December 1998 arXiv papers — page 11

Wolfgang Lucha, F. F. Schoberl

This talk reviews several aspects of the "semirelativistic" description of bound states by the spinless Salpeter equation (which represents the simplest equation of motion incorporating relativistic effects) and, in particular, presents or recalls some very simple and elementary methods which allow to derive rigorous statements on the corresponding s

Ilya F. Ginzburg

1. We discuss the opportunities of complete Higgs boson discovery at different colliders. Main conclusion here is: Photon collider is the best for this goal. 2. We discuss how to use the Higgs boson (after its discovery) as the window to a New Physics. Main conclusion here is: Higgs boson production in gluon and photon fusion together with production in proc

M. Ciafaloni, D. Colferai

On the basis of a renormalization group analysis of the kernel and of the solutions of the BFKL equation with subleading corrections, we propose and calculate a novel expansion of a properly defined effective eigenvalue function. We argue that in this formulation the collinear properties of the kernel are taken into account to all orders, and that the ensuin

Merab Gogberashvili

In the model where the Universe is considered as a thin shell expanding in 5-dimensional hyper-space there is a possibility to have just one scale for a particle theory corresponding to the Universe thickness. From a realistic model the relation of this parameter to the Universe size was found.

A. Rodrigues, R. Ugoccioni, J. Dias de Deus

We study continuum percolation in nuclear collisions for the realistic case in which the nuclear matter distribution is not uniform over the collision volume, and show that the percolation threshold is increased compared to the standard, uniform situation. In terms of quark-gluon plasma formation this means that the phase transition threshold is pushed to hi

Hsiang-nan Li

We derive a resummation formula for a $k_T$-dependent parton distribution function at threshold, where $k_T$ is a parton transverse momentum. The derivation requires infrared cutoffs for both longitudinal and transverse loop momenta as evaluating soft gluon emissions in the Collins-Soper resummation framework. This unified resummation exhibits suppression at

W. Hollik

In this conference report a summary is given on the theoretical work that has contributed to provide accurate theoretical predictions for testing the standard model in present and future experiments. Precision calculations for the vector boson masses, for the Z resonance, W pair production, and for the g-2 of the muon are reviewed and the theoretical situati

Sergio Caracciolo, Andrea Montanari, Andrea Pelissetto

We study the finite-size behaviour of a tree-level on-shell improved action for the N-vector model. We present numerical results for N=3 and analytic results in the large-N limit for the mass gap. We also report a perturbative computation at one loop of the mass gap for states of spatial momentum p. We present a detailed comparison of the behaviour of this a

M. Hasenbusch, R. R. Horgan

We consider a gauged O(n) spin model, n >= 2, in one dimension which contains both the pure O(n) and RP(n-1) models and which interpolates between them. We show that this model is equivalent to the non-interacting sum of the O(n) and Ising models. We derive the mass spectrum that scales in the continuum limit, and demonstrate that there are two universality

Srinath Cheluvaraja

We study the finite temperature properties of the SO(3) lattice gauge theory using mean field theory. The main result is the calculation of the effective action at finite temperature. The form of the effective action is used to explain the behaviour of the adjoint Wilson line in numerical simulations. Numerical simulations of the SO(3) lattice gauge theory s

The OPAL Collaboration, G. Abbiendi et al

The product branching ratio, f(b->Lambda_b).BR(Lambda_b->Lambda X), where Lambda_b denotes any weakly-decaying b-baryon, has been measured using the OPAL detector at LEP. Lambda_b are selected by the presence of energetic Lambda particles in bottom events tagged by the presence of displaced secondary vertices. A fit to the momenta of the Lambda particles sep

Andreas Raggl, Wolfgang Slany

Real world combinatorial optimization problems such as scheduling are typically too complex to solve with exact methods. Additionally, the problems often have to observe vaguely specified constraints of different importance, the available data may be uncertain, and compromises between antagonistic criteria may be necessary. We present a combination of approx

D. S. Rokhsar

We show that a ``fragmented Bose condensate'' in which two or more distinct single-particle states are macroscopically occupied by the same species of boson is inherently unstable to the formation of a conventional Bose condensate whose macroscopically occupied state is a linear combination of the ``fragments'' with definite relative phases.

A. Cacciuto, E. B. Gregory, A. Travesset

We investigate finite lattice approximations to the Wilson Renormalization Group in models of unconstrained spins. We discuss first the properties of the Renormalization Group Transformation (RGT) that control the accuracy of this type of approximations and explain different methods and techniques to practically identify them. We also discuss how to determin

Immanuel Bloch, Theodor W. Haensch, Tilman Esslinger

We demonstrate a continuous output coupler for magnetically trapped atoms. Over a period of up to 100 ms a collimated and monoenergetic beam of atoms is continuously extracted from a Bose- Einstein condensate. The intensity and kinetic energy of the output beam of this atom laser are controlled by a weak rf-field that induces spin flips between trapped and u

P. Lunkenheimer, U. Schneider, R. Brand, A. Loidl

Dielectric data on glycerol and propylene carbonate covering 18 decades of frequency are presented and compared to each other. Both materials exhibit qualitatively similar behavior except for marked differences in the high-frequency region just below the boson peak. The results on both materials are consistent with the mode coupling theory of the glass trans

S. Caprara, C. Di Castro, M. Grilli, A. Perali

We study the single-particle spectral properties of electrons coupled to quasicritical charge and spin fluctuations close to a stripe-phase, which is governed by a Quantum Critical Point near optimum doping. We find that spectral weight is transferred from the quasiparticle peak to incoherent dispersive features. As a consequence the distribution of low-layi

C. Oligschleger

Results on the dynamics of silica are presented: vibrations and relaxations. Using molecular dynamics, glass structures are generated by rapidly quenching melts below the glass transition. For the local minima of the structures the vibrational density of states is determined, the structures of the eigenmodes are analyzed, and the influence of the single comp

M. Niemeyer, J. K. Freericks, H. Monien

The Bose-Hubbard model in an external magnetic field is investigated with strong-coupling perturbation theory. The lowest-order secular equation leads to the problem of a charged particle moving on a lattice in the presence of a magnetic field, which was first treated by Hofstadter. We present phase diagrams for the two-dimensional square and triangular latt

J. Bonca, S. A. Trugman, I. Batistic

We describe a variational method to solve the Holstein model for an electron coupled to dynamical, quantum phonons on an infinite lattice. The variational space can be systematically expanded to achieve high accuracy with modest computational resources (12-digit accuracy for the 1d polaron energy at intermediate coupling). We compute ground and low-lying exc

P. A. Marchetti

We outline the basic ideas involved in a recently proposed derivation of a gauge theory for underdoped cuprates in the "spin-gap phase", performed essentially step by step starting from the t-J model, considered as a model Hamiltonian for the CuO_2 layers. The basic tool is the U(1)XSU(2) Chern-Simons bosonization, to which it is dedicated a somewhat

M. Mambrini, J. Trebosc, F. Mila

We show that the low-energy sector of the S=1/2, antiferromagnetic Heisenberg model on a one-dimensional lattice of coupled tetrahedra consists of 2^N replica of the spectrum of the dimerized Heisenberg chain, where N is the number of tetrahedra. This provides a proof of the following properties: i) there is a residual ground-state entropy per spin equal to

M. Mambrini, F. Mila

The large-plaquette scenario of the spin gap in CaV4O9 is investigated on the basis of extensive exact diagonalizations. We confirm the existence of a large-plaquette phase in a wide range of parameters, and we show that the most recent neutron scattering data actually require an intra-plaquette second neighbor exchange integral much larger than the inter-pl

Thomas Vojta, Frank Epperlein

We numerically investigate the transport properties of disordered interacting electrons in three dimensions in the metallic as well as in the insulating phases. The disordered many-particle problem is modeled by the quantum Coulomb glass which contains a random potential, long-range unscreened Coulomb interactions and quantum hopping between different sites.

A. Shelkan

The energy of the electron wave packet interacting with lattice distortion, is considered in anisotropic crystal. Anisotropy of the electron and phonon spectra as well as of the electron-phonon interaction are taken into account. The height of the barrier between free and self-trapped states is calculated in dependence on the anisotropy parameters. The calcu

R. M. Sardarli, A. P. Abdullayev, O. A. Samedov, N. A. Eubova

The results of differential-thermal analysis of various samples as well as dielectric measurements of solid solutions $TlIn_{1-x}Fe_x^{56,57}S_2$ are presented. It has been established that phase transitions become blurred and shift to low temperatures with increasing the concentration of defects in the layered structure. at some threshold value the structur

Indrani Bose, Indranath Chaudhuri

We study the Gierer-Meinhardt model of reaction-diffusion on a site-disordered square lattice. Let $p$ be the site occupation probability of the square lattice. For $p$ greater than a critical value $p_c$, the steady state consists of stripe-like patterns with long-range connectivity. For $p < p_c$, the connectivity is lost. The value of $p_c$ is found to be

Raymond Frésard, Walter Zimmermann

Using a spin-rotation invariant six-slave boson representation, we study the square lattice Hubbard model with nearest-neighbor hopping $t$ and next-nearest neighbor hopping $t&#39;$. We discuss the influence of $t&#39;$ on the charge and magnetic properties. In the hole-doped domain, we find that a negative $t&#39;$ strongly favors itinerant ferromagnetism

F. Pistolesi

The hybridization of the single-excitation branch with the two-excitation continuum is reconsidered from the theoretical point of view by including the effect of the interference term between one and two excitations. The phenomenological theory presented is used to reproduce the experimental data over a wide region of momentum (2.3-3.6 A^{-1}) and energy (0-

Valery I. Rupasov

We study a generalized Kondo model in which a spin-1/2 impurity is coupled to a conduction band by both s-d exchange and potential interactions. A strong potential scattering is shown to screen an exchange scattering, and the Kondo temperature of the system is decreased.

Pragya Shukla

We study the evolution of the distribution of eigenvalues of $N\times N$ matrix ensembles subject to a change of variances of its matrix elements. Our results indicate that the evolution of the probability density is governed by a Fokker- Planck equation similar to the one governing the time-evolution of the particle- distribution in Wigner-Dyson gas, with r

T. Antal, Z. Rácz, A. Rákos, G. M. Schütz

We study the connection between magnetization transport and magnetization profiles in zero-temperature XX chains. The time evolution of the transverse magnetization, m(x,t), is calculated using an inhomogeneous initial state that is the ground state at fixed magnetization but with m reversed from -m_0 for x<0 to m_0 for x>0. In the long-time limit, the magne

S. Das Sarma, E. H. Hwang

Collective charge density excitation spectra of both a spatially separated two-component quasi-one dimensional (1D) quantum plasma, as existing in a semiconductor double quantum wire structure, and a 1D homogeneous electron-hole plasma, as appropriate for a photoexcited semiconductor quantum wire system, are calculated within the two-component random-phase-a

K. Tsemekhman, V. Tsemekhman, C. Wexler

We present a consistent description of the current distribution in the quantum Hall effect, based on two main ingredients: the location of the extended states and the distribution of the electric field. We show that the interaction between electrons produces a boundary line below the Fermi energy, which extends from source to drain. The existence of this lin

Wellington da Cruz

We consider for an anyon gas its termodynamics properties taking into account the fractal statistics obtained by us recently. This approach describes the anyonic excitations in terms of equivalence classes labeled by fractal parameter or Hausdorff dimension $h$. An exact equation of state is obtained in the high-temperature and low-temperature limits, for ga

Wellington da Cruz

We obtain the distribution functions for anyonic excitations classified into equivalence classes labeled by Hausdorff dimension $h$ and as an example of such anyonic systems, we consider the collective excitations of the Fractional Quantum Hall Effect (FQHE). We also introduce the concept of duality between such classes, defined by $\tilde{h}=3-h$. In this w

R. Klages, K. Rateitschak, G. Nicolis

We present a mechanism for thermalizing a moving particle by microscopic deterministic scattering. As an example, we consider the periodic Lorentz gas. We modify the collision rules by including energy transfer between particle and scatterer such that the scatterer mimics a thermal reservoir with arbitrarily many degrees of freedom. The complete system is de

Yun Wang, David N. Spergel, Michael A. Strauss

In inflationary models with minimal amount of gravity waves, the primordial power spectrum of density fluctuations, $A_S^2(k)$, together with the basic cosmological parameters, completely specify the predictions for the cosmic microwave background (CMB) anisotropy and large scale structure. Here we show how we can strongly constrain both $A_S^2(k)$ and the c

Volker Bromm, Paolo Coppi, Richard Larson

In order to constrain the initial mass function of the first generation of stars (Population III), one has to study the fragmentation properties of primordial gas. We present results from 3D simulations, based on Smoothed Particle Hydrodynamics, which explore the idea that small-scale fluctuations in the (cold) dark matter recreate a filamentary and clumpy s

Kevork Abazajian, George M. Fuller

We investigate the effects of baryon/anti-baryon inhomogeneity on primordial nucleosynthesis. Recent work claims that electroweak baryogenesis could give rise to distinct regions of net baryon and anti-baryon number, which could survive until the nucleosynthesis epoch. We discuss neutron diffusion effects on nucleosynthesis yields in these models and specula

Kevork Abazajian, George M. Fuller, Xiangdong Shi

The formation of supermassive black holes through the gravitational collapse of supermassive objects ($M \ga 10^4 M_\odot$) has been proposed as a source of cosmological gamma-ray bursts. The major advantage of this model is that such collapses are far more energetic than stellar-remnant mergers. The major drawback of this idea is the severe baryon loading p

U. Fritze-v. Alvensleben

The Antennae is a pair of late type spirals in the course of merging. The interaction triggered an ongoing strong burst of star formation that also produced a large number of Young Star Clusters (YSCs), many of which seem to be young Globular Clusters (GCs). The observed Luminosity Function of the YSC system is a power-law. We use evolutionary synthesis mode

G. V. Ustyugova, A. V. Koldoba, M. M. Romanova, V. M. Chechetkin

Stationary magnetohydrodynamic (MHD) outflows from a rotating, conducting Keplerian accretion disk threaded by B-field are investigated numerically by time-dependent, axisymmetric (2.5D) simulations using a Godunov-type code. A large class of stationary magneto-centrifugally driven winds are found where matter is accelerated from a thermal speed at the disk

Shantanu Basu, Doug Johnstone, P. G. Martin

Recent observations have revealed a superbubble associated with the young stellar cluster OCl 352 near the W4 H II region: a void in H I emission (Normandeau, Taylor, and Dewdney), and a bright shell in H alpha emission (Dennison, Topasna, and Simonetti). We investigate the hypothesis that the bubble is blown by stellar winds from the O-type stars in the ass

Masao Mori, Yuzuru Yoshii, Ken&#39;ichi Nomoto

We simulate the dynamical, chemical, and spectro-photometric evolution of dwarf and normal elliptical galaxies embedded in a dark matter halo, using a three-dimensional N-body/SPH simulation code. For the forming dwarf elliptical galaxies, supernova-driven winds propagating outwards from inside the system collide with the infalling gas and produce the super-

Margaret Meixner, Toshiya Ueta, Aditya Dayal, Joseph L. Hora

We present the data from a mid-infrared imaging survey of 66 proto-planetary nebula candidates using two mid-IR cameras (MIRAC2 and Berkcam) at the NASA Infrared Telescope Facility and the United Kingdom Infrared Telescope. The goal of this survey is to determine the size, flux, and morphology of the mid-IR emission regions, which sample the inner regions of

Giovanni Carraro, Antonella Vallenari, Leo Girardi, Andrea Richichi

We report on near IR ($J$ and $K$ bands) observations of two $8 \times 8 \~(arcmin)^{2}$ regions centered on the old open clusters Berkeley~17 and Berkeley~18, for which only optical photometry (in $B$,$V$ and $I$ bands) exists. $J$ and $K$ photometry allows us to obtain an independent estimate of cluster metallicity by means of the relationship between the

Gerard Gilmore, IoA Cambridge, UK

Recent HST and ISO observations provide very severe limits on any compact baryonic contributions to galactic (dark) halos. When combined with Milky Way Galaxy microlensing results, almost the entire plausible range of massive compact baryonic objects is excluded by direct observation. Deep direct imaging at 7mu and 15mu with ISOCAM on the ISO spacecraft dire

Andrew W. Blain

To study large-scale structure in the Universe a full census of the contents are required. This is even more important when the processes of galaxy formation are being investigated. In the last year the population of distant galaxies that emit most of their energy in the infrared waveband have been studied in unprecedented detail. The intensity of background

G. Gavazzi, A. Boselli, M. Scodeggio, D. Pierini

We undertook a surface photometry survey of 200 galaxies in the Virgo cluster (complete to B<14.0 mag) carried out in the near-Infrared (NIR) H band. Combining velocity dispersion measurements from the literature with new spectroscopic data for 11 galaxies we derive distances of 59 early type galaxies using the Fundamental Plane (FP) method. The distance of

Kenneth M. Lanzetta, Hsiao-Wen Chen, John K. Webb, Xavier Barcons

Here we describe results of our attempt to determine what types of galaxies are responsible for the Lyman-alpha forest absorption systems, based on our ongoing imaging and spectroscopic survey of faint galaxies in fields of HST spectroscopic target QSOs. Our primary conclusions are that the bulk of the Lyman-alpha forest arises in more or less normal galaxie

Joel R. Primack, Michael A. K. Gross

The recent atmospheric neutrino data from Super-Kamiokande provide strong evidence of neutrino oscillations and therefore of non-zero neutrino mass. These data imply a lower limit on the hot dark matter (i.e., light neutrino) contribution to the cosmological density $Ω_ν>~ 0.001$ --- almost as much as that of all the stars in the universe --- and permit high

A. G. Bytsko, A. Fring

We demonstrate that certain Virasoro characters (and their linear combinations) in minimal and non-minimal conformal models which admit factorized forms are manifestly related to the ADE series. This permits to extract quasi-particle spectra of a Lie algebraic nature which resembles the features of Toda field theory. These spectra possibly admit a constructi

I. Antoniadis, G. D&#39;Appollonio, E. Dudas, A. Sagnotti

We study total and partial supersymmetry breaking by freely acting orbifolds, or equivalently by Scherk-Schwarz compactifications, in type I string theory. In particular, we describe a four-dimensional chiral compactification with spontaneously broken N=1 supersymmetry, some models with partial $N=4\to N=2$ and $N=4\to N=1$ supersymmetry breaking and their h

C. L. Carilli, Min Su Yun

We present models of the 1.4 GHz to 350 GHz spectral index, alpha(350/1.4), for starburst galaxies as a function of redshift. The models include a semi-analytic formulation, based on the well quantified radio-to-far infrared correlation for low redshift star forming galaxies, and an empirical formulation, based on the observed spectrum of the starburst galax

Lam Hui, Ewan D. Stewart

It is quite plausible that the mass of the dark matter particle increases significantly after its freeze-out, due to a scalar field rolling to large values. We describe a realization of this scenario in the context of thermal inflation which naturally gives a cold dark matter particle with the correct cosmological abundance and a mass around $10^{10} {\rm Ge

R. Adhikari, G. Rajasekaran

By combining the inputs from the neutrinoless double beta decay and the fits of cosmological models of dark matter with solar and atmospheric neutrino data, we obtain constraints on two of the mixing angles of Majorana neutrinos, which become stronger when coupled with the reactor neutrino data. These constraints are strong enough to rule out Majorana neutri

Leticia F. Cugliandolo, Jorge Kurchan

We study analytically the effect of temperature cyclings in mean-field spin-glasses. In accordance with real experiments, we obtain a strong reinitialization of the dynamics on decreasing the temperature combined with memory effects when the original high temperature is restored. The same calculation applied to mean-field models of structural glasses shows n

Piet Claus, Renata Kallosh, J. Rahmfeld

We study the boundary limit of the bulk isometries of AdS x S. The superconformal symmetry is realized on the coordinates of the AdS boundary, the fermionic superspace coordinates, and the harmonics on the sphere. We show how these may be related to the coordinates of an off-shell harmonic superspace of SCFT living on the boundary. In the special case of d=4

Maurizia Palummo, Giovanni Onida, Rodolfo Del Sole, Bernardo Mendoza

We compute the linear optical properties of different reconstructions of the clean and hydrogenated Si(100) surface within DFT-LDA, using norm-conserving pseudopotentials. The equilibrium atomic geometries of the surfaces, determined from self-consistent total energy calculations within the Car-Parrinello scheme, strongly influence Reflectance Anisotropy Spe

Vladimir Dotsenko, Jesper Lykke Jacobsen, Marc-Andre Lewis, Marco Picco

We consider q-state Potts models coupled by their energy operators. Restricting our study to self-dual couplings, numerical simulations demonstrate the existence of non-trivial fixed points for 2 <= q <= 4. These fixed points were first predicted by perturbative renormalisation group calculations. Accurate values for the central charge and the multiscaling e

S. M. Bilenky, C. Giunti, W. Grimus

This review is focused on neutrino mixing and neutrino oscillations in the light of the recent experimental developments. After discussing possible types of neutrino mixing for Dirac and Majorana neutrinos and considering in detail the phenomenology of neutrino oscillations in vacuum and matter, we review all existing evidence and indications in favour of ne

Martin Schlichenmaier, Oleg K. Sheinman

Elements of a global operator approach to the WZWN theory for compact Riemann surfaces of arbitrary genus $g$ are given. Sheaves of representations of affine Krichever-Novikov algebras over a dense open subset of the moduli space of Riemann surfaces (respectively of smooth, projective complex curves) with $N$ marked points are introduced. It is shown that th

H. Razmi, M. Golshani

Without imposing the locality condition,it is shown that quantum mechanics cannot reproduce all the predictions of a special stochastic realistic model used in certain spin-correlation experiments.This shows that the so-called locality condition is an unnecessary assumption of Bell's theorem.

R. Harlander, M. Steinhauser

Quantum corrections significantly influence the quantities observed in modern particle physics. The corresponding theoretical computations are usually quite lengthy which makes their automation mandatory. This review reports on the current status of automatic calculation of Feynman diagrams in particle physics. The most important theoretical techniques are i

P. Bonifacio, L. Pasquini, P. Molaro, G. Marconi

In this paper we present the first results of the analysis of intermediate resolution ($\Delta\lambda \sim 3.5 \AA$) spectra of giants of the Sagittarius dwarf galaxy acquired using the ESO NTT telescope. From the deep CCD photometry of Marconi et al (1998a) we have selected a sample of giants representative of the metallicity spread suggested by the compari

G. Marconi, P. Bonifacio, L. Pasquini, P. Molaro

The photometric study of the Sagittarius dwarf galaxy by Marconi et al (1998) has suggested the presence of a spread in metallicity (-0.7< [Fe/H] < -1.6), which may result from different bursts of star formation. We present the results from a Multi Object Slit spectroscopy program carried out at the NTT with the aim to determine spectroscopic abundances of S

J. Charles, A. Le Yaouanc, L. Oliver, O. Pène

We argue that the Large Energy Effective Theory (LEET), originally proposed by Dugan and Grinstein, is applicable to exclusive semileptonic, radiative and rare heavy-to-light transitions in the region where the energy release E is large compared to the strong interaction scale and to the mass of the final hadron, i.e. for q^2 not close to the zero-recoil poi

Jan de Gier, Bernard Nienhuis

The exact stationary state of an asymmetric exclusion process with fully parallel dynamics is obtained using the matrix product Ansatz. We give a simple derivation for the deterministic case by a physical interpretation of the dimension of the matrices. We prove the stationarity via a cancellation mechanism and by making use of an explicit representation of

George F R Ellis, Henk van Elst

The aim of this set of lectures is a systematic presentation of a 1+3 covariant approach to studying the geometry, dynamics, and observational properties of relativistic cosmological models. In giving (i) the basic 1+3 covariant relations for a cosmological fluid, the present lectures cover some of the same ground as a previous set of Carg\`{e}se lectures \c

J. Böckenhauer, D. E. Evans

In this paper we further develop the theory of $α$-induction for nets of subfactors, in particular in view of the system of sectors obtained by mixing the two kinds of induction arising from the two choices of braiding. We construct a relative braiding between the irreducible subsectors of the two ``chiral&#39;&#39; induced systems, providing a proper braidi

H. Dorn, H. -J. Otto

We give a short introduction to and a partial review of the work on the calculation of Wilson loops and $Q\bar Q$-potentials via the conjectured AdS/CFT duality. Included is a discussion of the relative weight of the stringy correction to the target space background versus the correction by the quantum fluctuations of the string world sheet.

Miloslav Znojil

We propose a new approach to the Rayleigh-Schrödinger perturbation expansions of bound states in quantum mechanics. We are inspired by the enormous flexibility of solvable interactions with several (N) discontinuities. Their standard matching solution is modified and transferred in perturbation regime. We employ the global renormalization freedom of the loca

S. Massar, R. Parentani

We analyse when and why unitarity violations might occur in quantum cosmology restricted to minisuperspace. To this end we discuss in detail backscattering transitions between expanding and contracting solutions of the Wheeler-DeWitt equation. We first show that upon neglecting only backscattering, one obtains an intermediate regime in which matter evolves u

H. Heiselberg, A. Levy

Elliptic flow and HBT are studied for non-central relativistic nuclear collisions. Azimuthal asymmetries show up in both elliptic flow and HBT radii and are calculated in both collisionless and hydrodynamic limits relevant for peripheral and central collisions respectively. Determining the reaction plane and measuring the HBT radii as function of the angle b

S. Das Sarma, E. H. Hwang

We calculate within the Boltzmann equation approach the charged impurity scattering limited low temperature electronic resistivity of low density $n$-type inversion layers in Si MOSFET structures. We find a rather sharp quantum to classical crossover in the transport behavior in the $0 - 5$K temperature range, with the low density, low temperature mobility s

Bogdan A. Dobrescu

It has been shown recently that the Higgs doublet may be composite, with the left-handed top-bottom doublet and a new right-handed anti-quark as constituents bound by some four-quark operators with nonperturbative coefficients. I show that these operators are naturally induced if there are extra space dimensions with a compactification scale in the multi-TeV

Marek Czachor

Cryptographic scheme proposed by Bennett, Brassard, and Mermin [Phys. Rev. Lett. {\bf 68}, 557 (1992)] is reformulated in a version involving two polarizing Mach-Zehnder interferometers. Such a form, although physically equivalent to the original one, makes its security explicit, suggestive and easy to explain to non-experts.

Giacomo M. D&#39;Ariano, Matteo G. A. Paris

An adaptive optimization technique to improve precision of quantum homodyne tomography is presented. The method is based on the existence of so-called null functions, which have zero average for arbitrary state of radiation. Addition of null functions to the tomographic kernels does not affect their mean values, but changes statistical errors, which can then

F. M. Fernandez, R. Guardiola, J. Ros, M. Znojil

We consider a two-parameter non hermitean quantum-mechanical hamiltonian that is invariant under the combined effects of parity and time reversal transformation. Numerical investigation shows that for some values of the potential parameters the hamiltonian operator supports real eigenvalues and localized eigenfunctions. In contrast with other PT symmetric mo

G. Bonvicini, J. Welch

A novel method to measure the beam-beam interaction in e+e- colliders is presented.

Paolo Bellomo, C. R. Stroud,

The hydrogen atom in weak external fields is a very accurate model for the multiphoton excitation of ultrastable high angular momentum Rydberg states, a process which classical mechanics describes with astonishing precision. In this paper we show that the simplest treatment of the intramanifold dynamics of a hydrogenic electron in external fields is based on

G. Bonvicini, D. Cinabro, E. Luckwald

The relation between beamstrahlung observables and beam-beam topologies is discussed.

Alexander V. Buryak, Yuri S. Kivshar, Ming-feng Shih, Mordechai Segev

We develop a theory of soliton spiraling in a bulk nonlinear medium and reveal a new physical mechanism: periodic power exchange via induced coherence, which can lead to stable spiraling and the formation of dynamical two-soliton states. Our theory not only explains earlier observations, but provides a number of predictions which are also verified experiment

J. C. Hardy, I. S. Towner

Superallowed $0^+ \to 0^+$ nuclear beta decay provides a direct measure of the weak vector coupling constant, $\GV$. We survey current world data on the nine accurately determined transitions of this type, which range from the decay of $^{10}$C to that of $^{54}$Co, and demonstrate that the results confirm conservation of the weak vector current (CVC) but di

Joseph N. Ginocchio

We review the status of a quasi - degenerate doublets in nuclei, called pseudospin doublets, which were discovered about thirty years ago and the origins of which have remained a mystery, until recently. We show that pseudospin doublets originate from an SU(2) symmetry of the Dirac Hamiltonian which occurs when the scalar and vector potentials are opposite i

Ivan G. Avramidi, Giampiero Esposito

The formulation of gauge theories on compact Riemannian manifolds with boundary leads to partial differential operators with Gilkey--Smith boundary conditions, whose peculiar property is the occurrence of both normal and tangential derivatives on the boundary. Unlike the standard Dirichlet or Neumann boundary conditions, this boundary-value problem is not au

Amanda R. Kay, Bernard S. Kay

We consider some questions concerning the monotonicity properties of entropy and mean entropy of states on translationally invariant systems (classical lattice, quantum lattice and quantum continuous). By taking the property of strong subadditivity, which for quantum systems was proven rather late in the historical development, as one of four primary axioms

An-Wen Deng

In this paper,we count the rational points on the weighted projective spaces defined over number fields w.r.t. ``size&#39;&#39;. An asymptotic formula which generalizes the result of Schanuel&#39;s ``Heights in number fields&#39;&#39; is obtained. Furthermore, we count also the rational points on the product of weighted projective spaces.

Yng-Ing Lee

Let $(N,g_{0})$ be a Kahler-Einstein surface with the first Chern class negative and assume that there exists a branched Lagrangian minimal surfaces with respect to the metric $g_{0}$. We show that when the Kahler-Einstein metric is changed in the same component (i.e. the complex structure is changed), the Lagrangian minimal surface can be deformed according

Dan Marshall

The symmetric Macdonald polynomials are able to be constructed out of the non-symmetric Macdonald polynomials. This allows us to develop the theory of the symmetric Macdonald polynomials by first developing the theory of their non-symmetric counterparts. In taking this approach we are able to obtain new results as well as simpler and more accessible derivati

Dimitri Shlyakhtenko

We define and study a relative free entropy quantity, analogous in its properties to Voiculescu&#39;s relative free entropy Chi^*(...:B). Our definition uses matricial microstates, unlike his definition, which involves non-commutative Hilbert transform. We prove a change of variable formula and certain maximization results for our quantity. We also exhibit a

D. Kaledin, M. Verbitsky

We study the partial resolutions of singularities related to Hilbert schemes of points on an affine space. Consider a quotient of a vector space $V$ by an action of a finite group $G$ of linear transforms. Under some additional assumptions, we prove that the partial desingularization of Hilbert type is smooth only if the action of $G$ is generated by complex

Daniel Ruberman

Techniques of gauge theory are used to define and compute an invariant of certain diffeomorphisms of 4-manifolds. The invariant vanishes for any diffeomorphism which is smoothly isotopic to the identity. As an application, we give the first example of a diffeomorphism of a simply-connected 4-manifold which is homotopic to the identity map, but not smoothly i

G. Arutyunov, S. Frolov, A. Polishchuk

The $S^N\R^8$ supersymmetric orbifold sigma model is expected to describe the IR limit of the Matrix string theory. In the framework of the model the type IIA string interaction is governed by a vertex which was recently proposed by R.Dijkgraaf, E.Verlinde and H.Verlinde. By using this interaction vertex we derive all four particle scattering amplitudes dire

P. H. Frampton

Compactification of Type IIB superstring on an $AdS_5 \times S^5/\Gamma$ background leads to SU(N) gauge field theories with prescribed matter representations. In the 't Hooft limit of large N such theories are conformally finite. For finite N and broken supersymmetry ($\cal N$ = 0) I derive the constraints to be two-loop conformal and examine the consequenc

S. V. Troitsky, M. B. Voloshin

We consider a classical field configuration, corresponding to intersection of two domain walls in a supersymmetric model, where the field profile for two parallel walls at a finite separation is known explicitly. An approximation to the solution for intersecting walls is constructed for a small angle at the intersection. We find a finite effective length of

C. R. Preitschopf, M. A. Vasiliev

We present a new framework for a Lagrangian description of conformal field theories in various dimensions based on a local version of d+2-dimensional conformal space. The results include a true gauge theory of conformal gravity in d=(1,3) and any standard matter coupled to it. An important feature is the automatic derivation of the conformal gravity constrai

Dmitri Antonov, Dietmar Ebert

Representations of the Abelian-projected SU(2)- and SU(3)-gluodynamics in terms of the magnetic monopole currents are derived. Besides the quadratic part, the obtained effective actions contain interactions of these currents with the world-sheets of electric strings in 4D or electric vortex lines in 3D. Next, we illustrate that 3D compact QED is a small gaug

Jeeva S. Anandan

A new force on the magnetic dipole, which exists in the presence of both electric and magnetic fields, is described. Its origin due to the `hidden momentum&#39;, implications and possible experimental tests are discussed.