March 2000 arXiv papers — page 12

Gungwon Kang, Y. S. Myung

We discuss the role of the trace part of metric fluctuations $h_{MN}$ in the Randall-Sundrum scenario of gravity. Without the matter, this field ($h=η^{MN}h_{MN}$) is a gauge-dependent term, and thus it can be gauged away. But, including the uniform source $\tilde{T}_{MN}$, this field satisfies the linearized equation $\Box_4 h =16πG_5 T^μ_μ$. This may corre

Rajdeep Chatterjee, Prabir Banerjee, Radhey Shyam

We investigate the Coulomb breakup of neutron rich nuclei 11Be and (19,17,15)C within a theory developed in the framework of Distorted Wave Born Approximation. Finite range effects are included by a local momentum approximation, which allows incorporation of realistic wave functions for these nuclei in our calculations. Energy and angular as well as parallel

Masahito Hayashi, Fuminori Sakaguchi

In this paper, subnormal operators, not necessarily bounded, are discussed as generalized observables. In order to describe not only the information about the probability distribution of the output data of their measurement but also a framework of their implementations, we introduce a new concept compound-system-type normal extension, and we derive the compo

Jinhyoung Lee, M. S. Kim, Hyunseok Jeong

Quantum teleportation of a continuous-variable state is studied for the quantum channel of a two-mode squeezed vacuum influenced by a thermal environment. Each mode of the squeezed vacuum is assumed to undergo the same thermal influence. It is found that when the mixed two-mode squeezed vacuum for the quantum channel is separable, any nonclassical features,

Hyunseok Jeong, Jinhyoung Lee, M. S. Kim

We investigate the time evolution of nonlocality for a two-mode squeezed state in the thermal environment. The initial two-mode pure squeezed state is nonlocal with a stronger nonlocality for a larger degree of squeezing. It is found that the larger the degree of initial squeezing is, the more rapidly the squeezed state loses its nonlocality. We explain this

G. P. Berman, G. D. Doolen, V. I. Tsifrinovich

We propose a magnetic resonance force microscopy (MRFM)-based nuclear spin quantum computer using tellurium impurities in silicon. This approach to quantum computing combines the well-developed silicon technology with expected advances in MRFM.

Sandra Savaglio, Vincenzo Carbone

World records in athletics provide a measure of physical as well as physiological human performance. Here we analyse running records and show that the mean speed as a function of race time can be described by two scaling laws that have a breakpoint at about 150-170 seconds (corresponding to the ~1,000 m race). We interpret this as being the transition time b

Manuel González, Joaquín M. Gutiérrez

Given Banach spaces E and F, we denote by ${\mathcal P}(^k!E,F)$ the space of all k-homogeneous (continuous) polynomials from E into F, and by ${\mathcal P}_{wb}(^k!E,F)$ the subspace of polynomials which are weak-to-norm continuous on bounded sets. It is shown that if E has an unconditional finite dimensional expansion of the identity, the following asserti

N. Aizawa

The explicit expressions of the representation functions (D-functions) for Jordanian quantum group SL_h(2) are obtained by combination of tensor operator technique and Drinfeld twist. It is shown that the D-functions can be expressed in terms of Jacobi polynomials as the undeformed D-functions can. Some of the important properties of the D-functions for SL_h

P. Etingof, O. Schiffmann

This paper is a continuation of math.QA/9907181 and math.QA/9908115. We consider traces of intertwiners between certain representations of the quantized enveloping algebra associated to a semisimple complex Lie algebra g, which are twisted by a ``generalized Belavin-Drinfeld triple'', i.e a triple consisting of two subdiagrams of the Dynkin diagram o

Alexei Grigoriev

An approach is proposed for bounding the number of zeros that solutions of linear differential systems with polynomial coefficients may have. A bound is obtained in a special case which improves upon currently existing.

Y. Kazama, T. Muramatsu

Supersymmetric Ward identity for the low energy effective action in the standard background gauge is derived for {\it arbitrary} trajectories of supergravitons in Matrix Theory. In our formalism, the quantum-corrected supersymmetry transformation laws of the supergravitons are directly identified in closed form, which exhibit an intricate interplay between s

A. Yu. Petrov

The effective action in general chiral superfield model with arbitrary kählerian potential $K(\barΦ,Φ)$ and chiral (holomorphic) potential $W(Φ)$ is considered. The one-loop and two-loop contributions to kählerian effective potential and two-loop (first non-zero) contribution to chiral effective potential are found for arbitrary form of functions $K(\barΦ,Φ)

L. C. Garcia de Andrade

Criteria for the existence of de Sitter inflation with dilaton fields in four-dimensional space-times with torsion is discussed.The relation between matter density perturbation and the spin-density perturbation is stablished based on this criteria.From COBE data it is shown that there is a linear relationship between the spin-torsion density and temperature

J. Eroles, G. Ortiz, A. V. Balatsky, A. R. Bishop

We argue that the superconducting state found in high-$T_c$ cuprates is inhomogeneous with a corresponding inhomogeneous superfluid density. We introduce two classes of microscopic models which capture the magnetic and superconducting properties of these strongly correlated materials. We start from a generalized t-J model, in which appropriate inhomogeneous

J. Eroles, G. Ortiz, A. V. Balatsky, A. R. Bishop

A t-J-like model for inhomogeneous superconductivity of cuprate oxides is presented, in which local anisotropic magnetic terms are essential. We show that this model predicts pairing, consistent with experiments, and argue how the macroscopic phase-coherent state gradually grows upon lowering of the temperature. We show that appropriate inhomogeneities are e

Francisco J. Solis, Monica Olvera de la Cruz

Polyelectrolytes such as single and double stranded DNA and many synthetic polymers undergo two structural transitions upon increasing the concentration of multivalent salt or molecules. First, the expanded-stretched chains in low monovalent salt solutions collapse into nearly neutral compact structures when the density of multivalent salt approaches that of

Ersin Kececioglu, Anupam Garg

The magnetic molecule Fe_8 has been observed to have a rich pattern of degeneracies in its magnetic spectrum as the static magnetic field applied to the molecule is varied. The points of degeneracy, or diabolical points in the magnetic field space, are found exactly in the simplest model Hamiltonian for this molecule. The points are shown to form a perfect c

S. I. Vainshtein, Z. Mikić, R. Rosner, J. A. Linker

We use direct numerical simulations to study the evolution, or relaxation, of magnetic configurations to an equilibrium state. We use the full single-fluid equations of motion for a magnetized, non-resistive, but viscous fluid; and a Lagrangian approach is used to obtain exact solutions for the magnetic field. As a result, the topology of the magnetic field

F. Fiore, F. La Franca, C. Vignali, A. Comastri

We report optical spectroscopic identifications of 10 hard (2-10 keV) X-ray selected sources discovered by Chandra. The X-ray flux of the sources ranges between 1.5 and 25 x 10-14 cgs, the lower value being 3 times fainter than in previous BeppoSAX and ASCA surveys. Their R band magnitudes are in the range 12.8-22. Six of the Chandra sources are broad line q

L. Piersanti, S. Cassisi, I. Iben, A. Tornambe'

Numerical experiments have been performed to investigate the thermal behavior of a cooled down white dwarf of initial mass $M_{\rm WD} = 0.516 M_{\sun}$ which accretes hydrogen-rich matter with Z = 0.02 at the rate $\dot{M}=10^{-8}$ \msun \yrm1, typical for a recurrent hydrogen shell flash regime. The evolution of the main physical quantities of a model duri

Sandip K. Chakrabarti, Sonali Chakrabarti

A vital ingredient of DNA molecule named adenine may be produced by successive addition of HCN during molecular cloud collapse and star formation. We compute its abundance in a collapsing cloud as a function of the reaction rate and show that in much of the circumstances the resulting amount may be sufficient to contaminate planets, comets and meteorites. We

J. F. Ormes, S. Digel, I. V. Moskalenko, A. Moiseev

Gamma rays in the band from 30 MeV to 300 GeV, used in combination with direct measurements and with data from radio and X-ray bands, provide a powerful tool for studying the origin of Galactic cosmic rays. Gamma-ray Large Area Space Telescope (GLAST) with its fine 10-20 arcmin angular resolution will be able to map the sites of acceleration of cosmic rays a

Michael R. Geller, Daniel Loss

We use chiral Luttinger liquid theory to study transport through a quantum dot in the fractional quantum Hall effect regime and find rich non-Fermi-liquid tunneling characteristics. In particular, we predict a remarkable Coulomb-blockade-type energy gap that is quantized in units of the noninteracting level spacing, new power-law tunneling exponents for volt

A. M. Garcia-Garcia, J. J. M. Verbaarschot

We propose a random matrix model that interpolates between the chiral random matrix ensembles and the chiral Poisson ensemble. By mapping this model on a non-interacting Fermi-gas we show that for energy differences less than a critical energy $E_c$ the spectral correlations are given by chiral Random Matrix Theory whereas for energy differences larger than

Rajesh Gopakumar, Shiraz Minwalla, Andrew Strominger

We find classically stable solitons (instantons) in odd (even) dimensional scalar noncommutative field theories whose scalar potential, $V(\ph)$, has at least two minima. These solutions are bubbles of the false vacuum whose size is set by the scale of noncommutativity. Our construction uses the correspondence between non-commutative fields and operators on

Achille Corsetti, Pran Nath

The effects of nonuniversality of gaugino masses on dark matter are examined within supersymmetric grand unification, and in string and D brane models with R parity invariance. In SU(5) unified models nonuniversality in the gaugino sector can be generated via the gauge kinetic energy function which may depend on the 24, 75 and 200 dimensional Higgs represent

S. Bandyopadhyay

In its most orthodox form, Bohr's Complementarity Principle states that a quanton (a quantum system consisting of a Boson or Fermion) can either behave as a particle or as wave, but never simultaneosuly as both. A less orthodox interpretation of this Principle is the ``duality condition'' embodied in a mathematical inequality due to Englert [B-G

I. Brevik, K. A. Milton, S. D. Odintsov, K. E. Osetrin

We apply the background field method and the effective action formalism to describe the four-dimensional dynamical Casimir effect. Our picture corresponds to the consideration of quantum cosmology for an expanding FRW universe (the boundary conditions act as a moving mirror) filled by a quantum massless GUT which is conformally invariant. We consider cases i

V. Barger, G. Geer, R. Raja, K. Whisnant

We consider the parameters of an entry-level neutrino factory designed to make the first observation of nu_e -> nu_mu oscillations, measure the corresponding amplitude sin^2 2theta_{13}, and determine the sign of the atmospheric-scale delta m_{32}^2 via matter effects. A 50 kt detector, a stored muon energy E_mu geq 20 GeV and 10^{19} muon decays would enabl

Ivar Martin, Gerardo Ortiz, A. V. Balatsky, A. R. Bishop

We present a minimal model of a doped Mott insulator that simultaneously supports antiferromagnetic stripes and d-wave superconductivity. We explore the implications for the global phase diagram of the superconducting cuprates. At the unrestricted mean-field level, the various phases of the cuprates, including weak and strong pseudogap phases, and two differ

F. Baldovin, M. Novello, S. E. Perez Bergliaffa, J. M. Salim

Using the effective metric formalism for photons in a nonlinear electromagnetic theory, we show that a certain field configuration in Born-Infeld electromagnetism in flat spacetime can be interpreted as an ultrastatic spherically symmetric wormhole. We also discuss some properties of the effective metric that are valid for any field configuration.

Eric R. Dufresne, Todd M. Squires, Michael P. Brenner, David G. Grier

We describe direct imaging measurements of the collective and relative diffusion of two colloidal spheres near a flat plate. The bounding surface modifies the spheres' dynamics, even at separations of tens of radii. This behavior is captured by a stokeslet analysis of fluid flow driven by the spheres' and wall's no-slip boundary conditions. In pa

E. A. Jagla, A. G. Rojo

We present a model that explains the origin and predicts the statistical properties of columnar quasi-hexagonal crack patterns, as observed in the columnar jointing of basaltic lava flows. Irregular fractures appear at the surface of the material, induced by temperature gradients during cooling. At later times fractures penetrate into the material, and tend

Seb Oliver, the ELAIS consortium

We describe the European Large Area ISO Survey (ELAIS). ELAIS was the largest single Open Time project conducted by ISO, mapping an area of 12 square degrees at 15mu with ISO-CAM and at 90mu with ISO-PHOT. Secondary surveys in other ISO bands were undertaken by the ELAIS team within the fields of the primary survey, with 6 square degrees being covered at 6.7

P. Hasenfratz, S. Hauswirth, K. Holland, T. Jorg

We discuss the steps to construct Dirac operators which have arbitrary fermion offsets, gauge paths, a general structure in Dirac space and satisfy the basic symmetries (gauge symmetry, hermiticity condition, charge conjugation, hypercubic rotations and reflections) on the lattice. We give an extensive set of examples and offer help to add further structures

M. Carena, J. Ellis, A. Pilaftsis, C. E. M. Wagner

We perform a systematic study of the one-loop renormalization-group-improved effective potential of the minimal supersymmetric extension of the Standard Model (MSSM), including CP violation induced radiatively by soft trilinear interactions related to squarks of the third generation. We calculate the charged and neutral Higgs-boson masses and couplings, incl

S. Bellucci, E. Ivanov

We work out the basics of conformal $N=(4,4)$, 2D supergravity in the $N=(4,4)$, 2D analytic harmonic superspace with two independent sets of harmonic variables. We define the relevant most general analytic superspace diffeomorphism group and show that in the flat limit it goes over into the ``large'' $N=(4,4)$, 2D superconformal group. The basic obj

W. F. Kao

A D-dimensional induced gravity theory is studied carefully in a $4 + (D-4)$ dimensional Friedmann-Robertson-Walker space-time. We try to extract information of the symmetry breaking potential in search of an inflationary solution with non-expanding internal-space. We find that the induced gravity model imposes strong constraints on the form of symmetry brea

Einan Gardi

Resummation and power-corrections play a crucial role in the phenomenology of event-shape variables like the thrust T. Previous investigations showed that the perturbative contribution to the average thrust is dominated by gluons of small invariant mass, of the order of 10% of Q, where Q is the center-of-mass energy. The effect of soft gluons is also importa

S. Kretzer

Fitting $Z^0$-pole data from ALEPH and SLD, and TPC data at a lower c.m.s.\ energy, we fix the boundary condition for NLO parton$\to$hadron (hadron$=π^\pm, K^\pm, \sum_h h^\pm$) fragmentation functions (FFs) at the low resolution scale of the radiative parton model of Glück, Reya and Vogt (GRV). Perturbative LO$\leftrightarrow$NLO stability is investigated.

P. Grandclement, S. Bonazzola, E. Gourgoulhon, J. -A. Marck

We present a spectral method for solving elliptic equations which arise in general relativity, namely three-dimensional scalar Poisson equations, as well as generalized vectorial Poisson equations of the type $Δ\vec{N} + λ\vec{\nabla}(\vec{\nabla}\cdot \vec{N}) = \vec{S}$ with $λ\not= -1$. The source can extend in all the Euclidean space ${\bf R}^3$, provide

Sergei Yu. Sakovich

The singularity analysis is carried out for a system of four first-order quadratic ODEs with a parameter, which was proposed recently by Golubchik and Sokolov. A transformation of dependent variables is revealed by the analysis, after which the transformed system possesses the Painlevé property and does not contain the parameter.

Miguel Alcubierre, Bernd Bruegmann, Thomas Dramlitsch, Jose A. Font

We study the stability of three-dimensional numerical evolutions of the Einstein equations, comparing the standard ADM formulation to variations on a family of formulations that separate out the conformal and traceless parts of the system. We develop an implementation of the conformal-traceless (CT) approach that has improved stability properties in evolving

Vanicson L. Campos, Gabriele Ferretti, Henric Larsson, Dario Martelli

We present an explicit study of the holographic renormalization group (RG) in six dimensions using minimal gauged supergravity. By perturbing the theory with the addition of a relevant operator of dimension four one flows to a non-supersymmetric conformal fixed point. There are also solutions describing non-conformal vacua of the same theory obtained by givi

Izumi Tsutsui, Tamas Fulop, Taksu Cheon

We study systems with parity invariant contact interactions in one dimension. The model analyzed is the simplest nontrivial one --- a quantum wire with a point defect --- and yet is shown to exhibit exotic phenomena, such as strong vs weak coupling duality and spiral anholonomy in the spectral flow. The structure underlying these phenomena is SU(2), which ar

Tommaso Torelli, Lubos Mitas

The electronic structure of C_(4N+2) carbon rings exhibits competing many-body effects of Huckel aromaticity, second-order Jahn-Teller and Peierls instability at large sizes. This leads to possible ground state structures with aromatic, bond angle or bond length alternated geometry. Highly accurate quantum Monte Carlo results indicate the existence of a cros

Aseshkrishna Datta, Biswarup Mukhopadhyaya

In an R-parity nonconserving supersymmetric theory, the lighter stop can dominantly decay into $bμ$ and $bτ$ if R-parity breaking has to explain the neutrino mass and mixing pattern suggested by the data on atmospheric muon neutrinos. This should give rise to $dilepton+dijet$ and $single-lepton+jets$, signals resembling those of the top quark at the Fermilab

A. Girlando, M. Masino, G. Visentini, R. G. Della Valle

The crystal structure and lattice phonons of (BEDT-TTF)_2I_3 superconducting β-phase are computed and analyzed by the Quasi Harmonic Lattice Dynamics (QHLD) method. Whereas the crystal structure and its temperature and pressure dependence are properly reproduced within a rigid molecule approximation, this has to be removed to account for the specific heat da

H. Collins, B. Holdom

We study the dynamics of branes in configurations where 1) the brane is the edge of a single anti-de Sitter (AdS) space and 2) the brane is the surface of a vacuum bubble expanding into a Schwarzschild or AdS-Schwarzschild bulk. In both cases we find solutions that resemble the standard Robertson-Walker cosmologies although in the latter, the evolution can b

Arkajyoti Misra, Bikas K Chakrabarti

Detailed mean field and Monte Carlo studies of the dynamic magnetization-reversal transition in the Ising model in its ordered phase under a competing external magnetic field of finite duration have been presented here. Approximate analytical treatment of the mean field equations of motion shows the existence of diverging length and time scales across this d

A. Panaitescu, P. Kumar

Assuming an adiabatic evolution of a Gamma-Ray Burst (GRB) remnant interacting with an external medium, we calculate the injection, cooling, and absorption break frequencies, and the afterglow flux for plausible orderings of the break and observing frequencies. The analytical calculations are restricted to a relativistic remnant and, in the case of collimate

J. Suzuki

We consider eigenvalue problems in quantum mechanics in one dimension. Hamiltonians contain a class of double well potential terms, x^6 + αx^2, for example . The space coordinate is continued to a complex plane and the connection problem of fundamental system of solutions is considered. A hidden U_q(\hat{gl}(2|1)) structure arises in "fusion relations&#3

E. Karpov, G. Ordonez, T. Petrosky, I. Prigogine

In a series of interesting papers G. C. Hegerfeldt has shown that quantum systems with positive energy initially localized in a finite region, immediately develop infinite tails. In our paper Hegerfeldt's theorem is analysed using quantum and classical wave packets. We show that Hegerfeldt's conclusion remains valid in classical physics. No violation

Hans Halvorson

Within the traditional Hilbert space formalism of quantum mechanics, it is not possible to describe a particle as possessing, simultaneously, a sharp position value and a sharp momentum value. Is it possible, though, to describe a particle as possessing just a sharp position value (or just a sharp momentum value)? Some, such as Teller (Journal of Philosophy,

S. Bose, L. Rallan, V. Vedral

By considering quantum computation as a communication process, we relate its efficiency to a communication capacity. This formalism allows us to rederive lower bounds on the complexity of search algorithms. It also enables us to link the mixedness of a quantum computer to its efficiency. We discuss the implications of our results for quantum measurement.

J. D. Franson

In a recent review article, Opatrny and Kurizki [submitted to Fortschr. Phys., e-print quant-ph/0003010] discussed a number of issues related to the feasibility of quantum computation based on photon-exchange interactions. This Reply summarizes my view of each of the issues and the overall prospects for quantum computing based on photon-exchange interactions

R. F. Werner

We establish a one-to-one correspondence between (1) quantum teleportation schemes, (2) dense coding schemes, (3) orthonormal bases of maximally entangled vectors, (4) orthonormal bases of unitary operators with respect to the Hilbert-Schmidt scalar product, and (5) depolarizing operations, whose Kraus operators can be chosen to be unitary. The teleportation

Holger F. Hofmann, Takayoshi Kobayashi, Akira Furusawa

The original purpose of measurements is to provide us with information about a previously unknown physical property of the system observed. In the Hilbert space formalism of quantum mechanics, this physical meaning of measurement information is not immediately apparent. In order to study the relationship between the Hilbert space coherence of the quantum sta

Henry P. Stapp

Recent theoretical and experimental papers support the prevailing opinion that large warm systems will rapidly lose quantum coherence, and that classical properties will emerge. This rapid loss of coherence would naturally be expected to block any critical role for quantum theory in explaining the interaction between our conscious experiences and the physica

Henry P. Stapp

Recent nonlocality results support a new picture of reality built on the ideas of John von Neumanm

Michael H. Freedman

A polynomial depth quantum circuit effects, by definition a poly-local unitary transformation of tensor product state space. It is a physically reasonable belief [Fy][L][FKW] that these are precisely the transformations which will be available from physics to help us solve computational problems. The poly-locality of discrete Fourier transform on cyclic grou

M. Baldo, A. Grasso

The explicit energy dependence of the single particle self-energy (dispersive effects), due to short range correlations, is included in the treatment of neutron matter superfluidity. The method can be applied in general to strong interacting fermion systems, and it is expected to be valid whenever the pairing gap is substantially smaller than the Fermi kinet

C. G. Roldao, A. A. Natale

We estimate the cross sections for the production of resonances, pion pairs and a central cluster of hadrons in peripheral heavy-ion collisions through two-photon and double-pomeron exchange, at energies that will be available at RHIC and LHC. The effect of the impact parameter in the diffractive reactions is introduced, and imposing the condition for realis

Sebastian M. Maurer, Bernardo A. Huberman

We present a dynamical model of web site growth in order to explore the effects of competition among web sites and to determine how they affect the nature of markets. We show that under general conditions, as the competition between sites increases, the model exhibits a sudden transition from a regime in which many sites thrive simultaneously, to a "winn

T. Carletti, J. Laskar

We study the behaviour of the Standard map critical function in a neighbourhood of a fixed resonance, that is the scaling law at the fixed resonance. We prove that for the fundamental resonance the scaling law is linear. We show numerical evidence that for the other resonances $p/q$, $q \geq 2$, $p \neq 0$ and $p$ and $q$ relatively prime, the scaling law fo

D. Korotkin

Here we review some recent developments in the theory of isomonodromic deformations on Riemann sphere and elliptic curve. For both cases we show how to derive Schlesinger transformations together with their action on tau-function, and construct classes of solutions in terms of multi-dimensional theta-functions.

Do Ngoc Diep

We report in this survey some new results concerning noncommutative Chern characters: construction and the cases when they are exactly computed. The major result indicates some clear relation of these noncommutative objects and their commutative counterparts. This survey can be considered as the second part of the previous survey (J. of Lie Theory vol. 3 (19

Simone Gutt

I have chosen, in this presentation of Deformation Quantization, to focus on 3 points: the uniqueness --up to equivalence-- of a universal star product (universal in the sense of Kontsevich) on the dual of a Lie algebra, the cohomology classes introduced by Deligne for equivalence classes of differential star products on a symplectic manifold and the constru

T. Carletti, S. Marmi

We study Siegel's center problem on the linearization of germs of diffeomorphisms in one variable. In addition of the classical problems of formal and analytic linearization, we give sufficient conditions for the linearization to belong to some algebras of ultradifferentiable germs closed under composition and derivation, including Gevrey classes. In the

Adam Logan

We prove relations among the classes of certain divisors on the moduli spaces of curves with marked points, generalizing the Brill-Noether Ray Theorem of Eisenbud and Harris.

G. L. Cardoso, B. de Wit, J. Käppeli, T. Mohaupt

We present a class of static supersymmetric multi-center black hole solutions arising in four-dimensional N=2 supergravity theories with terms quadratic in the Weyl tensor. We also comment on possible corrections to the metric on the moduli space of these black holes solutions.

Alon E. Faraggi

I contemplate the possibility that the mismatch between the maximally symmetric point (the free fermionic point) and the strictly self-dual point in the Narain moduli space plays a role in the string vacuum selection. The role of self-duality in the recent formulation of quantum mechanics from an equivalence postulate, and the new perspective that it offers

David I. Olive, Marcos Alvarez

We investigate the electromagnetic duality properties of an abelian gauge theory on a compact oriented four-manifold by analysing the behaviour of a generalised partition function under modular transformations of the dimensionless coupling constants. The true partition function is invariant under the full modular group but the generalised partition function

Hans Peter Nilles

Anomalous U(1) gauge symmetries can appear both in heterotic and type I string theories. In the heterotic case we find a single anomalous U(1), while in open string theories several such symmetries can appear. Nonetheless, there is a conjectured duality symmetry that might connect these two theories. We review the properties of anomalous gauge symmetries in

Wen-ge Wang

We study a simple model for which perturbation theory gives ultravioletly divergent results. We show that when the eigen-solution problem of the Hamiltonian of the model is treated nonperturbatively, it is possible for eigenenergies of the Hamiltonian to be finite.

Ze-sen Yang, Xianhui Li, Zhinig Zhou, Yushu Zhong

Since the SU(n) gauge theory with massive gauge bosons has been proven to be renormalisable we reinvestigate the renormalisability of the SU$_L$(2) $\times$ U$_Y$(1) electroweak theory with massive W Z bosons. We expound that with the constraint conditions caused by the W Z mass term and the additional condition chosen by us we can performed the quantization

Shin'ichi Nojiri, Octavio Obregon, Sergei D. Odintsov, Sachiko Ogushi

The family of brane-world solutions of d+1-dimensional dilatonic gravity is presented. It includes flat brane with small cosmological constant and (anti) de Sitter brane, dilatonic brane-world black holes (Schwarzschild-(anti-) de Sitter, Kerr, etc). Gravitational and dilatonic perturbations around such branes are found. It is shown that near dilatonic brane

M. Alford

I discuss recent developments in our understanding of the color-superconducting phases of cold, dense quark matter. I describe the phase diagram as a function of density and the strange quark mass, and outline some ideas about possible observational consequences of these exotic phases.

Frank Wilczek

Recently we have made considerable progress in our understanding of the behavior of QCD in extreme conditions of high temperature or large baryon number density. Among the highlights are the prediction of a well-characterized true critical point, and the discovery that the ground state of three-flavor QCD at asymptotically high densities exhibits color-flavo

S. L. Cherkas

T-odd P-even long-range electromagnetic interaction of a particle of spin 1/2 with the nucleus is considered. Though matrix element of the interaction is zero for the particles on mass shell, nevertheless, null test exists for the interaction. The test consists in measuring of the spin-dependent T-odd P-even forward elastic scattering amplitude of a particle

William J. Marciano

The status of various precisely measured electroweak parameters is reviewed. Natural relations among them are shown to constrain the Higgs mass, m_H, via quantum loop effects to relatively low values. A comparison with direct Higgs searches is made.

S. Moretti

We analyse the chances of detecting charged Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) at the Large Hadron Collider (LHC) in the $W^\pm h$ mode, followed by the dominant decay of the lightest Higgs scalar, $h\to b\bar b$. If the actual value of $M_h$ is already known, this channel offers possibly the optimal final state kinematics for c

Gregers Neergaard, Jes Madsen

We calculate the thermodynamic potential of bubbles of hadrons embedded in quark-gluon plasma, and of droplets of quark-gluon plasma embedded in hadron phase. This is a generalization of our previous results to the case of non-zero chemical potentials. As in the zero chemical potential case, we find that a quark-gluon plasma in thermodynamic equilibrium may

Chao-Hsi Chang, Liang Han, Yi Jiang, Wen-Gan Ma

The subprocess $gg \to t\bar{c}+\bar{t}c$ in the two-Higgs-doublet model with flavor-changing scalar couplings is examined at the one loop level. With perturbative QCD factorization theorem, the corresponding cross sections for hadron-hadron collisions are computed numerically. The results are applicable to the whole mass range of the weakly coupled Higgs bo

F. Finelli, R. Brandenberger

We study the parametric amplification of super-Hubble-scale scalar metric fluctuations at the end of inflation in some specific two-field models of inflation, a class of which is motivated by hybrid inflation. We demonstrate that there can indeed be a large growth of fluctuations due to parametric resonance and that this effect is not taken into account by t

V. A. Miransky

The dynamics in QCD with different number of fermion flavors N_f is discussed. The emphasis is on the description of the conformal phase transition with respect to N_f separating a phase with no confinement and chiral symmetry breaking and a phase with confinement and with chiral symmetry breaking.

Lior M. Burko

We study the self force acting on a scalar charge in uniform circular motion around a Schwarzschild black hole. The analysis is based on a direct calculation of the self force via mode decomposition, and on a regularization procedure based on Ori's mode-sum regularization prescription. We find the four self-force at arbitrary radii and angular velocities

M. Novello, V. A. De Lorenci, E. Elbaz, J. M. Salim

We show that non-linear electrodynamics may induce a photon to follow a closed path in spacetime. We exhibit a specific case in which such closed lightlike curve (CLC) appears

M. A. Clayton, J. W. Moffat

A vector-tensor theory of gravity that was introduced in an earlier publication is analyzed in detail and its consequences for early universe cosmology are examined. The multiple light cone structure of the theory generates different speeds of gravitational and matter wave fronts, and the contraction of these light cones produces acausal, superluminary infla

Paul Federbush

Partial results are obtained for Schwarzschild- like solutions in a gravity theory with action density (-g)^(1/2)[Rik^2+bR^2]. A seven parameter family of implicit solutions is found. A number of explicit solutions are also exhibited.

Maurice Bruynooghe, Michael Leuschel, Konstantinos Sagonas

We study the notion of binding-time analysis for logic programs. We formalise the unfolding aspect of an on-line partial deduction system as a Prolog program. Using abstract interpretation, we collect information about the run-time behaviour of the program. We use this information to make the control decisions about the unfolding at analysis time and to turn

Maurice Bruynooghe, Henk Vandecasteele, D. Andre de Waal, Marc Denecker

In solving a query, the SLD proof procedure for definite programs sometimes searches an infinite space for a non existing solution. For example, querying a planner for an unreachable goal state. Such programs motivate the development of methods to prove the absence of a solution. Considering the definite program and the query ``<- Q&#39;&#39; as clauses of a

Nicholas J. Ramer, Andrew M. Rappe

We employ a new method for studying compositionally disordered ferroelectric oxides. This method is based on the virtual crystal approximation (VCA), in which two or more component potentials are averaged into a composite atomic potential. In our method, we construct a virtual atom with the correctly averaged atomic size and atomic eigenvalues. We have used

D. V. Averin

Quasiclassical Green&#39;s functions of a short superconductor/normal metal/superconductor (SNS) junction are calculated for multi-mode junction with arbitrary electron transmission properties. They provide the basis for description of all of the junction transport characteristics, and are used to calculate the equilibrium spectral density of supercurrent fl

B. Raquet, A. Anane, S. Wirth, P. Xiong

Giant Random Telegraph Noise (RTN) in the resistance fluctuation of a macroscopic film of perovskite-type manganese oxide La2/3Ca1/3MnO3 has been observed at various temperatures ranging from 4K to 170K, well below the Curie temperature (TC = 210K). The amplitudes of the two-level-fluctuations (TLF) vary from 0.01% to 0.2%. We use a statistical analysis of t

S. A. Basylko, P. J. Kundrotas, V. A. Onischouk, E. E. Tornau

The Coulomb gap in a donor-acceptor model with finite charge transfer energy $Δ$ describing the electronic system on the dielectric side of the metal-insulator transition is investigated by means of computer simulations on two- and three-dimensional finite samples with a random distribution of equal amounts of donor and acceptor sites. Rigorous relations ref

D. Karevski, L. Turban, F. Igloi

We study the critical energy and magnetization profiles for the Ising quantum chain with a marginal extended surface perturbation of the form A/y, y being the distance from the surface (Hilhorst-van Leeuwen model). For weak local couplings, A<A_c, the model displays a continuous surface transition with A-dependent exponents, whereas, for A>A_c, there is surf

P. M. Hui, T. S. Lo, N. F. Johnson

We study a recently proposed model in which an odd number of agents are competing to be in the minority. The agents have one strategy in hand which is to follow the most recent history. Each agent is also assigned a value p, which is the probability that an agent will follow the trend. Evolution is introduced through the modification of the value of p when t

D. Bedeaux, J. M. Rubi

The common rules of classical nonequilibrium thermodynamics do not allow an Onsager coefficient like the viscosity to depend on the shear rate. Such a dependence is experimentally well documented, however. In this paper it is shown, using nonequilibrium thermodynamics alone, how it is possible that the effective viscosity coefficient of an isotropic colloida