October 1996 arXiv papers — page 2

Mark Bowick, Philippe Di Francesco, Olivier Golinelli, Emmanuel Guitter

Models of folding of a triangular lattice embedded in a discrete space are studied as simple models of the crumpling transition of fixed-connectivity membranes. Both the case of planar folding and three-dimensional folding on a face-centered-cubic lattice are treated. The 3d-folding problem corresponds to a 96-vertex model and exhibits a first-order folding

R. Berkovits, B. L. Altshuler

We study the effect of electron-electron (e-e) interactions on compressibility, capacitance and inverse compressibility of electrons in a quantum dot or a small metallic grain. The calculation is performed in the random-phase approximation. As expected, the ensemble-averaged compressibility and capacitance decreases as a function of the interaction strength,

Asimkumar Ghosh, Indrani Bose

We construct frustrated antiferromagnetic spin ladders with m chains for which the exact ground state can be determined in a particular parameter regime. The excitation spectrum is shown rigorously to be gapless ( with gap ) for odd ( even ) m. In a general parameter regime, the four-chain and periodic ladders are studied using a mean-field theory based on t

Arisato Kawabata, Tobias Brandes

We investigate the effect of electron-electron interactions on the transport properties of disordered quasi one-dimensional quantum wires with two or more subbands occupied. We apply two alternative methods to solve the logarithmic divergent problem, namely the parquet graph theory and a renormalization group calculation. We solve the group equations analyti

R. Kotlyar, S. Das Sarma

Using an exact diagonalization technique within a generalized Mott-Hubbard Hamiltonian, we predict the existence of a ground state persistent current in coherent two-dimensional semiconductor quantum dot arrays pierced by an external magnetic flux. The calculated persistent current, which arises from the nontrivial dependence of the ground state energy on th

C. Jarzynski

An expression is derived for the classical free energy difference between two configurations of a system, in terms of an ensemble of finite-time measurements of the work performed in parametrically switching from one configuration to the other. Two well-known equilibrium identities emerge as limiting cases of this result.

Wolfgang Lezius, Reinhard Rapp, Manfred Wettler

This paper presents an integrated tool for German morphology and statistical part-of-speech tagging which aims at making some well established methods widely available. The software is very user friendly, runs on any PC and can be downloaded as a complete package (including lexicon and documentation) from the World Wide Web. Compared with the performance of

A. Hof

This paper relates uniform alpha-Hoelder continuity, or alpha-dimensionality, of spectral measures in an arbitrary interval to the Fourier transform of the measure. This is used to show that scaling exponents of exponential sums obtained from time series give local upper bounds on the degree of Hoelder continuity of the power spectrum of the series. The resu

Giovannni Gallavotti

Kinematical and dynamical properties of chaotic systems are reviewed and a few applications are described.

Brian A. Vaughan, Michael A. Nowak

We describe how the coherence function, a Fourier frequency-dependent measure of the linear correlation between time series measured simultaneously in two energy channels, can be used in conjunction with energy spectra, power spectra, and time delays between energy channels to constrain models of the spectrum and variability of x-ray binaries. Here we presen

R. Ramaty, B. Kozlovsky, R. E. Lingenfelter

We derive constraints on the cosmic rays responsible for the Be and part of the B observed in stars formed in the early Galaxy: the cosmic rays cannot be accelerated from the ISM; their energy spectrum must be relatively hard (the bulk of the nuclear reactions should occur at $>$30 MeV/nucl); and only 10$^{49}$ erg/SNII in high metallicity, accelerated parti

Pawan Kumar, Douglas Abrams

Recent observations indicate that solar p-mode line profiles are not exactly Lorentzian, but rather exhibit varying amounts of asymmetry about their respective peaks. We analyze p-mode line asymmetry using both a simplified one-dimensional model and a more realistic solar model. We find that the amount of asymmetry exhibited by a given mode depends on the lo

S. Colombi, F. Bernardeau, F. R. Bouchet, L. Hernquist

Perturbation theory makes it possible to calculate the probability distribution function (PDF) of the large scale density field in the small variance limit. For top hat smoothing and scale-free Gaussian initial fluctuations, the result depends only on the linear variance, sigma_linear, and its logarithmic derivative with respect to the filtering scale -(n_li

L. Ciotti, B. Lanzoni

We study the dynamical properties of spherical galaxies with surface luminosity profile described by the R^{1/m}-law, in which a variable degree of orbital anisotropy is allowed. The parameter m for the present models covers the range [1,10]. For these models we study the self-consistently generated phase-space distribution function (DF), and we derive - as

Rob P. Olling

In a previous paper (Olling 1995, astro-ph/9505002) a method was developed to determine the shapes of dark matter halos of spiral galaxies from an accurate determination of the rotation curve, the flaring of the gas layer and the velocity dispersion in the HI. Here I report the results for the almost edge-on Scd galaxy NGC 4244 (Olling 1996a,astro-ph/9605110

Alexandre Refregier, Abraham Loeb

Gravitational lensing by clusters of galaxies affects the cosmic X-ray background (XRB) by altering the observed density and flux distribution of background X-ray sources. At faint detection flux thresholds, the resolved X-ray sources appear brighter and diluted, while the unresolved component of the XRB appears dimmer and more anisotropic, due to lensing. T

M. Ostrowski, G. Siemieniec-Oziȩbło

Energetic particles in a turbulent medium can be subject to second-order Fermi acceleration due to scattering on moving plasma waves. This mechanism leads to growing particle momentum dispersion and, at the same time, increases the mean particle energy. In the most frequently met situations both processes can be represented by a single momentum diffusion ter

Tal Alexander

The `Bloated Stars Scenario' proposes that AGN broad line emission originates in the winds or envelopes of bloated stars (BS). Alexander and Netzer (1994, 1996) established that ~ 5e4 BSs with dense, decelerating winds can reproduce the observed emission line spectrum and line profiles while avoiding rapid collisional destruction. Here, I investigate a t

Sandu Popescu, Daniel Rohrlich

We point out formal correspondences between thermodynamics and entanglement. By applying them to previous work, we show that entropy of entanglement is the unique measure of entanglement for pure states.

Sergei G. Matinyan, Berndt Müller

We discuss the intimate connection between the chaotic dynamics of a classical field theory and the instability of the one-loop effective action of the associated quantum field theory. Using the example of massless scalar electrodynamics, we show how the radiatively induced spontaneous symmetry breaking stabilizes the vacuum state against chaos, and we specu

Eric Sven Ristad, Peter N. Yianilos

In many applications, it is necessary to determine the similarity of two strings. A widely-used notion of string similarity is the edit distance: the minimum number of insertions, deletions, and substitutions required to transform one string into the other. In this report, we provide a stochastic model for string edit distance. Our stochastic model allows us

H. K. Janssen

It is shown by the method of renormalized field theory that in contrast to a statement based on a mathematically ill-defined invariance transformation and found in most of the recent publications on growth models with surface diffusion, the coupling constant of these models renormalizes nontrivially. This implies that the widely accepted supposedly exact sca

Klaus Behrndt

In recent times quantum corrections for N=2 black holes in 4 dimensions have been addressed in the framework of double extreme black hole solutions, which are characterised by constant scalar fields. In this paper we generalize these solutions to non-constant scalar fields. This enables us to discuss quantum corrections for massless black holes and for confi

Jerzy Lukierski

The difficulties with the measurability of classical space-time distances are considered. We outline the framework of quantum deformations of D=4 space-time symmetries with dimensionfull deformation parameter, and present some recent results.

I. V. Ponomarev, P. G. Silvestrov

Coherent propagation of two interacting particles in $1d$ weak random potential is considered. An accurate estimate of the matrix element of interaction in the basis of localized states leads to mapping onto the relevant matrix model. This mapping allows to clarify the mechanism of enhancement of the localization length which turns out to be rather different

F. J. Carrera, A. C. Fabian, X. Barcons

We have studied the fluctuations of the soft (0.9-2 keV) X-ray background intensity for ~10 arcmin and ~2 arcmin beam sizes, using 80 high galactic latitude medium-deep images from the ROSAT position sensitive proportional counter (PSPC). These fluctuations are dominated (and well reproduced) by confusion noise produced by sources unresolved with the beam si

D. Jido, M. Oka, A. Hosaka

The πNN^* and ηNN^* coupling constants are studied based on the two point functions between the vacuum and a one meson state in the soft meson limit. In terms of a suitably constructed interpolating field for the nucleon and resonances, we have found that the πNN^* couplings vanish, while ηNN^* couplings remain finite. This result explains a relatively suppr

Hiroyuki Kanada, Hiroto So, Shin Takeda

A Higgs-Yukawa system in a broken phase and Euclidean solutions are investigated. Although it has been believed that there are no Euclidean solutions in the broken phase in 4-dimension, we find numerically ones in the phase due to the effect of a strong Yukawa coupling. The complex Yukawa coupling is necessary for the stability of the solution. The extension

Ryotaro Arita, Koichi Kusakabe, Kazuhiko Kuroki, Hideo Aoki

The `extended Aharonov-Bohm (AB) period' recently proposed by Kusakabe and Aoki [J. Phys. Soc. Jpn (65), 2772 (1996)] is extensively studied numerically for finite size systems of strongly correlated electrons. While the extended AB period is the system length times the flux quantum for noninteracting systems, we have found the existence of the boundary acro

C. Glenn Boyd, Zoltan Ligeti, Ira Z. Rothstein, Mark B. Wise

We calculate near zero recoil the order $α_s$ corrections to the Bjorken and Voloshin sum rules that bound the $B\to D^{(*)}\ell\barν$ form factors. These bounds are derived by relating the result of inserting a complete set of physical states in a time ordered product of weak currents to the operator product expansion. The sum rules sum over physical states

M. I. Salkola, A. V. Balatsky, J. R. Schrieffer

The consequences of localized, classical magnetic moments in superconductors are explored and their effect on the spectral properties of the intragap bound states is studied. Above a critical moment, a localized quasiparticle excitation in an s-wave superconductor is spontaneously created near a magnetic impurity, inducing a zero-temperature quantum transiti

Arshad Momen, Carl Rosenzweig

Flux-string models can be used to study the deconfining phase transition. In this note, we study the models proposed by Patel. We also study the large N_c limits of Patel's model. To discuss the validity of the mean field theory results, the one-loop Coleman-Weinberg effective potential is calculated for N_c=3. We argue that the quantum corrections vanis

I. L. Chuang, Debbie W. Leung, Yoshihisa Yamamoto

Traditional quantum error correction involves the redundant encoding of k quantum bits using n quantum bits to allow the detection and correction of any t bit error. The smallest general t=1 code requires n=5 for k=1. However, the dominant error process in a physical system is often well known, thus inviting the question: given a specific error model, can mo

Konrad Banaszek, Peter L. Knight

We study degenerate three photon down conversion as a potential scheme for generating nonclassical states of light which exhibit clear signatures of phase space interference. The Wigner function representing these states contains an interference pattern manifesting quantum coherence between distinct phase space components, and has substantial areas of negati

J. Engel, S. Pittel, P. Vogel, M. Stoitsov

We examine isovector and isoscalar neutron-proton correlations in an exactly solvable model based on the algebra SO(8). We look particularly closely at Gamow-Teller strength and double beta decay, both to isolate the effects of the two kinds of pairing and to test two approximation schemes: the renormalized neutron-proton QRPA (RQRPA) and generalized BCS the

John N. Bahcall, P. I. Krastev, E. Lisi

We show that the effects of neutrino oscillations on 8B solar neutrinos are described well by the first two moments (the average and the variance) of the energy distribution of scattered or recoil electrons. For the SuperKamiokande and the Sudbury Neutrino Observatory experiments, the differences between the moments calculated with oscillations and the stand

W. Reisdorf

Collisions of Au on Au at incident energies of 150, 250 and 400 A MeV were studied with the FOPI-facility at GSI Darmstadt. Nuclear charge (Z < 16) and velocity of the products were detected with full azimuthal acceptance at laboratory angles of 1-30 degrees. Isotope separated light charged particles were measured with movable multiple telescopes in an angul

Edward Witten

On the world-volume of an $M$-theory five-brane propagates a two-form with self-dual field strength. As this field is non-Lagrangian, there is no obvious framework for determining its partition function. An analogous problem exists in Type IIB superstring theory for the self-dual five-form. The resolution of these problems and definition of the partition fun

Bjørn Jensen

We give a simple derivation of a new formal expression for the number of particles produced from a conformal scalar field vacuum due to the creation of a gauge cosmic string. We find that the number of particles released in string formation may be substantially lower than what previous estimates have indicated. Our derivation also indicates that there always

Guido Cognola, Sergio Zerbini

The analytic properties of the zeta-function for a Laplace operator on a generalised cone are studied in some detail using the Cheeger&#39;s approach and explicit expressions are given. In the compact case, the zeta-function of the Laplace operator turns out to be singular at the origin. As a result, strictly speaking, the zeta-function regularisation does n

H. Itoyama, M. Koike, H. Takashino

We examine some properties of supermultiplet consisting of the U(1)_{J} current, extended supercurrents, energy-momentum tensor and the central charge in N=2 supersymmetric Yang-Mills theory. The superconformal improvement requires adding another supermultiplet beginning with the U(1)_{R} current. We determine the anomalous (quantum mechanical) supersymmetry

Michael Luke, Aneesh V. Manohar

The problem of bound states in effective field theories is studied. A rescaled version of nonrelativistic effective field theory is formulated which makes the velocity power counting of operators manifest. Results obtained using the rescaled theory are compared with known results from NRQCD. The same ideas are then applied to study Yukawa bound states in 1+1

Guo-Hong Wu, John N. Ng

Measurement of the transverse muon polarization $P^{\bot}_μ$ in the $K^+ \rightarrow μ^+νγ$ decay will be attempted for the first time at the ongoing KEK E246 experiment and also at a proposed BNL experiment. We provide a general analysis of how $P^{\bot}_μ$ is sensitive to the physical $CP$-violating phases in new physics induced four-Fermi interactions, an

Michael Booth, George Chiladze, Adam F. Falk

We develop quenched chiral perturbation theory for vector mesons made of light quarks, in the limit where the vector meson masses are much larger than the pion mass. We use this theory to extract the leading nonanalytic dependence of the vector meson masses on the masses of the light quarks. By comparing with analogous quantities computed in ordinary chiral

K. G. Chetyrkin

The talk briefly reviews the current state of the art in doing multiloop QCD calculations in a completely analytic way. In particular, we discuss recent analytical calculation of 4-loop O(alpha_s**3) gluino contribution to R(s) and its implications to the Z boson and tau-lepton decay rates.

N. Brambilla, G. M. Prosperi

Taking advantage of a semirelativistic and a full relativistic representation of the quark propagator in an external field we present an unified derivation of the semirelativistic potential and of a Bethe-Salpeter like equation for the quark-antiquark system. We consider three different models for the evaluation of the Wilson loop: the Modified Area Law mode

Stefan Dittmaier

The most interesting theoretical features of W-pair production in e+e- collisions are reviewed. Based on an analysis of on-shell W-pairs, it is shown that the mere inclusion of leading $O(α)$ corrections--such as initial-state radiation, effects from the universal quantities $Δα$ and $Δr$, and the Coulomb singularity--cannot be expected to approximate the $O

Leonard P. A. Haakman, Oleg V. Kancheli, Justus H. Koch

Starting from the same input as the standard BFKL Pomeron, we directly calculate the ``hard&#39;&#39; Pomeron as a gluonic ladder by using Monte Carlo methods. We reproduce the characteristic features of the the BFKL Pomeron and are now also able to evaluate new observables. The applicability of the BFKL approach under realistic kinematical conditions can be

Nils A. Tornqvist, Matts Roos

We reply to the comment of Harada, Sannino and Schechter (hep-ph/9609428) on our recent paper in the Phys. Rev. Letters on the sigma meson. This concerns the question, raised by Isgur and Speth in another comment, of whether a detailed crossing symmetric form is necessary to understand the data. The discussion gives further support on the existence of the br

H. Nunokawa, A. Rossi, V. B. Semikoz, J. W. F. Valle

We present a generalization of the resonant neutrino conversion in matter, including a random component in the matter density profile. The study is focused on the effect of such matter perturbations upon both large and small mixing angle MSW solutions to the solar neutrino problem. This is carried out both for the active-active $ν_e \to ν_{μ,τ}$ as well as a

G. Nardulli, T. N. Pham

We analyze final state strong interaction effects in $B -> D ρ$ and $B -> D^{*}π$ decays using the Regge model. We find that, due to the smallness of the contributions from the non-leading Regge trajectories ($ρ$, $f$, $π$ etc.), final state interaction phases are small if the Pomeron coupling to the charm quark is suppressed in comparison to lighter quarks.

V. Barone, T. Calarco, A. Drago

We report the results of a quark model calculation of the transverse polarization distribution $h_1$. Predictions for the Drell-Yan double spin transverse asymmetry are also presented.

A. V. Anisovich

During several years the data on different channels ppbar (J^{PC}=0^{-+}) --> 3 mesons presented by Crystal Barrel Collaboration were successfully analyzed by extracting the leading amplitude singularities - pole singularities - with the aim to obtain information about two-meson resonances. But these analyses do not take into account three-body final state i

B. Kayser, L. Stodolsky

We discuss ``cascade mixing&#34;, where one particle mixture, say a B0, leads to another, say a K0. A simple analysis is possible in the amplitude approach, which avoids ``collapses of the wavefunction&#34; and is explicitly covariant. Some novel possibilities, both of conceptual and perhaps of experimental interest, arise. For example, we explain how such p

M. Hirai, S. Kumano, M. Miyama

Numerical solution of DGLAP $Q^2$ evolution equations is studied for polarized parton distributions by using a ``brute-force&#34; method. NLO contributions to splitting functions are recently calculated,and they are included in our analysis. Numerical results in polarized parton distributions and in the structure function $g_1$ are shown. In particular, we d

Monoranjan Guchait, D. P. Roy

The top quark data in the lepton plus $τ$ channel offers a viable probe for the charged Higgs boson signal. We analyse the recent Tevatron collider data in this channel to obtain a significant limit on the $H^\pm$ mass in the large $\tanβ$ region.

Alan L. Carey, Thierry Coulhon, Varghese Mathai, John Phillips

In this paper we study some new von Neumann spectral invariants associated to the Laplacian acting on L^2 differential forms on the universal cover of a closed manifold. These invariants coincide with the Novikov-Shubin invariants whenever there is no spectral gap in the spectrum of the Laplacian, and are homotopy invariants in this case. In the presence of

Varghese Mathai, Mikhail Shubin

We develop the theory of twisted L^2-cohomology and twisted spectral invariants for flat Hilbertian bundles over compact manifolds. They can be viewed as functions on the first de Rham cohomology of M and they generalize the standard notions. A new feature of the twisted L^2-cohomology theory is that in addition to satisfying the standard L^2 Morse inequalit

Igor E. Aronov, Gennady P. Berman, David K. Campbell, Sergey V. Dudiy

We have calculated the admittance of a two-dimensional quantum point contact (QPC) using a novel variant of the Wigner distribution function (WDF) formalism. In the semiclassical approximation, a Boltzman-like equation is derived for the partial WDF describing both propagating and nonpropagating electron modes in an effective potential generated by the adiab

Steven Spencer, Henrik Jeldoft Jensen

By using finite temperature molecular dynamics simulations, we consider the question of the existence of dynamical ordering as a two dimensional vortex lattice is driven through a random background potential. The shape of the current-voltage(I-V) characteristics are qualitatively the same as those seen in experiments on the conventional superconductors 2H-Nb

Carsten Timm

Spontaneously created vortex-antivortex pairs are the predominant source of flux noise in high-temperature superconductors. In principle, flux noise measurements allow to check theoretical predictions for both the distribution of vortex-pair sizes and for the vortex diffusivity. In this paper the flux-noise power spectrum is calculated for the highly anisotr

Enrique Diez, Francisco Dominguez-Adame, Angel Sanchez

We investigate the dephasing dynamics of Bloch oscillations in semiconductor superlattices by means of a very simple model including disorder and applied electric fields. A thorough numerical study of our model allows us to claim that small, unintentional well width fluctuations can be responsible for fast dephasing of Bloch oscillations at low temperatures.

B. Gotzelmann, S. Dietrich

A hard sphere fluid confined by hard, structureless, and parallel walls is investigated using a certain version of weighted density functional theory. The density profile, the excess coverage, the finite size contribution to the free energy, the solvation force, and the total correlation function are determined as function of the slit width $L$ for various b

Siegfried Clar, Barbara Drossel, Franz Schwabl

We review the properties of the self-organized critical (SOC) forest-fire model. The paradigm of self-organized criticality refers to the tendency of certain large dissipative systems to drive themselves into a critical state independent of the initial conditions and without fine-tuning of the parameters. After an introduction, we define the rules of the mod

Takashi Kimura, Kazuhiko Kuroki, Hideo Aoki

Quantum Monte Carlo method is used to look into the superconductivity in the three-leg Hubbard ladder. The enhanced correlation for the pairing across the central and edge chains, which has been predicted in the weak-coupling renormalization as an effect of coexistence of gapful and gapless spin modes, is here shown to persist for intermediate interaction st

J. S. Benensohn, D. Q. Lamb, R. E. Taam

We present the results of hydrodynamical simulations of nonaxisymmetric gas flow past a gravitating compact object in two dimensions. Calculations were performed with uniform flow as well as with transverse velocity and density gradients. We find that the flow is highly nonsteady, exhibiting the ``flip-flop'' behavior seen in previous studies in which accret

D. A. Verner, D. G. Yakovlev, I. M. Band, M. B. Trzhaskovskaya

Recently, Bautista (1996, A&AS, 119, 105) reported new calculations of photoionization cross sections for Fe V, and compared them with the earlier results of Reilman & Manson (1979, ApJS, 40, 815) and Verner et al. (1993, Atomic Data Nucl. Data Tables, 55, 233). Bautista claimed that beyond 10 Ry the new cross sections ``converge well toward the results by R

Ricardo P. Schiavon, Beatriz Barbuy, Silvia C. F. Rossi, Andre Milone

The NaI near-infrared doublet has been used to indicate the dwarf/giant population in composite systems, but its interpretation is still a contentious issue. In order to understand the behaviour of this controversial feature, we study the observed and synthetic spectra of cool stars. We conclude that the NaI infrared feature can be used as a dwarf/giant disc

N. Y. Lu, G. Helou, R. Tuffs, C. Xu

We use the ISOPHOT 60 micron image of Tuffs et al. (1996) to study the 60 micron light distribution and its correlation with radio continuum within the disk of spiral galaxy NGC6946, and to resolve the long-standing IRAS controversy as to whether the infrared-to-radio continuum ratio, Q, decreases radially out in galaxy disks. Our main results are: (1) The d

G. Helou, S. Malhotra, C. A. Beichman, H. Dinerstein

We analyze the new mid-infrared maps of NGC 6946 for variations in the color ratio of the 7-to-15 micron emission. Our preliminary findings are that this mid-infrared color is remarkably constant between arms and inter-arm regions, and as a function of radius in the disk, excluding the nuclear region. As surface brightness ranges by more than an order of mag

S. Malhotra, G. Helou, D. van Buren, M. Kong

The nearby spiral galaxy NGC 6946 was observed with ISO-CAM in the mid-infrared, achieving 7 arcsec resolution and sub-MJy/steradian sensitivity. Images taken with CAM filters LW2 (7 microns) and LW3 (15 microns) are analysed to determine the morphology of this galaxy and understand better the emission mechanisms. The mid-infrared emission follows an exponen

Sergio Campana

We discuss serendipitous ROSAT observations of the Be transient A0538-66, which contains the fastest known accreting X-ray pulsar (69 ms). We show that this transient is detected several times during quiescence at a level of about 10^34-35 erg/s. Considering this low luminosity it is more likely that X-rays are produced by matter falling onto the neutron sta

Sten Odenwald, Jeffrey Newmark, George Smoot

A comparison of the COBE, Diffuse Infrared Background Experiment (DIRBE) all-sky survey with the locations of known galaxies in the IRAS Catalog of Extragalactic Objects and the Center for Astrophysics Catalog of Galaxies led to the detection of as many as 56 galaxies. In this paper, we present the photometric analysis of these detections and an analysis of

M. Tavani

X-ray emission can provide a crucial diagnostic of gamma-ray bursts (GRBs). We calculate the X-ray and gamma-ray spectra of impulsive acceleration episodes related to GRB pulses. We use the synchrotron shock model (SSM) as a basis of our calculations. We show that the current data on soft-to-hard emission ratios of GRB pulse emission are in agreement with th

Stefano Andreon, Emmanuel Davoust

The traditional method of morphological classification, by visual inspection of images of uniform quality and by reference to standards for each type, is critically examined. The rate of agreement among traditional morphologists on the morphological type of galaxies is estimated from published classification works, and is estimated at about 20 %, when galaxi

Ruth Durrer

The analysis of anisotropies in the cosmic microwave background (CMB) has become an extremely valuable tool for cosmology. We even have hopes that planned CMB anisotropy experiments may revolutionize cosmology. Together with determinations of the CMB spectrum, they represent the first cosmological precision measurements. This is illustrated in the talk by An

Sangeeta Malhotra, James E. Rhoads, Edwin L. Turner

Foreground galaxies that amplify the light from background quasars may also dim that light if the galaxies contain enough dust. Extinction by dust in lenses could hide the large number of lensed systems predicted for a flat universe with a large value of the cosmological constant $Λ$. We look for one signature of dust, namely reddening, by examining optical-

Mary Crone, Fabio Governato, Joachim Stadel, Thomas Quinn

We test the precision with which weak lensing data can provide characteristic cluster mass profiles within Cold Dark Matter scenarios. Using a parallel treecode to simulate volumes as large as 500h-1 Mpc with good resolution, we generate samples of large clusters within a standard CDM model and an open CDM model with Omega_o=0.3. We mock high-quality lensing

P. Tozzi, F. Governato, A. Cavaliere

We study the formation and evolution of small groups of galaxies using new Monte Carlo simulations. These are directly based on the random walk approach to the statistics of condensations collapsing by gravitational instability, and the results are consistent with the Press and Schechter formula. We stress how observational features of groups, such as galaxy

Frederick M. Goodman, Hans Wenzl

In this paper, we explore the use of path idempotents for the Hecke algebra of type $A$ at roots of unity. For $q$ a primitive $\ell$-th root of unity we obain a non-unital imbedding of (a quotient of) the group algebra of $S_m$ into (a quotient of) the Hecke algebra $H_n(q)$ for certain $m$ and $n$. From this we recover certain instances of irreducibility c

B. Blok, M. Shifman, N. Uraltsev

We address the issue of the quark-hadron duality in the spectral densities induced by the heavy-light quark currents anti-Q q. In the limit m_Q ->oo, m_q ->0 we observe an enhancement of the physical spectral density compared to the quark one in the scalar and axial channels, due to the Goldstone meson contributions. This may imply that the scale where duali

J. W. Moffat

Gravity is treated as a stochastic phenomenon based on fluctuations of the metric tensor of general relativity. By using a (3+1) slicing of spacetime, a Langevin equation for the dynamical conjugate momentum and a Fokker-Planck equation for its probability distribution are derived. The Raychaudhuri equation for a congruence of timelike or null geodesics lead

Martin Bucher, Yong Zhu

We investigate non-Gaussian isocurvature perturbations generated by the evolution of Goldstone modes during inflation. If a global symmetry is broken ``before&#39;&#39; inflation, the resulting Goldstone modes are disordered during inflation in a precise and predictable way. After inflation these Goldstone modes order themselves in a self-similar way, much a

Riccardo Guida, Jean Zinn Justin

The equation of state of the universality class of the 3D Ising model is determined numerically in the critical domain from quantum field theory and renormalization group techniques. The starting point is the five loop perturbative expansion of the effective potential (or free energy) in the framework of renormalized $ϕ^4_3$ field theory. The 3D perturbative

L. C. Q. Vilar, C. A. G. Sasaki, S. P. Sorella

The supersymmetric descent equations in superspace are discussed by means of the introduction of two operators which allow to decompose the supersymmetric covariant derivatives as BRS commutators.

S. Zaroubi, I. Zehavi, A. Dekel, Y. Hoffman

The power spectrum (PS) of mass density fluctuations, independent of `biasing&#39;, is estimated from the Mark III catalog of peculiar velocities using Bayesian statistics. A parametric model is assumed for the PS, and the free parameters are determined by maximizing the probability of the model given the data. The method has been tested using detailed mock

Luis Bento, Rui Neves

We calculate the electromagnetic fermion form-factors induced by the anomalous gauge boson interactions contained in the operators ODW and ODB. Other results regarding anomalous triple gauge boson interactions are briefly overviewed. We study the interplay between vertex corrections and gauge boson self-energies extended to the longitudinal degrees of freedo

B. C. Allanach, S. F. King, G. K. Leontaris, S. Lola

We discuss the origin of Yukawa textures in the string-inspired and string derived models based on the gauge group SU(4)xSU(2)_LxSU(2)_R supplemented by a U(1)_X gauged family symmetry. The gauge symmetries are broken down to those of the minimal supersymmetric standard model which is the effective theory below 10^16 GeV. The combination of the U(1)_X family

E. V. Ivashkevich

All Lie symmetries of the Burgers equation driven by an external random force are found. Besides the generalized Galilean transformations, this equation is also invariant under the time reparametrizations. It is shown that the Gaussian distribution of a pumping force is not invariant under the symmetries and breaks them down leading to the nontrivial vacuum

Masato Arai, Hisakazu Minakata

We discuss the unitarity relation of the Aharonov-Bohm scattering amplitude with the hope that it distinguishes between the differing treatments which employ different incident waves. We find that the original Aharonov-Bohm scattering amplitude satisfies the unitarity relation under the regularization prescription whose theoretical foundation does not appear

She-Sheng Xue

Inspired by the vector-like phenomenon of chiral gauge theories at short distances, we postulate that the $W^\pm$-gauge boson has a vector-like gauge coupling in the high-energy region, beside its purely right-handed gauge coupling observed in the low-energy region. It is discussed that the top quark acquires its mass via spontaneous symmetry breaking, while

A. D. Dolgov, S. Pastor, J. C. Romao, J. W. F. Valle

We determine the restrictions imposed by primordial nucleosynthesis upon a heavy tau neutrino, in the presence of nu-tau annihilations into Majorons, as expected in a wide class of particle physics models of neutrino mass. We determine the equivalent number of light neutrino species $N_{eq}$ as a function of nu-tau mass and the nu-tau-Majoron coupling $g$. W

Elliott H. Lieb, Heinz Siedentop, Jan Philip Solovej

The stability of matter composed of electrons and static nuclei is investigated for a relativistic dynamics for the electrons given by a suitably projected Dirac operator and with Coulomb interactions. In addition there is an arbitrary classical magnetic field of finite energy. Despite the previously known facts that ordinary nonrelativistic matter with magn

Saburo Kakei

We investigate algebraic structure for the $B_N$-type Calogero model by using the exchange-operator formalism. We show that the set of the Jack polynomials whose arguments are Dunkl-type operators provides an orthogonal basis.

A. Cohen, R. Berkovits, A. Heinrich

We present numerical results for the zero temperature persistent currents carried by interacting spinless electrons in disordered one dimensional continuous rings. The disorder potential is described by a collection of delta-functions at random locations and strengths. The calculations are performed by a self-consistent Hartree-Fock (H-F) approximation. Beca

Markus Grassl, Thomas Beth, Thomas Pellizzari

The quantum erasure channel (QEC) is considered. Codes for the QEC have to correct for erasures, i. e., arbitrary errors at known positions. We show that four qubits are necessary and sufficient to encode one qubit and correct one erasure, in contrast to five qubits for unknown positions. Moreover, a family of quantum codes for the QEC, the quantum BCH codes

C. S. Kim, S. Alam

Recent CDF data of the inclusive jet cross section shows threshold-like structured deviation, around transverse momentum $E_T(j)\approx 200 \sim 350$ GeV. If this data is real, not just some statistical fluctuation, is it possible to interpret the anomaly in terms of virtual SUSY effects? The purpose of this note is to address this question. However, we find

Valery Telnov

A novel method of electron beam cooling is considered which can be used for linear colliders. The electron beam is cooled during collision with focused powerful laser pulse. With reasonable laser parameters (laser flash energy about 10 J) one can decrease transverse beam emittances by a factor about 10 per one stage. The ultimate transverse emittances are mu

B. Kaulakys

The quantum-classical correspondence for dynamics of the nonlinear classically chaotic systems is analysed. The problem of quantum chaos consists of two parts: the quasiclassical quantisation of the chaotic systems and attempts to understand the classical chaos in terms of quantum mechanics. The first question has been partially solved by the Gutzwiller semi

Hans E. Plesser, Dietmar Wendt

The discrete class algorithm presented in this paper is an efficient simulation tool for stochastic processes governed by a reasonably small set of transition rates. The algorithm is presented, its performance compared to prevailing methods and applications to epitaxial growth and neuronal models are sketched. Source code is available from the author&#39;s W