January 1998 arXiv papers — page 9
Showing 801–900 of 1,696 papers
Central charges, black-hole entropy and geometrical structure of N-extended supergravities in D=4
hep-thLaura Andrianopoli
The derivation of absolute (moduli-independent) U-invariants for all N>2 extended supergravities at D=4 in terms of (moduli-dependent) central and matter charges is reported. These invariants give a general definition of the ``topological'' Bekenstein-Hawking entropy formula for extremal black-holes and reduce to the square of the black-hole ADM mass
S. Bronoff, R. Buffa, C. P. Korthals Altes
One of the salient features of high temperature gluodynamics is the Z(N) groundstate degeneracy, key to the understanding of the transition. On the other hand impressive progress has been obtained with effective theories, that seemingly lack Z(N) symmetry. We give a simple unified desciption of the two. As a very useful byproduct we get a natural infrared re
Hitoshi Murayama
We discuss the prospect of studying physics at short distances, such as Planck length or GUT scale, using supersymmetry as a probe. Supersymmetry breaking parameters contain information on all physics below the scale where they are induced. We will gain insights into grand unification (or in some cases string theory) and its symmetry breaking pattern combini
Ursula Bassler, Gregorio Bernardi
The procedure used for structure function measurements at HERA is briefly described and related to the properties of kinematic reconstruction. The reconstruction methods of the inclusive deep inelastic scattering variables are reviewed and their sensitivity to the energy and angle miscalibrations are discussed in detail. New prescriptions are introduced and
S. H. Kettell
An overview of the Rare Kaon Decay program at the AGS is presented, with particular emphasis on the three major experiments currently running and analyzing data. A brief review of earlier kaon decay experiments and of recent improvements in AGS performance is provided. This review concludes with a discussion of proposed and developing experiments planned to
Madhavan Varadarajan
We show that only a sector of the classical solution space of the CGHS model describes formation of black holes through collapse of matter. This sector has either right or left moving matter. We describe the sector which has left moving matter in canonical language. In the nonperturbative quantum theory all operators are expressed in terms of the matter fiel
David Vanderbilt, R. D. King-Smith
An expression is given for the electronic polarization of an insulating crystal within the ultrasoft pseudopotential scheme. The pseudopotential charge-augmentation terms modify the usual Berry-phase expression, and also give rise to a second term that takes the form of a conventional expectation value.
Giorgio Parisi
In this note we put forward a conjecture on the average optimal length for bipartite matching with a finite number of elements where the different lengths are independent one from the others and have an exponential distribution.
Angela Foerster, Jon Links, Itzhak Roditi
Using Reshetikhin's construction for multiparametric quantum algebras we obtain the associated multiparametric quantum spin chains. We show that under certain restrictions these models can be mapped to quantum spin chains with twisted boundary conditions. We illustrate how this general formalism applies to construct multiparametric versions of the supers
A. G. Huibers, S. R. Patel, C. M. Marcus, P. W. Brouwer
Full distributions of conductance through quantum dots with single-mode leads are reported for both broken and unbroken time-reversal symmetry. Distributions are nongaussian and agree well with random matrix theory calculations that account for a finite dephasing time, $τ_ϕ$, once broadening due to finite temperature $T$ is also included. Full distributions
Yuri Ozhigov
LS is a particular type of computational processes simulating living tissue. They use an unlimited branching process arising from the simultaneous substitutions of some words instead of letters in some initial word. This combines the properties of cellular automata and grammars. It is proved that 1) The set of languages, computed in a polynomial time on such
Peter A. Heeman, Donna Byron, James F. Allen
In this paper, we present a method for identifying discourse marker usage in spontaneous speech based on machine learning. Discourse markers are denoted by special POS tags, and thus the process of POS tagging can be used to identify discourse markers. By incorporating POS tagging into language modeling, discourse markers can be identified during speech reco
Valerio Faraoni, Edgard Gunzig
The amplification of a light beam due to intervening gravitational waves is studied. The previous Jordan frame result according to which the amplification is many orders of magnitude larger in scalar-tensor gravity than in general relativity does not hold in the Einstein conformal frame. Lensing by gravitational waves is discussed in relation to the ongoing
C. G. Tinney
Observations are presented which show that LiI 6708A is detected with equivalent width of 0.53+-0.05A in the proper-motion object LP 944-20 (which is also known as BRI 0337-3535). This Li detection implies that LP 944-20 is a brown dwarf with mass between 0.057 and 0.063Mo and age between 475 and 650Myr, making it the first brown dwarf to have its mass and a
Pushing Back Studies of Galaxies Toward the Dark Ages: High-Redshift Lyman alpha Emission-Line Galaxies in the Field
astro-phEsther M. Hu
Lyman alpha emission presents a means of identifying very high redshift galaxies, provided such objects can be reliably distinguished from foreground emission-line galaxies. Here we report on a program of imaging and spectroscopic studies being conducted with the Keck telescope, in concert with additional efforts from the ground and with HST, to study such h
Andrew S. Fruchter, Elena Pian, Stephen E. Thorsett, Rosa Gonzalez
We report on observations of the fading optical counterpart of the gamma-ray burst GRB 970228, made on 4~September~1997 using the STIS CCD on the Hubble Space Telescope. The unresolved counterpart is detected at V=28 +/- 0.25, consistent with a continued power-law decline with exponent -1.14 +/- 0.05. No proper motion is detected, in contradiction of an earl
Stanley J. Brodsky, Mandeep S. Gill, Michael Melles, Johan Rathsman
The conventional definition of the running coupling $α_{\bar{MS}}(μ)$ in quantum chromodynamics is based on a solution to the renormalization group equations which treats quarks as either completely massless at a renormalization scale $μ$ above their thresholds or infinitely massive at a scale below them. The coupling is thus nonanalytic at these thresholds.
Wolfgang Bock, Maarten Golterman, Yigal Shamir
We study the gauge-fixing approach to the construction of lattice chiral gauge theories in one-loop weak-coupling perturbation theory. We show how infrared properties of the gauge degrees of freedom determine the nature of the continuous phase transition at which we take the continuum limit. The fermion self-energy and the vacuum polarization are calculated,
Finite Mass Effect on Two Photon Processes in Hydrogenic Systems: Effective Scalar Photon Interaction
physics.atom-phC. K. Au, C. S. Chu
We consider a hydrogenic system with a nucleus of finite mass. The coupling of the radiation field to the center of mass motion gives rise to an effective scalar type coupling. This induced scalar photon interaction emerges as a correction in competition with the usual multipole interactions. This effect is particularly important in positronium where the ele
A. Brignole, F. Feruglio, M. L. Mangano, F. Zwirner
If the gravitino (G) is very light and all the other supersymmetric particles are above threshold, supersymmetry may still be found at colliders, by looking at processes with only gravitinos and ordinary particles in the final state. We compute here the cross-sections for some distinctive signals at hadron colliders: photon plus missing energy, induced by (q
Sean Fleming, Thomas Mehen
Using the NRQCD factorization formalism, we calculate the total cross section for the photoproduction of h_c mesons. We include color-octet and color-singlet mechanisms as well as next-to-leading order perturbative QCD corrections. The theoretical prediction depends on two nonperturbative matrix elements that are not well determined from existing data on cha
Harel Primack, Uzy Smilansky
The semiclassical trace formula provides the basic construction from which one derives the semiclassical approximation for the spectrum of quantum systems which are chaotic in the classical limit. When the dimensionality of the system increases, the mean level spacing decreases as $\hbar^d$, while the semiclassical approximation is commonly believed to provi
Yu. L. Dokshitzer, A. Lucenti, G. Marchesini, G. P. Salam
The perturbative all-order analysis of the jet-broadening B-distribution in the small-B region is carried out with single-logarithmic accuracy, which requires the control of both the sum of the moduli and the modulus of the sum of the transverse momenta of soft gluons. We confirm the master equation for the B-distribution derived by Catani, Turnock and Webbe
Mark J. Gotay, James Isenberg, Jerrold E. Marsden, Richard Montgomery
This is the first paper of a five part work in which we study the Lagrangian and Hamiltonian structure of classical field theories with constraints. Our goal is to explore some of the connections between initial value constraints and gauge transformations in such theories (either relativistic or not). To do this, in the course of these four papers, we develo
Matteo Bertolini, Roberto Iengo, Claudio A. Scrucca
We present a general description of electromagnetic RR interactions between pairs of magnetically dual D-branes, focusing on the interaction of a magnetically charged brane with an electrically charged one. In the boundary state formalism, it turns out that while the electric-electric and/or magnetic-magnetic interaction corresponds to the usual RR even spin
Hagen Kleinert
With the help of variational perturbation theory we continue the renormalization constants $ϕ^4$-theories in $4- ε$ dimensions to strong bare couplings $g_0$ and find their power behavior in $g_0$, thereby determining all critical exponents without renormalization group techniques.
Gouranga C Nayak
We study dilepton production from a thermally equilibrating quark-gluon plasma expected to be formed in ultra relativistic heavy-ion collisions. The pre-equilibrium dynamics of quark-gluon plasma is studied within the color flux-tube model by solving non-abelian relativistic transport equations. This dilepton rate crucially depends on the collision time of t
Christopher J. Conselice, John S. Gallagher
We present evidence for a new morphologically defined form of small-scale substructure in the Coma Cluster, which we call galaxy aggregates. These aggregates are dominated by a central galaxy, which is on average three magnitudes brighter than the smaller aggregate members nearly all of which lie to one side of the central galaxy. We have found three such ga
M. M. Fogler, B. I. Shklovskii
We show that the the cyclotron resonance in a two-dimensional electron gas has non-trivial properties if the correlation length of the disorder is larger than the de Broglie wavelength: (a) the lineshape assumes three different forms in strong, intermediate, and weak magnetic fields (b) at the transition from the intermediate to the weak fields the linewidth
Ralf Schützhold, Guenter Plunien, Gerhard Soff
A canonical formalism is presented which allows for investigations of quantum radiation induced by localized, smooth disturbances of classical background fields by means of a perturbation theory approach. For massless, non-selfinteracting quantum fields at zero temperature we demonstrate that the low-energy part of the spectrum of created particles exhibits
L. Canton, A. Davini, P. J. Dortmans
The large variety of experimental data around the pion-production threshold are compared with a meson-exchange isobar model which includes the pion-nucleon interaction in s-- and p-waves. Theoretical results obtained with two different NN potentials (Bonn and Paris) indicate that the behavior of the excitation function at threshold is sensitive to the detail
L. Canton, G. Cattapan, G. Pisent, W. Schadow
The proton analyzing power Ay0 and the deuteron tensor analyzing power T20 are evaluated for the pd <-> pi+ t process, in the energy region around and above the Delta resonance. These calculations extend a previous analysis of the excitation function and differential cross-section, based on a model embodying one-- and two-body p-wave absorption mechanisms an
Makoto Oka
Two body weak processes $ΛN \leftrightarrow NN$ are studied from the viewpoint of quark substructure of baryons.They can be studied in nonmesonic weak decays of hypernuclei and also hyperon production in the $NN$ scattering. The direct quark mechanism in contrast to the one-pion exchange mechanism is shown to give sizable $\di=3/2$ contribution in the J=0 ch
J. Aclander, J. Alster, D. Barton, G. Bunce
The reaction 12C(p,2p+n) was measured at beam momenta of 5.9 and 7.5 GeV/c.. We established the quasi-elastic character of the reaction C(p,2p) at $θ_{cm}\simeq 90^o$, in a kinematically complete measurement. The neutron momentum was measured in triple coincidence with the two emerging high momentum protons. We present the correlation between the momenta of
D. Kotschick
We prove that there are infinitely many pairs of homeomorphic non-diffeomorphic smooth 4-manifolds, such that in each pair one manifold admits an Einstein metric and the other does not. We also show that there are closed 4-manifolds with two smooth structures which admit Einstein metrics with opposite signs of the scalar curvature.
Brooke Shipley
Symmetric spectra were introduced by Jeff Smith as a symmetric monoidal category of spectra. In this paper, a detection functor is defined which detects stable equivalences of symmetric spectra. This detection functor is useful because the classic stable homotopy groups do not detect stable equivalences in symmetric spectra. One of the advantages of a symmet
Donal O'Driscoll
We construct a one loop amplitude for any Abelian orientifold point group for arbitary complex dimensions. From this we show several results for orientifolds in this general class of models as well as for low dimensional compactifications. We also discuss the importance and structure of the contribution of orientifold planes to the dynamics of D-branes, and
Gabriel Lopes Cardoso
We review various three-dimensional solutions in the low-energy description of M-theory on $S^1/Z_2 \times T_7$. These solutions have an eleven dimensional interpretation in terms of intersecting M-branes.
Marco Billo, Frederik Denef, Pietro Fre, Igor Pesando
This is a résumé of an extensive investigation of some examples in which one obtains the rigid limit of N=2 supergravity by means of an expansion around singular points in the moduli space of a Calabi-Yau 3-fold. We make extensive use of the K3 fibration of the Calabi-Yau manifolds which are considered. At the end the fibration parameter becomes the coordina
S. Penati, A. Santambrogio, D. Zanon
This is a short introduction to the study of compactifications of F-theory on elliptic Calabi-Yau threefolds near colliding singularities. In particular we consider the case of non-transversal intersections of the singular fibers.
DJ Wagner, Thomas J. Weiler
We develop a model-independent "box" parameterization of neutrino oscillations. Oscillation probabilities are linear in these new parameters, so measurements can straightforwardly determine the box parameters which can then be manipulated to yield magnitudes of mixing matrix elements. We examine the effects of unitarity On the box parameters and redu
Johan Bijnens, Elisabetta Pallante, Joaquim Prades
We properly define off-shell $K\toπ$ transition amplitudes and use them to extract information for on-shell $K\toππ$ amplitudes within Chiral Perturbation Theory. At order $p^2$ in the chiral expansion all three parameters of weak interaction can be determined. At order $p^4$ we are able to fix eleven additional constants out of thirteen contributing to off-
W. L. van Neerven
We will give an outline of the computation of the QCD corrections to the spin structure function g_1(x,Q^2) and the spin fragmentation function g_1^H(x,Q^2) which are measured in deep inelastic electron-proton scattering and in electron-positron annihilation respectively. In particular we show how to deal with the gamma_5-matrix and the Levi-Civita tensor, a
S. Y. Choi
Charginos are expected to be the lightest observable supersymmetric particles in many of the supersymmetric models. In the scenario that lighter charginios are pair-produced at CERN LEP II, we present a straightforward procedure for determining the SUSY parameters, $\tanβ$, $M_2$, $μ$, and the electron sneutrino mass $m_{\tildeν}$ up to a four-fold discrete
Marcello Ciafaloni
I consider the next-to-leading,high-energy cluster expansion of large-k double-jet production in QCD, and I determine the corresponding one-loop quark and gluon impact factors, for a self-consistent energy scale. The result shows that coherent angular ordering of emitted gluons holds for hard emission also, and singles out a scale which is essentially the la
Connecting Experiment with Theory: A Model-Independent Parameterization of Neutrino Oscillations
hep-phDoris Jeanne Wagner
Many experiments are currently looking for evidence of neutrino mass in the form of neutrino oscillations. Oscillation probabilities are non-linear functions of the neutrino mixing matrix elements, so most comparisons of data to theory are based on simplifying models of the mixing matrix. We begin this dissertation with a review of neutrino interactions and
Zhou Yufeng, Peng Hongan, Liu Lianshou
We discuss in this paper The experimental results on maximum psedo-rapidity $η_{max}$ distribution in the charge exchange process $e+p\to e+n+X$ in ZEUS Collaboration at HERA. We calculate the contributions of \regg ($ρ$-Reggeon associated with $ρ$ meson) from regge phenomenology and $π^{+}$-exchange from pion cloud model. The results show that neither the \
Using Collider Event Topology in the Search for the Six-Jet Decay of Top Quark-Antiquark Pairs
hep-phR. D. Field, Y. A. Kanev
We investigate the use of the event topology as a tool in the search for the six-jet decay of top-pair production in proton-antiproton collisions at 1.8 TeV. Modified Fox-Wolfram "shape" variables, H_i, are employed to help distinguish the top-pair signal from the ordinary QCD multi-jet background. The H's can be constructed directly from the cal
J. Jersak
Recent numerical studies of the 4D pure compact U(1) lattice gauge theory, I have participated in, are reviewed. We look for a possibility to construct an interesting nonperturbatively renormalizable continuum theory at the phase transition between the confinement and Coulomb phases. First I describe the numerical evidence, obtained from calculation of bulk
M. Gürtler, E. -M. Ilgenfritz, A. Schiller, C. Strecha
We discuss the end of the first order phase transition and the bound state spectrum, both at weak transition and at the crossover.
A. Buzzo, P. Debevec, D. Drijard, R. A. Eisenstein
The reaction pbar p -> pbar p pi+ pi- has been studied with high statistics at CERN-LEAR with incident pbar momenta from 1.65 to 2.0 GeV/c by the JETSET (PS202) experiment. The aim of this paper is to search for narrow resonances decaying to pbar p. No evidence for such structures is found. In particular, an upper limit for the production of a 2.02 GeV state
Alessandro D. A. M. Spallicci
A novel method for calculation of the motion and radiation reaction for the two-body problem (body plus particle, the small parameter m/M being the ratio of the masses) is presented. In the background curvature given by the Schwarzschild geometry rippled by gravitational waves, the geodesic equations insure the presence of radiation reaction also for high ve
Hermann Grabert, Gert-Ludwig Ingold, Benjamin Paul
The supercurrent of a Josephson junction is reduced by phase diffusion. For ultrasmall capacitance junctions the current may be further decreased by Coulomb blockade effects. We calculate the Cooper pair current by means of time-dependent perturbation theory to all orders in the Josephson coupling energy and obtain the current-voltage characteristic in close
E. B. Bogomolny, D. C. Rouben
We derive a semiclassical formula for the tunneling current of electrons trapped in a potential well which can tunnel into and across a wide quantum well. The calculations idealize an experimental situation where a strong magnetic field tilted with respect to an electric field is used. The resulting semiclassical expression is written as the sum over special
Fabian Braun, Jan von Delft
We develop a theory of superconductivity in ultrasmall (nm-scale) metallic grains having a discrete electronic eigenspectrum with a mean level spacing of order of the bulk gap. The theory is based on calculating the eigenspectrum using a generalized BCS variational approach, whose applicability has been extensively demonstrated in studies of pairing correlat
Nearly Singular Magnetic Fluctuations in the Normal State of a High-T_c Cuprate Superconductor
cond-mat.str-elG. Aeppli, T. E. Mason, S. M. Hayden, H. A. Mook
Polarized and unpolarized neutron scattering was used to measure the wave vector- and frequency-dependent magnetic fluctuations in the normal state (from the superconducting transition temperature, T_c=35, up to 350 K) of single crystals of La_{1.86}Sr_{0.14}CuO_4. The peaks which dominate the fluctuations have amplitudes that decrease as T^{-2} and widths t
Collapse and Bose-Einstein condensation in a trapped Bose-gas with negative scattering length
cond-mat.stat-mechYu. Kagan, A. E. Muryshev, G. V. Shlyapnikov
We find that the key features of the evolution and collapse of a trapped Bose condensate with negative scattering length are predetermined by the particle flux from the above-condensate cloud to the condensate and by 3-body recombination of Bose-condensed atoms. The collapse, starting once the number of Bose-condensed atoms reaches the critical value, ceases
N. Hayashi, T. Isoshima, M. Ichioka, K. Machida
Focusing on a quantum-limit behavior, we study a single vortex in a clean s-wave type-II superconductor by self-consistently solving the Bogoliubov-de Gennes equation. The discrete energy levels of the vortex bound states in the quantum limit is discussed. The vortex core radius shrinks monotonically up to an atomic-scale length on lowering the temperature T
Alex Levine, Sriram Ramaswamy, Erwin Frey, Robijn Bruinsma
A coarse-grained stochastic hydrodynamical description of velocity and concentration fluctuations in steadily sedimenting suspensions is constructed, and analyzed using self-consistent and renormalization group methods. We find that there exists a dynamical, non-equilibrium phase transition from an "unscreened" phase in which we recover the Caflisch-
T. C. Wang
The hydrodynamical phase-slippage geometry and a semi-classical Josephson-RCSJ formulism are combined to make an analogy between the periodically driven Josephson ac effect and the quantum Hall effect. Both of these two macroscopic quantum effects are postulated to be originated from the one-dimensional linear vortex-electron relative motion. The mechanisms
Yuri Ozhigov
The work is concerned with the trade-offs between the dimension and the time and space complexity of computations on nondeterministic cellular automata. It is proved, that 1). Every NCA $\Cal A$ of dimension $r$, computing a predicate $P$ with time complexity T(n) and space complexity S(n) can be simulated by $r$-dimensional NCA with time and space complexit
R. Carretero-González
We study the dynamics of the travelling interface arising from a bistable piece-wise linear one-way coupled map lattice. We show how the dynamics of the interfacial sites, separating the two superstable phases of the local map, is finite dimensional and equivalent to a toral map. The velocity of the travelling interface corresponds to the rotation vector of
Quasi-Periodic Occultation by a Precessing Accretion Disk and Other Variabilities of SMC X-1
astro-phP. S. Wojdowski, G. W. Clark, A. M. Levine, J. W. Woo
We have investigated the variability of the binary X-ray pulsar, SMC X-1, in data from several X-ray observatories. We confirm the ~60-day cyclic variation of the X-ray flux in the long-term monitoring data from the RXTE and CGRO observatories. X-ray light curves and spectra from the ROSAT, Ginga, and ASCA observatories show that the uneclipsed flux varies b
R. J. Garcia Lopez, D. L. Lambert, B. Edvardsson, B. Gustafsson
We have observed the B I 2497 A line to derive the boron abundances of two very metal-poor stars selected to help in tracing the origin and evolution of this element in the early Galaxy: BD +23 3130 and HD 84937. The observations were conducted using the Goddard High Resolution Spectrograph on board the Hubble Space Telescope. A very detailed abundance analy
Exoplanets or Dynamic Atmospheres? The Radial Velocity and Line Shape Variations of 51 Pegasi and Tau Bootis
astro-phTimothy M. Brown, Rubina Kotak, Scott D. Horner, Edward J. Kennelly
Because of our relatively low spectral resolution, we compare our observations with Gray's line bisector data by fitting observed line profiles to an expansion in terms of orthogonal (Hermite) functions. To obtain an accurate comparison, we model the emergent line profiles from rotating and pulsating stars, taking the instrumental point spread function i
The Influence of Reprocessing in the Column on the Light Curves of Accretion Powered Neutron Stars
astro-phMiljenko Cemeljic, Tomasz Bulik
Flow of matter onto strongly magnetized neutron stars in X-ray binaries proceeds through accretion funnels that roughly follow geometry of the magnetic field. X-rays originate near surface of the neutron star, and it may happen that the accretion flow passes through the line of sight as the star rotates. We consider the effects of such accretion flow eclipse
Laurent Loinard Ronald J. Allen
We present new interferometric $^{12}CO$(1-0) and single-dish CO(3-2) observations of the central parts of D478, a large (> 200 pc) dark dust cloud located in a quiescent region of the inner disk of M31 where single-dish CO(1-0) and CO(2-1) observations were previously obtained. Only a small fraction (< 15%) of the CO(1-0) flux previously detected in this re
Peter Widerin, Christoph Schmid
We consider the evolution of cosmological perturbations at the QCD transition, in particular the sudden reheating from a supercooled universe to the transition temperature. Sudden reheating happens at a specific temperature, hence density, and singles out one specific hypersurface. Underdensities reach the reheating earlier than overdensities, there is a sho
D. S. Salopek
Hamilton-Jacobi theory for general relativity provides an elegant covariant formulation of the gravitational field. A general `coordinate-free' method of integrating the functional Hamilton-Jacobi equation for gravity and matter is described. This series approximation method represents a large generalization of the spatial gradient expansion that had bee
Ortwin Gerhard, Gunther Jeske, R. P. Saglia, Ralf Bender
The mass and anisotropy of an elliptical galaxy can be simultaneously determined from velocity dispersion and line profile shape measurements. We describe the principles, techniques, and limitations of this approach, and the results obtained sofar. We briefly discuss how best to combine these stellar-dynamical results with X-ray measurements and gravitationa
J. F. Gunion, T. Han, R. Sobey
We demonstrate that, at a 500 GeV e+e- collider, inclusion of the $ZZ$-fusion process for production of a light standard-model-like Higgs boson can substantially increase the precision with which the $ZZh$ coupling can be determined (using the model-independent recoil mass technique) as compared to employing only $Zh$ associated production.
Adrian L. Melott, Peter Coles, Hume A. Feldman, Brian Wilhite
We compare the statistical properties of structures normal and transverse to the line of sight which appear in theoretical N-body simulations of structure formation, and seem also to be present in observational data from redshift surveys. We present a statistic which can quantify this effect in a conceptually different way from standard analyses of distortio
Supersymmetric KP Hierarchy: ``Ghost'' Symmetry Structure, Reductions and Darboux-Backlund Solutions
solv-intH. Aratyn, E. Nissimov, S. Pacheva
This paper studies Manin-Radul supersymmetric KP hierarchy (MR-SKP) in three related aspects: (i) We find an infinite set of additional (``ghost'') symmetry flows spanning the same (anti-)commutation algebra as the ordinary MR-SKP flows; (ii) The latter are used to construct consistent reductions of the initial unconstrained MR-SKP hierarchy which in
J. Erlich, A. Naqvi, L. Randall
We determine the low energy description of N=2 supersymmetric SU(k) product group theories with bifundamental and fundamental matter based on M-theory fivebrane configurations. The dependence on moduli and scales of the coefficients in the non-hyperelliptic Seiberg-Witten curves for these theories is determined by considering various field theory and brane l
Everton M. C. Abreu, Nelson R. F. Braga, Cresus F. L. Godinho
We show that the generators of canonical transformations in the triplectic manifold must satisfy constraints that have no parallel in the usual field antifield quantization. A general form for these transformations is presented. Then we consider gauge fixing by means of canonical transformations in this Sp(2) covariant scheme, finding a relation between gene
Stefan Giller, Piotr Milczarski
It is shown that so called fundamental solutions the semiclassical expansions of which have been established earlier to be Borel summable to the solutions themselves appear also to be the unique solutions to the 1D Schrödinger equation having this property. Namely, it is shown in this paper that for the polynomial potentials the Borel function defined by the
N. D. Lambert, P. C. West
In this paper we provide a manifestly N=2 supersymmetric formulation of the M-fivebrane in the presence of threebrane solitons. The superspace form of four-dimensional effective equations for the threebranes are readily obtained and yield the complete Seiberg-Witten equations of motion for N=2 super-Yang-Mills. A particularly simple derivation is given by in
M. E. Carrington, Hou Defu, Markus H. Thoma
We verify the QED Ward identity for the two- and three -point functions at non-equilibrium in the HTL limit. We use the Keldysh formalism of real time finite temperature field theory. We obtain an identity of the same form as the Ward identity for a set of one loop self-energy and one loop three-point vertex diagrams which are constructed from HTL effective
D. Hinzke, U. Nowak
We investigate the thermally activated magnetization switching of small ferromagnetic particles driven by an external magnetic field. For low uniaxial anisotropy the spins can be expected to rotate coherently, while for sufficient large anisotropy they should behave Ising-like, i.e., the switching should then be due to nucleation. We study this crossover fro
M. Alimohammadi, H. Mohseni Sadjadi
Using the correlation function of chiral vertex operators of the Coulomb gas model, we find the Laughlin wavefunctions of quantum Hall effect, with filling factor $ν=1/m$, on Riemann sufaces with Poincare metric. The same is done for quasihole wavefunctions. We also discuss their plasma analogy.
Leo Girardi, Gianpaolo Bertelli
We discuss how the integrated V-K colours of single stellar populations evolve with age and metallicity. Some of the uncertainties associated to the properties of the underlying stellar models are throughfully discussed. First, we present the effects that different formulations for the mass-loss rates produce on the initial-final mass relation, and hence on
Electromagnetic form factors in the J/ψmass region: The case in favor of additional resonances
hep-phN. N. Achasov, A. A. Kozhevnikov
Using the results of our recent analysis of e^+e^- annihilation, we plot the curves for the diagonal and transition form factors of light hadrons in the time-like region up to the production threshold of an open charm quantum number. The comparison with existing data on the decays of J/ψinto such hadrons shows that some new resonance structures may be presen
Nine classes of integrable boundary conditions for the eight-state supersymmetric fermion model
cond-mat.str-elYao-Zhong Zhang, Huan-Qiang Zhou
Nine classes of integrable boundary conditions for the eight-state supersymmetric model of strongly correlated fermions are presented. The boundary systems are solved by using the coordinate Bethe ansatz method and the Bethe ansatz equations for all nine cases are given.
Wen-Jui Huang, Jiin-Chang Shaw, Ming-Hsien Tu
We give a matrix formulation of the Hamiltonian structures of constrained KP hierarchy. First, we derive from the matrix formulation the Hamiltonian structure of the one-constraint KP hierarchy, which was originally obtained by Oevel and Strampp. We then generalize the derivation to the multi-constraint case and show that the resulting bracket is actually th
Krzysztof Kowalski
It is demonstrated that very general nonlinear dynamical systems covering all cases arising in practice can be brought down to rate equations of chemical kinetics
Kjell Rosquist
We use a Riemannian (or pseudo-Riemannian) geometric framework to formulate the theory of the classical r-matrix for integrable systems. In this picture the r-matrix is related to a fourth rank tensor, named the r-tensor, on the configuration space. The r-matrix itself carries one connection type index and three tensorial indices. Being defined on the config
Vladimir S. Mashkevich
We argue that the participants of the discussion have overlooked an essential circumstance, in view of which Stapp's fifth proposition fails. The circumstance is that though $L$ and $R$ measurements, being causally separated, are not invariantly time ordered, quantum-jump hypersurfaces associated with the measurements are causelikewise ordered. Stapp'
T. Gruner, D. -G. Welsch
Interference of single-photon wave packets at a beam splitter usually leads to an anticorrelation of the light intensity in the two output ports of the beam splitter. The effect may be regarded as ``bunching'' of the photons at the beam splitter and has widely been interpreted as a result of quantum mechanical interference between the probability amp
Detuning Induced Effects: Symmetry-Breaking Bifurcations in Dynamic Model of One-Mode Laser
physics.opticsAlexei D. Kiselev
The concept of broken symmetry is used to study bifurcations of equilibria and dynamical instabilities in dynamic model of one-mode laser (nonresonant complex Lorenz model) on the basis of modified Hopf theory. It is shown that an invariant set of stationary points bifurcates into an invariant torus (doubly-periodic branching solution). Influence of the symm
Xin-Nian Wang
I will give a review with some comments of the parallel session on QCD and the related talks in the Quark Matter'97 meeting.
J. Sollfrank, P. Huovinen, P. V. Ruuskanen
We study the different nucleus-nucleus collisions, O+Au, S+S, S+Ag, S+Au and Pb+Pb, at the CERN-SPS energy in a one-fluid hydrodynamical approach using a parametrization based on baryon stopping in terms of the thickness of colliding nuclei. Good agreement with measured particle spectra is achieved. We deduce the mass number scaling behaviour of the initial
Saharon Shelah
We discuss some problems posed by Ciesielski. For example we show that, consistently, d_c is a singular cardinal and e_c<d_c. Next we prove that the Martin Axiom for sigma --centered forcing notions implies that for every function f:R^2 ---> R there are functions g_n,h_n:R ---> R, n< omega, such that f(x,y)= sum_{n=0}^{infty} g_n(x)h_n(y). Finally, we deal w
Krzysztof Ciesielski, Saharon Shelah
We will prove that there exists a model of ZFC+``c= omega_2'' in which every M subseteq R of cardinality less than continuum c is meager, and such that for every X subseteq R of cardinality c there exists a continuous function f:R-> R with f[X]=[0,1]. In particular in this model there is no magic set, i.e., a set M subseteq R such that the equation f
Renling Jin, Saharon Shelah
Let omega be the first infinite ordinal (or the set of all natural numbers) with the usual order <. In section 1 we show that, assuming the consistency of a supercompact cardinal, there may exist an ultrapower of omega, whose cardinality is (1) a singular strong limit cardinal, (2) a strongly inaccessible cardinal. This answers two questions in [CK], modulo
John T. Baldwin, Saharon Shelah
Based on computer simulations Wolfram presented in several papers conjectured classifications of cellular automata into 4 types. He distinguishes the 4 classes of cellular automata by the evolution of the pattern generated by applying a cellular automaton to a finite input. Wolfram's qualitative classification is based on the examination of a large numbe
Saharon Shelah, Otmar Spinas
Generalizing [ShSi:494], for every n< omega we construct a ZFC-model where the distributivity number of r.o. (P(omega)/fin)^{n+1}, h(n+1), is smaller than the one of r.o.(P(omega)/fin)^{n}. This answers an old problem of Balcar, Pelant and Simon. We also show that Laver and Miller forcing collapse the continuum to h(n) for every n<omega, hence by the first r
Saeed Zakeri
Let $f$ be a quadratic polynomial which has an irrationally indifferent fixed point $α$. Let $z$ be a biaccessible point in the Julia set of $f$. Then: 1. In the Siegel case, the orbit of $z$ must eventually hit the critical point of $f$. 2. In the Cremer case, the orbit of $z$ must eventually hit the fixed point $α$. Siegel polynomials with biaccessible cri
Dierk Schleicher, Saeed Zakeri
We prove that the only possible biaccessible points in the Julia set of a Cremer quadratic polynomial are the Cremer fixed point and its preimages. This gives a partial answer to a question posed by C. McMullen on whether such a Julia set can contain any biaccessible point at all
Saaed Zakeri
Let $f:z\mapsto z^2+c$ be a quadratic polynomial whose Julia set $J$ is locally-connected of the set of biaccessible points in $J$ is zero except when $f(z)=z^2-2$ is the Chebyshev quadratic polynomial for which the corresponding measure is one.
On the evaluation of the norm of an integral operator associated with the stability of one-electron atoms
math.SPV. I. Burenkov, W. D. Evans
The norm of an integral operator occurring in the partial wave decomposition of an operator B introduced by Brown and Ravenhall in a model for relativistic one-electron atoms is determined. The result implies that B is non-negative and has no eigenvalue at 0 when the nuclear charge does not exceed a specified critical value.