September 1999 arXiv papers — page 18

M. D. Reid

Correlations of the type discussed by EPR in their original 1935 paradox for continuous variables exist for the quadrature phase amplitudes of two spatially separated fields. These correlations were experimentally reported in 1992. We propose to use such EPR beams in quantum cryptography, to transmit with high efficiency messages in such a way that the recei

Enrico Meggiolaro

We study the asymptotic short-distance behaviour as well as the asymptotic large-distance behaviour of the gauge-invariant quark-antiquark nonlocal condensates in QCD. A comparison of some analytical results with the available lattice data is performed.

UKQCD Collaboration, J. Garden

We present UKQCD's latest results for the static quark potential and light hadron spectrum obtained from matched simulations using two flavours of dynamical quarks. We report that using matched ensembles helps disentangle screening effects from discretisation errors in the static quark potential.

A. A. Sen, N. Banerjee

A new solution for the spacetime outside the core of a U(1) static global string has been presented which is nonsingular. This is the first example of a nonsingular spacetime around a static global string.}}

Hang Bae Kim, Hyung Do Kim

We obtain the general inflationary solutions for the slab of five-dimensional AdS spacetime where the fifth dimension is an orbifold $S^1/Z_2$ and two three-branes reside at its boundaries, of which the Randall-Sundrum model corresponds to the static limit. The investigation of the general solutions and their static limit reveals that the RS model recasts bo

Bidhan Chandra Bag, Deb Shankar Ray

We examine the weak quantum noise limit of Wigner equation for phase space distribution functions. It has been shown that the leading order quantum noise described in terms of an auxiliary Hamiltonian manifests itself as an additional fluctuational degree of freedom which may induce chaotic and regular oscillations in a nonlinear oscillator.

Azusa Yamaguchi, Akio Sugamoto

Applying Genetic Algorithm for the Lattice Gauge Theory is formed to be an effective method to minimize the action of gauge field on a lattice. In 4 dimensions, the critical point and the Wilson loop behaviour of SU(2) lattice gauge theory as well as the phase transition of U(1) theory have been studied. The proper coding methodi has been developed in order

M. I. Katsnelson, V. V. Dobrovitski, B. N. Harmon

We study propagation of the decohering influence caused by a local measurement performed on a distributed quantum system. As an example, the gas of bosons forming a Bose-Einstein condensate is considered. We demonstrate that the local decohering perturbation exerted on the measured region propagates over the system in the form of a decoherence wave, whose dy

Anna Kalliomäki, Jukka Maalampi, Morimitsu Tanimoto

The CP violation effects in long baseline neutrino oscillations are studied in the framework of a four-neutrino model (three active neutrinos and one sterile neutrino). It is assumed that neutrino masses are devided into two nearly degenerate pairs, as indicated by the oscillation data. Approximative analytic expressions are derived for the probability diffe

R. Martinez, J-Alexis Rodriguez, M. Vargas

We analyze the vertex Zff in the framework of models that add a new bottom quark in a nonsequential way and we evaluate the tree level contribution to LEP/SLC data $R_{b}$, $R_{l}$ and the total Z width $Γ_{Z}$. We obtain bounds for the mixing angles through the experimentally allowed contour regions of the parameters $Λ_{L,R}$ introduced here. In order to g

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

We propose a nuclear spin quantum computer based on magnetic resonance force microscopy (MRFM). It is shown that an MRFM single-electron spin measurement provides three essential requirements for quantum computation in solids: (a) preparation of the ground state, (b) one- and two- qubit quantum logic gates, and (c) a measurement of the final state. The propo

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

We report the first simulations of the dynamics of quantum logic operations with a large number of qubits (up to 1000). A nuclear spin chain in which selective excitations of spins is provided by the gradient of the external magnetic field is considered. The spins interact with their nearest neighbors. We simulate the quantum control-not (CN) gate implementa

Mio Murao, Martin B. Plenio, Vlatko Vedral

We present a generalization of quantum teleportation that distributes quantum information from a sender's $d$-level particle to $N_o$ particles held by remote receivers via an initially shared multiparticle entangled state. This entangled state functions as a multiparty quantum information distribution channel between the sender and the receivers. The st

G. M. D'Ariano, M. F. Sacchi, R. Seno

The Standard Quantum Limit (SQL) for the measurement of a free mass position is illustrated, along with two necessary conditions for breaching it. A measurement scheme that overcomes the SQL is engineered. It can be achieved in three-steps: i) a pre-squeezing stage; ii) a standard von Neumann measurement with momentum-position object-probe interaction and ii

I. Vidana, A. Polls, A. Ramos, M. Hjorth-Jensen

We have developed a formalism for microscopic Brueckner-type calculations of dense nuclear matter that includes all types of baryon-baryon interactions and allows to treat any asymmetry on the fractions of the different species (n, p, $Λ$, $Σ^0$, $Σ^+$, $Σ^-$, $Ξ^-$ and $Ξ^0$). We present results for the different single-particle potentials focussing on situ

Yu. M. Sinyukov

The single- and multi- particle inclusive spectra for strongly inhomogeneous thermal boson systems are studied using the method of statistical operator. The thermal Wick's theorem is generalized and the analytical solution of the problem for an boost-invariant expanding boson gas is found. The results demonstrate the effects of inhomogeneity for such a s

L. Phair, L. Beaulieu, L. G. Moretto, G. J. Wozniak

Multifragment emission following Xe+Au collisions at 30, 40, 50 and 60 AMeV has been studied with multidetector systems covering nearly 4-pi in solid angle. The correlations of both the intermediate mass fragment and light charged particle multiplicities with the transverse energy are explored. A comparison is made with results from a similar system, Xe+Bi a

Elizabeth Gasparim, Pushan Majumdar

This is an expository paper which presents the holomorphic classification of rational complex surfaces from a simple and intuitive point of view, which is not found in the literature. Our approach is to compare this classification with the topological classification of real surfaces.

Edouard Brezin, Vladimir Kazakov

We study the statistics of a system of N random levels with integer values, in the presence of a logarithmic repulsive potential of Dyson type. This probleme arises in sums over representations (Young tableaux) of GL(N) in various matrix problems and in the study of statistics of partitions for the permutation group. The model is generalized to include an ex

Pawel Hitczenko, Stephen Montgomery-Smith

This paper considers how to measure the magnitude of the sum of independent random variables in several ways. We give a formula for the tail distribution for sequences that satisfy the so called Levy property. We then give a connection between the tail distribution and the pth moment, and between the pth moment and the rearrangement invariant norms.

David Bressoud, Mourad Ismail, Dennis Stanton

Versions of Bailey's lemma which change the base from q to q^2 or q^3 are given. Iterates of these versions give many new versions of multisum Rogers-Ramanujan identities. We also prove Melzer's conjectures for the Fermionic forms of the supersymmetric analogues of Virasoro characters.

Lajos Molnar

Let H be a Hilbert $C^*$-module over a matrix algebra A. It is proved that any function $T:H\to H$ which preserves the absolute value of the (generalized) inner product is of the form $Tf=ϕ(f)Uf$ $(f\in H)$, where $ϕ$ is a phase-function and U is an A-linear isometry. The result gives a natural extension of Wigner's classical unitary-antiunitary theorem

Lajos Molnar

In this paper we describe the form of those continuous multiplicative maps on B(H) (H being a separable complex Hilbert space of dimension not less than 3) which preserve the rank, or the corank. Furthermore, we characterize those continuous *-semigroup endomorphisms of B(H) which are spectrum non-increasing.

Lajos Molnar

Let X be a compact Hausdorff space and let H be a separable Hilbert space. We prove that the group of all order automorphisms of the $C^*$-algebra $C(X)\otimes B(H)$ is algebraically reflexive.

Lajos Molnar

We present the following reflexivity-like result concerning the automorphism group of the $C^*$-algebra B(H), H being a separable Hilbert space. Let $ϕ:B(H)\to B(H)$ be a multiplicative map (no linearity or continuity is assumed) which can be approximated at every point by automorphisms of B(H) (these automorphisms may, of course, depend on the point) in the

E. Izadi, C. Pauly

Let $P \cup P'$ be the two component Prym variety associated to an étale double cover $\tilde{C} \to C$ of a non-hyperelliptic curve of genus $g \geq 6$ and let $|2Ξ_0|$ and $|2Ξ_0'|$ be the linear systems of second order theta divisors on $P$ and $P'$ respectively. The component $P'$ contains canonically the Prym curve $\tilde{C}$. We show t

Yongbin Ruan

This is an expository article about the recent results on the relation between the naturality problem of quantum cohomology and birational geometry. We give a short survey on Li-Ruan's results. Some conjecture-proposals are discussed.

K. Foerger

We review open descendants of non-supersymmetric type IIB asymmetric orbifolds with zero cosmological constant. We find that supersymmetry remains unbroken on the branes at all mass levels, whereas it is broken in the bulk.

I. Martin, J. Ovalle, A. Restuccia

The hamiltonian formulation of the supersymmetric closed 2-brane dual to the double compactified D=11 closed supermembrane is presented. The formulation is in terms of two U(1) vector fields related by the area preserving constraint of the SUSY 2-brane. Stable solutions of the field equations, which are local minima of the hamiltonian, are found. In the semi

Stephen Hewson

We consider the problem of creating locally supersymmetric theories in signature (10,2). The most natural algebraic starting point is the F-algebra, which is the de Sitter-type (10,2) extension of the super-Poincare algebra. We derive the corresponding geometric group curvatures and evaluate the transformations of the associated gauge fields under the action

Alexey A. Petrov

I give a brief review of final state interactions in meson decays. I describe possible effects of FSI in K, D and B systems, paying particular attention to the description of the heavy meson decays. Available theoretical methods for dealing with the effects of FSI are discussed.

J. R. Pelaez, S. J. Brodsky, C. Merino, N. Toumbas

We review our recent works on tests of perturbative QCD, inspired by the relation between the hadronic decay of the tau lepton and the e+ e- annihilation into hadrons. First, we present a set of commensurate scale relations that probe the self-consistency of leading-twist QCD predictions for any observable which defines an effective charge. These tests are i

B. W. Harris

An introduction and overview of charm production in deep inelastic scattering at HERA is given. The existing next-to-leading order perturbative QCD calculations are then reviewed, and key results are summarized. Finally, comparisons are made with the most recent HERA data, and unresolved issues are highlighted.

Tamas S. Biro, Natascha Hoermann, Harald Markum, Rainer Pullirsch

We analyze the leading Lyapunov exponents of U(1) and SU(2) gauge field configurations on the lattice which are initialized by quantum Monte Carlo simulations. We find that configurations in the strong coupling phase are substantially more chaotic than in deconfinement.

Sergio Pastor, Julien Lesgourgues

We consider some consequences of the presence of a cosmological lepton asymmetry in the form of neutrinos. A relic neutrino degeneracy enhances the contribution of massive neutrinos to the present energy density of the Universe, and modifies the power spectrum of radiation and matter. Comparing with current observations of cosmic microwave background anisotr

Ming-qiu Huang, Cheng-zu Li, Yuan-ben Dai

We present a QCD sum rule calculation of the Isgur-Wise form-factor tau_1(v.v') and tau_2(v.v') for the semileptonic decays B->D_1(2420)l\barνand B->D_2^*(2460)l\barνin the framework of heavy quark effective theory. These two universal functions, associated with the matching of the weak currents in QCD onto those in the effective theory, appear at th

I. L. Solovtsov, D. V. Shirkov

We investigate a new ``renormalization invariant analytic formulation'' of calculations in quantum chromodynamics, where the renormalization group summation is correlated with the analyticity with respect to the square of the transferred momentum $Q^2$. The expressions for the invariant charge and matrix elements are then modified such that the unphy

Harald Fritzsch, Zhi-zhong Xing

We propose a phenomenological model of lepton mixing and CP violation based on the flavor democracy of charge leptons and the mass degeneracy of neutrinos. A nearly bi-maximal flavor mixing pattern, which is favored by current data on atmospheric and solar neutrino oscillations, emerges naturally from this model after explicit symmetry breaking. The rephasin

Harald Fritzsch

In view of the observed strong hierarchy of quark masses, we discuss a new description of flavor mixing which is particularly suited for models of quark mass matrices based on flavor symmetries. The necessary and sufficient conditions for CP violation are clarified. The emergence of CP violation is primarily linked to a large phase difference (near 90^{\circ

Hoang Ngoc Long, Vo Thanh Van

Contributions of flavour-changing neutral currents in the 3 3 1 model with right-handed neutrinos to mass difference of the neutral meson system $Δm_P (P = K, D, B)$ are calculated. Using the Fritzsch anzats on quark mixing, we show that the third family should be different from the first two. We obtain a lower bound on mass of the new heavy neutral gauge bo

Jiro Kodaira, Kazuhiro Tanaka

We review the nucleon's twist-3 polarized structure functions from the viewpoint of gauge invariant, nonlocal light-cone operators in QCD. We discuss a systematic treatment of the polarized structure functions and the corresponding parton distribution functions. We emphasize unique features of higher twist distributions, and the role of the QCD equations

Carleton DeTar, Urs Heller, Pierre Lacock

We have been examining the phenomenon of string breaking in QCD with two flavors of dynamical staggered quarks. We construct a transfer matrix from a combination of ``string'' and ``two-meson'' channels. Preliminary results with low statistics show the expected signs of string breaking.

C. Bernard, T. DeGrand, C. DeTar, S. Gottlieb

We are studying a variety of semileptonic decays of heavy-light mesons in an effort to improve the determination of the heavy-quark Standard-Model CKM matrix elements. Our fermion action is a novel, improved ``fat'' clover action that promises to reduce problems with exceptional configurations. Dynamical sea quarks are included in a mixed approach, i

PACS Collaboration, A. Ali Khan, S. Aoki, R. Burkhalter

We study finite-temperature phase transition and equation of state for two-flavor QCD at $N_t=4$ using an RG-improved gauge action and a meanfield-improved clover quark action. The pressure is computed using the integral method. The O(4) scaling of chiral order parameter is also examined.

S. Catterall, E. Mottola

We verify that summing 2D DT geometries correctly reproduces the Polyakov action for the conformal mode, including all ghost contributions, at large volumes. The Gaussian action is reproduced even for central charges greater than one lending strong support to the hypothesis that the space of all possible dyamical triangulations approximates well the space of

PACS Collaboration, A. Ali Khan, S. Aoki, R. Burkhalter

We present results for the equation of state for pure SU(3) gauge theory obtained with a renormalization-group (RG) improved action. The energy density and pressure are calculated on a $16^3\times 4$ and a $32^3\times 8$ lattice employing the integral method. Extrapolating the results to the continuum limit, we find the energy density and pressure to be in g

A. Hart, M. Teper

We report first calculations of the topological susceptibility measured using the field theoretic method on SU(3) gauge configurations produced by the UKQCD collaboration with two flavours of dynamical, improved, Wilson fermions. Using three ensembles with matched lattice spacing but differing sea quark mass we find that hybrid Monte Carlo simulation appears

Alessandra Feo, Robert Kirchner, Istvan Montvay, Anastassios Vladikas

We report on the latest results of the low-lying spectrum of bound states in SU(2) Yang-Mills theory with light gluinos. The behavior of the disconnected contributions in the critical region is analyzed. A first investigation of a three-gluino state is also discussed.

Maarten Golterman, Elisabetta Pallante

We calculate the logarithmic corrections to the matrix elements for $K^+\toπ^+$ and $K\to$vacuum (which are used on the lattice to determine $K\toππ$ amplitudes), in one-loop quenched and unquenched Chiral Perturbation Theory. We find that these corrections can be large. We also discuss, and present some results for, the direct determination of $K\toππ$ ampl

G. Burgio, R. De Pietri, H. A. Morales-Tecotl, L. F. Urrutia

The main problem in the Hamiltonian formulation of Lattice Gauge Theories is the determination of an appropriate basis avoiding the over-completeness arising from Mandelstam relations. We short-cut this problem using Harmonic analysis on Lie-Groups and intertwining operators formalism to explicitly construct a basis of the Hilbert space. Our analysis is base

Yoshio Kikukawa

We derive the effective action of the light fermion field of the domain-wall fermion, which is referred as q(x) and \bar q(x) by Furman and Shamir. The inverse of the effective Dirac operator turns out to be identical to the inverse of the truncated overlap Dirac operator except a local contact term, which would give the chiral symmetry breaking in the Ginsp

Azusa Yamaguchi, Hideo Nakajima

A class of algorithms for the Landau gauge fixing is proposed, which makes the steepest ascent (SA) method be more efficient by concepts of genetic algorithm. Main concern is how to incorporate random gauge transformation (RGT) %, mutation in genetic algorithm (GA) terminology, to gain higher achievement of the minimal Landau gauge fixing, and to keep lower

G. Bauer

We report on two spectroscopy results from CDF. First, we observe the orbitally excited $B^{**}$ mesons in $B \to \ell D^{(*)}X$ events. We find $28 \pm 6 \pm 3$% of light $B$ mesons produced are $B^{**}$ states. A collective mass fit results in a $B_1$ mass of $5.71 \pm 0.02$ GeV/$c^2$. Secondly, we observe $20.4^{+6.2}_{-5.5}$ decays of $B^+_c \to J/ψ\ell^

I. V. Kanatchikov

Quantization of gravity is discussed in the context of field quantization based on an analogue of canonical formalism (the De Donder-Weyl canonical theory) which does not require the space+time decomposition. Using Horava's (1991) De Donder-Weyl formulation of General Relativity we put forward a covariant generalization of the Schrödinger equation for th

Jeeva S. Anandan

A quantum equivalence principle is formulated by means of a gravitational phase operator which is an element of the Poincare group. This is applied to the spinning cosmic string which suggests that it may, but not necessarily, contain gravitational torsion. A new exact solution of the Einstein- Cartan-Sciama-Kibble equations for the gravitational field with

S. Guruswamy, A. LeClair, A. W. W. Ludwig

We consider the non-hermitian 2D Dirac Hamiltonian with (A): real random mass, imaginary scalar potential and imaginary gauge field potentials, and (B) arbitrary complex random potentials of all three kinds. In both cases this Hamiltonian gives rise to a delocalization transition at zero energy with particle-hole symmetry in every realization of disorder. Ca

S. J. Mitchell, M. A. Novotny, Jose D. Munoz

The Projected Dynamics method was originally developed to study metastable decay in ferromagnetic discrete spin models. Here, we apply it to a classical, continuous Heisenberg model with anisotropic ferromagnetic interactions, which evolves under a Monte Carlo dynamic. The anisotropy is sufficiently large to allow comparison with the Ising model. We describe

A. A. Maradudin, I. Simonsen, T. A. Leskova, E. R. Mendez

We present a method for generating a one-dimensional random metal surface of finite length L that suppresses leakage, i.e. the roughness-induced conversion of a surface plasmon polariton propagating on it into volume electromagnetic waves in the vacuum above the surface. Perturbative and numerical simulation calculations carried out for surfaces generated in

G. Fano, F. Ortolani, A. Parola, L. Ziosi

A tight binding model of electrons interacting via bare Coulomb repulsion is numerically investigated by use of the Density Matrix Renormalization Group method which we prove applicable also to very long range potentials. From the analysis of the elementary excitations, of the spin and charge correlation functions and of the momentum distribution, a picture

F. J. Rodriguez, L. Quiroga, N. F. Johnson

We report on exciton-acoustic-phonon coupling effects on the generation of exciton maximally entangled states in N=2 and 3 quantum dot systems. In particular, we address the question of the combined effect of laser pulses, appropriate for generating Bell and Greenberger-Horne-Zeilinger entangled states, together with decoherence mechanisms as provided by a p

J. M. Rubi, P. Mazur

The reformulation of nonequilibirum thermodynamics, to include the treatment of thermodynamic fluctuations, is applied to the hydrodynamic fluctuations of a simple fluid. It is shown that the nonequilibrium thermodynamic scheme leads to the explicit form of the Fokker-Planck equation which describes the time behaviour of the probability distribution function

Llorens Serra, Antonio Puente, Enrico Lipparini

An orbital current mode peculiar to deformed quantum dots is theoretically investigated; first by using a simple model that allows to interpret analytically its main characteristics, and second, by numerically solving the microscopic equations of time evolution after an initial perturbation within the time-dependent local-spin-density approximation. Results

S. Feldkemper, W. Weber

Calculations for spin-phonon coupling constants in CuGeO3 are presented, applying fourth order superexchange perturbation theory to an extended Hubbard model. In our treatment, the intermediate oxygen ligand states are described by band-like cluster states, due to the presence of significant O(p)-O(p) hopping. We also include the effect of the Ge ions on the

B. N. Narozhny, I. L. Aleiner

We consider mesoscopic fluctuations of the Coulomb drag coefficient $ρ_D$ in the system of two separated two-dimensional electron gases. It is shown that at low temperatures sample to sample fluctuations of $ρ_D$ exceed its ensemble average. It means that in such a regime the sign of $ρ_D$ is random and the temperature dependence almost saturates $ρ_D \sim 1

A. Ozpineci, D. M. Leitner, S. Ciraci

Understanding mechanisms for energy dissipation from nanoparticles in contact with large samples is a central problem in describing friction microscopically. Calculation of the reduced density matrix appears to be the most suitable metho to study such systems that are coupled to a large environment. In this paper the time evolution of the reduced density mat

Giulia Iori, Vassilis Koulovassilopoulos

We study consumption behaviour in systems with heterogeneous interacting agents. Two different models are introduced, respectively with long and short range interactions among agents. At any time step an agent decides whether or not to consume a good, doing so if this provides positive utility. Utility is affected by idiosyncratic preferences and costs as we

Victor Yakhot

An unusual symmetry of the equation for the generating function of transverse velocity differences $Δv=v(x+r)-v(x)$ is used to obtain a closed equation for the probability density function $P(Δv,r)$ in strong three-dimensional turbulence. It is shown that the terms, mixing longitudinal and transverse components of velocity field, dominate the pressure contri

Doron Cohen

The angle coordinate of the Quantum Kicked Rotator problem is treated as if it were an extended coordinate. A new mechanism for destruction of coherence by noise is analyzed using both heuristic and formal approach. Its effectiveness constitutes a manifestation of long-range non-trivial dynamical correlations. Perturbation theory fails to quantify certain as

D. Saumon, G. Chabrier, D. J. Wagner, X. Xie

The recent development of techniques for laser-driven shock compression of hydrogen has opened the door to the experimental determination of its behavior under conditions characteristic of stellar and planetary interiors. The new data probe the equation of state (EOS) of dense hydrogen in the complex regime of pressure ionization. The structure and evolution

Mark Brodwin, Simon Lilly, David Crampton

The Canada-France Deep Fields (CFDF) is a large, deep, multi-colour imaging survey undertaken primarily at CFHT. It is about 10 times fainter than the CFRS (Lilly et al 1995a) and contains over 100 times as many galaxies. With three common fields, CFDF redshifts will be estimated photometrically using the CFRS spectroscopic catalogue as a training set. The p

Mark R. Metzger, Chung-Pei Ma

We present new optical observations of the z=0.282 cluster Abell 697 from the Keck II telescope. Images show an unusual disturbed structure in the cD halo and a previously unknown faint gravitational lens arc. A spectrum of the arc did not yield a redshift, but its spectrum and colors suggest it lies at z>1.3. We construct models to reproduce the arc that sh

Mark Lacy, Susan Ridgway, Neil Trentham

The most massive black holes lie in the most massive elliptical galaxies, and at low-z all radio-loud AGNs lie in giant ellipticals. This strongly suggests a link between radio-loudness and black hole mass. We argue that the increase in the radio-loud fraction with AGN luminosity in optically-selected quasar samples is consistent with this picture. We also u

B. Roscherr, B. E. Schaefer

The spectra of type IIn supernovae indicate the presence of apre-existing slow, dense circumstellar wind (CSW). If the CSW extends sufficiently far from the progenitor star, then dust formation should occur in the wind. The light from the supernova explosion will scatter off this dust and produce a light echo. Continuum emission seen after the peak will have

Mark Lacy

We have imaged 8C 1435+635 (z=4.25; Lacy et al. 1994; Spinrad, Dey & Graham 1995) and 6C 0140+326 (z=4.41; Rawlings et al. 1996) in both continuum and Lyalpha plus continuum bands with the HST. Our images show patchy distributions of continuum and line emission with a tendency for the peaks in the two types of emission to be offset. When compared to Keck K-b

L. Van Waerbeke

Gravitational lensing is potentially able to observe mass-selected halos, and to measure the projected cluster mass function. An optimal mass-selection requires a quantitative understanding of the noise behavior in mass maps. This paper is an analysis of the noise properties in mass maps reconstructed using a maximum likelihood method. The noise power spectr

L. L. Kiss, Gy. Szabo, K. Sarneczky

We present new R filtered CCD observations of 5 faint and moderately faint asteroids carried out between October, 1998 and January, 1999. The achieved accuracy is between 0.01-0.03 mag, depending mainly on the target brightness. The obtained sinodic periods and amplitudes: 683 Lanzia - 4.6+/-0.2 h, 0.13 mag; 725 Amanda - >3.0 h, >=0.40 mag; 852 Wladilena - 4

Yehuda Hoffman

Radial velocity surveys are examined in terms of eigenmode analysis within the framework of CDM-like family of models. Rich surveys such as MARK III and SFI, which consist of more than $10^{3}$ radial velocities, are found to have a few tens of modes that are not noise dominated. Poor surveys, which have only a few tens of radial velocities, are noise domina

F. W. Stecker, M. H. Salamon

We show that GLAST should be able to support or rule out the unresolved-blazar hypothesis for the origin of the diffuse, extragalactic gamma-ray background.

A. Del Popolo, M. Gambera

We study the effect of non-radial motions on the mass function, the velocity dispersion function (hereafter VDF) and on the shape of clusters of galaxies using the model introduced in Del Popolo & Gambera (1998a,b; 1999). The mass function of clusters, obtained using the quoted model, is compared with the statistical data by Bahcall & Cen (1992a,b) and Girar

Katrin Reblinsky, Matthias Bartelmann

We propose a new cluster deprojection algorithm for recovering cluster structure along the line of sight (los) based on the Richardson-Lucy (RL) algorithm, which recovers a nonnegative theoretical distribution from a given projection. To optimize our reconstruction we combine X-ray and Sunyaev-Zeldovich (SZ) data with gravitational lensing maps. The combinat

A. A. Gvozdev, I. S. Ognev

URCA neutrino reemission processes under the conditions in the mantle of a supernova with a strong toroidal magnetic field are investigated. It is shown that parity violation in these processes can be manifested macroscopically as a torque that rapidly spins up the region of the mantle occupied by such a field. Neutrino spin-up of the mantle can strongly aff

Chris R. Benn, Sara L. Ellison

The brightness of the moonless night sky above La Palma was measured on 427 CCD images taken with the Isaac Newton and Jacobus Kapteyn Telescopes on 63 nights during 1987 - 1996. The median sky brightness at high elevation, high galactic latitude and high ecliptic latitude, at sunspot minimum, is B = 22.7, V = 21.9, R = 21.0, similar to that at other dark si

N. Stergioulas, W. Kluzniak, T. Bulik

It has been suggested that the frequency in the co-rotating innermost stable circular orbit (ISCO) about a compact stellar remnant can be determined through X-ray observations of low-mass X-ray binaries, and that its value can be used to constrain the equation of state of ultradense matter. Upon constructing numerical models of rapidly rotating strange (quar

E. Antonello, L. Mantegazza, D. Fugazza, M. Bossi

The light curves of Cepheids and other variable stars in Field A of IC 1613, obtained with a CCD and no filter ($Wh$ photometry), have been analyzed. It is possible to separate first overtone from fundamental mode population I Cepheids taking into account the pulsation amplitude, the shape of the light curve and the period. The expected separation is verifie

J. Hwang

The evolutions of linear structures in a spatially homogeneous and isotropic world model are characterized by some conserved quantities: the amplitude of gravitational wave is conserved in the super-horizon scale, the perturbed three-space curvature in the comoving gauge is conserved in the super-sound-horizon scale, and the angular momentum of rotational pe

T. M. Tauris, G. J. Savonije

We have performed detailed numerical calculations of the non-conservative evolution of close binary systems with low-mass (1.0-2.0 M_sun) donor stars and a 1.3 M_sun accreting neutron star. Rather than using analytical expressions for simple polytropes, we calculated the thermal response of the donor star to mass loss, in order to determine the stability and

Silas R. Beane

We review recent computations of neutral pion photoproduction and Compton scattering on the deuteron in baryon chiral perturbation theory. Progress in extracting the neutron electric dipole amplitude, which is relevant in neutral pion photoproduction, and the neutron polarizabilities, which are relevant in Compton scattering, is discussed.

Sohrab Ismail-Beigi, T. A. Arias

This article addresses a fundamental problem faced by the ab initio community: the lack of an effective formalism for the rapid exploration and exchange of new methods. To rectify this, we introduce a novel, basis-set independent, matrix-based formulation of generalized density functional theories which reduces the development, implementation, and disseminat

K. Agashe, N. G. Deshpande

The CLEO collaboration has recently reported a (first) measurement of $BR (B \to π^+ π^-) = (4.7^{+1.8}_{-1.5} \pm 0.6) \times 10^{-6}$. We study, using recent results on QCD improved factorization, the implications of this measurement for the determination of the CKM phase $α$ and also for the rate for $B \to π^0 π^0$. If the $B \to π^-$ form factor is larg

Jerome Benoit

In this thesis I present my research on the exotic configurations of antiferromagnetic systems characterised by a topological invariant. The research presented outlines the construction of novel local antiferromagnetic degrees of freedom for low dimensional antiferromagnetic lattices. This new construction reproduces the real division algebra hierarchy satis

Yuval Grossman, Alexander L. Kagan, Matthias Neubert

Some rare hadronic decays of B mesons, such as B->pi K, are sensitive to isospin-violating contributions from physics beyond the Standard Model. Although commonly referred to as electroweak penguins, such contributions can often arise through tree-level exchanges of heavy particles, or through strong-interaction loop diagrams. The Wilson coefficients of the

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

We simulate Shor's algorithm on an Ising spin quantum computer. The influence of non-resonant effects is analyzed in detail. It is shown that our ``$2πk$''-method successfully suppresses non-resonant effects even for relatively large values of the Rabi frequency.

A. L. Chernyshev, A. H. Castro Neto, A. R. Bishop

The problems of charge stripe formation, spin-charge separation, and stability of the antiphase domain wall (ADW) associated with a stripe are addressed using an analytical approach to the t-J_z model. We show that a metallic stripe together with its ADW is the ground state of the problem in the low doping regime. The stripe is described as a system of spino

I. Bakas, K. Sfetsos

We consider the sector of N=8 five-dimensional gauged supergravity with non-trivial scalar fields in the coset space SL(6,R)/SO(6), plus the metric. We find that the most general supersymmetric solution is parametrized by six real moduli and analyze its properties using the theory of algebraic curves. In the generic case, where no continuous subgroup of the

B. Moussallam

How fast does the quark condensate in QCD-like theories vary as a function of $N_f$ is inferred from real QCD using chiral perturbation theory at order one-loop. A sum rule is derived for the single relevant chiral coupling-constant, $L_6$. A model independent lower bound is obtained. The spectral function satisfies a Weinberg-type superconvergence relation.

K. F. Liu, S. J. Dong, F. X. Lee, J. B. Zhang

We present results on hadron masses and quark condensate from Neuberger's overlap fermion. The scaling and chiral properties and finite volume effects from this new Dirac operator are studied. We find that the generalized Gell-Mann-Oakes-Renner relation is well satisfied down to the physical u and d quark mass range. We find that in the range of the latt

J. Garriga, V. F. Mukhanov, K. D. Olum, A. Vilenkin

We discuss the large-scale structure of the universe in inflationary cosmology and the implications that it may have for the long-term future of civilizations. Although each civilization is doomed to perish, it may be possible to transmit its accumulated knowledge to future civilizations. We consider several scenarios of this sort. If the cosmological consta

H. A. Fertig, W. Kohn

The density of an atom in a state of well-defined angular momentum has a specific finite spherical harmonic content, without and with interactions. Approximate single-particle schemes, such as the Hartree, Hartree-Fock, and Local Density Approximations, generally violate this feature. We analyze, by means of perturbation theory, the degree of this violation

L. Girardello, M. Petrini, M. Porrati, A. Zaffaroni

We find an exact, N=1 supersymmetric kink solution of 5d gauged supergravity. We associate this solution with the RG flow from N=4 super Yang-Mills theory, deformed by a relevant operator, to pure N=1 super Yang-Mills in the IR. We test this identification by computing various QFT quantities using the supergravity dual: the tension of electric and magnetic s

James M. Gelb, S. P. Rosen

We construct a mass matrix for the four neutrino flavors, three active and one sterile, needed to fit oscillations in all three neutrino experiments: atmospheric, solar, and LSND, simultaneously. It organizes the neutrinos into two doublets whose central values are about 1 eV apart, and whose splittings are of the order of 10^(-3) eV. Atmospheric neutrino os