December 1999 arXiv papers — page 15

Mauro Sellitto

Kinetic lattice-gas models display fragile glass behavior, in spite of their trivial Gibbs-Boltzmann measure. This suggests that the nature of glass transition might be, at least in some cases, understood in purely kinetic or dynamical terms.

E. B. Sonin

The Josephson-plasma and vortex modes in layered superconductors have been studied theoretically for low magnetic fields parallel and perpendicular to layers. The two modes belong to the same lowest-frequency branch of collective-mode spectrum localized near vortices. This is the Josephson-plasma resonance if pancakes are strongly pinned and cannot move. Oth

I. Vekhter, A. Houghton

We present the results of a microscopic calculation of the longitudinal thermal conductivity of quasiparticles, $κ_{xx}$, in a 2D d-wave superconductor in the vortex state. Our approach takes into account both impurity scattering and a contribution to the thermal transport lifetime due to the scattering of quasiparticles off of vortices. We compare the resul

I. Vekhter, P. J. Hirschfeld

We analyse the behavior of the thermal conductivity, $κ(H)$, in the vortex state of a quasi-two-dimensional d-wave superconductor when both the heat current and the applied magnetic field are in the basal plane. At low temperature the effect of the field is accounted for in a semiclassical approximation, via a Doppler shift in the spectrum of the nodal quasi

Sigmund Kohler, Fernando Sols

We study the competition between phase definition and quantum phase fluctuations in interference experiments between independently formed Bose condensates. While phase-sensitive detection of atoms makes the phase progressively better defined, interactions tend to randomize it faster as the uncertainty in the relative particle number grows. A steady state is

H. M. Ronnow, M. Enderle, D. F. McMorrow, L. -P. Regnault

CuGeO$_3$ undergoes a transition from a spin-Peierls phase to an incommensurate phase at a critical field of $H_c\approx 12.5$ T. In the high-field phase a lattice of solitons forms, with both structural and magnetic components, and these have been studied using neutron scattering techniques. Our results provide direct evidence for a long-ranged magnetic sol

Bosiljka Tadic

Using dynamic renormalization group we study the transport in driven diffusive systems in the presence of quenched random drift velocity with long-range correlations along the transport direction. In dimensions $d\mathopen< 4$ we find fixed points representing novel universality classes of disorder-dominated self-organized criticality, and a continuous phase

Avraham Schiller, Selman Hershfield

A comprehensive theory is presented for the voltage, temperature, and spatial dependence of the tunneling current between a scanning tunneling microscope (STM) tip and a metallic surface with an individual magnetic adatom. Modeling the adatom by a nondegenerate Anderson impurity, a general expression is derived for a weak tunneling current in terms of the dr

Takashi Yamamoto, Yasuhiro Saiga, Mitsuhiro Arikawa, Yoshio Kuramoto

The dynamical structure factor $S(q,ω)$ of the K-component (K = 2,3,4) spin chain with the 1/r^2 exchange is derived exactly at zero temperature for arbitrary size of the system. The result is interpreted in terms of a free quasi-particle picture which is generalization of the spinon picture in the SU(2) case; the excited states consist of K quasi-particles

K. C. Huang, R. J. Needs, G. Rajagopal

Recently Schautz and Flad concluded that the Hellmann-Feynman theorem holds within the fixed-node diffusion quantum Monte Carlo (DMC) method. We show that the Hellmann-Feynman expression is not in general equal to the derivative of the DMC energy with respect to some parameter $λ$ if the nodal surface depends on $λ$.

L. V. Butov, A. V. Mintsev, Yu. E. Lozovik, K. L. Campman

In-plane magnetic field is found to change drastically the photoluminescence spectra and kinetics of interwell excitons in GaAs/AlGaAs coupled quantum wells. The effect is due to the in-plane magnetic field induced displacement of the interwell exciton dispersion in a momentum space, which results in the transition from the momentum-space direct exciton grou

G. M. Wysin, M. E. Gouvea, A. S. T. Pires

The effect of damping of spinwaves in a two-dimensional classical ferromagnetic XY model is considered. The damping rate $Γ_{q}$ is calculated using the leading diagrams due to the quartic-order deviations from the harmonic spin Hamiltonian. The resulting four-dimensional integrals are evaluated by extending the techniques developed by Gilat and others for s

D. S. Dean

In this paper we calculate the mean number of metastable states for spin glasses on so called random thin graphs with couplings taken from a symmetric binary distribution $\pm J$. Thin graphs are graphs where the local connectivity of each site is fixed to some value $c$. As in totally connected mean field models we find that the number of metastable states

E. A. Jagla, E. Tosatti

A glass surface may still flow below the bulk glass transition temperature, where the underlying bulk is frozen. Assuming the existence at T=T* of a bulk thermodynamical glass transition, we show that the glass-vapor interface is generally wetted by a liquid layer of thickness ~ -ln(T*-T) when T--> T*. Contrary to standard surface melting of crystals however

Andreas Mielke

The over-damped motion of a Brownian particle in an asymmetric, bistable, fluctuating potential shows noise induced stability: For intermediate fluctuation rates the mean occupancy of minima with an energy above the absolute minimum is enhanced. The model works as a detector for potential fluctuations being not too fast and not too slow. This effect occurs d

S. Daul, D. J. Scalapino

Half-filled two-leg Hubbard ladders have spin-gapped short-range antiferromagnetic correlations while three-leg ladders have power law antoferromagnetic correlations, and both systems have d_{x^2-y^2}-power law pairing correlations when they are doped. Thus these ladders exhibit some of the phenomenology seen in the layered cuprates. Here we report results f

I. A. Campbell, D. Petit, P. O. Mari, L. W. Bernardi

We give an overview of numerical and experimental estimates of critical exponents in Spin Glasses. We find that the evidence for a breakdown of universality of exponents in these systems is very strong.

M. Arai, T. Nishijima, Y. Endoh, A. W. Garrett

The spin dynamics of an optimally doped YBa2Cu3O7 (Tc = 93 K) crystal array have been investigated in a wide range of momentum and energy (Q - E) space using the time-of-flight neutron scattering method. Incommensurate spin modulation in Q is a characteristic feature, as it is in the under-doped YBa2Cu3O6.7 with a different incommensurability. A linear relat

S. Sugai, T. Hosokawa

The relation between the electronic excitation and the magnetic excitation for the superconductivity in Bi2Sr2Ca{1-x}YxCu2O{8+δ} was investigated by wide-energy Raman spectroscopy. In the underdoping region the B1g scattering intensity is depleted below the two-magnon peak energy due to the &#34;hot spots&#34; effects. The depleted region decreases according

Alberto Zannoni

An english translation of the original work of Enrico Fermi on the quantization of the monoatomic ideal gas, is given in this paper. Fermi introduced here for the first time the statistical law obeyed by most of the particles in nature: Fermi-Dirac statistics. The formalism that he used is based on the quantization of the monoatomic ideal gas in a harmonic t

D. Manske, T. Dahm, K. H. Bennemann

We study Cooper-pair phase fluctuations in cuprate superconductors for a spin fluctuation pairing interaction. Using an electronic theory we calculate in particular for the underdoped cuprate superconductors the superfluid density $n_s(T)$, the superconducting transition temperature $T_c(x) \propto n_s$ below which phase coherent Cooper-pairs occur, and $T_c

Gaetano Bertoldi

The introduction of a modulus z(K), analogous to u=<tr phi^2> in the N=2 SUSY SU(2) gauge theory solved by Seiberg and Witten, and whose defining property is the invariance under the symmetry and duality transformations of the effective coupling K, reveals an intriguing correspondence between the D=2 Ising and Potts models on the square lattice. The moduli s

A. Osterloh, L. Amico, U. Eckern

We define one-dimensional particles with generalized exchange statistics. The exact solution of a Hubbard-type Hamiltonian constructed with such particles is achieved using the Coordinate Bethe Ansatz. The chosen deformation of the statistics is equivalent to the presence of a magnetic field produced by the particles themselves, which is present also in a ``

Nguyen Que Huong, Joseph L. Birman

We propose a new model to implement organic exciton-semiconductor exciton hybridization by embedding a semiconductor quantum dot array into an organic medium. A Wannier-Mott transfer exciton is formed when the exciton in each semiconductor dot interacts via the multipole-multipole coupling with other excitons in the different dtos of the array. A new hybrid

Denis Boyer

We point out some similitudes between the statistics of high Reynolds number turbulence and critical phenomena. An analogy is developed for two-dimensional decaying flows, in particular by studying the scaling properties of the two-point vorticity correlation function within a simple phenomenological framework. The inverse of the Reynolds number is the analo

Denis Boyer, Fernando Lund

In an idealized way, some turbulent flows can be pictured by assemblies of many vortices characterized by a set of particle distribution functions. Ultrasound provide an useful, nonintrusive, tool to study the spatial structure of vorticity in flows. This is analogous to the use of elastic neutron scattering to determine liquid structure. We express the disp

D. J. Schade, B. J. Boyle, M. Letawsky

We report on the initial results of a comprehensive Hubble Space Telescope (HST) snapshot imaging survey of 76 low redshift (z < 0.15) X-ray-selected active galactic nuclei (AGN) in the Einstein Extended Medium Sensitivity Survey. This survey is expected to show no bias with respect to host galaxy types and so is arguably one of the best available samples wi

Henry Lee, Michael G. Richer, Marshall L. McCall

We present the results of optical spectroscopy of a newly discovered H II region residing in the H I gas cloud located between the dwarf irregular galaxy UGC 7636 and the giant elliptical galaxy NGC 4472 in the Virgo Cluster. By comparing UGC 7636 with dwarf irregular galaxies in the field, we show that the H I cloud must have originated from UGC 7636 becaus

Joanne Hughes, George Wallerstein

We have observed (with vby filters) a field north of the core of the most massive globular cluster in our galaxy, Omega Centauri. We have found a correlation of age and metallicity in a region which avoids the dense core and the inhomogeneous foreground dust emission shown by the IRAS satellite. Our observations show that the comparatively metal-rich stars (

Frederic A. Rasio

Coalescing compact binaries with neutron star (NS) or black hole (BH) components are important sources of gravitational waves for the laser-interferometer detectors currently under construction, and may also be sources of gamma-ray bursts at cosmological distances. This paper focuses on the final hydrodynamic coalescence and merger of NS--NS binaries, and ad

I. Szapudi, S. Colombi, F. Bernardeau

The errors on statistics measured in finite galaxy catalogs are exhaustively investigated. The theory of errors on factorial moments by Szapudi & Colombi (1996) is applied to cumulants via a series expansion method. All results are subsequently extended to the weakly non-linear regime. Together with previous investigations this yields an analytic theory of t

A. A. Gvozdev, I. S. Ognev

Direct URCA processes in a collapsing star envelope with a strong magnetic field are investigated. It is shown that in the toroidal magnetic field these processes can develope a torque which quickly unwinds an envelope. A general expression for a force density along the field direction is obtained. An influence of the neutrino unwinding effect on a dynamics

A. A. Gvozdev, I. S. Ognev

The neutrino-nucleon scattering in a collapsing star envelope with a strong magnetic field is investigated. The transferred by neutrinos momentum asymmetry along the field direction is obtained. It is shown that the neutrino-nucleon scattering gives a contribution to the asymmetry comparable with direct URCA processes. Hence, the neutrino-nucleon scattering

M. Rowan-Robinson

39 galaxies are now known, from follow-up of faint IRAS sources and from submm observations of high redshift AGN, with far infrared luminosities > 10^{13} Lo. 13 of these, which have been found in 60 or 850 mu surveys, form an important unbiased sub-sample. 12 have been found by comparison of 60 mu surveys with quasar or radio-galaxy catalogues, or from infr

V. M. Kaspi

Following a summary of the basic principles of pulsar timing, we present a review of recent results from timing observations of relativistic binary pulsars. In particular, we summarize the status of timing observations of the much celebrated original binary pulsar PSR B1913+16, draw attention to the recent confirmation of strong evidence for geodetic precess

V. M. Kaspi

The evidence for associations between neutron stars and supernova remnants is reviewed. After summarizing the situation for young radio pulsars, I consider the evidence from associations that young neutron stars can have properties very different from those of radio pulsars. This, though still controversial, shakes our simple perception of the Crab pulsar as

J. Greiner, M. Orio, R. Schwarz

We present new photometric and spectroscopic observations of the transient supersoft X-ray source RX J0537.7-7034 and find a periodicity of approximately 3.5 hrs. This establishes RX J0537.7-7034 as the supersoft X-ray source with the shortest orbital period. We furthermore derive an inclination of the binary system of 45<i<70 deg, and the masses of the two

G. De Zotti, G. L. Granato, L. Silva, D. Maino

We have explored, in the general framework of the ``young source&#39;&#39; scenario, evolutionary models for GHz Peaked Spectrum (GPS) galaxies and quasars which reproduce the observed counts, redshift and peak frequency distributions of currently available samples. Substantially different cosmological evolution properties are found for the two populations:

V. M. Kaspi, F. Camilo, A. G. Lyne, R. N. Manchester

We report the discovery of two isolated radio pulsars having the largest inferred surface dipole magnetic fields yet seen in the population: 4.1e10^13 G and 5.5e10^13 G. These pulsars show apparently normal radio emission in a regime of magnetic field strength where some models predict no emission should occur. They have spin parameters and magnetic fields s

D. Tschoeke, G. Hensler

We present spatial and spectral results of ROSAT observations of two galaxies: NGC 4569 and NGC 4303. Both objects are members of the Virgo Cluster and have nearby smaller companions with which they have probably gone through an encounter. Both soft X-ray spectra (0.1-2.4 keV) can be fitted with a two-component model consisting of a power-law component from

Rien van de Weygaert

Voronoi Tessellations form an attractive and versatile geometrical asymptotic model for the foamlike cosmic distribution of matter and galaxies. In the Voronoi model the vertices are identified with clusters of galaxies. For a substantial range out to a scale in the order of the cellsize, their spatial two-point correlation function is a power-law with a slo

J. U. Fynbo, P. Moller, B. Thomsen

We present results from an ongoing search for galaxy counterparts of a subgroup of Quasar Absorption Line Systems called Damped Ly-alpha Absorbers (DLAs). DLAs have several characteristics that make them prime candidates for being the progenitors of typical present day galaxies.

D. A. Bramel, R. C. Nichol, A. C. Pope

Abridged] We present here new results on the space density of rich, optically-selected, clusters of galaxies at low redshift (z<0.15). These results are based on the application of the matched filter cluster-finding algorithm to 1067 deg2 of the Edinburgh/Durham Southern Galaxy Catalogue (EDSGC). This is the first major application of this methodology at low

T. Bulik, B. Rudak, J. Dyks

In the advent of next generation gamma-ray missions, we present general properties of spectral features of high-energy emission above $1\MeV$ expected for a class of millisecond, low magnetic field ($\sim 10^9\G$) pulsars. We extend polar-cap model calculations of Rudak & Dyks (1999) by including inverse Compton scattering events in ambient field of thermal

Rita M. Sambruna, Lester L. Chou, C. Megan Urry

We present the first observations at medium-hard X-rays with ASCA in 1998 August--November of four Flat Spectrum Radio Quasars (FSRQs), characterized by unusually steep soft X-ray spectra (photon index, Γ_{0.2-2.4 keV} \sim 2-2.5), as previously measured with ROSAT. Such steep X-ray slopes are similar to those observed in synchrotron-dominated BL Lacs and ar

R. P. Mignani, L. Pulone, G. Marconi, G. Iannicola

The 16ms X-ray pulsar PSR J0537-6910 in SNR N157B is the fastest known isolated (non-recycled) pulsar and, with a rotational energy loss dE/dt ~ 4.8 10^38 erg/s, is the most energetic (together with the Crab). Here we report the results of optical observations of the field, recently performed with the SUSI2 camera of the NTT. Few objects are observed inside

A. Kruszewski, I. Semeniuk

This paper contains the list of Hipparcos eclipsing binaries that fulfill the following conditions: the star is classified in the Hipparcos Catalogue as EA-type eclipsing binary and its parallax is either larger than 5 mas or it is five times larger than its mean error. An eclipsing binary with known distance and with photometric and double-line spectroscopi

P. E. Nissen, Y. Q. Chen, W. J. Schuster, G. Zhao

Sc and Mn abundances are determined for 119 F and G main-sequence stars with -1.4 < [Fe/H] < +0.1, representing stars from the thin disk, the thick disk and the halo. The results indicate that Sc behaves like an alpha-element, showing a decreasing [Sc/Fe] with increasing metallicity in disk stars and a dual pattern in the kinematically selected halo stars. I

J. U. Fynbo, B. Thomsen, P. Moller

We present results from an ongoing search for galaxy counterparts of a subgroup of Quasar Absorption Line Systems called Damped Ly-alpha Absorbers (DLAs). DLAs have several characteristics that make them essential in the process of understanding how galaxies formed in the early universe and evolved to the galaxies we see today in the local universe. Finally

G. Meynet, M. Arnould

Radioisotopes are natural clocks which can be used to estimate the age of the solar system. They also influence the shape of supernova light curves. In addition, the diffuse emission at 1.8 MeV from the decay of 26Al may provide a measure of the present day nucleosynthetic activity in the Galaxy. Therefore, even if radionuclides represent only a tiny fractio

Rick Edelson, Anuradha Koratkar, Kirpal Nandra, Michael Goad

During 1998 April 13-16, NGC 3516 was monitored almost continuously with HST for 10.3 hr in the UV and 2.8 d in the optical, and simultaneous RXTE and ASCA monitoring covered the same period. The X-rays were strongly variable with the soft (0.5-2 keV) showing stronger variations (~65% peak-to-peak) than the hard (2-10 keV; ~50% peak-to-peak). The optical con

Francesco R. Ferraro, Paolo Montegriffo, Livia Origlia, Flavio Fusi Pecci

We present high quality near infrared Color Magnitude Diagrams of 10 Galactic Globular Clusters (GCs) spanning a wide metallicity range (-2.15<[Fe/H]<-0.2). This homogeneous data-base has been used to perform a detailed analysis of the Red Giant Branch (RGB), adopting a variety of observables to describe its physical and chemical properties. First, a set of

Chris Flynn, J. Sommer-Larsen, B. Fuchs, David S. Graff

Ibata et al (1999) have recently discovered faint, moving objects in the Hubble Deep Field. The quantity, magnitudes and proper motions of these objects are consistent with old white dwarfs making up the Galactic dark halo. We review a number of ground-based proper motion surveys in which nearby dark halo white dwarfs might be present, if they have the colou

Heino Falcke, Fulvio Melia, Eric Agol

In recent years, the evidence for the existence of an ultra-compact concentration of dark mass associated with the radio source Sgr A* in the Galactic Center has become very strong. However, an unambiguous proof that this object is indeed a black hole is still lacking. A defining characteristic of a black hole is the event horizon. To a distant observer, the

F. Mantovani, W. Junor, I. M. McHardy, C. Valerio

The VLBI observations at 22 GHz and 43 GHz of the quasar 3C273 obtained during a multi-frequency campaign in late 1992 in the radio, millimetre and X-ray bands allow us to derive the components&#39; angular sizes, their peak fluxes and turnover frequencies. Lower limits to the Doppler factors have been derived by comparing the observed X-ray fluxes with thos

Masafumi Ikeda, Hiroyuki Maezawa, Tetsuya Ito, Gaku Saito

Large scale mapping observations of the 3P1-3P0 fine structure transition of atomic carbon (CI, 492 GHz) and the J=3-2 transition of CO (346 GHz) toward the Orion A molecular cloud have been carried out with the Mt. Fuji submillimeter-wave telescope. The observations cover 9 square degrees, and include the Orion nebula M42 and the L1641 dark cloud complex. T

George Davies, Lawrence M. Widrow

We demonstrate that the Biermann battery mechanism for the creation of large scale magnetic fields can arise in a simple model protogalaxy. Analytic calculations and numerical simulations follow explicitly the generation of vorticity (and hence magnetic field) at the outward-moving shock that develops as the protogalactic perturbation collapses. Shear angula

Eric W. Deutsch, Bruce Margon, Scott F. Anderson

Evidence is emerging that the luminous X-ray sources in the cores of globular clusters may often consist of, or perhaps even as a class be dominated by, ultracompact (P < 1 hr) binary stars. To the two such systems already known, in NGC 6624 and NGC 6712, we now add evidence for two more. We detect large amplitude variability in the candidate optical counter

Christopher R. Mullis

We have used the ROSAT All-Sky Survey around the North Ecliptic Pole to construct a complete sample of galaxy clusters. The deep and contiguous nature of the survey affords us the opportunity to examine large-scale structure in the Universe on scales of hundreds of megaparsecs. We have identified over 99% of the 446 X-ray sources in the survey area. The clus

Alexander Knebe, Andrey V. Kravtsov, Stefan Gottloeber, Anatoly Klypin

We present a study of numerical effects in dissipationless cosmological simulations. The numerical effects are evaluated and studied by comparing results of a series of 64^3-particle simulations of varying force resolution and number of time steps, performed using three different N-body techniques: the Particle Mesh (PM), the adaptive P3M (AP3M) code, and th

Azita Valinia, Robert L. Kinzer, Francis E. Marshall

The Galactic background radiation near the Scutum Arm was observed simultaneously with RXTE and OSSE in order to determine the spectral shape and the origin of the emission in the hard X-ray/soft gamma-ray band. The spectrum in the 3 keV to 1 MeV band is well modeled by 4 components: a high energy continuum dominating above 500 keV that can be characterized

Ian S. Glass, D. R. Alves, ISOGAL team, MACHO team

The Baade&#39;s Windows of low obscuration towards the inner parts of the Galactic bulge represent ideal places in which to develop an understanding of the ISOGAL colour-magnitude diagrams. Unlike the case for the solar neighbourhood, their contents are at a uniform distance from the Sun, affected only by the finite thickness of the Bulge. The objects detect

S. Seager, D. D. Sasselov

The recent transit observation of HD 209458 b - an extrasolar planet orbiting a sun-like star - confirmed that it is a gas giant and determined that its orbital inclination is 85 degrees. This inclination makes possible investigations of the planet atmosphere. In this paper we discuss the planet transmission spectra during a transit. The basic tenet of the m

P. Danielewicz

Midrapidity nucleon elliptic flow is studied within the Boltzmann-equation simulations of symmetric heavy-ion collisions. The simulations follow a lattice Hamiltonian extended to relativistic transport. It is demonstrated that in the peripheral heavy-ion collisions the high-momentum elliptic flow is strongly sensitive to the momentum dependence of mean field

D. J. Garcia, K. Hallberg, C. D. Batista, M. Avignon

We study numerically the one dimensional ferromagnetic Kondo lattice, a model widely used to describe nickel and manganese perovskites. By including a nearest neighbor Coulomb interaction (V) and a superexchange interaction between the localized moments (K), we obtain the phase diagram in parameter space for several dopings at T=0. Due to the competition bet

Claudio A. Scrucca, Marco Serone

The cancellation of U(1)-gauge and U(1)-gravitational anomalies in certain D=4 N=1 Type IIB orientifolds is analyzed in detail, from a string theory point of view. We verify the proposal that these anomalies are cancelled by a Green-Schwarz mechanism involving only twisted Ramond-Ramond fields. By factorizing one-loop partition functions, we also get the ano

F. S. Roux, T. Torma

We provide an instanton effective action formalism in terms of which one can investigate the nonperturbative generation of 2-point and 4-point functions.

Laurent Lellouch, C. -J. David Lin

We present updates of our results for neutral $B$-meson mixing and leptonic decay constants obtained in the quenched approximation from a mean-field-improved Sheikholeslami-Wohlert action at two values of lattice spacing. We consider quantities such as $B_{B_{d(s)}}$, $f_{D_{(s)}}$, $f_{B_{(s)}}$ and the full $ΔB=2$ matrix-elements, as well as the correspond

V. Krakoviack, C. Alba-Simionesco

A quantitative application to real supercooled liquids of the mean-field scenario for the glass transition ($T_g$) is proposed. This scenario, based on an analogy with spin-glass models, suggests a unified picture of the mode-coupling dynamical singularity ($T_c$) and of the entropy crisis at the Kauzmann temperature ($T_K$), with $T_c>T_g>T_K$. Fitting a si

Clément Sire, Pierre-Henri Chavanis

In this paper, we introduce a numerical renormalization group procedure which permits long-time simulations of vortex dynamics and coalescence in a 2D turbulent decaying fluid. The number of vortices decreases as $N\sim t^{-ξ}$, with $ξ\approx 1$ instead of the value $ξ=4/3$ predicted by a na\&#34;ıve kinetic theory. For short time, we find an effective expo

S. Parsons

We show that the conformal invariance conditions for a general sigma-model with torsion are invariant under T-duality through two loops.

Weyls LiMing, Gregoire Misguich, Philippe Sindzingre, Claire Lhuillier

The phase diagram of the multiple-spin exchange model on the triangular lattice is studied using exact diagonalizations. The two-spin (J_2) and four-spin (J_4) exchanges have been taken into account for 12, 16, 19, 21, 24, and 27 site samples in the parameter region J_4=0 - 0.25 (for a fixed J_2=1). It is found that the three-sublattice Néel ordered state bu

Sven Aerts, Paul Kwiat, Jan-Åke Larsson, Marek Zukowski

The two-photon interferometric experiment proposed by Franson [Phys. Rev. Lett. 62, 2205 (1989)] is often treated as a "Bell test of local realism". However, it has been suggested that this is incorrect due to the 50% postselection performed even in the ideal gedanken version of the experiment. Here we present a simple local hidden variable model of the expe

V. Pasquier, D. Serban

Motivated by recent experimental results, we reconsider the theory of the edge excitations for the fractional Hall effect at filling factors $ν=p/(2np+1)$. We propose to modify the standard $u(1)\otimes su(p)$ edge theory for this series by introducing twist fields which change the boundary conditions of the bosonic fields and simulate the effect of fraction

N. Z. Scoville, A. S Evans, R. Thompson, M. Rieke

We present near-infrared images obtained with the HST NICMOS camera for a sample of 9 luminous (LIGs: L_IR (8-1000 microns) >~ 10^11 L_sun) and 15 ultra-luminous (ULIGS: L_IR >~ 10^12 L_sun) infrared galaxies. The sample includes representative systems classified as warm (f_25/f_60 > 0.2) and cold (f_25/f_60 <~ 0.2) based on the mid-infrared colors and syste

D. Polyakov, M. M. Sheikh-Jabbari

We study the mass and different RR charge distributions of the BPS (p,p-2)-brane bound states in the closed string brane-like $σ$-model. We show that such brane bound states can be realized by introducing a constant B field in the closed string theory. In addition we show that the worldvolume coordinates of these brane bound states turn out to be noncommutat

V. N. Gorbachev, A. I. Trubilko

Teleportation of a pure two particle entangled state of continuous variables by triplet of the Greenberger-Horne-Zeilinger form is considered. The three-particle basis needed for a joint measurement is found. It describes a measurement of momentum one of single particle and total moment and relative position of the two others. Optical realization using squee

Naoto Yokoi, Toshio Nakatsu

We discuss the microscopic states of the extremal BTZ black holes. Degeneracy of the primary states corresponding to the extremal BTZ black holes in the boundary N=(4,4) SCFT is obtained by utilizing the elliptic genus and the unitary representation theory of N=4 SCA. The degeneracy is consistent with the Bekenstein-Hawking entropy.

P. Bizoń, T. Chmaj, Z. Tabor

We study numerically the Cauchy problem for equivariant wave maps from 3+1 Minkowski spacetime into the 3-sphere. On the basis of numerical evidence combined with stability analysis of self-similar solutions we formulate two conjectures. The first conjecture states that singularities which are produced in the evolution of sufficiently large initial data are

S. Hashimoto, K-I. Ishikawa, T. Onogi, N. Yamada

We compute the matrix element of the four-quark operator $\Op_S$ = $\bar{b}(1-γ_5) s \bar{b} (1-γ_5) s$ in the $B_s-\bar{B}_s$ mixing on the lattice using NRQCD, which gives a leading contribution in the calculation of the width difference $ΔΓ_s$ in the $1/m_b$ expansion. Using the next-to-leading formula of Beneke \textit{et al.}, we obtain $(ΔΓ/Γ)_s$ = 0.1

Hiroaki Onishi, Seiji Miyashita

We investigate thermodynamic properties of a one-dimensional S=1/2 antiferromagnetic Heisenberg model coupled to a lattice distortion by a quantum Monte Carlo method. In particular we study how spin and lattice dimerize as a function of the temperature, which gives a fundamental process of the spin-Peierls transition in higher dimensions. The degree of freed

Ken-ji Hamada

We present evidence that there is a 4D model that satisfies the conditions of renormalizability and diffeomorphism invariance simultaneously at the 2-loop level. The traceless mode is treated perturbatively, while the conformal mode can be managed exactly. The two conditions constrain the theory strongly and determine the measure of the gravitational field u

H. Kusunose, S. Yotsuhashi, K. Miyake

A realization of heavy fermion state is investigated on the basis of two-band Hubbard model. By means of the slave-boson mean-field approximation, it is shown that for the intermediate electron density, n_e=1.5, the inter-band Coulomb repulsion U strongly emphasizes initially small difference between bands, and easily stabilizes integral valence in the lower

J. de Gier, M. T. Batchelor

We present a solvable ladder model which displays magnetization plateaus at fractional values of the total magnetization. Plateau signatures are also shown to exist along special lines. The model has isotropic Heisenberg interactions with additional many-body terms. The phase diagram can be calculated exactly for all values of the rung coupling and the magne

Won-Ho Kye, Chil-Min Kim

Near the point of tangent bifurcation, the scaling properties of the laminar length of type-I intermittency are investigated in the presence of noise. Based on analytic and numerical studies, we show that the scaling relation of the laminar length is dramatically deformed from $\frac{1}{\sqrtε}$ for $ε>0$ to $\exp\{\frac{1}{D}|ε|^{3/2}\}$ for $ε<0$ as $ε$ pa

Morris L. Swartz

A review of the decade of Z-pole electroweak physics is presented. Although all experimental work has been completed, it represents a ``Golden Age&#39;&#39; in our understanding of the Minimal Electroweak Standard Model (MSM). The latest (and nearly final) results from the LEP and SLC experiments are presented. The remaining inconsistencies are discussed and

Angelo Bassi, GianCarlo Ghirardi

Griffiths claims that the ``single family rule&#39;&#39;, a basic postulate of the decoherent histories approach, rules out our requirement that any decoherent history has a unique truth value, independently from the decoherent family to which it may belong. Here we analyze the reasons which make our requirement indispensable and we discuss the consequences

D. V. Kosachiov, E. A. Korsunsky

Frequency conversion process is studied in a medium of atoms with a $Λ$ configuration of levels, where transition between two lower states is driven by a microwave field. In this system, conversion efficiency can be very high by virtue of the effect of electromagnetically induced transparency (EIT). Depending on intensity of the microwave field, two regimes

E. A. Korsunsky, D. V. Kosachiov

We propose a scheme for generation of continuous-wave THz radiation. The scheme requires a medium where three discrete states in a $Λ$ configuration can be selected, with the THz-frequency transition between the two lower metastable states. We consider the propagation of three-frequency continuous-wave electromagnetic (e.m.) radiation through a $Λ$ medium. U

Andreas Ruschhaupt

We propose a covariant algorithm for relativistic ideal measurements and for relativistic continuous measurements, its non-relativistic limit results the algorithm of the Event-Enhanced Quantum Theory. Therefore an additional intrinsic parameter, the proper time, is used. As an application we compute the time of arrival of a particle at a detector and find g

T. R. Hovhannisyan, A. G. Markossian, G. F. Mkrtchian

On the base of relativistic generalized eikonal approximation wave function the multiphoton cross sections of a Dirac particle bremsstrahlung on an arbitrary electrostatic potential and strong laser radiation field are presented. In the limit of the Born approximation the ultimate analytical formulas for arbitrary polarization of electromagnetic wave have be

L. Lanz, O. Melsheimer, B. Vacchini

The relationship between microsystems and macrosystems is considered in the context of quantum field formulation of statistical mechanics: it is argued that problems on foundations of quantum mechanics can be solved relying on this relationship. This discussion requires some improvement of non-equilibrium statistical mechanics that is briefly presented.

Michael J. York

We consider the implications of the Revised Symmetrization Postulate (see quant-ph/9908078) for states of more than two particles. We show how to create permutation symmetric state vectors and how to derive alternative state vectors that may be asymmetric for any pair by creating asymmetric interdependencies in their state descriptions. Because we can choose

Michael J. W. Hall

The Fisher information of a quantum observable is shown to be proportional to both (i) the difference of a quantum and a classical variance, thus providing a measure of nonclassicality; and (ii) the rate of entropy increase under Gaussian diffusion, thus providing a measure of robustness. The joint nonclassicality of position and momentum observables is show

Pretterebner Julius

This article shows the relation between the inertial mass and the gravity mass. The gravity field can propagate only with a limited velocity. Therefore the Helmholz equation is introduced for the gravity potential. The analysis of the Helmholz equation leads to the &#34;Maxwell equations&#34; for the gravity field. The dualism between the electricity and the

Agris Gailitis, Olgerts Lielausis, Sergej Dement&#39;ev, Ernests Platacis

In an experiment at the Riga sodium dynamo facility, a slowly growing magnetic field eigenmode has been detected over a period of about 15 seconds. For a slightly decreased propeller rotation rate, additional measurements showed a slow decay of this mode. The measured results correspond satisfactory with numerical predictions for the growth rates and frequen

Ali Riza akcay

This paper describes a &#39;New Formula&#39; in place of Einstein&#39;s Famous Formula (EFF) to provide the compatibility between the Special Theory of Relativity (STR), black holes and strings. The &#39;New Formula&#39; can also predict and describe the space-time singularities without the distribution of mass and energy. According to the &#39;New Formula&#

J. Brian Conrey, David W. Farmer

Recently Katz and Sarnak introduced the idea of a symmetry group attached to a family of L-functions, and they gave strong evidence that the symmetry group governs many properties of the distribution of zeros of the L-functions. We consider the mean-values of the L-functions and the mollified mean-square of the L-functions and find evidence that these are al

Jonathan A. Scott

Let X be a finite, n-dimensional, r-connected CW complex. We prove the following theorem: If p \geq n/r is an odd prime, then the loop space homology Bockstein spectral sequence modulo p is a spectral sequence of universal enveloping algebras over differential graded Lie algebras.

Weiqiang Wang

Various algebraic structures have recently appeared in a parallel way in the framework of Hilbert schemes of points on a surface and respectively in the framework of equivariant K-theory [N1,Gr,S2,W], but direct connections are yet to be clarified to explain such a coincidence. We provide several non-trivial steps toward establishing our main conjecture on t