January 2003 arXiv papers — page 22

Frank Froemel, Horst Lenske, Ulrich Mosel

The density and temperature dependence of nucleonic single particle spectral function in symmetric nuclear matter at finite temperatures and densities beyond normal nuclear matter density is investigated in a model emphasizing short-range correlations and phase space aspects. A simple but self-consistent approach based on quantum transport theory is used. In

C. Godreche

The dynamics of a class of zero-range processes exhibiting a condensation transition in the stationary state is studied. The system evolves in time starting from a random disordered initial condition. The analytical study of the large-time behaviour of the system in its mean-field geometry provides a guide for the numerical study of the one-dimensional versi

Anthony Aguirre, Steven Gratton

We develop our recent suggestion that inflation may be made past eternal, so that there is no initial cosmological singularity or "beginning of time". Inflation with multiple vacua generically approaches a steady-state statistical distribution of regions at these vacua, and our model follows directly from making this distribution hold at all times. W

N. Jarosik, C. L. Bennett, M. Halpern, G. Hinshaw

The Microwave Anisotropy Probe (MAP) satellite, launched June 30, 2001, will produce full sky maps of the cosmic microwave background radiation in 5 frequency bands spanning 20 - 106 GHz. MAP contains 20 differential radiometers built with High Electron Mobility Transistor (HEMT) amplifiers with passively cooled input stages. The design and test techniques u

Michel Bauer, Denis Bernard

We present an explicit relation between representations of the Virasoro algebra and polynomial martingales in stochastic Loewner evolutions (SLE). We show that the Virasoro algebra is the spectrum generating algebra of SLE martingales. This is based on a new representation of the Virasoro algebra, inspired by the Borel-Weil construction, acting on functions

Sudhakar Panda, Dmitri Sorokin

We propose a generic supersymmetric and kappa-invariant action for describing coincident D0-branes with non-abelian matter fields on their worldline. The action is shown to be in agreement with the Matrix Theory limit of the ND0-brane effective action.

R. Hänninen, E. V. Thuneberg

The standard treatment of impurities in metals assumes a homogeneous distribution of impurities. In this paper we study distributions that are inhomogeneous. We discuss in detail the "isotropic inhomogeneous scattering model" which takes into account the spatially varying scattering on the scale of the superfluid coherence length. On a large scale th

M. Ansorg, A. Kleinwächter, R. Meinel

We give a detailed description of the recently developed multi-domain spectral method for constructing highly accurate general-relativistic models of rapidly rotating stars. For both "ordinary" and "critical" configurations, it is exhibited by means of representative examples, how the accuracy improves as the order of the approximation increa

Alexander Tarasov, Olga Voskresenskaya

The quantum mechanical consideration of a passage of relativistic elementary atoms (EA) through a target matter is given. A set of quantum-kinetic equations for the density matrix elements describing their internal state evolution at EA rest frame is derived.

H. I. Elim, W. Ji, A. H. Yuwono, J. M. Xue

With 780-nm, 250-fs laser pulses, ultrafast optical nonlinearity has been observed in a series of thin films containing PMMA-TiO2 nanocomposites, which are synthesized by a simple technique of in-situ sol-gel/polymerization. The best figures of merit are found in one of the films prepared with a 60% weight percentage of titanium isopropoxide. TEM shows the p

D. Blaschke, M. K. Volkov, V. L. Yudichev

The phase diagram for quark matter is investigated within a simple Nambu-Jona-Lasinio model without vector correlations. It is found that the phase structure in the temperature-density plane depends sensitively on the parametrization of the model. We present two schemes of parametrization of the model where within the first one a first order phase transition

A. A. Andrianov, A. V. Sokolov

We study the Nonlinear (Polynomial, N-fold,...) Supersymmetry algebra in one-dimensional QM. Its structure is determined by the type of conjugation operation (Hermitian conjugation or transposition) and described with the help of the Super-Hamiltonian projection on the zero-mode subspace of a supercharge. We show that the SUSY algebra with transposition symm

E. -M. Ilgenfritz, B. V. Martemyanov, M. Müller-Preussker, S. Shcheredin

We report the observation of calorons with nontrivial holonomy and fractional topological charge objects in cooled lattice samples derived from SU(2) equilibrium ensembles at $T<T_c$.

A. Giacomini, N. Pinamonti

In this article we compute the black hole entropy by finding a classical central charge of the Virasoro algebra of a Liouville theory using the Cardy formula. This is done by performing a dimensional reduction of the Einstein Hilbert action with the ansatz of spherical symmetry and writing the metric in conformally flat form. We obtain two coupled field equa

S. V. Chekanov, V. L. Morgunov

A method of reconstruction of the top quarks produced in the process E+E- -> t\bar{t} -> 6 jets at a Linear Collider (LC) is proposed. The approach does not involve a kinematic fit, as well as assumptions on the invariant masses of the dijets originating from the decays of W bosons and, therefore, the method is expected to be less sensitive to theoretical an

S. Schippers, S. Boehm, A. Mueller, G. Gwinner

The basic approach for measuring electron-ion recombination rate coefficients in merged-beams electron-ion collision experiments at heavy-ion storage rings is outlined. As an example experimental results for the low temperature recombination of C IV ions are compared with the recommended theoretical rate coefficient by Mazzotta et al. The latter deviates by

Sebastian Risau-Gusman, Alexandre S. Martinez, Osame Kinouchi

A random walk is performed over a disordered media composed of $N$ sites random and uniformly distributed inside a $d$-dimensional hypercube. The walker cannot remain in the same site and hops to one of its $n$ neighboring sites with a transition probability that depends on the distance $D$ between sites according to a cost function $E(D)$. The stochasticity

Debendranath Sahoo

Observables of quantum or classical mechanics form algebras called quantum or classical Hamilton algebras respectively (Grgin E and Petersen A (1974) {\it J Math Phys} {\bf 15} 764\cite{grginpetersen}, Sahoo D (1977) {\it Pramana} {\bf 8} 545\cite{sahoo}). We show that the tensor-product of two quantum Hamilton algebras, each characterized by a different Pla

Antonio Scala, Chantal Valeriani, Francesco Sciortino, Piero Tartaglia

We study the out-of-equilibrium dynamics following a temperature-jump in a model for a strong liquid, BKS-silica, and compare it with the well known case of fragile liquids. We calculate the fluctuation-dissipation relation, from which it is possible to estimate an effective temperature $T_{eff}$ associated to the slow out-of-equilibrium structural degrees o

M. I. Adamovich, V. Bradnova, M. M. Chernyavsky, V. A. Dronov

The use of emulsions for studying nuclear clustering in light nucleus fragmentation processes at energies higher than 1A GeV is discussed. New results on the topologies of relativistic Li-7 and B-10 nucleus fragmentation in peripheral interactions are given. A program of research of the cluster structure in stable and radioactive nuclei is suggested.

D. Grumiller, W. Kummer, D. V. Vassilevich

Some simple observations concerning certain kappa-deformations in the framework of 2D dilaton gravity formulated as Poisson-sigma models are discussed, and the question of (non-)triviality is addressed.

Holger Baumgardt, Douglas C. Heggie, Piet Hut, Junichiro Makino

This paper considers the phenomenon of deep core collapse in collisional stellar systems, with stars of equal mass. The collapse takes place on some multiple, $ξ^{-1}$, of the central relaxation time, and produces a density profile in which $ρ\propto r^{-α}$, where $α$ is a constant. The parameters $α$ and $ξ$ have usually been determined from simplified mod

Kentaro Miuchi, Hidetoshi Kubo, Tsutomu Nagayoshi, Atsuhiko Ochi

Micro-TPC, a time projection chamber(TPC) with micro pixel chamber($μ$-PIC) readout was developed for the detection of the three-dimensional fine(sub-m illimeter) tracks of charged particles. We developed a two-dimensional position sensitive gaseous detector, or the $μ$-PIC, with the detection area of 10$\times$10 cm${}^{2}$ and 65536 anode electrodes of 400

C. Stock, R. J. Birgeneau, S. Wakimoto, J. S. Gardner

The relaxors Pb(Zn$_{1/3}$Nb$_{2/3}$)O$_{3}$ (PZN) and Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$ (PMN) have very similar properties based on the dielectric response around the critical temperature $T_{c}$ (defined by the structural transition under the application of an electric field). It has been widely believed that these materials are quite different below $T_{c}$

Todd A. Brun

Decoherence is the process by which quantum systems interact and become correlated with their external environments; quantum trajectories are a powerful technique by which decohering systems can be resolved into stochastic evolutions, conditioned on different possible ``measurements&#39;&#39; of the environment. By calling on recently-developed tools from qu

Igor Bjelakovic, Arleta Szkola

We extend the data compression theorem to the case of ergodic quantum information sources. Moreover, we provide an asymptotically optimal compression scheme which is based on the concept of high probability subspaces. The rate of this compression scheme is equal to the von Neumann entropy rate.

Daxiu Wei, Jun Luo, Xiaodong Yang, Xianping Sun

We propose a scalable method on the basis of nth-order coupling operators to construct f-dependent phase transformations in the n-qubit modified Deutsch-Jozsa (D-J) quantum algorithm. The novel n-qubit entangling transformations are easily implemented via J-couplings between neighboring spins. The seven-qubit modified D-J quantum algorithm and seventh-order

S. A. Zaitsev

The Marchenko phase-equivalent transformation of the Schrödinger equation for two coupled channels is discussed. The combination of the Marchenko transformations valid in the Bargmann potential case is suggested.

Chiu Fan Lee, Neil F. Johnson

It is always possible to decide, with one-sided error, whether two quantum states are the same under a specific unitary transformation. However we show here that it is {\em impossible} to do so if the transformation is anti-linear and non-singular. This result implies that unitary and anti-unitary operations exist on an unequal footing in quantum information

Gabriel Ramos-Fernandez, Jose Luis Mateos, Octavio Miramontes, Germinal Cocho

Scale invariant patterns have been found in different biological systems, in many cases resembling what physicists have found in other nonbiological systems. Here we describe the foraging patterns of free-ranging spider monkeys (Ateles geoffroyi) in the forest of the Yucatan Peninsula, Mexico and find that these patterns resemble what physicists know as Levy

Keang-Po Ho

The probability density function of Kerr effect phase noise, often called the Gordon-Mollenauer effect, is derived analytically. The Kerr effect phase noise can be accurately modeled as the summation of a Gaussian random variable and a noncentral chi-square random variable with two degrees of freedom. Using the received intensity to correct for the phase noi

T. Bartsch

The Kustaanheimo-Stiefel (KS) transformation maps the non-linear and singular equations of motion of the three-dimensional Kepler problem to the linear and regular equations of a four-dimensional harmonic oscillator. It is used extensively in studies of the perturbed Kepler problem in celestial mechanics and atomic physics. In contrast to the conventional ma

Peter C. Tandy

We summarize recent progress in soft QCD modeling based on the set of Dyson--Schwinger equations truncated to ladder-rainbow level. This covariant approach to hadron physics accommodates quark confinement and implements the QCD one-loop renormalization group behavior. We compare the dressed quark propagator, pseudoscalar and vector meson masses as a function

Bao-An Li

Central collisions induced by high energy radioactive beams can be used as a novel means to obtain crucial information about the high density ({\rm HD}) behaviour of nuclear symmetry energy. This information is critical for understanding several key issues in astrophysics. Within an isospin-dependent hadronic transport model using phenomenological equations

M. Benayoun, P. David, L. DelBuono, Ph. Leruste

We analyze a pion form factor formulation which fulfills the Analyticity requirement within the Hidden Local Symmetry (HLS) Model. We show that it implies an $s$--dependent dressing of the $ρ-γ$ VMD coupling and an account of several coupled channels. The corresponding function $F_π(s)$ provides nice fits of the pion form factor data from $s=-0.25$ to $s=1$

Sasa Ceci, Alfred Svarc

Total cross section for pp->pp eta process has been calculated in meson exchange model. Eta production T-matrices are from our PWA. Initial and final state interactions are disregarded for the moment, due to large uncertainties. Preliminary results do not show rho meson exchange dominance.

Caiwan Shen, Y. S. Chen, E. G. Zhao

The three dimensional Total Routhian Surface (TRS) calculations are carried out for 64 nuclei between $70\leq A\leq 90$ to find triaxial superdeformed nuclei. Total of 12 nuclei were predicted to have triaxial superdeformation in which the neutron rotational energy plays a key role and the neutron shell energy plays additional role in the formation of triaxi

N. Kaiser

We calculate the imaginary part of the induced pseudoscalar form factor of the nucleon $G_P(t)$ in the framework of two-loop heavy baryon chiral perturbation theory. The effect of the calculated three-pion continuum on the pseudoscalar constant $g_P = (m_μ/2M) G_P(t=-0.877m_μ^2)$ measurable in ordinary muon capture $μ^-p\to ν_μn$ turns out to be negligibly s

M. Di Toro, V. Baran, M. Colonna, A. Drago

We present several possibilities offered by the reaction dynamics of dissipative heavy ion collisions to study in detail the symmetry term of the nuclear equation of state, $EOS$. In particular we discuss isospin effects on the nuclear liquid-gas phase transition, {\it Isospin Distillation}, and on collective flows. We stress the importance of a microscopic

David W. Hertzog

The muon anomalous magnetic moment measurement, when compared with theory, can be used to test many extensions to the standard model. The most recent measurement made by the Brookhaven E821 Collaboration reduces the uncertainty on the world average of a_mu to 0.7 ppm, comparable in precision to theory. This paper describes the experiment and the current theo

C. Verhoeven, M. Musette, R. Conte

We integrate with hyperelliptic functions a two-particle Hamiltonian with quartic potential and additionnal linear and nonpolynomial terms in the Liouville integrable cases 1:6:1 and 1:6:8.

Kathleen Cotrill-Shepherd, Mark Naber

A generalization of exterior calculus is considered by allowing the partial derivatives in the exterior derivative to assume fractional orders. That is, a fractional exterior derivative is defined. This is found to generate new vector spaces of finite and infinite dimension, fractional differential form spaces. The definitions of closed and exact forms are e

Ricardo Weder

In this paper we prove the $L^{p}-L^{\acute{p}}$ estimate for the Schrödinger equation on the half-line and with homogeneous Dirichlet boundary condition at the origin.

Davide Guzzetti

We study the singularity of the Kontsevich&#39;s solution of the WDVV equations of associativity. We prove that it corresponds to a singularity in the change of two coordinates systems of the Frobenius manifold given by the quantum cohomology of $CP^2$.

V. E. Markushin, R. Rosenfelder, A. W. Schreiber

We discuss the function wt(x) defined via the implicit equation wt(x)*tan[wt(x)]=x which appears in certain quantum mechanical and field theoretic applications. We investigate its analytic structure, develop series expansions for both small and large x, and provide various techniques for its numerical evaluation in the complex plane.

Michael P. Friedlander, Michael A Saunders

For optimization problems with nonlinear constraints, linearly constrained Lagrangian (LCL) methods sequentially minimize a Lagrangian function subject to linearized constraints. These methods converge rapidly near a solution but may not be reliable from arbitrary starting points. The well known example \MINOS\ has proven effective on many large problems. It

D. Iglesias-Ponte, J. C. Marrero

Locally conformal symplectic (l.c.s.) groupoids are introduced as a generalization of symplectic groupoids. We obtain some examples and we prove that l.c.s. groupoids are examples of Jacobi groupoids in the sense of \cite{IM}. Finally, we describe the Lie algebroid of a l.c.s. groupoid.

Dmitry S. Kalyuzhnyi-Verbovetzkii

The class of operator-valued functions which are homogeneous of degree one, holomorphic in the open right polyhalfplane, have positive semidefinite real parts there and take selfadjoint operator values at real points, and its subclass consisting of functions representable in the form of Schur complement of a block of a linear pencil of operators with positiv

Vesselin Drensky, Lakhdar Hammoudi

We construct new examples of non-nil algebras with any number of generators, which are direct sums of two locally nilpotent subalgebras. As all previously known examples, our examples are contracted semigroup algebras and the underlying semigroups are unions of locally nilpotent subsemigroups. In our constructions we make more transparent than in the past th

Jan H. Bruinier

We show (under some hypothesis in small dimensions) that the analytic degree of the divisor of a modular form on the orthogonal group O(2,p) is determined by its weight. Moreover, we prove that certain integrals, occurring in Arakelov intersection theory, associated with modular forms on O(2,p) converge.

Michael Joswig, G&#34;unter M. Ziegler

This paper presents a new algorithm for the convex hull problem, which is based on a reduction to a combinatorial decision problem POLYTOPE-COMPLETENESS-COMBINATORIAL, which in turn can be solved by a simplicial homology computation. Like other convex hull algorithms, our algorithm is polynomial (in the size of input plus output) for simplicial or simple inp

Francesca Antoci

Applying a theorem due to Belopol&#39;ski and Birman, we show that the Laplace-Beltrami operator on 1-forms on ${\bf R}^n$ endowed with an asymptotically Euclidean metric has absolutely continuous spectrum equal to $[0, +\infty)$.

Huaiyu Jian, Xingwang Xu

It is proved that the vortices are attracted by impurities or inhomogeities in the superconducting materials. The strong H^1-convergence for the corresponding Ginzburg-Landau system is also proved.

Huaiyu Jian

A heat flow method is used to deform convex hypersurfaces in a ring domain to a hypersurface whose harmonic mean curvature is a prescribed function.

Shinobu Hosono, Bong H. Lian, Keiji Oguiso, Shing-Tung Yau

Narain lattices are unimodular lattices {\it in} $\R^{r,s}$, subject to certain natural equivalence relation and rationality condition. The problem of describing and counting these rational equivalence classes of Narain lattices in $\R^{2,2}$ has led to an interesting connection to binary forms and their Gauss products, as shown in [HLOYII]. As a sequel, in

Bertrand Toen, Gabriele Vezzosi

These are expanded notes from some talks given during the fall 2002, about ``homotopical algebraic geometry&#39;&#39; (HAG) with special emphasis on its applications to ``derived algebraic geometry&#39;&#39; (DAG) and ``derived deformation theory&#39;&#39;. We use the general framework developed in Toen, Vezzosi, ``Homotopical Algebraic Geometry I: Topos the

Stefan Wewers

We study Galois covers of the projective line branched at three points with bad reduction to characteristic p, under the condition that p exactly divides the order of the Galois group. As an application of our results, we prove that the field of moduli of such a cover is at most tamely ramified at p.

J. V. Chipalkatti, A. V. Geramita

The set of all artin level quotients of a polynomial algebra in n variables having specified socle degree and type admits a parameter space. It is in fact a quasiprojective variety, naturally embedded in a Grassmannian. We give a geometric description of this variety in the case of two variables. Then we give some sufficient conditions for the parameter vari

Peter Kaste, Ruben Minasian, Michela Petrini, Alessandro Tomasiello

We discuss how in the presence of a nontrivial RR two-form field strength and nontrivial dilaton the conditions of preserving supersymmetry on six-dimensional manifolds lead to generalized monopole and Killing spinor equations. We show that the manifold is Kähler in the ten-dimensional string frame if F_0^{(1,1)}=0. We then determine explicitly the intrinsic

Philip A. DeBoer, Moshe Rozali

We calculate, using holographic duality, the thermal two-point function in finite temperature little string theory. The analysis of those correlators reveals possible instabilities of the thermal ensemble, as in previous discussions of the thermodynamics of little string theory. We comment on the dependence of the instability on the spatial volume of the sys

Akira Kato, Doug Singleton

The idea of gauging (i.e. making local) symmetries of a physical system is a central feature of many modern field theories. Usually, one starts with a Lagrangian for some scalar or spinor matter fields, with the Lagrangian being invariant under a global phase symmetry transformation of the matter fields. Making this global phase symmetry local results in the

David A. Kosower

I present a class of functions unifying all singular limits for the emission of soft or collinear gluons in gauge-theory amplitudes at any order in perturbation theory. Each function is a generalization of the antenna functions of ref. [1]. The helicity-summed interferences these functions are thereby also generalizations to higher orders of the Catani--Seym

R. B. Nevzorov, K. A. Ter-Martirosyan, M. A. Trusov

The considerable part of the parameter space in the MSSM corresponding to the infrared quasi fixed point scenario is excluded by LEP II bounds on the lightest Higgs boson mass. In the NMSSM the mass of the lightest Higgs boson reaches its maximum value in the strong Yukawa coupling limit when Yukawa couplings are essentially larger than gauge ones at the Gra

Fritz W. Bopp, Johannes Ranft

Charge fluctuations observed in early fixed-target proton-proton experiments are consistent with string models. In central heavy ion events the picture can change in two ways: strings can interact and find new ways to hadronize or they can be effectively inactivated to lose their dynamical role as ordering mechanism. Widely different charge fluctuations can

M. E. Gomez, G. Lazarides, C. Pallis

Although recent data on the muon anomalous magnetic moment strongly disfavor the constrained minimal supersymmetric standard model with mu<0, they cannot exclude it because of theoretical ambiguities. We consider this model supplemented by a Yukawa quasi-unification condition which allows an acceptable b-quark mass. We find that the cosmological upper bound

Xin-zhou Li, Xiang-hua Zhai

We show two analytical solutions of the tachyon inflation for which the spectrum of curvature (density) perturbations can be calculated exactly to linear order, ignoring both gravity and the self-interactions of the tachyon field . The main feature of these solutions is that the spectral indices are independent with scale.

Marco Battaglia, Magali Gruwe

The determination of the smuon mass at the CLIC multi-TeV e+e- linear collider has been studied for two CMSSM benchmarks. Results are given for both the analysis of the muon energy spectrum and the threshold scan method. The effects of detector resolution, beam-beam interactions and accelerator- induced backgrounds are discussed. The energy spectrum techniqu

M. N. Chernodub, E. -M. Ilgenfritz, A. Schiller

We report on a lattice study of the gauge boson propagator of 3D compact QED in Landau gauge at zero and finite temperature. Non-perturbative effects are reflected by the generation of a mass m and by an anomalous dimension alpha. These effects can be attributed to monopoles and are absent in the propagator of the regular part of the gauge field.

S. Stickan

We discuss modifications of hadron properties in the heat bath extracted from Euclidian correlation functions and spectral functions r econstructed with the Maximum Entropy Method. To investigate the cut-off dependencies we perform simulation on various lattice sizes and present the result of an analytic calculation of the mesonic spectral functions in the i

M. Incurvati, F. Terranova

The experimental problem of the calibration of magnetic field in large iron detectors is discussed. Emphasis is laid on techniques based on ballistic measurements as the ones employed by MINOS or OPERA.In particular, we provide analytical formulas to model the behavior of the apparatus in the transient regime, keeping into account eddy current effects and th

The OPAL collaboration, G. Abbiendi

Di-jet producion is studied in collisions of quasi-real photons at e+e- centre- of-mass energies sqrt(s)ee from 189 to 209 GeV at LEP. The data were collected with the OPAL detector. Jets are reconstructed using an inclusive k_t clustering algorithm for all cross-section measurements presented. A cone jet algorithm is used in addition to study the different

the BABAR Collaboration, B. Aubert

We report a measurement of the rate for $B \to η&#39; X_s$ transitions where the $η&#39;$ meson has center-of-mass momentum in the range 2.0 to 2.7\gevc and $X_s$ represents a system comprising a kaon and up to four pions. Our study is based on 22.2 million $B\bar{B}$ pairs collected at the $Υ(4S)$ with the BABAR detector at the Stanford Linear Accelerator C

M. Sharif, Sehar Aziz

The spherically symmetric static spacetimes are classified according to their matter collineations. These are studied when the energy-momentum tensor is degenerate and also when it is non-degenerate. We have found a case where the energy-momentum tensor is degenerate but the group of matter collineations is finite. For the non-degenerate case, we obtain eith

Luca Lusanna, Massimo Pauri

(Abridged Abstract) This paper deals with a number of technical achievements that are instrumental for a dis-solution of the so-called {\it Hole Argument} in general relativity. The work is carried through in metric gravity for the class of Christoudoulou-Klainermann space-times, in which the temporal evolution is ruled by the {\it weak} ADM energy. The main

O. B. Karpov

The expansion of the closed two-component universe has been considered. The potential barrier of the expansion has been investigated and its overcoming condition has been obtained. The restrictions on the Friedmann integrals, cosmological constant and density parameters have been analyzed. The phase-space has been considered and the phase curves of eternally

George E. A. Matsas

After a brief review of the historical development and CLASSICAL properties of the BLACK HOLES, we discuss how our present knowledge of some of their QUANTUM properties shed light on the very concept of ELEMENTARY PARTICLE. As an illustration, we discuss in this context the decay of accelerated protons, which may be also relevant to astrophysics.

Nathalie Deruelle

We review here how Newton&#39;s law can be approximately recovered in the simple, &#34;paradigmatic&#34;, case of a flat $Z_2$-symmetric brane in a 5-D anti-de Sitter bulk. We then comment on the difficulties encountered so far in extending this analysis to cosmological perturbations on a Robertson-Walker brane.

Nathalie Deruelle

Since the Randall-Sundrum 1999 papers, braneworlds have been a favourite playground to test string inspired cosmological models. The subject has developped into two main directions : elaborating more complex models in order to strenghten the connection with string theories, and trying to confront them with observations, in particular the Cosmic Microwave Bac

N. Chernov, J. L. Lebowitz, Ya. Sinai

We study a dynamical system consisting of a massive piston in a cubical container of large size $L$ filled with an ideal gas. The piston has mass $M\sim L^2$ and undergoes elastic collisions with $N\sim L^3$ non-interacting gas particles of mass $m=1$. We find that, under suitable initial conditions, there is, in the limit $L \to \infty$, a scaling regime wi

Ruslan L. Davidchack, Brian B. Laird

Extending to continuous potentials a cleaving wall molecular-dynamics simulation method recently developed for the hard-sphere system [Phys.Rev.Lett 85, 4751 (2000)], we calculate the crystal-melt interfacial free energies, $γ$, for a Lennard-Jones system as functions of both crystal orientation and temperature. At the triple point, T* = 0.617, the results a

A. Simoni, F. Ferlaino, G. Roati, G. Modugno

We predict the presence of several magnetic Feshbach resonances in selected Zeeman sublevels of the isotopic pairs K(40)-Rb(87) and K(41)-Rb(87) at magnetic fields up to 1000 G. Positions and widths are determined combining a new measurement of the K(40)-Rb(87) inelastic cross section with recent experimental results on both isotopes. The possibility of driv

Giorgio Parisi

In these lectures I will review the approach to glasses based on the replica formalism. Many of the physical ideas are very similar to those of older approaches. The replica approach has the advantage of describing in an unified setting both the behaviour near the dynamic transition (mode coupling transition) and near the equilibrium transition (Kauzman tran

Dexin Zhong, Roan Dawkins, Daniel ben-Avraham

We present results from computer simulations for diffusion-limited $n$-species annihilation, $A_i+A_j\to0$ $(i,j=1,2,...,n;i\neq j)$, on the line, for lattices of up to $2^{28}$ sites, and where the process proceeds to completion (no further reactions possible), involving up to $10^{15}$ time steps. These enormous simulations are made possible by the renorma

Nikolai Brilliantov, Thorsten Poeschel

The hydrodynamics of granular gases of viscoelastic particles, whose collision is described by an impact-velocity dependent coefficient of restitution, is developed using a modified Chapman-Enskog approach. We derive the hydrodynamic equations and the according transport coefficients with the assumption that the shape of the velocity distribution function fo

Dafang Zheng, Steffen Trimper, Bo Zheng, P. M. Hui

We propose and study a model of weighted scale-free networks incorporating a stochastic scheme for weight assignments to the links, taking into account both the popularity and fitness of a node. As the network grows the weights of links are driven either by the connectivity with probability $p$ or by the fitness with probability $1-p$. Results of numerical s

F. de los Santos, M. Tasinkevych, J. M. Tavares, P. I. C. Teixeira

We report a Monte Carlo simulation of deposition of magnetic particles on a one-dimensional substrate. Incoming particles interact with those that are already part of the deposit via a dipole-dipole potential. The strength of the dipolar interaction is controlled by an effective temperature $T^*$, the case of pure diffusion-limited deposition being recovered

Marian Boguna, Romualdo Pastor-Satorras, Alessandro Vespignani

We review the behavior of epidemic spreading on complex networks in which there are explicit correlations among the degrees of connected vertices.

M. I. J. Probert, M. C. Payne

We present a systematic methodology for the accurate calculation of defect structures in supercells which we illustrate with a study of the neutral vacancy in silicon. This is a prototypical defect which has been studied extensively using ab initio methods, yet remarkably there is still no consensus about the energy or structure of this defect, or even wheth

P. Sens, M. S. Turner

We study a physical model for the formation of bud-like invaginations on fluid membranes under tension, and apply this model to caveolae formation. We demonstrate that budding can be driven by membrane-bound inclusions (proteins) provided that they exert asymmetric forces on the membrane that give rise to bending moments. In particular, Caveolae formation ma

A. R. Evans, M. S. Turner, P. Sens

We study a physical model for the interaction between general inclusions bound to fluid membranes that possess finite tension, as well as the usual bending rigidity. We are motivated by an interest in proteins bound to cell membranes that apply forces to these membranes, due to either entropic or direct chemical interactions. We find an exact analytic soluti

Igor S. Burmistrov, Mikhail A. Baranov

We study two-dimensional interacting electrons in a weak perpendicular magnetic field with the filling factor $ν\gg 1$ and in the presence of a quenched disorder. In the framework of the Hartree-Fock approximation, we obtain the mean-field phase diagram for the partially filled highest Landau level. We find that the CDW state can exist if the Landau level br

R. Tyer, G. van der Laan, W. M. Temmerman, Z. Szotek

Comment on F. Wilhelm et al., Phys. Rev. Lett. 87, 207202 (2001)

Yoichi Asada, Keith Slevin, Tomi Ohtsuki

We report a numerical investigation of localization in the SU(2) model without diagonal disorder. At the band center, chiral symmetry plays an important role. Our results indicate that states at the band center are critical. States away from the band center but not too close to the edge of the spectrum are metallic as expected for Hamiltonians with symplecti

Michael Potthoff

The grand potential of a system of interacting electrons is considered as a stationary point of a self-energy functional. It is shown that a rigorous evaluation of the functional is possible for self-energies that are representable within a certain reference system. The variational scheme allows to construct new non-perturbative and thermodynamically consist

Mini P. Balakrishnan, M. C. Valsakumar, P. Rameshan

Langevin equation pertinent to diffusion limited aggregation of charged particles in the presence of an external magnetic field is solved exactly. The solution involves correlated random variables. A new scheme for exactly sampling the components of the position and velocity is proposed.

Yoichi Asada, Keith Slevin, Tomi Ohtsuki

We report an analysis of the Anderson transition in an SU(2) model with chiral symmetry. Clear single parameter scaling behaviour is observed. We estimate the critical exponent for the divergence of the localization length to be $ν=2.72\pm.02$ indicating that the transition belongs to the symplectic universality class.

Ming-Chang Huang, Yu-Pin Luo, Tsong-Ming Liaw

The two-dimensional Ising model defined on square lattices with diamond-type bond-decorations is employed to study the nature of the ferromagnetic phase transitions of inhomogeneous systems. The model is studied analytically under the bond-renormalization scheme. For an $n$-level decorated lattice, the long-range ordering occurs at the critical temperature g

T. N. Mukhamedjanov, V. A. Dzuba, O. P. Sushkov

Effects caused by the electron electric dipole moment (EDM) in gadolinium garnets are considered. Experimental studies of these effects could improve current upper limit on the electron EDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculations of observable effects in gadolinium gallium garnet and gadolinium iron

K. Yaji, A. Kimura, C. Hirai, H. Sato

The 2p core excited XAS and XMCD spectra of Cr$_{1-δ}$Te with several concentrations of $δ$=0.11-0.33 have been measured. The observed XMCD lineshapes are found to very weakly depend on $δ$. The experimental results are analyzed in terms of the configuration-interaction picture with consideration of hybridization and electron correlation effects. The calcula

S. T. Chui, V. N. Ryzhov

For mixtures of Bose and Fermi alkali atoms, the Fermion degrees of freedom can be integrated out in their {\bf finite temperature} partition function. The final result can be expanded as a power series in the Boson density. Under appropriate conditions, the pairwise interaction between the bosons can be changed from positive to negative at a low enough temp