March 2001 arXiv papers — page 27

W. Hollik, D. Stöckinger

We calculate symmetry-restoring counterterms in supersymmetric QCD at the one-loop level. First we determine loop corrections to the supersymmetry and gauge transformations and find counterterms in such a way that the symmetry algebra holds at the one-loop level. Then these results are used to derive the symmetry-restoring counterterms to all trilinear inter

Takehiro Azuma

This paper reports the investigation of a matrix model via super Lie algebra, following the proposal of L. Smolin. We consider the osp(1|32,R) nongauged matrix model and gl(1|32,R) gauged matrix model, especially paying attention to the supersymmetry and the relationship with IKKT model. This paper is based on the collaboration with the collaboration with S.

D. Challet, M. Marsili, Y. -C. Zhang

The Minority Game is a generic model of competing adaptive agents, which is often believed to be a model of financial markets. We discuss to which extend this is a reasonable statement, and present minimal modifications that make this model reproduce stylized facts. The resulting model shows that without speculators, prices follow random walks, and that styl

M. B. Stone, Y. Chen, J. Rittner, H. Yardimci

Inelastic neutron scattering measurements are reported for the quantum antiferromagnetic material Cu_2(C_5H_12N_2)_2Cl_4 (CuHpCl). The magnetic excitation spectrum forms a band extending from 0.9 meV to 1.4 meV. The spectrum contains two modes that disperse throughout the a-c plane of the monoclinic unit cell with less dispersion along the unique b-axis. Sim

Stefano Bellucci, Armen Nersessian

We present two examples of SUSY mechanics related with Kähler geometry. The first system is the N=4 supersymmetric one-dimensional sigma-model proposed in hep-th/0101065. Another system is the N=2 SUSY mechanics whose phase space is the external algebra of an arbitrary Kähler manifold. The relation of these models with antisymplectic geometry is discussed.

Amit K. Chattopadhyay

Starting from a continuum description, we study the non-equilibrium roughening of a thermal re-emission model for etching in one and two spatial dimensions. Using standard analytical techniques, we map our problem to a generalized version of an earlier non-local KPZ (Kardar-Parisi-Zhang) model. In 2+1 dimensions, the values of the roughness and the dynamic e

C. Quentmeier, H. -H. Adam, J. T. Balewski, A. Budzanowski

The near threshold total cross section and angular distributions of K+K- pair production via the reaction pp --> ppK+K- have been studied at an excess energy of Q = 17 MeV using the COSY-11 facility at the cooler synchrotron COSY. The obtained cross section as well as an upper limit at an excess energy of Q = 3 MeV represent the first measurements on the K+K

Nicola Fabiano

We estimate the total ee to stoponium cross section near threshold for a Coulombic potential and compare it to the Born approximation. The effect of the beam energy spread for present and future ee colliders is discussed.

Gabriele Ghisellini, Annalisa Celotti

The recent discovery, by the Chandra satellite, that jets of blazars are strong X-ray emitters at large scales (0.1-1 Mpc) bears support to the hypothesis that (also) on these scales the emitting plasma is moving at highly relativistic speeds. In this case in fact the emission via inverse Compton scattering off cosmic background photons is enhanced and the r

Gautam I. Menon

A general phenomenology for phase behaviour in the mixed phase of type-II superconductors with weak point pinning disorder is outlined. We propose that the ``Bragg glass'' phase generically transforms via two separate thermodynamic phase transitions into a disordered liquid on increasing the temperature. The first transition is into a glassy phase, t

M. Hofmann, T. Lorenz, G. S. Uhrig, H. Kierspel

Measurements of the thermal conductivity as a function of temperature and magnetic field in the 2D dimer spin system SrCu$_2$(BO$_3$)$_2$ are presented. In zero magnetic field the thermal conductivity along and perpendicular to the magnetic planes shows a pronounced double-peak structure as a function of temperature. The low-temperature maximum is drasticall

M. K. Volkov, V. L. Yudichev

Ground and first radially excited scalar isoscalar meson states and a scalar glueball are described in a nonlocal U(3)xU(3) quark model. The glueball is introduced into the effective meson Lagrangian by means of the dilaton model on the base of the scale invariance of the meson Lagrangian. The scale invariance breaking by current quark masses and gluon anoma

S. Bandyopadhyay, A. S. Majumdar, D. Home

A curious effect is uncovered by calculating the it time evolving probability of reflection of a Gaussian wave packet from a rectangular potential barrier while it is perturbed by reducing its height. A time interval is found during which this probability of reflection is larger (``superarrivals'') than in the unperturbed case. This nonclassical effe

I. L. Aleiner, P. W. Brouwer, L. I. Glazman

We review the quantum interference effects in a system of interacting electrons confined to a quantum dot. The review starts with a description of an isolated quantum dot. We discuss the status of the Random Matrix theory (RMT) of the one-electron states in the dot, present the universal form of the interaction Hamiltonian compatible with the RMT, and derive

Jerome Benoit, Avadh Saxena, Turab Lookman

We apply the Bogomol'nyi technique, which is usually invoked in the study of solitons or models with topological invariants, to the case of elastic energy of vesicles. We show that spontaneous bending contribution caused by any deformation from metastable bending shapes falls in two distinct topological sets: shapes of spherical topology and shapes of no

Jin Young Kim, Y. S. Myung

We consider the perturbation of giant gravitons in the background of dilatonic D-branes whose geometry is not of a conventional form of ${\rm AdS}_m \times {\rm S}^n$. We use the quadratic approximation to the brane action to investigate their vibrations around the equilibrium configuration. We found the normal modes of small vibrations of giant gravitons an

Falk Herwig

Sakurai's object (V4334 Sgr) is a born again AGB star following a very late thermal pulse. So far no stellar evolution models have been able to explain the extremely fast evolution of this star, which has taken it from the pre-white dwarf stage to its current appearance as a giant within only a few years. A very high stellar mass can be ruled out as the

V. Hushwater

One can get the impression from the Reissner-Nordstrom solution of Einstein's equations that the charge of a body reduces its gravitational field. This looks surprising since the energy of the electrostatic field surrounding a charged body, must contribute positively, as an additional, "electromagnetic mass", to the gravitational field produced b

T. Eggeling, K. G. H. Vollbrecht, M. M. Wolf

In a recent paper (quant-ph/0102133) Chen, Liang, Li and Huang suggest a necessary and sufficient separability criterion, which is supposedly practical in judging the separability of any mixed state. In this note we briefly recapitulate their main result and show that it is a reformulation of the problem rather than a practical criterion.

Ch. Silberhorn, P. K. Lam, O. Weiss, F. Koenig

We report on the generation of a continuous variable Einstein-Podolsky-Rosen (EPR) entanglement using an optical fibre interferometer. The Kerr nonlinearity in the fibre is exploited for the generation of two independent squeezed beams. These interfere at a beam splitter and EPR entanglement is obtained between the output beams. The correlation of the amplit

Raoul Nakhmanson

The wave-particle duality is a mind-body one. In the real 3d-space there exists only the particle; the wave exists in its consciousness, as well as the reflection of the whole world. If there are many particles, their distribution in accordance with the wave function looks as a real wave in real space.

Aleksey E. Bolotnikov, Steven E. Boggs, C. M. Hubert Chen, Walter R. Cook

In this paper we present studies of the I-V characteristics of CdZnTe detectors with Pt contacts fabricated from high-resistivity single crystals grown by the high-pressure Brigman process. We have analyzed the experimental I-V curves using a model that approximates the CZT detector as a system consisting of a reversed Schottky contact in series with the bul

V. S. Filinov, M. Bonitz, W. Ebeling, V. E. Fortov

This work is devoted to the thermodynamics of high-temperature dense hydrogen plasmas in the pressure region between $10^{-1}$ and $10^2$ Mbar. In particular we present for this region results of extensive calculations based on a recently developed path integral Monte Carlo scheme (direct PIMC). This method allows for a correct treatment of the thermodynamic

Babken V. Khachatryan

It is shown, that the force acting on a radiating charge is stipulated by two reasons - owing to exchange of a momentum between radiating charge and electromagnetic field of radiation, and also between a charge and field accompanying the charge.

Carlos Castro

We construct (assuming the quantum inverse scattering problem has a solution ) the operator that yields the zeroes of the Riemman zeta function by defining explicitly the supersymmetric quantum mechanical model (SUSY QM) associated with the p-adic stochastic dynamics of a particle undergoing a Brownian random walk . The zig-zagging occurs after collisions wi

Makito Oi, Philip M. Walker, Ahmad Ansari

We have performed tilted-axis-cranked Hartree-Fock-Bogoliubov calculations for a neutron-rich hafnium isotope ($^{182}$Hf) whose proton and neutron numbers are both in the upper shell region. We study whether the shell effects play a role in producing high-$K$ isomers or highly gamma-deformed states at high spin. In particular, the possibility of shape coexi

Javid A. Sheikh, Yang Sun, Rudrajyoti Palit

Transition probabilities of the ground-state bands in $γ$-soft nuclei are studied for the first time using the triaxial projected shell model approach. It is observed that the angular-momentum dependence of the transition quadrupole moment $Q_t$ is related to the triaxial deformation of the nuclear mean-field potential. The introduction of the $γ$-degree of

S. Nagornii, A. E. L. Dieperink

The tensor analyzing power in p+ \vec{d} radiative capture is investigated in a covariant and gauge invariant approach.The results of the present calculation are compared with those of other theoretical approaches and with experiment. Predictions for Ayy at Ed = (150-350) MeV are given. At forward and backward angles T20, T22 and Ayy are sensitive to the eff

J. Dobaczewski, W. Nazarewicz, P. -G. Reinhard

Particle and pairing densities in spherical even-even neutron-rich nuclei are studied within the Skyrme-Hartree-Fock-Bogoliubov approach with the density-dependent pairing interaction. The influence of the density dependence of the pairing interaction on asymptotic properties of nucleonic distributions are analyzed. It is demonstrated that the size of the ne

Tomaz Prosen, Marko Znidaric

We study numerically classical and quantum dynamics of a piecewise parabolic area preserving map on a cylinder which emerges from the bounce map of elongated triangular billiards. The classical map exhibits anomalous diffusion. Quantization of the same map results in a system with dynamical localization and pure point spectrum.

F. V. Andreev, A. V. Kitaev

A combination of rational mappings and Schlesinger transformations for a matrix form of the hypergeometric equation is used to construct higher order transformations for the Gauss hypergeometric function.

Brian C. Hall

This paper gives necessary conditions and slightly stronger sufficient conditions for a holomorphic function to be the Segal-Bargmann transform of a function in L^p(R^d) with respect to a Gaussian measure. The proof relies on a family of inversion formulas for the Segal-Bargmann transform, which can be "tuned" to give the best estimates for a given v

K. Okikiolu

Let M be a closed compact n-dimensional manifold with n odd. We calculate the first and second variations of the zeta-regularized determinants det^\primeΛand det L as the metric on M varies, where Δdenotes the Laplacian on functions and L denotes the conformal Laplacian. We see that the behavior of these functionals denotes the conformal Laplacian. We see th

Michiel van den Berg, Erwin Bolthausen, Frank den Hollander

For a>0,let W^a(t) be the a-neighbourhood of standard Brownian motion in R^d starting at 0 and observed until time t.It is well-known that E|W^a(t)|~kappa_a t (t->infty) for d >= 3,with kappa_a the Newtonian capacity of the ball with radius a. We prove that lim_{t->infty} 1/t^{(d-2)/d}log P(|W^a(t)|<=bt) = -I^{kappa_a}(b) in (-infty,0) for all 0<b<kappa_a an

Matthew Emerton, Mark Kisin

Let f: X -> Y be a separated morphism of schemes of finite type over a finite field of characteristic p, let Lambda be an artinian local Z_p-algebra with finite residue field, let m be the maximal ideal of Lambda, and let L^\bullet be a bounded constructible complex of sheaves of finite free Lambda-modules on the étale site of Y. We show that the ratio of L-

Takuji Kashiwabara

We compute the Brown-Peterson cohomology of QX, the free infinite loop-space on X, when X is a space whose Morava K-theory is flat over its BP-cohomology, in particular a space whose Morava K-theory is concentrated in even degrees. Our computation is in terms of a destabilization functor for BP-cohomology. We also show that for such X, the Morava K-homology

Stephen Berman, Yun Gao, Shaobin Tan

We present a general vertex operator construction based on the Fock space for an affine Lie algebras of type $A$. This construction allows us to give a unified treatment for both the homogeneous and principle realizations of the affine Lie algebras $\hat{gl}_N$ as well as for some extended affine Lie algebras coordinatized by certain quantum tori.

Laurent Berger

This expository article proves some results of Ferguson, on the approximation of continuous functions on a compact subset of R by polynomials with integral coefficients.

Julio Bernues, Javier Pascual

We give criteria of total incomparability for certain classes of mixed Tsirelson spaces. We show that spaces of the form $T[(M_k,θ_k)_{k=1}^{\ell}]$ with index $i(M_k)$ finite are either $c_0$ or $\ell_p$ saturated for some $p$ and we characterize when any two spaces of such a form are totally incomparable in terms of the index $i(M_k)$ and the parameter $θ_

Yuri A. Rylov

A geometric conception is a method of a geometry construction. The Riemannian geometric conception and a new T-geometric one are considered. T-geometry is built only on the basis of information included in the metric (distance between two points). Such geometric concepts as dimension, manifold, metric tensor, curve are fundamental in the Riemannian conceptio

Fabio Podesta&#39;, Andrea Spiro

We deal with compact Kaehler manifolds M which are acted on by a semisimple compact Lie group G of isometries with codimension one regular orbits. We provide an explicit description of the standard blow-ups of such manifolds along complex singular orbits, in case b_1(M) = 0 and the regular orbits are Levi nondegenerate. Up to very few exceptions, all the non

Philippe Monnier

We try to generalize the Poisson cohomology of a 2-dimensional Poisson manifold to the n-vectors on a n-dimensional manifold. We define several cohomologies and we compute locally some of them, in the case of germs at 0 of n-vectors on a real or complex vector field of dimension n.

Meng Chen

Suppose X is a smooth projective 3-fold of general type and |mK_X| is composed of a pencil of surfaces with m>1. This pencil naturally induces a fibration f:X->C onto a smooth curve C after the Stein-factorization, which is the main objects of this article. Based on Koll&#39;ar&#39;s earlier works, we improve on it and try to understand the family in terms o

Bobby Acharya, Cumrun Vafa

We study the BPS domain walls of supersymmetric Yang-Mills for arbitrary gauge group. We describe the degeneracies of domain walls interpolating between arbitrary pairs of vacua. A recently proposed large N duality sheds light on various aspects of such domain walls. In particular, for the case of G = SU(N) the domain walls correspond to wrapped D-branes giv

Ichiro Oda

We study the localization property of antisymmetric tensor fields in the locally localized gravity models. It is shown that all the antisymmetric tensor fields, including the vector field, in a bulk space-time are trapped on an $AdS$ brane by a gravitational interaction where the presence of the brane cosmological constant plays an important role as in the c

V. B. Petkova, J. -B. Zuber

The question of boundary conditions in conformal field theories is discussed, in the light of recent progress. Two kinds of boundary conditions are examined, along open boundaries of the system, or along closed curves or ``seams&#39;&#39;. Solving consistency conditions known as Cardy equation is shown to amount to the algebraic problem of finding integer va

E. Langmann, J. Mickelsson, S. Rydh

We study the quantization of chiral fermions coupled to generalized Dirac operators arising in NCG Yang-Mills theory. The cocycles describing chiral symmetry breaking are calculated. In particular, we introduce a generalized locality principle for the cocycles. Local cocycles are by definition expressions which can be written as generalized traces of operato

A. Gorsky, V. Rubtsov

We discuss geometrical aspects of different dualities in the integrable systems of the Hitchin type and its various generalizations. It is shown that T duality known in the string theory context is related to the separation of variables procedure in dynamical system. We argue that there are analogues of S duality as well as mirror symmetry in the many-body s

Paul H. Frampton, Sheldon L. Glashow, Tadashi Yoshikawa

We propose a model of soft CP violation that evades the strong CP problem and can describe observed CP violation in the neutral kaon sector, both direct and indirect. Our model requires two ``duark&#39;&#39; mesons carrying quark number two that have complex (CP-violating) bare masses and are coupled to quark pairs. Aside from the existence of these potentia

Don Colladay

Overview of spontaneous Lorentz and CPT breaking mechanism in the context of the standard model contributed to the proceedings for the Coral Gables meeting.

E. O. Alt, T. Csorgo, B. Lorstad, J. Schmidt-Sorensen

We report on a systematic treatment of Coulomb corrections for 3- and n-particle (Bose-Einstein) correlations, leading to a removal of a 100 % systematic error from earlier Coulomb corrections of 5-particle Bose-Einstein correlations in heavy ion collisions. These results are generalized to include strong final state interactions and core-halo effects.

L. Epele, H. Fanchiotti, D. Gomez Dumm, A. G. Grunfeld

We revisit the theoretical predictions for anomalous radiative decays of pseudoscalar and vector mesons. Our analysis is performed in the framework of the Nambu-Jona-Lasinio model, introducing adequate parameters to account for the breakdown of chiral symmetry. The results are comparable with those obtained in previous approaches.

M. S. Dvornikov, A. M. Egorov, A. E. Lobanov, A. I. Studenikin

Within the recently proposed Lorentz invariant formalism for description of neutrino spin evolution in presence of an arbitrary electromagnetic fields effects of matter motion and polarization are considered.

A. B. Kaidalov

Basic properties of Regge poles are reviewed. Regge poles are considered from both t-channel and s-channel points of view. The main part of the review is devoted to the Regge poles in QCD. The method of the Wilson-loop path integral is used to calculate trajectories of Regge poles for $q-\bar q$ and gluonic states. The problem of the Pomeron in QCD is discus

A. G. Akeroyd, Y. -Y. Keum, S. Recksiegel

We investigate the effect of supersymmetric CP violating phases on the inclusive decay B\to X_dγ. Although such a decay contains a large background from B\to X_sγ, if isolated it may exhibit sizeable CP violation, both in the Standard Model (SM) and in the context of models beyond the SM. With unconstrained supersymmetric CP violating phases we show that the

V. A. Khoze, A. D. Martin, M. G. Ryskin

We present model-independent estimates of the signal-to-background ratio for Higgs --> b anti-b detection in double-diffractive events at the Tevatron and the LHC. For the missing-mass approach to be able to identify the Higgs boson, it will be necessary to tag the b quark jets in the central region. The signal is predicted to be very small at the Tevatron,

P. N. Pandita

We carry out a comprehensive analysis of the nonminimal supersymmetric standard model (NMSSM) with baryon and lepton number violation. We catalogue the baryon and lepton number violating dimension four and five operators of the model. We then study the renormalization group evolution and infrared stable fixed points of the Yukawa couplings and the soft super

Dayeeta Roy, Toshiyuki Morii, and Alexander I. Titov

We analyze a possible manifestation of f_1-trajectory in elastic J/psi photoproduction at high energy and large momentum transfer. Inspite of the small contribution of f_1-trajectory in total cross sections, it becomes significant in various spin observables. In particular, we show that the crucial test for f_1-exchange can be made by measuring the single be

A. Ferroglia, G. Ossola, A. Sirlin

We present a calculation of the electroweak mixing parameter $\sin^2 θ_{eff}^{lept}$ that incorporates known higher order effects, shares the desirable convergence properties of the $\bar{MS}$ scheme, and has the important theoretical advantage of being strictly independent of the electroweak scale in finite orders of perturbation theory . We also show how t

Marko B. Popovic

A brief overview of some of the last decade&#39;s developments in the Top-mode/Topcolor class of models is presented. In addition, a new Topcolor type scenario, named Top-Bottom Color, is suggested. A seesaw mechanism with new weak doublet quarks has been introduced to lower the previous theoretical prediction for the large top quark mass; without a seesaw m

The K2K Collaboration, S. H. Ahn

The KEK to Kamioka long-baseline neutrino experiment (K2K) has begun its investigation of neutrino oscillations suggested by atmospheric neutrino observations. Twenty-eight neutrino events have been detected in coincidence with the expected arrival time of the beam in the 22.5 kt fiducial volume of Super--Kamiokande, the far detector at 250 km distance. The

A. Miyazaki

The cosmological constant $(1/2)λ_{1}ϕ_{, μ}ϕ^{, μ}/ϕ^{2}$ is introduced to the generalized scalar-tensor theory of gravitation with the coupling function $ω(ϕ)=η/(ξ-2)$ and the Machian cosmological solution satisfying $ϕ=O(ρ/ω)$ is discussed for the homogeneous and isotropic universe with a perfect fluid (with negative pressure). We require the closed model

A. Miyazaki

The Machian cosmological solution satisfying $ϕ=O(ρ/ω)$ for the perfect-fluid with negative pressure is discussed. When the coefficient of the equation of state $γ\to -1/3$, the gravitational constant approaches to constant. If we assume the present mass density $ρ_{0}\sim ρ_{c}$ (critical density), the parameter $ε$ ($γ=(ε-1)/3$) has a value of order $10^{-

G. Mario A. Higuera, Humberto Sarria, Diana Fonseca, John Idarraga

It has been designed,built and executed a code for the Fast Fourier Transform (FFT),compiled and executed in a cluster of 2^n computers under the operating system MacOS and using the routines MacMPI. As practical application,the code has been used to obtain the transformed from an astronomic imagen,to execute a filter on its and with a transformed inverse to

Antonio M. Garcia-Garcia

We consider a generalized chiral Gaussian Unitary Ensemble (chGUE) based on a weak confining potential. We study the spectral correlations close to the origin in the thermodynamic limit. We show that for eigenvalues separated up to the mean level spacing the spectral correlations coincide with those of chGUE. Beyond this point, the spectrum is described by a

Joseph A. Both, Daniel C. Hong

The onset of condensation of hard spheres in a gravitational field is studied using density functional theory. In particular, we find that the local density approximation yields results identical to those obtained previously using the kinetic theory [Physica A 271, 192, (1999)], and a weighted density functional theory gives qualitatively similar results, na

J. K. Jung, Seung Ho Baek, F. Borsa, S. L. Bud&#39;ko

$^{11}B$ NMR and nuclear spin-lattice relaxation rate (NSLR) are reported at 7.2 Tesla and 1.4 Tesla in powder samples of the intermetallic compound $MgB_2$ with superconducting transition temperature in zero field $T_c$ = 39.2 K. From the first order quadrupole perturbed NMR specrum a quadrupole coupling frequency of 835 $\pm$ 5 kHz is obtained. The Knight

Shirish M. Chitanvis

We have mapped the physics of a system of semi-flexible inextensible polymers onto a complex Ginzburg-Landau field theory using techniques of functional integration. It is shown in the limit of low number density of monomers in a melt of semi-flexible, inextensible polymers, kept apart by an excluded volume interaction, the radius of gyration scales as N^{nu

Edo Kussell, Jun Shimada, Eugene I. Shakhnovich

To examine the relationship between sidechain geometry and sidechain packing, we use an all-atom Monte Carlo simulation to sample the large space of sidechain conformations. We study three models of excluded volume and use umbrella sampling to effectively explore the entire space. We find that while excluded volume constraints reduce the size of conformation

H. A. Mook, F. Dogan

Striped phases in which spin and charge separate into different regions in the material have been proposed to account for the unusual properties of the high-$T_c$ cuprate superconductors. The driving force for a striped phase is the charge distribution, which self-organizes itself into linear regions. In the highest $T_c$ materials such regions are not stati

J. E. Flores-Mena, Marcia C. Barbosa, Yan Levin

A theory of a confined two dimensional electrolyte is presented. The positive and negative ions, interacting by a $1/r$ potential, are constrained to move on an interface separating two solvents with dielectric constants $ε_1$ and $ε_2$. It is shown that the Debye-Hückel type of theory predicts that the this 2d Coulomb fluid should undergo a phase separation

C. Grimaldi, P. Ryser, S. Straessler

In this paper, we study the piezoresistive response and its anisotropy for a bond percolation model of granular metals. Both effective medium results and numerical Monte Carlo calculations of finite simple cubic networks show that the piezoresistive anisotropy is a strongly dependent function of bond probability p and of bond conductance distribution width Δ

R. Lövenich, A. B. Schumacher, J. S. Dodge, D. S. Chemla

We present a comparative experimental and theoretical investigation of the two--dimensional charge-transfer gap in the strongly correlated material Sr$_2$CuO$_2$Cl$_2$. We observe an Urbach behaviour in the absorption profile over a surprisingly wide range of energies and temperatures. We present a model that accounts for phonon scattering to infinite order

K. Ivanova, M. Ausloos

The Euro (EUR) has been a currency introduced by the European Community on Jan. 01, 1999. This implies eleven countries of the European Union which have been found to meet the five requirements of the Maastricht convergence criteria. In order to test EUR behavior and understand various features, we have extrapolated the EUR backwards and therefore have obtai

Mickael Profeta, Francesco Mauri

We present a practical method to compute the vibrational resonant Raman spectra in solids with delocalized excitations. We apply this approach to the study of tetrahedrous amorphous carbon. We determine the vibrational eigenmodes and eigenvalues using density functional theory in the local density approximation, and the Raman intensities using a tight bindin

L. Fruchter

The flux lattice driven by a uniform driving force in a superconductor with hot, strong, sharp and randomly distributed pinning centers, with applied magnetic field half the matching field is simulated. At low temperature both a non activated regime, where flux motion occurs within a robust percolative flux flow channel, and an activated regime are obtained

Denis Boyer, Jorge Viñals

We study the motion of a grain boundary that separates two sets of mutually perpendicular rolls in Rayleigh-Bénard convection above onset. The problem is treated either analytically from the corresponding amplitude equations, or numerically by solving the Swift-Hohenberg equation. We find that if the rolls are curved by a slow transversal modulation, a net t

Anders Johansen

A new experiment measuring the dynamical response of the Internet population to a ``point-like&#39;&#39; perturbation has been performed. The nature of the perturbation was that of an announcement, specifically a web-interview on stock market crashes, which contained the URL to the author&#39;s articles on the subject. It was established that the download ra

H. Schiessel, H. Aranda-Espinoza

We consider DNA-cationic lipid complexes that form lamellar stacks of lipid bilayers with parallel DNA strands intercalated in between. We calculate the electrostatically induced elastic deformations of the lipid bilayers. It is found that the membranes undulate with a periodicity that is set by the DNA interaxial distance. As a consequence the lamellar repe

Y. Malevergne, D. Sornette

Using a family of modified Weibull distributions, encompassing both sub-exponentials and super-exponentials, to parameterize the marginal distributions of asset returns and their natural multivariate generalizations, we give exact formulas for the tails and for the moments and cumulants of the distribution of returns of a portfolio make of arbitrary composit

K. Staliunas

Spatial and temporal noise power spectra of stripe patterns are investigated, using as a model a Swift-Hohenberg equation with a stochastic term. In particular, the analytical and numerical investigations show: 1) the temporal noise spectra are of 1/f^alpha form, where alpha=1+(3-D)/4 with D the spatial dimension of the system; 2) that the stochastic fluctua

E. B. Sonin

The paper addresses the problem whether and how it is possible to detect the Luttinger-liquid behavior from the $IV$ curves for tunneling to 1D or quasi-1D conductors. The power-law non-ohmic $IV$ curve, which is usually considered as a manifestation of the Luttinger-liquid behavior, can be also deduced from the theory of the Coulomb blockaded junction betwe

S. Luding

One essential question in material sciences is how to bridge the gap between the microscopic picture and a macroscopic description. The former involves contact forces and deformations, whereas the latter concerns tensorial quantities like the stress or the velocity gradient. A two-dimensional shear-cell filled with disks of different sizes is examined by mea

S. Luding, O. Strauss

Simulation results of dense granular gases with particles of different size are compared with theoretical predictions concerning the pair-correlation functions, the collison rate, the energy dissipation, and the mixture pressure. The effective particle-particle correlation function, which enters the equation of state in the same way as the correlation functi

S. Luding

Hard sphere systems in two dimensions are examined for arbitrary density. Simulation results are compared to the theoretical predictions for both the low and the high density limit, where the system is either disordered or ordered, respectively. The pressure in the system increases with the density, except for an intermediate range of volume fractions $0.65

R. Buegel, J. Wosnitza, H. v. Loehneysen, T. Ono

We report on high-resolution specific-heat and magnetocaloric-effect measurements of the triangular-lattice antiferromagnets CsMn(Br_xI_{1-x})_3 with different x. The evolution of the magnetic phase diagrams from the easy-axis system for x = 0 to the easy-plane system for x = 1 was studied in detail. The specific-heat critical exponent alpha of the almost is

Kim Louis, J. V. Alvarez, Claudius Gros

We derive the one-loop renormalization equations for the shift in the Fermi-wavevectors for one-dimensional interacting models with four Fermi-points (two left and two right movers) and two Fermi velocities v_1 and v_2. We find the shift to be proportional to (v_1-v_2)U^2, where U is the Hubbard-U. Our results apply to the Hubbard ladder and to the t_1-t_2 H

I. Ichinose, T. Matsui, M. Onoda

We study the slave-boson t-J model of cuprates with high superconducting transition temperatures, and derive its low-energy effective field theory for the charge-spin separated state in a self-consistent manner. The phase degrees of freedom of the mean field for hoppings of holons and spinons can be regarded as a U(1) gauge field, $A_i$. The charge-spin sepa

Masatoshi Imada

Superconducting mechanism mediated by interband exchange Coulomb repulsion is examined in an extended two-band Hubbard models with a wide band crossing the Fermi level and coexisting with a narrower band located at moderately lower energy. We apply newly developed path-integral renormalization group method to reliably calculate pairing correlations. The corr

Hsi-Sheng Goan, Gerard J. Milburn

We present the conditional quantum dynamics of an electron tunneling between two quantum dots subject to a measurement using a low transparency point contact or tunnel junction. The double dot system forms a single qubit and the measurement corresponds to a continuous in time readout of the occupancy of the quantum dot. We illustrate the difference between c

Zhi-Rong Liu, Wenhui Duan, Bing-Lin Gu, Xiao-Wen Zhang

We propose a mechanism of stochastic resonance induced by spatial noise (electric random fields) in ferroelectrics. The calculations demonstrate the characteristic of the stochastic resonance: certain random field can increase the susceptibility, the phonon occupancy, and the overcooled temperature. This mechanics of stochastic resonance may be general in ot

Zhi-Rong Liu, Wenhui Duan, Bing-Lin Gu, Xiao-Wen Zhang

The soft modes in the two- and eight-direction order-disorder ferroelectrics are calculated under the mean-field approximation. We find that the conventional method of the pseudospin model to calculate the soft-mode frequency is incorrect, and present a valid modified method. It is demonstrated that the conventional method does not show the soft-mode frequen

Zhi-Rong Liu, Yong Zhang, Bing-Lin Gu, Xiao-Wen Zhang

A Landau-type phenomenological cluster theory was presented to model the freezing process of local polarization in relaxors. Based on the theory, the proportion of frozen polarization in Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_3$-PbTiO$_3$ (PMNT) was calculated from the experiment of dielectric nonlinearity. The local polarization was shown to freeze continuously in a co

D. B. Saakian

A set of general physical principles is proposed as the structural basis for the theory of complex systems. First the concept of harmony is analyzed and its different aspects are uncovered. Then the concept of reflection is defined and illustrated by suggestive examples. Later we propose the principle of (random) projection of symmetrically expanded prereali

D. B. Saakian

A set of general physical principles is proposed as the structural basis for the theory of complex systems. First the concept of harmony is analyzed and its different aspects are uncovered. Then the concept of reflection is defined and illustrated by suggestive examples. Later we propose the principle of (random) projection of symmetrically expanded prereali

K. M. Leighly, J. P. Halpern, D. J. Helfand, R. H. Becker

We report the discovery of a new bright quasar PHL 1811 as part of a followup program to identify bright quasars in the FIRST radio survey. With B=13.9, R=13.9, and z=0.192, this quasar is now the second brightest quasar (in apparent magnitude) known beyond z=0.1. Optically classified as a Narrow-line Seyfert 1 galaxy (NLS1), PHL 1811 is unusual for an objec

Ronald J. Allen

In the currently-accepted model for star formation out of the interstellar gas in galaxies, the basic construction material is assumed to be large clouds of atomic hydrogen (HI). These clouds are thought to form higher-density complexes of gas and dust, and turn molecular (H2). Stars then form out of this molecular gas. In this paper arguments are advanced f

Matthias Liebendoerfer, O. E. Bronson Messer, Anthony Mezzacappa, W. Raphael Hix

We present self-consistent general relativistic simulations of stellar core collapse, bounce, and postbounce evolution for 13, 15, and 20 solar mass progenitors in spherical symmetry. Our simulations implement three-flavor Boltzmann neutrino transport and standard nuclear physics. The results are compared to our corresponding simulations with Newtonian hydro

B. Scott Gaudi, A. O. Petters

The generic, qualitative, local behavior of center-of-light curves near folds and cusps are studied. The results apply to any finite number of lens planes.

Arunav Kundu, Brad Whitmore

We present an analysis of the globular cluster systems of 28 elliptical galaxies using archival WFPC2 images in the V and I-bands. The V-I color distributions of at least 50% of the galaxies appear to be bimodal {\it at the present level of photometric accuracy}. We argue that this is indicative of multiple epochs of cluster formation early in the history of