January 2000 arXiv papers — page 10

A. V. Balatsky, P. Kumar, J. R. Schrieffer

We consider a superconducting state with a mixed symmetry order parameter components, e.g. d+is or d+id' with d'= d_{xy}. We argue for the existence of the new orbital magnetization mode which corresponds to the oscillations of relative phase ϕbetween two components around an equilibrium value of ϕ= π/2. It is similar to the so called ``clapping'

D. Sornette, A. Sornette

Melosh [1996] has suggested that acoustic fluidization could provide an alternative to theories that are invoked as explanations for why some crustal faults appear to be weak. We show that there is a subtle but profound inconsistency in the theory that unfortunately invalidates the results. We propose possible remedies but must acknowledge that the relevance

Ahmed A. Maarouf, Charles L. Kane, Eugene J. Mele

We present a tight binding theory to analyze the motion of electrons between carbon nanotubes bundled into a carbon nanotube rope. The theory is developed starting from a description of the propagating Bloch waves on ideal tubes, and the effects of intertube motion are treated perturbatively in this basis. Expressions for the interwall tunneling amplitudes b

Alan J. Bray, Andrea Cavagna

We consider the ordering kinetics of a nonconserved scalar field advected by a uniform shear flow. Using the Ohta-Jasnow-Kawasaki approximation, modified to allow for shear-induced anisotropy, we calculate the asymptotic time dependence of the characteristic length scales, L_parallel and L_perp, that describe the growth of order parallel and perpendicular to

I. S. Aranson, V. A. Kalatsky, V. M. Vinokur

We develop continuum field model for crack propagation in brittle amorphous solids. The model is represented by equations for elastic displacements combined with the order parameter equation which accounts for the dynamics of defects. This model captures all important phenomenology of crack propagation: crack initiation, propagation, dynamic fracture instabi

Francis W. Starr, Srikanth Sastry, Francesco Sciortino, H. E. Stanley

The anomalous properties of water in the supercooled state are numerous and well-known. Particularly striking are the strong changes in dynamic properties that appear to display divergences at temperatures close to -- but beyond -- the lowest temperatures attainable either experimentally or in computer simulations. Recent work on slow or glassy dynamics in w

T. Antal, G. M. Schütz

We study the steady-state behavior of a driven non-equilibrium lattice gas of hard-core particles with next-nearest-neighbor interaction. We calculate the exact stationary distribution of the periodic system and for a particular line in the phase diagram of the system with open boundaries where particles can enter and leave the system. For repulsive interact

N. Vandewalle, J. F. Lentz, S. Dorbolo, F. Brisbois

We report acoustic experiments on foam systems. We have recorded the sound emitted by crackling cells during the collapsing of foams. The sound pattern is then analyzed using classical methods of statistical physics. Fundamental processes at the surface of the collapsing foam are found. In particular, size is not a relevant parameter for exploding bubbles.

N. Vandewalle, Ph. Boveroux, F. Brisbois

In order to emphasize cross-correlations for fluctuations in major market places, series of up and down spins are built from financial data. Patterns frequencies are measured, and statistical tests performed. Strong cross-correlations are emphasized, proving that market moves are collective behaviors.

N. Vandewalle, C. Lenaerts, S. Dorbolo

The electrical properties of a two-dimensional packing of metallic beads are studied. Small mechanical perturbations of the packing leads to giant electrical fluctuations. Fluctuations are found to be non-gaussian and seem to belong to Levy stable distributions. Anticorrelations have been also found for the sign of these fluctuations.

Mario Castro, Angel Sánchez, Francisco Domínguez-Adame

We propose a simple, versatile and fast computational model tounderstand the deviations from the well-known Kolmogorov-Johnson-Mehl-Avrami kinetic theoryfound in metal recrystallization and amorphous semiconductor crystallization. Our model describes in detail the kinetics of the transformation and the grain size distribution of the product material, and is

F. Carvalho Dias, I. R. Pimentel, R. Orbach

We study the renormalization of the staggered magnetization of a two-dimensional antiferromagnet as a function of hole doping, in the framework of the t-J model. It is shown that the motion of holes generates decay of spin waves into ''particle-hole'' pairs, which causes the destruction of the long-range magnetic order at a small hole concent

Franco Dalfovo, Ricardo Mayol, Marti Pi, Manuel Barranco

Using a density functional method, we investigate the properties of liquid 4He droplets doped with atoms (Ne and Xe) and molecules (SF_6 and HCN). We consider the case of droplets having a quantized vortex pinned to the dopant. A liquid drop formula is proposed that accurately describes the total energy of the complex and allows one to extrapolate the densit

Peter Nagel, Volker Pasler, Christoph Meingast, Alexandre I. Rykov

We present high-resolution capacitance dilatometry studies from 5 - 500 K of untwinned YBa2Cu3Ox (Y123) single crystals for x ~ 6.95 and x = 7.0. Large contributions to the thermal expansivities due to O-ordering are found for x ~ 6.95, which disappear below a kinetic glass-like transition near room temperature. The kinetics at this glass transition is gover

L. F. Lemmens, F. Brosens, J. T. Devreese

For a spinor gas, i.e., a mixture of identical particles with several internal degrees of freedom, we derive the partition function in terms of the Feynman-Kac functionals of polarized components. As an example we study a spin-1 Bose gas with the spins subjected to an external magnetic field and confined by a parabolic potential. From the analysis of the fre

Aninda Jiban Bhattacharyya, Abhijit Mookerjee, A. K. Bhattacharyya

In this communication we study the equilibrium shapes and energetics of Cu clusters of various sizes upto 20 atoms using the Full-Potential Tight Binding Muffin-tin Orbitals Molecular Dynamics. We compare our results with earlier works by physicists and chemists using different methodologies.

C. H. Lee, H. Oyanagi, C. Sekine, I. Shirotani

Valency of Ce and Pr in LRu4P12 (L = Ce and Pr) was studied by L2,3-edge x-ray absorption near-edge structure (XANES) spectroscopy. The Ce-L3 XANES spectrum suggests that Ce is mainly trivalent, but the 4f state strongly hybridizes with ligand orbitals. The band gap of CeRu4P12 seems to be formed by strong hybridization of 4f electrons. Pr-L2 XANES spectra i

Sushan Konar

Both neutron stars and strange stars are capable of supporting fast rotations observed in pulsars. On the basis of this it has been argued that some of the pulsars could be strange stars. We investigate whether strange stars can sustain characteristic pulsar magnetic fields ($10^8 - 10^{13.5} Gauss$) over astronomically significant time-scales. Furthermore,

Guenther Hasinger

Deep X-ray surveys have shown that the cosmic X-ray background (XRB) is largely due to accretion onto supermassive black holes, integrated over cosmic time. However, the characteristic hard spectrum of the XRB can only be explained if most AGN spectra are heavily absorbed. The absorbed AGN will suffer severe extinction and therefore, unlike classical QSOs, w

Norman Gray

There is increasing interest in extended source effects in microlensing events, as probes of the unresolved sources. Previous work has either presumed a uniform source, or else required an approximate or numerical treatment of the amplification function averaged over the source disk. In this paper, I present analytic expressions for the angle-averaged amplif

Ravi Sankrit, J. Jeff Hester

We present a grid of photoionization models for the emission from photoevaporative interfaces between the ionized gas and molecular cloud in blister HII regions. For the density profiles of the emitting gas in the models, we use a general power law form calculated for photoionized, photoevaporative flows by Bertoldi (1989). We find that the spatial emission

D. Clowe, G. Luppino, N. Kaiser, I. Gioia

We present the results of a weak lensing survey of six high-redshift (z > 0.5), X-ray selected clusters of galaxies. We have obtained ultra-deep R-band images of each cluster with the Keck Telescope, and have measured a weak lensing signal from each cluster. From the background galaxy ellipticities we create two-dimensional maps of the surface mass density o

T. Mineo, G. Cusumano, L. Kuiper, W. Hermsen

We present the results of a BeppoSAX observation of PSR J0218+4232 which, for the first time, provides detailed information on the pulsar's temporal and spectral emission properties in the broad band 1-10 keV. We detected X-ray pulses with a pulsed fraction of 73 +/- 12 %. The pulse profile is characterized by two peaks phase separated by 0.47 +/-0.05. T

Ioav Waga, Joshua A. Frieman

We explore the implications of gravitationally lensed QSOs and high-redshift SNe Ia observations for spatially flat cosmological models in which a classically evolving scalar field currently dominates the energy density of the Universe. We consider two representative scalar field potentials that give rise to effective decaying $Λ$ (``quintessence'')

Avigdor Eldar, Amir Levinson

Internal shocks propagating through an ambient radiation field, are subject to a radiative drag that, under certain conditions, can significantly affect their dynamics and, consequently, the evolution of the beaming cone of emission produced behind the shocks. The resultant change of the Doppler factor combined with opacity effects leads to a strong dependen

Sushan Konar

There has been sufficient observational indication suggesting a causal connection between the binary history of neutron stars and the evolution of their magnetic field. In particular, it is believed that the generation of the low-field millisecond pulsars is a consequence of the processing of normal high-field neutron stars in binary systems. We try to under

P. Lampens, H. M. J. Boffin

We present a list of delta Scuti stars in double and multiple systems, ranging from the very wide binaries to the very close ones such as spectroscopic and eclipsing systems including the optical visual pairs which are of no further use here. Our aim is to group the information from the binarity on the one hand and the pulsational characteristics on the othe

Peter Englmaier

The observed gas dynamics in the Milky Way can only be explained by a bar in the galactic center. Such a bar is directly visible in the near-IR maps of the bulge, where it causes a distinctive asymmetric light distribution pattern. Another large-scale structure is the grand-design 4-arm spiral pattern, most clearly observed in the spatial distribution of mol

Kentaro Motohara, Fumihide Iwamuro, Hiroshi Terada, Miwa Goto

We report on infrared imaging observations of the z=2.429 radio galaxy B3 0731+438 with the Subaru telescope. The images were taken with the K'-band filter and the 2.25 um narrow-band filter to examine the structure and properties of the Ha+[N II] 6548,6583 emission-line components. The Ha+[N II] emission-line image shows biconical lobes with an extent o

Long-Long Feng, Li-Zhi Fang

We investigate the effect of non-Gaussianity on the reconstruction of the initial mass field from the Ly$α$ forest. We show that the transmitted flux of QSO absorption spectra are highly non-Gaussian in terms of the statistics, the kurtosis spectrum and scale-scale correlation. These non-Gaussianities can not be completely removed by the conventional algorit

Chung-Pei Ma, J. N. Fry

We investigate the nonlinear two- and three-point correlation functions of the cosmological density field in Fourier space and test the popular hierarchical clustering model, that the three-point amplitude Q is independent of scale. In high-resolution N-body simulations of both n=-2 scale-free and cold dark matter models, we find that Q at late times is not

David A. Buote

Using spatially resolved, deprojected ROSAT PSPC spectra of 10 of the brightest cooling flow galaxies and groups with low Galactic column densities we have detected intrinsic absorption over energies ~0.4-0.8 keV in half of the sample. Since no intrinsic absorption is indicated for energies below ~0.4 keV, the most reasonable model for the absorber is collis

Shin'ichi Nojiri, Sergei D. Odintsov, Sachiko Ogushi

Gauged supergravity (SG) with single scalar (dilaton) and arbitrary scalar potential is considered. Such dilatonic gravity describes special RG flows in extended SG where scalars lie in one-dimensional submanifold of total space. The surface counterterm and finite action for such gauged SG in three-, four- and five-dimensional asymptotically AdS space are de

Robert J. Nemiroff

The pulses that compose gamma-ray bursts (GRBs) are hypothesized to have the same shape at all energies, differing only by scale factors in time and amplitude. This "Pulse Scale Conjecture" is confirmed here between energy channels of the dominant pulse in GRB 930214c (BATSE trigger 2193), the single most fluent single-pulsed GRB that occurred before

Valeri N. Kotov, Michael E. Zhitomirsky, Oleg P. Sushkov

We construct and analyze a two-dimensional frustrated quantum spin model with plaquette order, in which the low-energy dynamics is controlled by spin singlets. At a critical value of frustration the singlet spectrum becomes gapless, indicating a quantum transition to a phase with dimer order. This T=0 transition belongs to the 3D Ising universality class, wh

Paul Langacker, Michael Plumacher

There are theoretical and phenomenological motivations that there may exist additional heavy Z' bosons with family non-universal couplings. Flavor mixing in the quark and lepton sectors will then lead to flavor changing couplings of the heavy Z', and also of the ordinary Z when Z-Z' mixing is included. The general formalism of such effects is des

Andrea Brignole

We consider a general d=4 N=1 globally supersymmetric lagrangian involving chiral and vector superfields, with arbitrary superpotential, Kahler potential and gauge kinetic function. We compute perturbative quantum corrections by employing a component field approach that respects supersymmetry and background gauge invariance. In particular, we obtain the full

Gouranga C. Nayak, Adrian Dumitru, Larry McLerran, Walter Greiner

We study the production and equilibration of the gluon-minijet plasma expected to be formed in the central region of ultrarelativistic heavy-ion collisions at the BNL-RHIC and the CERN-LHC by solving a self-consistent relativistic transport equation. We compute the minijet production within perturbative QCD. Subsequent collisions among the semi-hard partons

M. G. Olsson

A new sum rule determines the nucleon sigma term by the πN elastic scattering threshold parameters alone. This &#34;threshold&#34; value of σ(2μ^2) provides an independent check of existing values obtained from global dispersive analyses, and also provides a realistic error assignment. Employing a recent analysis of low energy (T_π< 100 MeV) πN data our sum

Jeremy S. Heyl

The magnetic fields of white dwarfs distort their shape generating an anisotropic moment of inertia. A magnetized white dwarf which rotates obliquely relative to the symmetry axis has a mass quadrupole moment which varies in time, so it will emit gravitational radiation. LISA may be able to detect the gravitational waves from two nearby, quickly rotating whi

Bing Zhang, Alice K. Harding, Alexander G. Muslimov

We reinvestigate the radio pulsar ``death lines'' within the framework of two different types of polar cap acceleration models, i.e., the vacuum gap model and the space-charge-limited flow model, with either curvature radiation or inverse Compton scattering photons as the source of pairs. General relativistic frame-dragging is taken into account in both mode

J. Perello, J. M. Porra, M. Montero, J. Masoliver

Options financial instruments designed to protect investors from the stock market randomness. In 1973, Fisher Black, Myron Scholes and Robert Merton proposed a very popular option pricing method using stochastic differential equations within the Ito interpretation. Herein, we derive the Black-Scholes equation for the option price using the Stratonovich calcu

H. Kachkachi, D. A. Garanin

We study the effect of free boundaries in finite magnetic systems of cubic shape on the field and temperature dependence of the magnetization within the isotropic model of D-component spin vectors in the limit D \to \infty. This model is described by a closed system of equations and captures the Goldstone-mode effects such as global rotation of the magnetic

Oleg Andreev

We consider the open string sigma-model in the presence of a constant Neveu-Schwarz B-field on the world-sheet that is topologically equivalent to a disk with n holes. First, we compute the sigma-model partition function. Second, we make a consistency check of ideas about the appearance of noncommutative geometry within open strings.

Scott Aaronson

In this note we investigate the relationship between worst-case quantum query complexity and average-case classical query complexity. Specifically, we show that if a quantum computer can evaluate a total Boolean function f with bounded error using T queries in the worst case, then a deterministic classical computer can evaluate f using O(T^5) queries in the

X. -W. Guan, U. Grimm, R. A. Roemer, Michael Schreiber

Employing the graded versions of the Yang-Baxter equation and the reflection equations, we construct two kinds of integrable impurities for a small-polaron model with general open boundary conditions: (a) we shift the spectral parameter of the local Lax operator at arbitrary sites in the bulk, and (b) we embed the impurity fermion vertex at each boundary of

Shan-Wen Tsai, J. B. Marston

We present a simple method, combining the density-matrix renormalization-group (DMRG) algorithm with finite-size scaling, which permits the study of critical behavior in quantum spin chains. Spin moments and dimerization are induced by boundary conditions at the chain ends and these exhibit power-law decay at critical points. Results are presented for the sp

M. Boglione, P. J. Mulders

The recent measurements of azimuthal single spin asymmetries by the HERMES collaboration at DESY may shed some light on presently unknown fragmentation and distribution functions. We present a study of such functions and give some estimates of weighted integrals directly related to those measurements.

Naohito Nakasato, Masao Mori, Ken&#39;ichi Nomoto

We examine various physical processes associated with the formation of globular clusters by using the three-dimensional Smoothed Particle Hydrodynamics (SPH) code. Our code includes radiative cooling of gases, star formation, energy feedback from stars including stellar winds and supernovae, and chemical enrichment by stars. We assume that, in the collapsing

Giovanni Bonanno, Nicolas Vandewalle, Rosario N. Mantegna

We investigate sets of financial non-redundant and nonsynchronously recorded time series. The sets are composed by a number of stock market indices located all over the world in five continents. By properly selecting the time horizon of returns and by using a reference currency we find a meaningful taxonomy. The detection of such a taxonomy proves that inter

Yasunori Fujii

We show how the scalar field, a candidate of quintessence, in a proposed model of the scalar-tensor theories of gravity provides a way to understand a small but nonzero cosmological constant as indicated by recent observations. A particular emphasis is placed on the effort to inherit the success of the scenario of a decaying cosmological constant. Discussion

T. Kojima, Y. -H. Quano

The higher rank analogue of the XXZ model with a boundary is considered on the basis of the vertex operator approach. We derive difference equations of the quantum Knizhnik-Zamolodchikov type for 2N-point correlations of the model. We present infinite product formulae of two point functions with free boundary condition by solving those difference equations w

M. Lavagna, C. Pépin

We present a study of the critical phenomena around the quantum critical point in heavy-fermion systems. In the framework of the S=1/2 Kondo lattice model, we introduce an extended decoupling scheme of the Kondo interaction which allows one to treat the spin fluctuations and the Kondo effect on an equal footing. The calculations, developed in a self-consiste

V. Dzhunushaliev

It is assumed that in some sense the High-T$_c$ superconductivity is similar to the quantum chromodynamics (QCD). This means that the phonons in High-T$_c$ superconductor have the strong interaction between themselves like to gluons in the QCD. At the experimental level this means that in High-T$_c$ superconductor exists the nonlinear sound waves. It is poss

David A. Buote

Previous studies of the Fe abundances in the hot gas of galaxies and groups have reported conflicting results with most studies finding very sub-solar Fe abundances that disagree with standard theory. To investigate the possible role of Fe abundance gradients on these measurements we present deprojection analysis of the ROSAT PSPC data of 10 of the brightest

David A. Buote

The inhomogeneous cooling flow scenario predicts the existence of large quantities of gas in massive elliptical galaxies, groups, and clusters that have cooled and dropped out of the flow. Using spatially resolved, deprojected X-ray spectra from the ROSAT PSPC we have detected strong absorption over energies ~0.4-0.8 keV intrinsic to the central ~1 arcmin of

Greg Huey, Paul J. Steinhardt, Burt A. Ovrut, Daniel Waldram

In this paper, we show how the generic coupling of moduli to the kinetic energy of ordinary matter fields results in a cosmological mechanism that influences the evolution and stability of moduli. As an example, we reconsider the problem of stabilizing the dilaton in a non-perturbative potential induced by gaugino condensates. A well-known difficulty is that

Tudor D. Stanescu, Ivar Martin, Philip Phillips

We report on a strong coupling approach (on-site Coulomb repulsion, U larger than the nearest-neighbour hopping energy |t|) to the Hubbard model. Starting from the Hubbard operators which diagonalize the interaction term, we generate a hierarchy of composite operators from the equations of motion. Using the Hubbard operators as a basis, we are able to comput

Rennan Barkana, Abraham Loeb

We show that the cosmic star formation rate per comoving volume should exhibit a distinct drop around the reionization redshift, when the HII regions in the intergalactic medium around individual ionizing sources first overlapped. The drop results from the increase in the temperature of the intergalactic medium as it was photo-ionized, and the consequent sup

Arno R. Bohm, Raymond Scurek

The observed probabilities of quantum mechanics possess a time asymmetry which is based on the truism that a state must be prepared before an observable can be measured in it. While Hilbert space quantum theory cannot incorporate this arrow of time, the Rigged Hilbert Space (RHS) formulation of quantum mechanics provides a theory of time symmetric as well as

Tabish Qureshi

It is shown that the conclusion of the paper &#34;Hidden assumptions in decoherence theory&#34; (quant-ph/0001021) is the result of a misunderstanding of the concept of pointer states. It is argued that pointer states are selected by the interaction of quantum systems with the environment, and are not based on any measurement by a conscious observer.

C. P. Sun, D. L. Zhou, S. Yu, X. F. Liu

In order to understand quantum decoherence of a quantum system due to its interaction with a large system behaving classically, we introduce the concept of adiabatic quantum entanglement based on the Born-Oppenhemeir approximation. In the adiabatic limit, it is shown that the wave function of the total system formed by the quantum system plus the large syste

Yu-Xi Liu, C. P Sun, S. X. Yu, D. L. Zhou

The high density Frenkel exciton which interacts with a single mode microcavity field is dealed with in the framework of the q-deformed boson. It is shown that the q-defomation of bosonic commutation relations is satisfied naturally by the exciton operators when the low density limit is deviated. An analytical expression of the physical spectrum for the exci

Michel Zamboni-Rached, Erasmo Recami

We show that localized (non-evanescent) solutions to Maxwell equations exist, which propagate without distortion along normal waveguides with Superluminal speed.

A. Leviatan, J. N. Ginocchio

We use the empirical evidence that F-spin multiplets exist in nuclei for only selected states as an indication that F-spin can be regarded as a partial symmetry. We show that there is a class of non-F-scalar IBM-2 Hamiltonians with partial F-spin symmetry, which reproduce the known systematics of collective bands in nuclei. These Hamiltonians predict that th

O. Benhar, N. N. Nikolaev, J. Speth, A. A. Usmani

At large proton energy, the final state interactions of the knocked out nucleon in $\eep$ reactions off nuclear targets can be described within the eikonal approximation, treating the spectator particles as a collection of fixed scattering centers. We use a generalization of this approach, suitable to take into account the possible occurrence of color transp

Akihisa Kohama, Koichi Yazaki, Ryoichi Seki

We calculate cross sections of high energy electron inclusive scattering off nuclear matter in a new and consistent formulation based on the Green&#39;s function method with the Glauber approximation, which is an extension of our previous work on the nuclear transparency in (e, e&#39;p) reaction. The comparison with other approaches is discussed. In this fra

Thomas Schreiber

An information theoretic measure is derived that quantifies the statistical coherence between systems evolving in time. The standard time delayed mutual information fails to distinguish information that is actually exchanged from shared information due to common history and input signals. In our new approach, these influences are excluded by appropriate cond

Tsampikos Kottos, Holger Schanz

We study the statistical properties of the scattering matrix associated with generic quantum graphs. The scattering matrix is the quantum analogue of the classical evolution operator on the graph. For the energy-averaged spectral form factor of the scattering matrix we have recently derived an exact combinatorial expression. It is based on a sum over familie

N. V. Antonov, A. Lanotte, A. Mazzino

The problem of anomalous scaling in magnetohydrodynamics turbulence is considered within the framework of the kinematic approximation, in the presence of a large-scale background magnetic field. The velocity field is Gaussian, $δ$-correlated in time, and scales with a positive exponent $ξ$. Explicit inertial-range expressions for the magnetic correlation fun

R. Skip Garibaldi

Freudenthal triple systems come in two flavors, degenerate and nondegenerate. The best criterion for distinguishing between the two which is available in the literature is by descent. We provide an identity which is satisfied only by nondegenerate triple systems. We then use this to define algebraic structures whose automorphism groups produce all adjoint al

Alexandr Borisov

It is pretty well-known that toric Fano varieties of dimension k with terminal singularities correspond to convex lattice polytopes P in R^k of positive finite volume, such that intersection of P and Z^k consists of the point 0 and vertices of P. Likewise, Q-factorial terminal toric singularities essentially correspond to lattice simplexes with no lattice po

Thomas Schick

For non-compact manifolds with boundary we prove that bounded geometry defined by coordinate-free curvature bounds is equivalent to bounded geometry defined using bounds on the metric tensor in geodesic coordinates. We produce a nice atlas with subordinate partition of unity on manifolds with boundary of bounded geometry, and we study the change of geodesic

Francisco Javier Gallego, B. P. Purnaprajna

The goal of this article is to study the equations and syzygies of embeddings of rational surfaces and certain Fano varieties. Given a rational surface X and an ample and base-point-free line bundle L on X, we give an optimal numerical criterion for L to satisfy property Np. This criterion turns out to be a characterization of property Np if X is anticanonic

Maximilian Kreuzer, Harald Skarke

During the last years we have generated a large number of data related to Calabi-Yau hypersurfaces in toric varieties which can be described by reflexive polyhedra. We classified all reflexive polyhedra in three dimensions leading to K3 hypersurfaces and have nearly completed the four dimensional case relevant to Calabi-Yau threefolds. In addition, we have a

J. Denef, F. Loeser

We express the Lefschetz number of iterates of the monodromy of a function on a smooth complex algebraic variety in terms of the Euler characteristic of a space of truncated arcs.

Stefan Schroeer

Given an invertible sheaf, does it come from a Cartier divisor? This might fail in presence of embedded components. I give some examples and characterize those invertible sheaves that allow a Cartier divisor.

M. G. Ivanov, I. V. Volovich

Recently a realization of the four-dimensional gravity on a brane in five-dimensional spacetime has been discussed. Randall and Sundrum have shown that the equation for the longitudinal components of the metric fluctuations admit a normalizable zero mode solution, which has been interpreted as the localized gravity on the brane. We point out that the equatio

V. Ch. Zhukovsky, N. A. Peskov

Exact constant solutions of field equations in the classical nonabelian SU(2) field theory with the Chern-Simons topological mass in 2+1-dimensional space-time have been obtained. One-loop contributions of boson and fermion fluctuations to the gauge field energy have been calculated.

V. R. Khalilov, Choon-Lin Ho

The thermodynamic properties of an ideal gas of charged vector bosons (with mass m and charge e) is studied in a strong external homogeneous magnetic field no greater than the critical value B_{cr}=m^2/e. The thermodynamic potential, after appropriate analytic continuation, is then used in the study of the spontaneous production of charged spin-one boson pai

Sukanta Bose, Naresh Dadhich

The electrogravity transformation is defined by an interchange of the ``active&#39;&#39; and ``passive&#39;&#39; electric parts of the Riemann tensor. Such a transformation has been used to find new solutions that are ``dual&#39;&#39; to the Kerr family of black hole spacetimes in general relativity. In such a case, the dual solution is a similar black hole

S. B. Afanas&#39;ev

The concept of the space (space-time) of the formless finite fundamental elements (FFFE) is suggested. This space can be defined as a set of coverings of the continual space by non-overlapping simply connected regions of any form and arbitrary sizes with some probability measure. The average sizes of each fundamental element are equal to the fundamental leng

Philip D. Mannheim, Aharon Davidson

Using the Dirac constraint method we show that the pure fourth-order Pais-Uhlenbeck oscillator model is free of observable negative norm states. Even though such ghosts do appear when the fourth order theory is coupled to a second order one, the limit in which the second order action is switched off is found to be a highly singular one in which these states

N. Mohammedi

It is shown, at the level of the classical action, that the Wess-Zumino-Witten-Novikov model is equivalent to a combined BF theory and a Chern-Simons action in the presence of a unique boundary term. This connection relies on the techniques of non-Abelian T-duality in non-linear sigma models. We derive some consistency conditions whose various solutions lead

Keiichi Akama

Here we place the TeX-typeset version of the old preprint SMC-PHYS-66 (1982), which was published in K. Akama, &#34;Pregeometry&#34;, in Lecture Notes in Physics, 176, Gauge Theory and Gravitation, Proceedings, Nara, 1982, edited by K. Kikkawa, N. Nakanishi and H. Nariai, (Springer-Verlag) 267--271. In the paper, we presented the picture that we live in a &#

Chao-hsi Chang, Tai-fu Feng

The minimum supersymmetric standard model (MSSM) without R-parity through various lepton-number violations is investigated systematically. All kinds of possible mixing in the model are formulated precisely. The remarkable issue that the lightest `Higgs&#39; $H_1^0$ may be heavier than the weak-boson $Z$ at tree level is kept, as the special R-parity violatio

Arno R. Bohm, N. L. Harshman

The ambiguity in the definition for the mass and width of relativistic resonances is discussed, in particular for the case of the Z-boson. This ambiguity can be removed by requiring that a resonance&#39;s width $Γ$ (defined by a Breit-Wigner lineshape) and lifetime $τ$ (defined by the exponential law) always and exactly fulfill the relation $Γ= \hbar/τ$. To

L. M. A. Bettencourt, Nuno D. Antunes, W. H. Zurek

The Ginzburg temperature has historically been proposed as the energy scale of formation of topological defects at a second order symmetry breaking phase transition. More recently alternative proposals which compute the time of formation of defects from the critical dynamics of the system, have been gaining both theoretical and experimental support. We inves

Gregory Mahlon, Stephen Parke

The top quark pairs produced at a polarized muon collider are in a (nearly) pure spin configuration. This result holds for all center-of-mass energies, and is insensitive to the next-to-leading order QCD radiative corrections. The decay products of a polarized top quark show strong angular correlations. We describe an interesting interference effect between

P. Colangelo, F. De Fazio, G. Nardulli

We use QCD sum rules to estimate the universal form factors describing the semileptonic B decays into excited charmed resonances, such as the $1^-$ and $2^-$ states $D_1^{*}$ and $D_2^{*}$ belonging to the $s_\ell^P={3/2}^-$ heavy quark doublet, and the $2^-$ and $3^-$ states $D_2^{*\prime}$ and $D_3$ belonging to the $s_\ell^P={5\2}^-$ doublet.

T. Barreiro, B. de Carlos

In this talk we discuss a few relevant aspects of heterotic M-theory. These are the stabilization of the two relevant moduli (the length of the eleventh segment (pi rho) and the volume of the internal six manifold (V)) in models where supersymmetry is broken by multiple gaugino condensation and non-perturbative corrections to the Kahler potential; the existe

Giorgio Calucci, Daniele Treleani

A Hamiltonian eikonal model for the multiple production in high energy hadron hadron collisions is presented and worked out in the aim of providing a simple frame for many different observables of these processes. The Hamiltonian formulation ensures that it has the unitarity built in by construction and the eikonal approximation makes easier the discussion o

R. J. Rivers

Kibble and Zurek have provided a unifying causal picture for the appearance of classical defects like cosmic strings or vortices at the onset of phase transitions in relativistic QFT and condensed matter systems respectively. In condensed matter the predictions are partially supported by agreement with experiments in superfluid helium. We provide an alternat

N. I. Kochelev, T. Morii, S. Oyama

To test the model of the polarized gluon distribution $ΔG(x, Q^2)$ in the proton, we propose a new process, diffractive $Λ_c^+$ productions in polarized $pp$ reactions, which will be observed in the forthcoming RHIC and also the proposed HERA-$\vec {\rm N}$ experiments. The spin correlation between the target proton and the $Λ_c^+$ produced in the target fra

Dmitri Antonov

A test for the Gaussian and exponential Ansaetze for the nonperturbative parts of the coefficient functions, D^{nonpert.} and D_1^{nonpert.}, which parametrize the gauge-invariant bilocal correlator of the field strength tensors in the stochastic vacuum model of QCD, is proposed. It is based on the evaluation of the heavy-quark condensate within this model b

P. A. Baikov, V. A. Smirnov

We show that the problem of solving recurrence relations for L-loop (R+1)-point Feynman integrals within the method of integration by parts is equivalent to the corresponding problem for (L+R)-loop vacuum or (L+R-1)-loop propagator-type integrals. Using this property we solve recurrence relations for two-loop massless vertex diagrams, with arbitrary numerato

Wolfgang Lucha, F. F. Schoberl

A recent determination of the mass of the b quark, based exclusively on quantum chromodynamics (by avoiding strictly to introduce any phenomenological interaction potential of nonperturbative origin), may be improved by allowing for a merely numerical solution of the corresponding eigenvalue problem.

Edmond L. Berger, Lionel E. Gordon, Michael Klasen

We show that massive lepton-pair production, the Drell-Yan process, should be a good source of independent constraints on the polarized gluon density, free from the experimental and theoretical complications of photon isolation that beset studies of prompt photon production. We provide predictions for the spin-averaged and spin-dependent differential cross s

W. Porod, D. Restrepo, J. W. F. Valle

We discuss the phenomenology of the lightest stops in models where R-parity is broken by bilinear terms. In this class of models we consider scenarios where the R-parity breaking two-body decay stop_1 -> tau + b competes with the leading three-body decays stop_1 -> W^+ + b + neutralino_1, H^+ + b + neutralino_1, b slepton^+_i neutrino_l, b sneutrino_l l^+ (l

Stefan Groote, Junko Shigemitsu

One-loop corrections to the fermion rest mass M_1, wave function renormalization Z_2 and speed of light renormalization C_0 are presented for lattice actions that combine improved glue with clover or D234 quark actions and keep the temporal and spatial lattice spacings, a_t and a_s, distinct. We explore a range of values for the anisotropy parameter χ= a_s/a