition of dynamical non-degeneracy stems from particle physics where the fermion masses are non-degenerate.

S. Balaska, K. Demmouche

We build the Z$_{3}$ invariants fusion rules associated to the (D$_{4}$,A$_{6}$) conformal algebra. This algebra is known to describe the tri-critical Potts model. The 4-pt correlation functions of critical fields are developed in the bootstrap approach, and in the other hand, they are written in term of integral representation of the conformal blocks. By co

I. Bakas

The renormalization group equations of two-dimensional sigma models describe geometric deformations of their target space when the world-sheet length changes scale from the ultra-violet to the infra-red. These equations, which are also known in the mathematics literature as Ricci flows, are analyzed for the particular case of two-dimensional target spaces, w

L. M. Slad

Qualitative characteristics and the rigorous definition of a concept of the double symmetry is given. We use some double symmetry for constructing a theory of fields not investigated before which transform as the proper Lorentz group representations decomposable into infinite direct sums of finite-dimentional irreducible representations. All variants of the

Ashok Chatterjee, P. Mitra

It is well known that a vector potential cannot be defined over the whole surface of a sphere around a magnetic monopole. A recent claim to the contrary is shown to have problems. It is explained however that a potential of the proposed type works if two patches are used instead of one. A general derivation of the Dirac quantization condition attempted with

Yoshiki Watanabe, Kenji Fukushima, Tetsuo Hatsuda

We discuss the possibility of the spontaneous symmetry breaking characterized by order parameters with higher dimensionful composite fields. By analyzing general Ginzburg-Landau potential for a complex scalar field ϕ=ϕ_1 + i ϕ_2 with O(2) symmetry, we demonstrate that a phase characterized by < ϕ_1^2 - ϕ_2^2 > \neq 0 with < ϕ_1 >=< ϕ_2 >=0 is realized in a c

Hyeong-Chan Kim, Jae Hyung Yee

We use the variational approximation with double Gaussian type trial wave-functional approximation, in which we use the square root of the dispersion of the zero-mode wave-function as an order parameter, to study the out of equilibrium quantum dynamics of time-dependent second order phase transitions in (3+1) dimensions. We study the time evolution of symmet

Frank Ferrari

Large N geometric transitions and the Dijkgraaf-Vafa conjecture suggest a deep relationship between the sum over planar diagrams and Calabi-Yau threefolds. We explore this correspondence in details, explaining how to construct the Calabi-Yau for a large class of M-matrix models, and how the geometry encodes the correlators. We engineer in particular two-matr

Zurab Berezhiani

We briefly review the concept of a parallel `mirror&#39; world which has the same particle physics as the observable world and couples to the latter by gravity and perhaps other very weak forces. The nucleosynthesis bounds demand that the mirror world should have a smaller temperature than the ordinary one. By this reason its evolution should substantially d

The Small x Collaboration, J. Andersen, S. Baranov, J. Collins

A second workshop on small x physics, within the Small x Collaboration, was held in Lund in June 2002 with the aim of over-viewing recent theoretical progress in this area and summarizing the experimental status. This paper is dedicated to the memory of Jan Kwiecinski, who died unexpectedly on August 29, 2003.

M. Beneke, A. P. Chapovsky, A. Signer, G. Zanderighi

Using the hierarchy of scales between the mass, $M$, and the width, $Γ$, of a heavy, unstable particle we construct an effective theory that allows calculations for resonant processes to be systematically expanded in powers of the coupling $α$ and $Γ/M$. We illustrate the method by computing the next-to-leading order line shape of a scalar resonance in an ab

W. Grimus, L. Lavoura

Quark flavor mixing may originate in the soft breaking of horizontal symmetries. Those symmetries, which in the simplest case are three family U(1) groups, are obeyed only by the dimension-4 Yukawa couplings and lead, when unbroken, to the absence of mixing. Their breaking may arise from the dimension-3 mass terms of SU(2)-singlet vector-like quarks. Those g

Eung Jin Chun, Dong-Won Jung, Sin Kyu Kang, Jong Dae Park

We study the correlation between the neutrino oscillation and the production/decay of the lightest supersymmetric particle(LSP) in the context of the minimal supergravity model(mSUGRA) without R-parity. We show how the neutrino masses and mixing which are consistent with the recent neutrino data can be obtained in this model, and describe how to probe the mo

Hideaki Iida, Makoto Oka, Hideo Suganuma

For the study of dynamical chiral-symmetry breaking (DCSB) in QCD, we investigate the Schwinger-Dyson (SD) formalism based on lattice QCD data. From the quenched lattice data for the quark propagator in the Landau gauge, we extract the SD kernel function K(p^2), which is the product of the quark-gluon vertex and the polarization factor in the gluon propagato

C. Munoz

We compute the neutralino-nucleon cross section in several supersymmetric scenarios, taking into account all kind of experimental and astrophysical constraints. In addition, the constraints that the absence of dangerous charge and colour breaking minima imposes on the parameter space are also considered. This computation is relevant for the theoretical analy

Daisuke Ida, Kin-ya Oda, Seong Chan Park

The hierarchy between the electroweak and Planck scales can be reduced when the extra dimensions are compactified with large volume or with warped geometry, resulting in the fundamental scale of the order of TeV. In such a scenario, one can experimentally study the physics above the Planck scale. We discuss black hole/ring production at future colliders.

Yurii V. Dumin

The data on a strongly-nonequilibrium superconducting phase transition in the multi-Josephson-junction loop (MJJL), which represents a close analog of one-dimensional Friedmann-Robertson-Walker cosmological model, are used to refine a concentration of topological defects after the phase transitions of Higgs fields in the early Universe. The thermal correlati

Saumen Datta, Frithjof Karsch, Peter Petreczky, Ines Wetzorke

We present a study of charmonia in hot gluonic plasma, for temperatures upto three times the deconfinement transition temperature Tc. q \bar{q} systems with quark masses close to the charm mass and different spin-parity quantum numbers were studied on very fine isotropic lattices. The analysis of temporal correlators, and spectral functions constructed from

Martin Bojowald, Kevin Vandersloot

For many years, the most active area of quantum cosmology has been the issue of choosing boundary conditions for the wave function of a universe. Recently, loop quantum cosmology, which is obtained from loop quantum gravity, has shed new light on this question. In this case, boundary conditions are not chosen by hand with some particular physical intuition i

D. B. Papadopoulos

The equations which determine the response of a spinning charged particle moving in a uniform magnetic field to an incident gravitational wave are derived in the linearized approximation to general relativity. We verify that 1) the components of the 4-momentum, 4-velocity and the components of the spinning tensor, both electric and magnetic moments, exhibit

Krzysztof C. Kiwiel

We show that several versions of Floyd and Rivest&#39;s algorithm Select for finding the $k$th smallest of $n$ elements require at most $n+\min\{k,n-k\}+o(n)$ comparisons on average and with high probability. This rectifies the analysis of Floyd and Rivest, and extends it to the case of nondistinct elements. Our computational results confirm that Select may

Krzysztof C. Kiwiel

We introduce several modifications of the partitioning schemes used in Hoare&#39;s quicksort and quickselect algorithms, including ternary schemes which identify keys less or greater than the pivot. We give estimates for the numbers of swaps made by each scheme. Our computational experiments indicate that ternary schemes allow quickselect to identify all key

C. Reichhardt, C. J. Olson Reichhardt, M. B. Hastings

We investigate the dynamical motion of particles on a two-dimensional symmetric periodic substrate in the presence of both a dc drive along a symmetry direction of the periodic substrate and an additional circular ac drive. For large enough ac drives, the particle orbit encircles one or more potential maxima of the periodic substrate. In this case, when an a

J. E. Hirsch

We predict the existence of large electric fields near the surface of superconducting bodies of ellipsoidal shape of dimensions comparable to the penetration depth. The electric field is quadrupolar in nature with significant corrections from higher order multipoles. Prolate (oblate) superconducting ellipsoids are predicted to exhibit fields consistent with

T. Senthil, Leon Balents, Subir Sachdev, Ashvin Vishwanath

We present the critical theory of a number of zero temperature phase transitions of quantum antiferromagnets and interacting boson systems in two dimensions. The most important example is the transition of the S = 1/2 square lattice antiferromagnet between the Neel state (which breaks spin rotation invariance) and the paramagnetic valence bond solid (which p

Sandro Stringari

The frequencies of the collective oscillations of a harmonically trapped Fermi gas interacting with large scattering lengths are calculated at zero temperature using hydrodynamic theory. Different regimes are considered, including the molecular Bose-Einstein condensate and the unitarity limit for collisions. We show that the frequency of the radial compressi

M. R. Trunin, Yu. A. Nefyodov, A. F. Shevchun

The in-plane and out-of-plane surface impedance and microwave conductivity components of one and the same YBa_2Cu_3O_{7-x} (0.07\le x\le 0.47) single crystal are determined in the wide ranges of temperature T and carrier concentration p in CuO_2 planes. The following features of the superfluid density n_s(T,p)\proptoλ_{ab}^{-2}(T,p) are observed at T<Tc/2 an

Rene Meyer, Hermann Kohlstedt

The operation of a novel nonvolatile memory device based on a conductive ferroelectric/non-ferroelectric thin film multilayer stack is simulated numerically. The simulation involves the self-consistent steady state solution of Poisson&#39;s equation and the transport equation for electrons assuming a Drift-Diffusion transport mechanism. Special emphasis is p

C. A. Dartora, G. G. Cabrera

In this paper we analyze different contributions to the magnetoresistance of magnetic tunneling junctions at low voltages. A substantial fraction of the resistance drop with voltage can be ascribed to variations of the density of states and the barrier transmission with the bias. However, we found that the anomaly observed at zero bias and the magnetoresista

D. A. Drabold, P. Biswas, D. Tafen, R. Atta-Fynn

In this paper, we review some recent work on amorphous materials using current &#34;first principles&#34; electronic structure/molecular dynamics techniques. The main theme of the paper is to emphasize new directions in the use of such ab initio methods. Some of these, being quite new, need development, but we believe have promise for solving new and importa

M. Ausloos, K. Ivanova, Z. Siwy

The process of ion transport through a locust potassium channel is described by means of the Fokker-Planck equation (FPE). The deterministic and stochastic components of the process of switching between various conducting states of the channel are expressed by two coefficients, $D^{(1)}$ and $D^{(2)}$, a drift and a diffusion coefficient, respectively. The F

Yu. A. Kolesnichenko, A. N. Omelyanchouk, S. N. Shevchenko

A stationary Josephson effect in the ballistic contact of two d-wave superconductors with different axes orientation and with tangential transport current in the banks is considered theoretically. We study the influence of the transport current on the current-phase dependence for the Josephson and tangential currents at the interface. It is demonstrated that

Stefano Fabris, Stefano de Gironcoli, Stefano Baroni

The electronic and structural properties of pure and defective cerium oxide are investigated using a unified LDA+U approach which allows to treat the different valence states of Ce occurring for different stoichiometries on a same ground, without any {\it a priori} assumptions on the defect chemistry. The method correctly predicts the atomistic and electroni

Takahiro Yamamoto, Satoshi Watanabe, Kazuyuki Watanabe

The universal features of quantized thermal conductance of carbon nanotubes (CNTs) are revealed through theoretical analysis based on the Landauer theory of heat transport. The phonon-derived thermal conductance of semiconducting CNTs exhibits a universal quantization in the low temperature limit, independent of the radius or atomic geometry. The temperature

H. Hong, Hyunggyu Park, M. Y. Choi

We study collective behavior of locally-coupled limit-cycle oscillators with scattered intrinsic frequencies on $d$-dimensional lattices. A linear analysis shows that the system should be always desynchronized up to $d=4$. On the other hand, numerical investigation for $d= 5$ and 6 reveals the emergence of the synchronized (ordered) phase via a continuous tr

Akihiro Kasahara, Hiizu Nakanishi

We study the static structure of piles made of polydisperse disks in the rigid limit with and without friction using molecular dynamic simulations for various elasticities of the disks and pile preparation procedures. The coordination numbers are calculated to examine the isostaticity of the pile structure. For the frictionless pile, it is demonstrated that

S. -W. Han, J. S. Gardner, C. H. Booth

Although materials that exhibit nearest-neighbor-only antiferromagnetic interactions and geometrical frustration theoretically should not magnetically order in the absence of disorder, few such systems have been observed experimentally. One such system appears to be the pyrochlore Tb2Ti2O7. However, previous structural studies indicated that Tb2Ti2O7 is an i