April 1999 arXiv papers — page 10

V. B. Kopeliovich, W. J. Zakrzewski

Static properties of multiskyrmions with baryon numbers up to 8 are calculated starting from recently given rational map ansaetze. The spectra of baryonic systems with strangeness, charm and bottom are estimated within a "rigid oscillator" version of the bound state soliton model. It is suggested that the recently observed negatively charged nuclear

M. Skrzypek, Z. Was

We present a scheme for integrating the matrix element of an arbitrary e^+e^-\to f_1f_2\bar f_3\bar f_4 process over the complete four-fermion phase space, or its any part, by means of the Monte Carlo technique. The presented algorithm has been successfully implemented in the KORALW Monte Carlo code.

Merab Gogberashvili

Five dimensional model with extended dimensions investigated. It is shown that four dimensionality of our world is the result of stability requirement. Extra component of Einstein equations giving trapping solution for matter fields coincides with the one of conditions of stability.

M. Jezabek, Y. Sumino

Solar and atmospheric neutrino anomalies are described by bimaximal mixing of three neutrinos. Neutrino oscillations in appearance nu_e <--> nu_mu,nu_tau and in disappearance nu_e long baseline and atmospheric experiments are sensitive to deviations from the ideal bimaximal mixing. It is suggested that these deviations may be dominated by a rotation in the e

R. M. Godbole

In this talk I present a discussion of the theoretical bounds on the mass of the Higgs in the Standard Model (SM) as well as in the Minimal Supersymmetric Standard Model (MSSM). Then I will point out a few facts about the couplings of scalars that are relevant for its search at hadronic colliders. After that I discuss the search possibilities at the Tevatron

M. Campanelli

After the first observations of W bosons in leptonic interactions, about 4000 WW candidate events per experiment have been collected at LEP2. This data allows the measurement of the WW production cross section at different centre-of-mass energies, as well as W decay branching fractions. The W hadronic branching fraction can be converted into a test of the un

Simonetta Frittelli, Oscar A. Reula

We show that well-posed, conformally-decomposed formulations of the 3+1 Einstein equations can be obtained by densitizing the lapse and by combining the constraints with the evolution equations. We compute the characteristics structure and verify the constraint propagation of these new well-posed formulations. In these formulations, the trace of the extrinsi

Marco Cavaglia

We derive the general $Σ_2\times S$ solution of topologically massive gravity in vacuum and in presence of a cosmological constant. The field equations reduce to three-dimensional Einstein equations and the solution has constant Ricci tensor. We briefly discuss the emergence of non-Ricci flat solutions when spin is introduced.

F. I. Cooperstock

The energy localization hypothesis of the author that energy is localized in non-vanishing regions of the energy-momentum tensor implies that gravitational waves do not carry energy in vacuum. If substantiated, this has significant implications for current research. Support for the hypothesis is provided by a re-examination of Eddington&#39;s classic calcula

Robert A. Bartnik, Andrew H. Norton

We describe numerical techniques used in the construction of our 4th order evolution for the full Einstein equations, and assess the accuracy of representative solutions. The code is based on a null gauge with a quasi-spherical radial coordinate, and simulates the interaction of a single black hole with gravitational radiation. Techniques used include spheri

B. Linet

We explicitly determine the expression of the electrostatic potential generated by a point charge at rest in the Schwarzschild black hole pierced by a cosmic string. We can then calculate the electrostatic self-energy. From this, we find again the upper entropy bound for a charged object by employing thermodynamics of the black hole.

Wai-Mo Suen

A multi-TeraFlop/TeraByte machine will enable the application of the Einstein theory of gravity to realistic astrophysical processes. Without the computational power, the complexity of the Einstein theory restricts most studies based on it to the quasi static/linear near-Newtonian regime of the theory. The application of the Einstein theory to realistic astr

Ian Redmount, Wai-Mo Suen, Kenneth Young

One classical theory, as determined by an equation of motion or set of classical trajectories, can correspond to many unitarily {\em in}equivalent quantum theories upon canonical quantization. This arises from a remarkable ambiguity, not previously investigated, in the construction of the classical (and hence the quantized) Hamiltonian or Lagrangian. This am

Mark Miller, Wai-Mo Suen, Malcolm Tobias

We study the question of prompt vs. delayed collapse in the head-on collision of two neutron stars. We show that the prompt formation of a black hole is possible, contrary to a conjecture of Shapiro which claims that collapse is delayed until after neutrino cooling. We discuss the insight provided by Shapiro's conjecture and its limitation. An understanding

P. H. E Tiesinga, Jorge V Jose

Recent experiments suggest that inhibitory networks of interneurons can synchronize the neuronal discharge in in vitro hippocampal slices. Subsequent theoretical work has shown that strong synchronization by mutual inhibition is only moderately robust against neuronal heterogeneities in the current drive, provided by activation of metabotropic glutamate rece

D. R. Link, L. Radzihovsky, G. Natale, J. E. Maclennan

Ring patterns of concentric 2pi-solitons in molecular orientation, form in freely suspended chiral smectic-C films in response to an in-plane rotating electric field. We present measurements of the zero-field relaxation of ring patterns and of the driven dynamics of ring formation under conditions of synchronous winding, and a simple model which enables thei

David L. Feder, Charles W. Clark, Barry I. Schneider

Vortex states of weakly-interacting Bose-Einstein condensates confined in three-dimensional rotating harmonic traps are investigated numerically at zero temperature. The ground state in the rotating frame is obtained by propagating the Gross-Pitaevskii equation for the condensate in imaginary time. The total energies between states with and without a vortex

H. Srikanth, E. E. Carpenter, C. J. O&#39;Connor

A precision radio-frequency (RF) transverse modulation technique based on a resonant tunnel diode oscillator (TDO) has been used to study the dynamic susceptibility in novel ring-shaped single domain Fe nanoparticles synthesized using reverse-micelle chemistry. Hysteresis loops measured using a SQUID magnetometer indicate a large coercivity (Hc = 400Oe) belo

E. G. D. Cohen, L. Rondoni

The intriguing relations between Kolmogorov-Sinai entropy and self diffusion coefficients and the excess (thermodynamic) entropy found by Dzugutov and collaborators do not appear to hold for hard sphere and hard disks systems.

Michael Promberger, Michael Kastner, Alfred Hueller

In the microcanonical ensemble, suitably defined observables show non-analyticities and power law behaviour even for finite systems. For these observables, a microcanonical finite-size scaling theory is established which facilitates an approach to the critical exponents of the infinite system.

G. Haran, A. D. S. Nagi

We discuss the weak-coupling BCS theory of a superconductor with the impurities, accounting for their anisotropic momentum-dependent potential. The impurity scattering process is considered in the t-matrix approximation and its influence on the superconducting critical temperature is studied in the Born and unitary limit for a d- and (d+s)-wave superconducto

G. Haran, J. Taylor, A. D. S. Nagi

A combined effect of the orthorhombic crystal field and potential impurity scattering on several superconducting states of a tetragonal symmetry is studied within a weak-coupling mean field approach. It is shown that the nonmagnetic impurities stabilize the states belonging to the identity irreducible representation. The electronic specific heat jump at the

G. Haran, A. D. S. Nagi

We discuss a case of a strong anisotropic impurity scattering within the model introduced in our previous paper [Phys. Rev. B54, 15463 (1996)] and clarify our former statement about a possible enhancement of the critical temperature in this scattering regime. We show that for the anisotropy of the impurity potential determined by the functions from the non-i

Yoshihiro Nishiyama

Ground state of the dissipative two-state system is investigated by means of the Lanczos diagonalization method. We adopted the Hilbert-space-reduction scheme proposed by Zhang, Jeckelmann and White so as to reduce the overwhelming reservoir Hilbert space to being tractable in computers. Both the implementation of the algorithm and the precision applied for

M. Fuchs, M. Müller

The inter-molecular structure of semidilute polymer solutions is studied theoretically. The low density limit of a generalized Ornstein-Zernicke integral equation approach to polymeric liquids is considered. Scaling laws for the dilute-to-semidilute crossover of random phase (RPA) like structure are derived for the inter-molecular structure factor on large d

Andreas Mielke

A Hubbard model with a single, partially flat band has ferromagnetic ground states. It is shown that local stability of ferromagnetism implies its global stability in such a model: The model has only ferromagnetic ground states if there are no single spin-flip ground states. Since a single-band Hubbard model away from half filling describes a metal, this res

Erik Koch, Olle Gunnarsson, Richard M. Martin

We study the static screening in a Hubbard-like model using fixed-node diffusion Monte Carlo. We find that the random phase approximation is surprisingly accurate even for metallic systems close to the Mott transition. As a specific application we discuss the implications of the efficient screening for the superconductivity in the doped Fullerenes. In the Mo

Gert-Ludwig Ingold, Hermann Grabert

In the presence of phase fluctuations the dc Josephson effect is modified and the supercurrent at zero voltage is replaced by a peak at small but finite voltages. It is shown that at zero temperature this peak is determined by two complementary expansions of finite radius of convergence. The leading order expressions are related to results known from the reg

Yoshihiro ASAI

We propose a new sampling method to calculate the ground state of interacting quantum systems. This method, which we call the adaptive sampling quantum monte carlo (ASQMC) method utilises information from the high temperature density matrix derived from the monte carlo steps. With the ASQMC method, the negative sign ratio is greatly reduced and it becomes ze

D. van der Marel

The optical conductivity along and perpendicular to the planes is calculated assuming strong k-dependence of the scattering rate and the c-axis hopping parameter. Closed analytical expressions for the optical conductivy along these directions are obtained, and are shown to be integrable at low and high frequencies. A large and qualitatively different frequen

Sanjoy K. Sarker

A spin-charge recombination route to superconductivity, proposed earlier (1992)], is examined using the Schwinger boson representation of the t-J model. The representation is known to work well at half-filling. It was shown in the earlier paper that, away from half filling, spin-charge recombination into electrons occurs directly through the hopping term as

A. Surda

A new approach to derivation of various effective-field approximation for lattice spin models is presented. It is shown that it can give a number of methods, including the DMRG method, that can be used to find generally inhomogeneous solutions of 2D classical lattice problems. A method, closely related the DMRG method but without necessity to perform any ren

Maria Barbi, Simona Cocco, Michel Peyrard

We present a new dynamical model of DNA. This model has two degrees of freedom per base-pair: one radial variable related to the opening of the hydrogen bonds and an angular one related to the twisting of each base-pair responsible for the helicoidal structure of the molecule. The small amplitude dynamics of the model is studied analytically : we derive smal

Simona Cocco, Maria Barbi, Michel Peyrard

Group velocity and group velocity dispersion for a wave packet in vectorial discrete Klein-Gordon models are obtained by an expansion, based on perturbation theory, of the linear system giving the dispersion relation and the normal modes. We show how to map this expansion on the Multiple Scale Expansion in the real space and how to find Non Linear Schrödinge

U. S. Nilsson, C. Uggla, J. Wainwright, W. C. Lim

In this letter we will show that, contrary to what is widely believed, an almost isotropic cosmic microwave background (CMB) temperature does not imply that the universe is ``close to a Friedmann-Lemaitre universe&#39;&#39;. There are two important manifestations of anisotropy in the geometry of the universe, (i) the anisotropy in the overall expansion, and

Sidney van den Bergh

The history of the discovery of dark matter in the Universe is briefly reviewed. Special emphasis is placed on the early work by Zwicky (1933), Smith (1936), Babcock (1939) and Oort (1940).

Philip Kaaret, Santina Piraino, Jules Halpern, Michael Eracleous

We have discovered an x-ray source, SAX J0635+0533, with a hard spectrum within the error box of the GeV gamma-ray source in Monoceros, 2EG J0635+0521. The unabsorbed x-ray flux is 1.2*10^-11 erg cm^-2 s^-1 in the 2-10 keV band. The x-ray spectrum is consistent with a simple powerlaw model with absorption. The photon index is 1.50 +/- 0.08 and we detect emis

C. L. Carilli, M. A. Holdaway

We review millimeter interferometric phase variations caused by variations in the precipitable water vapor content of the troposphere, and we discuss techniques proposed to correct for these variations. We present observations with the Very Large Array at 22 GHz and 43 GHz designed to test these techniques. We find that both the Fast Switching and Paired Arr

S. E. Zepf, K. M. Ashman, J. English, K. C. Freeman

We present images of the recent galaxy merger NGC 3256 obtained with the WFPC2 of the Hubble Space Telescope in B and I filters. We show that there is a large population of more than 1,000 compact, bright blue objects in this galaxy within the 7 kpc x 7 kpc region studied. These objects have sizes, colors and luminosities like those expected for young Galact

Jayadev Rajagopal, G. Srinivasan, K. S. Dwarakanath

In the preceding paper (paper I), we presented HI absorption spectra towards radio sources very close to the lines of sight towards 25 bright stars against which optical absorption spectra had been obtained earlier. In this paper we analyse the results and draw some conclusions. To summarize briefly, in most cases we found HI absorption at velocities corresp

G. S. Bisnovatyi-Kogan, A. N. Timokhin

We investigated influence of cosmological GRB on the surrounding interstellar medium. It was shown that γ-radiation from the burst heats interstellar gas to the temperatures > 10^4 K up to the distance \sim 10 pc. For high density ISM optical and UV radiation of the heated gas can be observed on the Eath several years as a GRB`s counterpart

Jayadev Rajagopal, G. Srinivasan, K. S. Dwarakanath

This investigation is aimed at clarifying the nature of the interstellar gas seen in absorption against bright O and B stars. Towards this end we have obtained for the first time HI absorption spectra towards radio sources very close to the lines of sight towards 25 bright stars previously studied. In this paper we describe the selection criteria, the detail

M. Cappi, L. Bassani, G. Malaguti, the BeppoSAX Compton thin Sey2s collaboration

The broad band 0.1-200 keV spectra of a sample of 5 Seyfert 2 galaxies (NGC 7172, Mkn 3, NGC 2110, NGC 4507 and NGC 7674) have been measured within the first year of the $BeppoSAX$ Core program. All sources have been detected up to \~ 100 keV and their spectral characteristics derived with good accuracy. Although the results obtained from the detailed analys

Judith G. Cohen, Raffaele G. Gratton, Bradford B. Behr, Eugenio Carretta

We provide a high dispersion line-by-line abundance analysis of five red HB stars in the extremely metal rich galactic globular cluster NGC 6553. These red HB stars are significantly hotter than the very cool stars near the tip of the giant branch in such a metal rich globular cluster and hence their spectra are much more amenable to an abundance analysis th

Achim Weiss, Maurizio Salaris

Reliable temperature-colour transformations are a necessary ingredient for isochrones to be compared with observed colour-magnitude-diagrams of globular clusters. We show that both theoretical and empirical published transformations to (V-I) to a large extend exhibit significant differences between them. Based on these comparisons we argue for particular tra

A. Refregier

While the major contribution to the Cosmic Microwave Background (CMB) anisotropies are the sought-after primordial fluctuations produced at the surface of last scattering, other effects produce secondary fluctuations at lower redshifts. These secondary fluctuations must be carefully accounted for, in order to isolate primordial fluctuations. In addition, the

W. Hofmann, I. Jung, A. Konopelko, H. Krawczynski

For air showers observed simultaneously by more than two imaging atmospheric Cherenkov telescopes, the shower geometry is overconstrained by the images and image information should be combined taking into account the quality of the images. Different algorithms are discussed and tested experimentally using data obtained from observations of Mkn 501 with the H

Xue-Bing Wu, Norbert Bade, Volker Beckmann

X-ray luminous radio-quiet high redshift QSOs are rare and can be used for the investigation of several important astronomical questions. We have conducted a large area survey for radio-quiet high redshift QSOs in the ROSAT All-Sky Survey, from which QSO candidates are selected using the digitized objective prism spectra from the Hamburg Quasar Survey. The 2

A. Ortiz-Gil, K. M. Lanzetta, J. K. Webb, X. Barcons

We present new GHRS observations of Lyman alpha absorption lines associated with a group of galaxies towards the QSO 1545+2101. We have identified eight distinct Lyman alpha absorption features in the spectrum of QSO 1545+2101 at a mean redshift of z=0.2648 with a velocity dispersion of 163 km/s. A group of galaxies is detected in the vicinity of this QSO at

Mark Halpern, Douglas Scott

We summarise some aspects of experiments currently being built or planned, and indulge in wild speculation about possibilities on the more distant horizon.

Ryoitiro Huzimura, Toyoki Matsuyama

When a small number of individuals of organism of single species is confined in a closed space with limited amount of indispensable resources, their breading may start initially under suitable conditions, and after peaking, the population should go extinct as the resources are exhausted. Starting with the logistic equation and assuming that the carrying capa

M. Bucher, K. Moodley, N. Turok

We consider the most general primordial cosmological perturbation in a universe filled with photons, baryons, neutrinos, and a hypothetical cold dark matter (CDM) component within the framework of linearized perturbation theory. We give a careful discussion of the different allowed modes, distinguishing modes which are regular at early times, singular at ear

Thomas G. Rizzo

Arkani-Hamed, Dimopoulos and Dvali have recently proposed that gravity may become strong at energies near 1 TeV thus removing the hierarchy problem. This scenario can be tested in several ways at present and future colliders. In this paper we examine the exchange of towers of Kaluza-Klein gravitons and their influence on the production of pairs of massive ga

JM Figueroa-O&#39;Farrill

We present a systematic attempt at classification of supersymmetric M-theory vacua with zero flux; that is, eleven-dimensional lorentzian manifolds with vanishing Ricci curvature and admitting covariantly constant spinors. We show that there are two distinct classes of solutions: static spacetimes generalising the Kaluza-Klein monopole, and non-static spacet

Tony Gherghetta, Gian F. Giudice, James D. Wells

In the supersymmetric standard model there exist pure gravity contributions to the soft mass parameters which arise via the superconformal anomaly. We consider the low-energy phenomenology with a mass spectrum dominated by the anomaly-induced contributions. In a well-defined minimal model we calculate electroweak symmetry breaking parameters, scalar masses,

Hungchong Kim

Within the conventional QCD sum rules, we calculate the $πNN$ coupling constant, $g_{πN}$, beyond the chiral limit using two-point correlation function with a pion. We consider the Dirac structure, $iγ_5$, at $m_π^2$ order, which has clear dependence on the PS and PV coupling schemes for the pion-nucleon interactions. For a consistent treatment of the sum ru

S. A. E. G. Falle, S. S. Komissarov

In this paper we study the general relationship between the evolutionary conditions for discontinuous solutions of hyperbolic conservation laws with a concave entropy function and the existence and uniqueness of steady dissipative shock structure. Our results confirm the classical shock theory. We also show that the appearance of intermediate shocks in numer

Mina Teicher

We describe various properties of Hirzebruch surfaces and related constructions: degenerations, braid monodromy, Galois covers and their Chern classes.

V. V. Vershinin

Virtual knots arise in the study of Gauss diagrams and Vassiliev invariants of usual knots. Virtual braids correspond naturally to virtual knots. We consider the group of virtual braids on n strings VB_n and its Burau representation, in particular we study their homological properties. We prove that the plus-construction of the classifying space of the virtu

Douglas Singleton

Finding solutions to non-linear field theories, such as Yang-Mills theories or general relativity, is usually difficult. The field equations of Yang-Mills theories and general relativity are known to share some mathematical similarities, and this connection can be used to find solutions to one theory using known solutions of the other theory. For example, th

Yishi Duan, Libin Fu, Guan Jia

We present a new general topological tensor current of $\tilde{p}$-branes by making use of the $ϕ$-mapping theory. It is shown that the current is identically conserved and behave as $δ(\vecϕ),$ and every isolated zero of the vector field $\vecϕ(x)$ corresponds to a `magnetic&#39; $\tilde{p}$-brane. Using this topological current, the generalized Nambu actio

G. C. Branco, F. Cagarrinho, F. Krüger

We study the possible existence of a real Cabibbo-Kobayashi-Maskawa (CKM) matrix, with CP violation originating from physics beyond the standard model (SM). We show that present experimental data allow for a real CKM matrix provided that new physics also contributes to Delta m_{B_d} by at least 20% of the SM contribution (for rho > 0), besides generating CP

G. Bauer

$B^0$ mixing measurements from the Tevatron Run I data are reported. These include time-integrated measurements of the average mixing parameter $\barχ$, six time-dependent oscillation measurements of $Δm_d$, and a time-dependent limit on $Δm_s$. Such measurements provide constraints on CKM matrix elements. A sample of $B^0/\bar{B}{^0} \to J/ψK^0_S$ decays is

Lorrie Faith Cranor, Joseph Reagle, Mark S. Ackerman

People are concerned about privacy, particularly on the Internet. While many studies have provided evidence of this concern, few have explored the nature of the concern in detail, especially for the online environment. With this study, we have tried to better understand the nature of online privacy concerns; we look beyond the fact that people are concerned

N. Shah, P. Chandra, P. Coleman, J. A. Mydosh

We review current attempts to characterize the underlying nature of the hidden order in $URu_2Si_2$. A wide variety of experiments point to the existence of two order parameters: a large primary order parameter of unknown character which co-exists with secondary antiferromagnetic order. Current theories can be divided into two groups determined by whether or

V. Yu. Irkhin, A. A. Katanin

Orientational phase transitions are investigated within the Heisenberg model with single-site anisotropy. The temperature dependence of the cone angle is calculated within the spin-wave theory. The role of the quantum renormalizations of anisotropy constants is discussed. A comparison with the experimental data on the cone-plane orientational transition in h

Victor Barzykin

We obtain the logarithmic corrections to the dynamic response function and NMR T_1 and T_{2G} rates in the spin-1/2 antiferromagnetic Heisenberg chain using perturbative renormalization group in the leading irrelevant operator. The result is compared with NMR experiments in Sr_2CuO_3.

Nir Gov

In this work we investigate implications of the quantum nature of bcc $^{4}$% He. We show that it is a unique solid phase with both a lattice structure and an Off-Diagonal Long Range Order of coherently oscillating local electric dipole moments. These dipoles arise from the local motion of the atoms in the crystal potential well, and oscillate in synchrony t

Carl H. Gibson

The theory of gravitational structure formation in astrophysics and cosmology is revised based on real fluid behavior and turbulent mixing theory. Gibson&#39;s 1996-1998 theory balances fluid mechanical forces with gravitational forces and density diffusivity with gravitational diffusivity at critical viscous, turbulent, magnetic, and diffusion length scales

J. P. Zibin, Douglas Scott, Martin White

The detection of a stochastic background of long-wavelength gravitational waves (tensors) in the cosmic microwave background (CMB) anisotropy would be an invaluable probe of the high energy physics of the early universe. Unfortunately a combination of factors now makes such a detection seem unlikely: the vast majority of the CMB signal appears to come from d

M. D. Lehnert, T. M. Heckman, K. A. Weaver

We discuss the properties and implications of a 3.7x0.9 kpc region of spatially-coincident X-ray and H-alpha emission about 11.6 kpc to the north of the galaxy M82 previously discussed by Devine and Bally (1999). The PSPC X-ray spectrum is fit by thermal plasma (kT=0.80+-0.17 keV) absorbed by only the Galactic foreground column density. We evaluate the relat

M. Contini, S. M. Viegas

A multi-cloud model is presented which explains the soft X-ray excess in NGC 4051 and, consistently, the optical line spectrum and the SED of the continuum. The clouds are heated and ionized by the photoionizing flux from the active center and by shocks. Diffuse radiation, partly absorbed throughout the clouds, nicely fits the bump in the soft X-ray domain,

E. Cappellaro, R. Evans, M. Turatto

We have computed new estimates of the local rates of supernovae (SNe) adding the updated log of Evans&#39; visual search to our SN search database. In this way, we have accumulated the largest SN statistics ever assembled for this purpose. The new SN rates are corrected on an empirical basis for the bias in the inner regions of galaxies and that in inclined

S. Gueron, Mandar M. Deshmukh, E. B. Myers, D. C. Ralph

We measure electron tunneling via discrete energy levels in ferromagnetic cobalt particles less than 4 nm in diameter, using non-magnetic electrodes. Due to magnetic anisotropy, the energy of each tunneling resonance shifts as an applied magnetic field rotates the particle&#39;s magnetic moment. We see both spin-increasing and decreasing tunneling transition

Matteo Palassini, Sergio Caracciolo

We study the three-dimensional Edwards-Anderson model with binary interactions by Monte Carlo simulations. Direct evidence of finite-size scaling is provided, and the universal finite-size scaling functions are determined. Monte Carlo data are extrapolated to infinite volume with an iterative procedure up to correlation lengths xi \approx 140. The infinite v

M. M. Fogler, David A. Huse

Motivated by puzzling results of recent experiments, we re-examine the response of a weakly pinned two-dimensional Wigner crystal to a uniform AC electric field. We confirm that at some disorder and magnetic field dependent frequency $ω_p$, an inhomogeneously broadened absorption line emerges. Although the line is conventionally broad in zero magnetic field,

Spencer Bloch, Hélène Esnault

see the old abstract and the comments here.

Sasanka Ghosh, Anjan Kundu, Sudipta Nandy

Exact integrability of the Sasa Satsuma eqation (SSE) in the Liouville sense is established by showing the existence of an infinite set of conservation laws. The explicit form of the conserved quantities in term of the fields are obtained by solving the Riccati equation for the associated 3x3 Lax operator. The soliton solutions in particular, one and two sol

Fumihiko Sugino

In this paper we consider IIA and IIB matrix string theories which are defined by two-dimensional and three-dimensional super Yang-Mills theory with the maximal supersymmetry, respectively. We exactly compute the partition function of both of the theories by mapping to a cohomological field theory. Our result for the IIA matrix string theory coincides with t

Yuji Ohta

Prepotentials in N=2 supersymmetric Yang-Mills theories are known to obey non-linear partial differential equations called Witten-Dijkgraaf-Verlinde-Verlinde (WDVV) equations. In this paper, the prepotentials at one-instanton level in N=2 supersymmetric SU(4) Yang-Mills theory are studied from the standpoint of WDVV equations. Especially, it is shown that th

Arun Kumar Pati

We propose a protocol where one can exploit dual quantum and classical channels to achieve perfect ``cloning&#39;&#39; and ``orthogonal-complementing&#39;&#39; of an unknown state with a minimal assistance from a state preparer (without revealing what the input state is). The first stage of the protocol requires usual teleportation and in the second stage, t

Valery P. Dmitriyev

A discontinuity of a turbulent ideal fluid is considered. It is supposed to be split and dispersed, or spread in the stochastic environment forming a gas without hydrostatic pressure. Two equal-mass fragments of a discontinuity are indistinguishable from each other. A gas, that possesses such properties, must behave itself as the Madelung medium.

V. V. Dmitrieva, A. V. Gladkov, R. A. Sharipov

For the system of second order quasilinear parabolic equations the problem of reducing them to the equations of diffusion type is considered. In non-degenerate case an effective algorithm for solving this problem is suggested.

O. V. Teryaev

The partition of nucleon spin between total angular momenta of quarks and gluons is described by the energy momentum tensor formfactors manifested also in the nucleon scattering by weak classical gravitational field. Natural generalization of equivalence principle is resulting in the identically zero &#34;Anomalous gravitomagnetic moment&#34; being the strai

D. L. Khokhlov

It is shown that the data on the decay of neutral kaons may be explained without CP-violation.

M. Steinhauser

In this contribution recent developments are discussed which lead to a significant reduction of the error for $α(M_Z^2)$ and $(g-2)_μ$.

David H. Lyth

In a large region of parameter space, the tree-level hybrid inflation model is likely to be be invalidated by loop corrections. In particular, this is likely to be the case if both quartic couplings are of order unity, as is often supposed. It is likely also to be the case if there is an ultra-violet cutoff far below the Planck scale, ($\luv\lsim 10^9\GeV(V_

K. Maltman

The strange quark mass is determined from a study of the correlator of the divergence of the strange vector current using a family of finite energy sum rules recently shown to be very accurately satisfied in the isovector vector channel. It is shown that the match between the OPE and hadronic representations for the sum rules employed is extremely good once

G. Gelmini

We review bounds on neutrino properties, in particular on their masses, coming mostly from cosmology, and also from astrophysics.

G. Giacomelli

Using multihadronic Z0 decays recorded in 1991-1995 by the OPAL detector in e+e- collisions at LEP1, experimental analyses were made of the following subjects: (a) Bose-Einstein correlations; (b) Intermittency and correlations; (c) rho and omega spin alignments; (d) A search for the tensor glueball candidate fj(2200).

Feng Chen, Nicholas Kioussis

We have studied the one-dimensional periodic, symmetric Anderson model at half filling in the presence of disorder using finite-temperature quantum Monte Carlo techniques. We have examined for the first time the disorder both in hybridization between the local $f$-orbitals and the conduction electrons and in the local $f$-site energy, using a uniform distrib

C. Waidacher, J. Richter, R. E. Hetzel, K. W. Becker

For the calculation of charge excitations as those observed in, e.g., photo-emission spectroscopy or in electron-energy loss spectroscopy, a correct description of ground-state charge properties is essential. In strongly correlated systems like the undoped cuprates this is a highly non-trivial problem. In this paper we derive a non-perturbative analytical ap

Bang-Gui Liu

We study the spin-$s$ quantum Heisenberg antiferromagnetic models in a magnon theory free of any unphysical magnon state. Because the unphysical magnon states are completely removed in the magnon Hamiltonians and during the approximation process, we derive spin-s (s>1/2) reliable Neel temperature $T_N$ and reasonable sublattice magnetization unified for $T\l

Vassiliki Kalogera

Merger events of close double neutron stars (DNS) lie at the basis of a number of current issues in relativistic astrophysics, such as the indirect and possible direct detection of gravitational waves, the production of gamma-ray bursts at cosmological distances, and the origin of r-process elements in the universe. In assessing the importance or relevance o

Fred Hamann, Gary Ferland

Quasar (or QSO) elemental abundances provide unique probes of high-redshift star formation and galaxy evolution. There is growing evidence from both the emission and intrinsic absorption lines that QSO environments have roughly solar or higher metallicities out to redshifts >4. The range is not well known, but solar to a few times solar appears to be typical

Idit Zehavi, Avishai Dekel

Recent observations of high-redshift supernovae seem to suggest that the global geometry of the Universe may be affected by a `cosmological constant&#39;, which acts to accelerate the expansion rate with time. But these data by themselves still permit an open universe of low mass density and no cosmological constant. Here we derive an independent constraint

W. A. Heindl, W. Coburn, D. E. Gruber, M. R. Pelling

We have discovered a third harmonic cyclotron resonance scattering feature (CRSF) in observations of the recent outburst of 4U 0115+63 with the Rossi X-ray Timing Explorer (RXTE). The spectrum in a narrow pulse phase range shows CRSFs at 12.40+0.65/-0.35, 21.45+0.25/-0.38, and 33.56+0.70/-0.90 keV. With centroid energy ratios to the fundamental of 1.73+/-0.0

Marius Grigorescu

The ground and first excited state of two superconducting layers in interaction are studied considering two different coupling terms, one represented by the standard Josephson interaction, and one new, which is a superexchange pairing force between bilayer pairs. It is shown that a moderate-to strong Josephson interaction produces a low-lying collective stat

Andrea Brignole, Elena Perazzi, Fabio Zwirner

We perform a general analysis of the contributions to the muon anomalous magnetic moment in models with a superlight gravitino. We discuss the interpretation and the phenomenological implications of the results. We find that present constraints on the model parameters are comparable and complementary to the ones coming from collider searches and from perturb

K. S. Babu, B. Dutta, R. N. Mohapatra

In a recent paper, we showed that tree level up-down unification of fermion Yukawa couplings is a natural consequence of a large class of supersymmetric models. They can lead to viable quark masses and mixings for moderately large values of $\tanβ$ with interesting and testable predictions for CP violation in the hadronic sector. In this letter, we extend ou