September 1999 arXiv papers — page 16

R. Lazzari, N. Vast, J. M. Besson, S. Baroni

The atomic structure of icosahedral B$_4$C boron carbide is determined by comparing existing infra-red absorption and Raman diffusion measurements with the predictions of accurate {\it ab initio} lattice-dynamical calculations performed for different structural models. This allows us to unambiguously determine the location of the carbon atom within the boron

P. A. Sreeram, Suresh G. Mishra

Pair fluctuation theory has been used to study the crossover from the weak coupling BCS theory to the strong coupling Bose Einstein Condensation. The effect of fluctuations has been studied over the whole crossover regime. It has been shown that the pair fluctuations are enhanced considerably in both two and three dimensions and hence mean field theory is in

E. Kierlik, M. L. Rosinberg, G. Tarjus

We propose a self-consistent Ornstein-Zernike approximation for studying the Edwards-Anderson spin glass model. By performing two Legendre transforms in replica space, we introduce a Gibbs free energy depending on both the magnetizations and the overlap order parameters. The correlation functions and the thermodynamics are then obtained from the solution of

M. Bergère

We calculate the partition function for "composite particles". For any finite number of states d, and in the following two cases: 1)all states have the same energy, 2)the energy is linearly distributed over the states, we transform the partition function into a finite sum of terms which exhibit trivially their $% d $dependance. The infinite d thermod

L. C. Garcia de Andrade

A teleparallel geometrical description of the nematic phases of liquid crystals is proposed.In the case of the twisted geometry of nematics Cartan torsion is given by a spatial helical form which depends on the twist angle. Geodesics of a test particle around the teleparallel liquid crystal are given.

Jian-Sheng Wang

We discuss a sampling algorithm which generates flat histogram in energy. In combination with transition matrix Monte Carlo, the density of states and derived quantities such as entropy and free energy as a function of temperature can be computed in a single simulation.

Fei Zhou

In this paper, I study the topological excitations in a pairing state in double layer systems at Landau level filling factor $ν=1/2$ in the presence of disorders. Due to mismatches between single particle wave functions of composite Fermions in different layers, the sensitivity of the Chern number of the pairing state, with respect to changes of impurities,

Regina E. Schulte-Ladbeck, Ulrich Hopp, Laura Greggio, Mary M. Crone

We present near-infrared single-star photometry for the low-metallicity Blue Compact Dwarf galaxy VII~Zw~403. We achieve limiting magnitudes of F110W~$\approx$~25.5 and F160W~$\approx$~24.5 using one of the NICMOS cameras with the HST equivalents of the ground-based J and H filters. The data have a high photometric precision (0.1 mag) and are $>95$% complete

M. H. Cohen, P. M. Ogle, H. D. Tran, R. W. Goodrich

We have made high-quality measurements of the polarization spectra of 13 FR II radio galaxies and taken polarization images for 11 of these with the Keck telescopes. Seven of the eight narrow-line radio galaxies (NLRG) are polarized, and six of the seven show prominent broad Balmer lines in polarized light. The broad lines are also weakly visible in total fl

Donald H. Gudehus

The peculiar radial velocities of eight clusters of galaxies, as determined from a variety of distance indicators, are consistent with a bulk flow not greatly different in direction and magnitude from the velocity vector of the Local Group relative to the microwave background radiation. The bulk flow vector is directed to l=266+-18 deg, b=17+-15 deg with a m

J. N. Fry, David Thomas

Second order perturbation theory predicts a specific dependence of the bispectrum, or three-point correlation function in the Fourier transform domain, on the shape of the configuration of its three wave vector arguments, which can be taken as a signature of structure formed by gravitational instability. Comparing this known dependence on configuration shape

O. Le Fevre, R. Abraham, S. J. Lilly, R. S. Ellis

HST images of a sample of 285 galaxies with measured z from the CFRS and Autofib-LDSS redshift surveys are analysed to derive the evolution of the merger fraction out to z~1. We have performed visual and machine-based merger identifications, as well as counts of bright pairs of galaxies with magnitude differences less than 1.5 mag. We find that the pair frac

A. Zirm, A. Dey, M. Dickinson, P. J. McCarthy

We have obtained near-infrared (1.6 micron) images of 11 powerful 3CR radio galaxies at redshifts 0.8 < z < 1.8 using NICMOS on board HST. The high angular resolution permits a detailed study of galaxy morphology in these systems at rest-frame optical wavelengths, where starlight dominates over the extended, aligned UV continuum. The NICMOS morphologies are

Corinne Charbonnel, Suzanne Talon

We extend to the case of A and early-F type stars our study of the transport of matter and angular momentum by wind-driven meridional circulation and shear turbulence. We show that our fully consistent treatment of the same hydrodynamical processes which can account for C and N anomalies in B type stars (Talon et al. 1997) and for the shape of the hot side o

M. Balucinska-Church, M. J. Church, T. Oosterbroek, A. Segreto

During a BeppoSAX observation of the low-mass X-ray binary dip source XB 1323-619 a total of 10 type I X-ray bursts and parts of 12 intensity dips were observed. During non-bursting, non-dipping intervals, the 1-150 keV BeppoSAX spectrum can be modelled by a cutoff power-law with a photon index of 1.48 +/- 0.01, a cutoff energy of 44.1 +5.1/-4.4 keV together

P. Richter, K. S. de Boer, D. J. Bomans, Y. -N. Chin

ORFEUS far UV echelle spectra have been used to investigate HI, H_2 and CO absorption lines along the line of sight towards LH 10:3120 in the LMC, extending the study presented by de Boer et al. (1998). While H_2 absorption is clearly visible, no CO absorption at LMC velocities is detected, but an upper limit of N(CO) < 3.3 10^13 cm^-2 for the CO column dens

Xiang-Ping Wu, Yan-Jie Xue

While X-ray measurements have so far revealed an increase in the volume-averaged baryon fractions $f_b(r)$ of galaxy clusters with cluster radii $r$, $f_b(r)$ should asymptotically reach a universal value $f_b(\infty)=f_b$, provided that clusters are representative of the Universe. In the framework of hydrostatic equilibrium for intracluster gas, we have der

A. Malizia, M. Capalbi, F. Fiore, P. Giommi

The results of a BeppoSAX TOO observation of the BL Lac object Mkn421 during a high intensity state are reported and compared with monitoring X-ray data collected with the BeppoSAX Wide Field Cameras (WFC) and the RXTE All Sky Monitor(ASM). The 0.1-100 keV spectrum of Mkn421 shows continuous convex curvature that can be interpreted as the high-energy end of

Grazyna Stasinska, Daniel Schaerer

We have used the radiation field from a starburst population synthesis model appropriate for the brightest HII region of IZw 18 to perform a photoionization model analysis of this object. We have investigated whether, with the observed nebular density distribution as revealed by the HST images and a total stellar radiation compatible with the observed UV flu

Ewa L. Lokas

I propose a modification of the spherical infall model for the evolution of density fluctuations with initially Gaussian probability distribution and scale-free power spectra. I introduce a generalized form of the initial density distribution around an overdense region and cut it off at half the inter-peak separation accounting in this way for the presence o

L. Lara, G. Giovannini, W. D. Cotton, L. Feretti

We present observations of two radio galaxies, J1835+620 and 3C338, both with signs of having passed through different stages of core activity. The former presents two symmetric and bright components within a typical FR II structure, possibly resulting from two distinct phases of activity; the latter is a FR I radio galaxy with two separated regions with dif

P. A. James, M. S. Seigar

We present K-band spectroscopy for several regions of three nearby spiral galaxies, NGC 613, NGC 628 and NGC 7741. Analysis of the depth of the 2.293 micron CO absorption feature in these spectra reveals that some regions have deep absorptions, indicative of recent star formation, while others have anomalously shallow absorptions. We interpret the latter as

Fulvio Buonomo, Giovanni Carraro, Cesare Chiosi, Cesario Lia

In this paper we present a critical discussion of the algorithms commonly used in N-body simulations of Galaxy Formation to deal with the energy equation governing heating and cooling, to model star formation and the star formation rate, and to account for energy feed-back from stars. First, we propose our technique for solving the energy equation in presenc

A. M. Piersimoni, G. Bono, M. Castellani, G. Marconi

We present deep (I,V-I) and (I,B-I) color-magnitude diagrams (CMDs) of the Antlia dwarf galaxy, based on Science Verification (SV) data collected with the FORS I camera on the ESO Very Large Telescope (VLT). The CMDs present two key features: a well-defined RGB, and a sample of bright blue stars, belonging to a young stellar component. The comparison between

Shude Mao

We study the first microlensing event toward the Carina spiral arm discovered by the OGLE collaboration. We demonstrate that this long duration event exhibits strong parallax signatures. Additional information from the parallax effect allows us to determine the lens transverse velocity projected onto the Sun-source line to be ~145 km/s We also estimate the o

Michael T. Murphy, Michael S. Bessell

Hαand [O III] narrow band, wide field (7 * 7 degree), CCD images of the Small Magellanic Cloud were compared and a catalogue of candidate planetary nebulae and Hαemission-line stars was compiled. The catalogue contains 131 planetary nebulae candidates, 23 of which are already known to be or are probable planetary nebulae or very low excitation objects. Also,

D. V. Ahluwalia

Atoms and the planets acquire their stability from the quantum mechanical incompatibility of the position and momentum measurements. This incompatibility is expressed by the fundamental commutator [x, p_x]=i hbar, or equivalently, via the Heisenberg&#39;s uncertainty principle Delta x Delta p_x sim hbar. A further stability-related phenomenon where the quant

Mladen Pavicic, Norman D. Megill

It is shown that propositional calculuses of both quantum and classical logics are non-categorical. We find that quantum logic is in addition to an orthomodular lattice also modeled by a weakly orthomodular lattice and that classical logic is in addition to a Boolean algebra also modeled by a weakly distributive lattice. Both new models turn out to be non-or

Jean Marie Linhart

We study singularity formation in spherically symmetric solitons of the charge one sector of the (2+1) dimensional S^2 sigma model, also known as $\IC P^1$ wave maps, in the adiabatic limit. These equations are non-integrable, and so studies are performed numerically on radially symmetric solutions using an iterative finite differencing scheme. Analytic esti

Henryk Fuks

We present a rigorous derivation of the flow at arbitrary time in a deterministic cellular automaton model of traffic flow. The derivation employs regularities in preimages of blocks of zeros, reducing the problem of preimage enumeration to a well known lattice path counting problem. Assuming infinite lattice size and random initial configuration, the flow c

Alberto Collino

Title: Indecomposable Higher Chow Cycles on Low Dimensional Jacobians Authors: Alberto Collino Comments: AMS-TeX, 10 pages Subj-class: Algebraic Geometry MSC-class: 14C30 ;19E15 There is a basic indecomposable higher cycle K in Bloch&#39;s higher Chow group CH^{g}(J(C),1) on the Jacobian J(C) of a general hyperelliptic curve C of genus g. Consider K(t) the t

Yuri G. Zarhin

We prove that the jacobian of a hyperelliptic curve y^2=f(x) has no nontrivial endomorphisms over an algebraic closure of the ground field of characteristic zero if the Galois group of the polynomial f is ``very big&#39;&#39;.

Jonathan L. Feng, Konstantin T. Matchev, Takeo Moroi

We analyze focus points in supersymmetric theories, where a parameter&#39;s renormalization group trajectories meet for a family of ultraviolet boundary conditions. We show that in a class of models including minimal supergravity, the up-type Higgs mass has a focus point at the weak scale, where its value is highly insensitive to the universal scalar mass. A

E. Accomando, R. Arnowitt, B. Dutta

The question of CP violating phases and electric dipole moments (EDMs)for the electron ($d_e$) and the neutron ($d_n$) for supergravity models with nonuniversal soft breaking is considered for models with a light ($\stackrel{<}{\sim}$1 TeV) mass spectrum and R-parity invariance. As with models with universal soft breaking (mSUGRA) one finds a serious fine tu

Christian Y. Cardall

In the simplistic quantum mechanical picture of flavor mixing, conditions on the maximum size and minimum coherence time of the source and detector regions for the observation of interference---as well as the very viability of the approach---can only be argued in an ad hoc way from principles external to the formalism itself. To examine these conditions in a

T. Tomoda

We treat 0+ -> 2+ neutrinoless double beta decays taking into account recoil corrections to the nuclear currents. The decay probability can be written as a quadratic form of the effective coupling constants of the right-handed leptonic currents and the effective neutrino mass. We calculate the nuclear matrix elements for the 0+ -> 2+ neutrinoless double beta

J. -F. Lagae, D. K. Sinclair

We study the chiral properties of domain-wall quarks at high temperatures on an ensemble of quenched configurations. Low lying eigenmodes of the Dirac operator are calculated and used to check the extent to which the Atiyah-Singer index theorem is obeyed on lattices with finite $N_5$. We calculate the connected and disconnected screening propagators for the

K. Amemiya, H. Suganuma

We study the properties of gluons in QCD in the maximally abelian (MA) gauge. In the MA gauge, the off-diagonal gluon behaves as the massive vector boson with the mass $\Meff \simeq 1.2 {\rm GeV}$, and therefore the off-diagonal gluon cannot carry the long-range interaction for $r \gg \Meff^{-1} \simeq 0.2$ fm. The essence of the infrared abelian dominance i

B. G. Dimitrov

The purpose of the paper is to develop further a projection variational approach in relativistic hydrodynamics. The approach, previously proposed in [gr-qc/9908032], is based on the variation of the vector field and the projection tensor (instead of the given metric tensor) and their first partial derivatives. The previously proved property of non-commutativ

E. Ben-Naim, P. L. Krapivsky

We study relaxation properties of two-body collisions in infinite spatial dimension. We show that this process exhibits multiscaling asymptotic behavior as the underlying distribution is characterized by an infinite set of nontrivial exponents. These nonequilibrium relaxation characteristics are found to be closely related to the steady state properties of t

W. E. Pickett, R. Weht, A. B. Shick

Relying on the inhomogeneous (layered) crystal, electronic, and magnetic structure, we show how superconductivity can coexist with the ferromagnetic phase of RuSr2GdCu2O8 as observed by Tallon and coworkers. Since the Cu d_{x^2-y^2} orbitals couple only to apical O p_x, p_y orbitals (and only weakly), which also couple only weakly to the magnetic Ru t_{2g} o

E. M. Baskin, M. V. Entin

The low-temperature equilibrial state of a system of small metal grains, embedded into insulator, is studied. We find, that the grains may be charged due to the fluctuations of the surface energy of electron gas in grains, rather than quantization of electron states. The higherst-occupied level in a grain fluctuates within the range of order of charging ener

S. S. Manna, H. J. Herrmann

The dynamics of intermittent granular flow through an orifice in a granular bin and the associated clogging due to formation of arches blocking the outlet, is studied numerically in two-dimensions. Our numerical results indicate that for small hole sizes, the system self-organizes to a steady state and the distribution of the grain displacements decays as po

Wei-Min Zhang

I present a microscopic theory I proposed recently to describe high-T_c superconductivity in cuprates. I show that coherent pairing states consisting of extended singlet Cooper pairs and triplet $π$ pairs can manifest both the Mott insulating antiferromagnetic order and the d-wave superconducting order. From this configuration of coherent pairing states, I c

T. M. Malm

The etiology of the large scale peculiar velocity (large scale streaming motion) of clusters would increasingly seem more tenuous, within the context of the gravitational instability hypothesis. Are there any alternative testable models possibly accounting for such large scale streaming of clusters?

Suzanne M. Linder

The effects of galaxy selection on our ability to constrain the nature of weak Lyαabsorbers at low redshift are explored. Current observations indicate the existence of a population of gas-rich, low surface brightness (LSB) galaxies, and these galaxies may have large cross sections for Lyαabsorption. Absorption arising in LSB galaxies may be attributed to HS

Eliot Quataert, Tiziana Di Matteo, Ramesh Narayan, Luis C. Ho

M81 and NGC 4579 are two of the few low-luminosity active galactic nuclei which have an estimated mass for the central black hole, detected hard X-ray emission, and detected optical/UV emission. In contrast to the canonical ``big blue bump,&#39;&#39; both have optical/UV spectra which decrease with increasing frequency in a $νL_ν$ plot. Barring significant r

G. H. Bauer, D. M. Ceperley, Nigel Goldenfeld

Path integral Monte Carlo (PIMC) simulations of liquid helium at negative pressure have been carried out for a temperature range from the critical temperature to below the superfluid transition. We have calculated the temperature dependence of the spinodal line as well as the pressure dependence of the isothermal sound velocity in the region of the spinodal.

Jong-Phil Lee, Chun Liu, H. S. Song

The decay of $Λ_b\toΣ_c^{(*)}πl{\barν}$ processes are calculated in the framework of heavy baryon chiral perturbation theory with help of the $1/N_c$ expansion. The decay rate distributions over $v\cdot v^{\prime}$ where $v$ and $v^{\prime}$ are the 4-vector velocities of $Λ_b$ and $Σ_c^{(*)}$ respectively, and over the pion and lepton energies are given. Th

N. J. Cerf, A. Ipe, X. Rottenberg

The cloning of quantum variables with continuous spectra is analyzed. A universal - or Gaussian - quantum cloning machine is exhibited that copies equally well the states of two conjugate variables such as position and momentum. It also duplicates all coherent states with a fidelity of 2/3. More generally, the copies are shown to obey a no-cloning Heisenberg

W. Luecke

A general method for testing essential nonlocality of nonlinear modifications of quantum mechanics is presented and applied to show the inconsistency of I. Bialynicki-Birula&#39;s and J. Mycielski&#39;s nonlinear quantum theory.

Gavriel Segre

Unfortunately, after an imprudent sumbission of the paper to the e-print archive, I discovered in it many serious mistakes. So I draw back it .

Nilanjana Datta, Alain Messager, Bruno Nachtergaele

We analyze the thermodynamic properties of interfaces in the three-dimensional Falicov Kimball model, which can be viewed as a primitive quantum lattice model of crystalline matter. In the strong coupling limit, the ionic subsystem of this model is governed by the Hamiltonian of an effective classical spin model whose leading part is the Ising Hamiltonian. W

Bernd Ammann, Christian Baer

It has recently been conjectured that the eigenvalues $λ$ of the Dirac operator on a closed Riemannian spin manifold $M$ of dimension $n\ge 3$ can be estimated from below by the total scalar curvature: $$ λ^2 \ge \frac{n}{4(n-1)} \cdot \frac{\int_M S}{vol(M)}. $$ We show by example that such an estimate is impossible.

G. I. Barenblatt, A. J. Chorin

We present a status report on a discrete approach to the the near-equilibrium statistical theory of three-dimensional turbulence, which generalizes earlier work by no longer requiring that the vorticity field be a union of discrete vortex filaments. The idea is to take a special limit of a dense lattice vortex system, in a way that brings out a connection be

Victor M. Villalba

In the present article we analyze the phenomenon of particle creation in a cosmological anisotropic universe when a constant electric field is present. We compute, via the Bogoliubov transformations, the density number of particles created.

I. V. Lavrinenko

We establish a direct correspondence between certain higher-rank p-form Chern-Simons topological type theories in the bulk of a manifold with boundary and particular sectors of supergravity models on the boundary, provided that certain boundary conditions are satisfied. The cases we investigate include eleven-dimensional supergravity and both of the type II

Stephan Dürr, Joachim Kambor

We present our calculation of the correlator $<T\{V_sV_s^†\} >$ between two external vector-currents with the quantum-numbers of a charged kaon. The renormalized expression to $O(p^6)$ in $SU(3) \times SU(3)$ standard chiral perturbation theory is finite and scale-independent. The result is used to determine, via an IMFESR, the phenomenologically relevant fi

Firooz Arash, Ali Naghi Khorramian

We have calculated the partonic structure of a constituent quark in the leading order in QCD for the first time and examined its ipmlications on the proton structure function, $F^{p}_{2}, data from HERA. It turned out that although qualitatively it agrees with the data but for a finer refinement we need to consider an {\it{inherent}} component due to gluons

A. Agodi, G. Andronico

The Constraint Effective Potential (CEP) allows a determination of the mass and other quantities directly, without relying upon asymptotic correlator decays. We report and discuss the results of some mass calculations in $(λΦ^4)_4$, obtained from CEP and our improved version of CEP (ICEP).

Xiang-Qian Luo, C. Q. Huang, J. Q. Jiang, H. Jirari

With our recently proposed effective Hamiltonian via Monte Carlo, we are able to compute low energy physics of quantum systems. The advantage is that we can obtain not only the spectrum of ground and excited states, but also wave functions. The previous work has shown the success of this method in (1+1)-dimensional quantum mechanical systems. In this work we

Shoichi Sasaki

We present preliminary results for the mass spectrum of the nucleon and its low-lying excited states from quenched lattice QCD using the domain wall fermion method which preserves the chiral symmetry at finite lattice cutoff. Definite mass splitting is observed between the nucleon and its parity partner. This splitting grows with decreasing valence quark mas

O. E. Raichev, P. Vasilopoulos

A linear theory of electron transport is developed for a system of two ideal quantum wires, of length L, coupled by tunneling and Coulomb interaction. The interaction of electrons with acoustical phonons is included and the results are valid in both the ballistic and diffusive regime. In the {\it ballistic} regime, both tunneling and Coulomb drag lead to a {

Gurgen Melkonyan, Helmut Kröger, Armen M. Gulian

We consider tunnel microrefrigerators at low temperature. There is a number of experimental studies performed on microrefrigeration in tunneling superconductor--normal metal (SN) structures. Related to these experiments, only the electron subsystem has been considered theoretically. Independently, the phonon deficit effect has been studied a while ago in sup

V. F. Elesin, L. A. Openov

Formation of clusters of interstitial carbon atoms between the surface and second atomic layers of graphite is demonstrated by means of molecular dynamics simulations. It is shown that interstitial clusters result in the dome-like surface features that may be associated with some of the hillocks observed by STM on the irradiated graphite surface.

E. Zepezauer, A. Kalbeck, S. D. Ganichev, W. Korzenietz

A novel approach to intrinsic Josephson-detection of far infrared radiation is reported utilizing near-zone field effects at electric contacts on c-axis oriented YBa_2Cu_3O_7-delta films. While only a bolometric signal was observed focusing the radiation far off the contacts on c-axis normal films, irradiating the edge of contacts yielded an almost wavelengt

Andrew G. Cohen, David B. Kaplan, Ann E. Nelson

A massless up quark is an intriguing solution to the strong CP problem. We discuss how lattice computations can be used in conjunction with chiral perturbation theory to address the consistency of $m_u=0$ with the observed hadron spectrum and interactions. It is not necessary to simulate very light quarks-three flavor partially quenched computations with com

Adam Ritz, Arkady Vainshtein

We consider instanton contributions to chiral correlators, such as <0| Tr λ^2 (x) Tr λ^2(x&#39;) |0>, in N=1 supersymmetric Yang-Mills theory with either light adjoint or fundamental matter. Within the former model, extraction of the gluino condensate from a connected 1-instanton diagram, evaluated at strong coupling, can be contrasted with expectations from

Uwe R. Fischer

The geometric theory of vortex tunnelling in superfluid liquids is developed. Geometry rules the tunnelling process in the approximation of an incompressible superfluid, which yields the identity of phase and configuration space in the vortex collective co-ordinate. To exemplify the implications of this approach to tunnelling, we solve explicitly for the two

J. A. Harvey, S. Kachru, G. Moore, E. Silverstein

We propose a simple universal formula for the tension of a D-brane in terms of a regularized dimension of the associated conformal field theory statespace.

M. E. J. Newman, C. Moore, D. J. Watts

The small-world network model is a simple model of the structure of social networks, which simultaneously possesses characteristics of both regular lattices and random graphs. The model consists of a one-dimensional lattice with a low density of shortcuts added between randomly selected pairs of points. These shortcuts greatly reduce the typical path length

Kostas Skenderis, Paul K. Townsend

First-order `Bogomol&#39;nyi&#39; equations are found for dilaton domain walls of D-dimensional gravity with the general dilaton potential admitting a stable anti-de Sitter vacuum. Implications for renormalization group flow in the holographically dual field theory are discussed.

D. A. Demir, A. Masiero, O. Vives

We address the following question. Take the Constrained Minimal Supersymmetric Standard Model (CMSSM) with the two CP violating SUSY phases different from zero, and neglect the bound coming from the electric dipole moment of the neutron (EDM): is it possible to fully account for CP violation in the kaon and B systems using only the SUSY contributions with va

Lev I. Deych, A. A. Lisyansky, B. L. Altshuler

The variance of the Lyapunov exponent is calculated exactly in the one-dimensional Anderson model with random site energies distributed according to the Cauchy distribution. We find a new significant scaling parameter in the system, and derive an exact analytical criterion for single parameter scaling which differs from the commonly used condition of phase r

D. Toussaint

After a brief introduction to hybrid and glueball source operators, I summarize recent lattice results for these particles.

Nobuyuki Sakai, Paul Haines

As a study of peculiar velocities of nonlinear structure, we analyze the model of a relativistic thin-shell void in the expanding universe. (1) Adopting McVittie (MV) spacetime as a background universe, we investigate the dynamics of an uncompensated void with negative MV mass. Although the motion itself is quite different from that of a compensated void, as

R. Luzzi, A. R. Vasconcellos, J. G. Ramos

We describe a particular approach for the construction of a nonequilibrium statistical ensemble formalism for the treatment of dissipative many-body systems. This is the so-called Nonequilibrium Statistical Operator Method, based on the seminal and fundamental ideas set forward by Boltzmann and Gibbs. The existing approaches can be unified under a unique var

Damir Becirevic, Vicente Gimenez, Vittorio Lubicz, Guido Martinelli

We compute non-perturbatively the average up-down and strange quark masses from the large momentum (short-distance) behaviour of the quark propagator in the Landau gauge. This method, which has never been applied so far, does not require the explicit calculation of the quark mass renormalization constant. Calculations were performed in the quenched approxima

Gavin Johnstone

The modular transformation properties of admissible characters of the affine superalgebra sl(2|1;C) at fractional level k=1/u-1, u=2,3,... are presented. All modular invariants for u=2 and u=3 are calculated explicitly and an A-series and D-series of modular invariants emerge.

M. Caselle, P. Grinza, N. Magnoli

We study the spin-spin, spin-energy and energy-energy correlators in the 2d Ising model perturbed by a magnetic field. We compare the results of a set of high precision Montecarlo simulations with the predictions of two different approximations: the Form Factor approach, based on the exact S-matrix description of the model, and a short distance perturbative

Bodo Geyer, Dietmar Mülsch

A superspace formulation is proposed for the osp(1,2)-covariant Lagrangian quantization of general massive gauge theories. The superalgebra os0(1,2) is considered as subalgebra of sl(1,2); the latter may be considered as the algebra of generators of the conformal group in a superspace with two anticommuting coordinates. The mass-dependent (anti)BRST symmetri

O. Haug, J. D. Vergados, Amand Faessler, S. Kovalenko

Using the neutrino oscillations and neutrinoless double beta decay experimental data we reconstructed an upper limit for the three generation neutrino mass matrix. We compared this matrix with the predictions of the minimal supersymmetric(SUSY) model with R-parity violation(\rp) and extracted stringent limits on trilinear \rp coupling constants $λ_{i33}, λ&#

L. Vichi, M. Amoruso, A. Minguzzi, S. Stringari

We study a confined mixture of bosons and fermions in the regime of quantal degeneracy, with particular attention to the effects of the interactions on the kinetic energy of the fermionic component. We are able to explore a wide region of system parameters by identifying two scaling variables which completely determine its state at low temperature. These are

Ashoke Sen

We construct the world-volume action for non-BPS D-branes in type II string theories. This action is invariant under all the unbroken supersymmetries in the bulk, but these symmetries are realised as spontaneously broken symmetries in the world-volume theory. Coupling of this action to background supergravity fields is straightforward. We also discuss the fa

James E. Lidsey, David Wands, E. J. Copeland

Aspects of superstring cosmology are reviewed with an emphasis on the cosmological implications of duality symmetries in the theory. The string effective actions are summarized and toroidal compactification to four dimensions reviewed. Global symmetries that arise in the compactification are discussed and the duality relationships between the string effectiv

Michael Cahill, Mark Fleharty, Kevin Cahill

We have developed a simple, phenomenological, Monte-Carlo code that predicts the three-dimensional structure of globular proteins from the DNA sequences that define them. We have applied this code to two small proteins, the villin headpiece (1VII) and cole1 rop (1ROP). Our code folds both proteins to within 5 A rms of their native structures.

S. Y. Choi, Jae Sik Lee

A muon collider with controllable energy resolution and transverse beam polarization provides a powerful probe of the Higgs sector in the minimal supersymmetric standard model with explicit CP violation, through s-channel production of Higgs bosons. The production rates and the CP-even and CP-odd transverse-polarization asymmetries are complementary in diagn

Jyotipratim Ray Chaudhuri, Bidhan Chandra Bag, Deb Shankar Ray

We show that Wigner-Leggett-Caldeira equation for Wigner phase space distribution function which describes the quantum Brownian motion of a particle in a force field in a high temerature, Ohmic environment can be identified as a semiclassical version of Kramers&#39; equation. Based on an expansion in powers of $\hbar$ we solve this equation to calculate the

J. T. Lunardi, B. M. Pimentel, R. G. Teixeira

In this work we analyze the generalization of Duffin-Kemmer-Petiau equation to the case of Riemannian space-times and show that the usual results for Klein-Gordon and Proca equations in Riemannian space-times can be fully recovered when one selects, respectively, the spin 0 and 1 sectors of Duffin-Kemmer-Petiau theory.

SDSS Collaboration, Xiaohui Fan

This is the second paper in a series aimed at finding high-redshift quasars from five-color (u&#39;g&#39;r&#39;i&#39;z&#39;) imaging data taken along the Celestial Equator by the Sloan Digital Sky Survey (SDSS) during its commissioning phase. In this paper, we present 22 high-redshift quasars (z>3.6) discovered from ~250 deg^2 of data in the spring Equatoria

Seungjoon Hyun, Youngjai Kiem, Sangmin Lee, Chang-Yeong Lee

Closed string dynamics in the presence of noncommutative Dp-branes is investigated. In particular, we compute bulk closed string two-point scattering amplitudes; the bulk space-time geometries encoded in the amplitudes are shown to be consistent with the recently proposed background space-time geometries dual to noncommutative Yang-Mills theories. Three-poin

Klaus Behrndt, Mirjam Cvetic

We address a supersymmetric embedding of domain walls with asymptotically anti-deSitter (AdS) space-times in five-dimensional simple, N=2 U(1) gauged supergravity theory constructed by Gunaydin, Townsend and Sierra. These conformally flat solutions interpolate between supersymmetric AdS vacua, satisfy the Killing spinor (first order) differential equations,

Hans J. Wospakrik, Freddy P. Zen

We show that the auto-Backlund transformations of the sine-Gordon, Korteweg-deVries, nonlinear Schrodinger, and Ernst equations are related to their respective CPT symmetries. This is shown by applying the CPT symmetries of these equations to the Riccati equations of the corresponding pseudopotential functions where the fields are allowed to transform into n

Andrey Tsiganov

We consider compositions of the transformations of the time variable and canonical transformations of the other coordinates, which map completely integrable system into other completely integrable system. Change of the time gives rise to transformations of the integrals of motion and the Lax pairs, transformations of the corresponding spectral curves and R-m

N. G. de Almeida, C. J. Villas-Boas, E. Solano, M. H. Y. Moussa

We show how to teleport reliably an arbitrary superposition of n=0 and n=1 vibrational number state between two distant ions. This is done by first mapping the vibrational state to be teleported into the internal degrees of freedom of a given ion. Then we handle with the internal superposition state following Bennett&#39;s original protocol and a recently pr

D. Kielpinski, B. E. King, C. J. Myatt, C. A. Sackett

One limit to the fidelity of quantum logic operations on trapped ions arises from heating of the ions&#39; collective modes of motion. Sympathetic cooling of the ions during the logic operations may eliminate this source of errors. We discuss benefits and drawbacks of this proposal, and describe possible experimental implementations. We also present an overv

Gang Zhao

By assuming that the kinetic energy,potential energy,momentum,and some other physical quantities of a particle exist in the field out of the particle,the Schrodinger equation is an equation describing field of a particle,but not the particle itself.

Constantine Yannouleas, Uzi Landman, Robert N. Barnett

This pedagogical review presents the Shell Correction Method (SCM) and variants thereof, appropriate for describing shape deformations and electronic shell effects, energetics and decay pathways of metal-cluster fragmentation processes (e.g., monomer/dimer dissociation and fission). The experimental trends are compared to the theoretical SCM interpretations,

M. A. Garland, R. E. Schenter, R. J. Talbert, S. G. Mashnik

Through decades of effort in nuclear data development and simulations of reactor neutronics and accelerator transmutation, a collection of reaction data is continuing to evolve with the potential of direct applications to the production of medical isotopes. At Los Alamos the CINDER&#39;90 code and library have been developed for nuclide inventory calculation

J. H. Thywissen, R. M. Westervelt, M. Prentiss

We show that the conductance of neutral atoms through a tightly confining waveguide constriction is quantized in units of lambda_dB^2/pi, where lambda_dB is the de Broglie wavelength of the incident atoms. Such a constriction forms the atom analogue of an electron quantum point contact and is an example of quantum transport of neutral atoms in an aperiodic s