April 2001 arXiv papers — page 7

Pedro L. Garrido, Pablo I. Hurtado, Bjoern Nadrowski

We present the computer simulation results of a chain of hard point particles with alternating masses interacting on its extremes with two thermal baths at different temperatures. We found that the system obeys Fourier's law at the thermodynamic limit. This result is against the actual belief that one dimensional systems with momentum conservative dynami

C. Rossel, G. I. Meijer, D. Bremaud, D. Widmer

Combining scanning electron microscopy (SEM) and electron-beam-induced current (EBIC) imaging with transport measurements, it is shown that the current flowing across a two-terminal oxide-based capacitor-like structure is preferentially confined in areas localized at defects. As the thin-film device switches between two different resistance states, the distr

Giuliano Benenti, Giulio Casati, Italo Guarneri, Marcello Terraneo

We numerically analyse quantum survival probability fluctuations in an open, classically chaotic system. In a quasi-classical regime, and in the presence of classical mixed phase space, such fluctuations are believed to exhibit a fractal pattern, on the grounds of semiclassical arguments. In contrast, we work in a classical regime of complete chaoticity, and

I. Pagonabarraga, M. E. Cates

The Flory Huggins equation of state for monodisperse polymers can be turned into a density functional by adding a square gradient term, with a coefficient fixed by appeal to RPA (random phase approximation). We present instead a model nonlocal functional in which each polymer is replaced by a deterministic, penetrable particle of known shape. This reproduces

E. S. Choi, J. S. Brooks, J. S. Qualls

We have used a low-frequency magneto-thermopower (MTEP) method to probe the high magnetic field ground state behavior of $α$-(BEDT-TTF)$_2$KHg(SCN)$_4$ along all three principal crystallographic axes at low temperatures. The thermopower tensor coefficients ($S_{xx}, S_{yx}$ and $S_{zz}$) have been measured to 30 T, beyond the anomalous low temperature, field

A. L. Cornelius, P. G. Pagliuso, M. F. Hundley, J. L. Sarrao

We have measured the field-dependent heat capacity in the tetragonal antiferromagnets CeRhIn$_{5}$ and Ce$_{2}$RhIn$_{8}$, both of which have an enhanced value of the electronic specific heat coefficient $γ\sim 400$ mJ/mol-Ce K$^{2}$ above $T_{N}$. For $T<T_{N},$ the specific heat data at zero applied magnetic field are consistent with the existence of an an

S. Veilleux, D. -C. Kim, D. B. Sanders

For the past several years, our group has pursued a vigorous ground-based program aimed at understanding the nature of ultraluminous infrared galaxies. We recently published the results from a optical/near-infrared spectroscopic survey of a large statistically complete sample of ultraluminous infrared galaxies (the &#34;IRAS 1-Jy sample&#34;). We now present

David V. Bowen, Walter Huchtmeier, Elias Brinks, Todd M. Tripp

We detect 21-cm emission from the Low Surface Brightness (LSB) galaxy SBS 1543+593, which gives rise to a Damped Lyman-alpha (DLA) absorption line in the spectrum of the background QSO HS 1543+5921 (z=0.807). We obtain an accurate measure of the velocity of the H I gas in the LSB galaxy, v=2868 km/s, and derive a mass of 1.3e9 solar masses. We compare this v

S. Jester, H. -J. Roeser, K. Meisenheimer, R. Perley

We present HST images at 622 nm and 300 nm of the jet in 3C273 and determine the run of the optical spectral index at 0.2&#34; along the jet. The smoothness of spectral index changes shows that the physical conditions are varying smoothly across the jet. There is no correlation between the optical flux and spectral index, as would be expected for relativisti

A. Sozzetti, S. Casertano, M. G. Lattanzi, A. Spagna

We use detailed numerical simulations and the $\upsilon$ Andromedae, planetary system as a template to evaluate the capability of the ESA Cornerstone Mission GAIA in detecting and measuring multiple planets around solar-type stars in the neighborhood of the Solar System. For the outer two planets of the $\upsilon$ Andromedae, system, GAIA high-precision glob

Pablo Reig, Nikolaos D. Kylafis, Henk C. Spruit

We have performed Monte Carlo simulations of Compton upscattering of low-energy photons in an accretion disk around a Schwarzschild black hole. The photons gain energy from the rotational motion of the electrons in the disk. The upscattering occurs near the black hole horizon, where the flow velocity of the electrons approaches the speed of light. We show th

D. R. Lorimer

We review the properties and applications of binary and millisecond pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1300. There are now 56 binary and millisecond pulsars in the Galactic disk and a further 47 in globular clusters. Th

Dominik J. Bomans

Dwarf galaxies provide a special environment due to their low mass, small size and generally low metal content. These attributes make them perfect laboratories for the interaction of massive stars with the interstellar medium on small and especially large spatial scales. The natural result of the spatially concentrated energy output from stellar winds and su

Arun V. Thampan

Disk accretion onto a neutron star possessing a weak surface magnetic field ($B \le 10^8$ G) provides interesting X-ray emission scenarios, and is relevant for understanding X-ray bursters and low-mass X-ray binaries (LMXBs). The standard (Newtonian) theory of disk-accretion predicts that the matter spiralling in from infinity loses one-half of its total gra

Sudip Bhattacharyya, Arun V. Thampan, Ignazio Bombaci

We compute the temperature profiles of accretion discs around rapidly rotating strange stars, using constant gravitational mass equilibrium sequences of these objects, considering the full effect of general relativity. Beyond a certain critical value of stellar angular momentum ($J$), we observe the radius ($r_{\rm orb}$) of the innermost stable circular orb

R. Kothes, W. Reich

We present radio maps of the historical supernova remnant G11.2-0.3 in the frequency range from 4.85 GHz to 32 GHz. The integrated spectrum with α= -0.50 (S ~ ν^α) is dominated by its steep spectrum shell emission (α~ -0.57), although a flat spectrum core structure classifies G11.2-0.3 as a composite supernova remnant. A radial magnetic field structure is ob

G. Goldhaber, D. E. Groom, A. Kim, G. Aldering

R-band intensity measurements along the light curve of Type Ia supernovae discovered by the Supernova Cosmology Project (SCP) are fitted in brightness to templates allowing a free parameter the time-axis width factor w = s(1+z). The data points are then individually aligned in the time-axis, normalized and K-corrected back to the rest frame, after which the

Duiliu-Emanuel Diaconescu

We construct D-brane categories in B-type topological string theory as solutions to string field equations of motion. Using the formalism of superconnections, we show that these solutions form a variant of a construction of Bondal and Kapranov. This analysis is an elaboration on recent work of Lazaroiu. We also comment on the relation between string field th

W. Fischler, A. Kashani-Poor, R. McNees, S. Paban

Recent astronomical observations indicate that the universe is accelerating. We argue that generic quintessence models that accommodate the present day acceleration tend to accelerate eternally. As a consequence the resulting spacetimes exhibit event horizons. Hence, quintessence poses the same problems for string theory as asymptotic de Sitter spaces.

Dmitry Strekalov, Jonathan Dowling

We discuss advantages of using non-classical states of light for two aspects of optical imaging: creating of miniature images on photosensitive substrates, which constitutes the foundation for optical lithography, and imaging of micro objects. In both cases, the classical resolution limit given by the Rayleigh criterion is approximately a half of the optical

Rudnei O. Ramos

We study the presence of chaotic behavior in phase space in the pre-inflationary stage of hybrid inflation models. This is closely related to the problem of initial conditions associated to these inflationary type of models. We then show how an expected dissipative dynamics of fields just before the onset of inflation can solve or ease considerably the probl

Z. Y. Zeng, F. Claro

We study the transport of electrons in a Fibonacci magnetic superlattice produced on a two-dimensional electron gas modulated by parallel magnetic field stripes arranged in a Fibonacci sequence. Both the transmission coefficient and conductance exhibit self-similarity and the six-circle property. The presence of extended states yields a finite conductivity a

Charles Gale

We discuss the measurement of electromagnetic radiation produced in heavy ion collisions at SPS energies. We review the low invariant mass dilepton sector, the real photon data, and the spectra of intermediate mass dimuons. Along with this, we discuss the theoretical interpretations of those observables.

Rudolph C. Hwa, C. B. Yang

The signatures of the creation of a disoriented chiral condensate in heavy-ion collisions are studied in the Ginzburg-Landau description of chiral phase transition. Scaling properties are found that characterize the fluctuations of charged particles. There exists also an explicitly calculable measure that can directly be measured. Experimental procedures nee

Sumit R. Das, Andrei Zelnikov

A uniformly acclerated observer in anti-deSitter space-time is known to detect thermal radiation when the acceleration exceeds a critical value. We investigate the holographic interpretation of this phenomenon. For uniformly accelerated trajectories transverse to the boundary of the AdS space, the hologram is a blob which expands along the boundary. Observer

P. Zanardi

The Fock space of a system of indistinguishable particles is isomorphic (in a non-unique way) to the state-space of a composite i.e., many-modes, quantum system. One can then discuss quantum entanglement for fermionic as well as bosonic systems. We exemplify the use of this notion -central in quantum information - by studying some e.g., Hubbard,lattice fermi

Vladimir S. Dotsenko, Xuan Son Nguyen, Raoul Santachiara

We have studied the conformal models WD_{n}^{(p)}, n=3,4,5,..., in the presence of disorder which couples to the energy operator of the model. In the limit of p<<1 where p is the corresponding minimal model index, the problem could be analyzed by means of the perturbative renormalization group, with $epsilon$-expansion in $ε$=1/p. We have found that the diso

D. V. Fil

A mechanism for orientation of bilayer classical Wigner crystals in a piezoelectric medium is considered. For the GaAs system the piezoelectric correction to the electrostatic interaction between electrons is calculated. It is shown that taking into account the correction due to the piezoelectric effect leads to a dependence of the total energy of the electr

A. Kapustnikov, A. Shcherbakov

The coordinate transformations which establish the direct relationship between the actions of linear and nonlinear realizations of supermembranes are proposed. It is shown that the Rocek-Tseytlin constraint known in the framework of the linear realization of the theory is simply equivalent to a limit of a &#34;pure&#34; nonlinear realization in which the fie

E. B. Fomalont, B. J. Geldzahler, C. F. Bradshaw

The radio components associated with the LMXB Sco X-1 have been monitored with extensive VLBI imaging at 1.7 and 5.0 GHz over four years, including a 56-hour continuous VLBI observation in 1999 June. We often detected one strong and one weak compact radio component, moving in opposite directions from the radio core. We suggest that the moving components are

S. M. Bilenky, S. Pascoli, S. T. Petcov

Assuming four-neutrino mixing and massive Majorana neutrinos, we study the implications of the neutrino oscillation solutions of the solar and atmospheric neutrino problems, of the results of the LSND experiment and of the constraints on neutrino oscillations, obtained in reactor and accelerator experiments, for the predictions of the effective Majorana mass

A. V. Smilga

We study the structure of the tenacious (existing for all values of masses of the matter fields) BPS domain walls interpolating between different chirally asymmetric vacua in supersymmetric QCD in the limit of large masses. We show that the wall consists in this case of three layers: two outer layers form a ``coat&#39;&#39; with the characteristic size deter

P. H. Frampton, R. N. Mohapatra, Sungwook Suh

The possibility that non-supersymmetric conformal field theories softly broken below 100 TeV may provide an alternative to conventional grand unification is explored. We consider a low energy theory presumed to be of this type arising from the Type IIB superstring compactified on a $AdS_5 \times S_5/Γ$ space whose gauge group and the particle content are sev

Michael Melles

Experiments at future colliders will attempt to unveil the origin of electroweak symmetry breaking in the TeV range. At these energies the Standard Model (SM) predictions have to be known precisely in order to disentangle various viable scenarios such as supersymmetry and its manifestations. In particular, large logarithmic corrections of the scale ratio $\s

M. C. Diamantini

We extend the duality between massive and topologically massive antisymmetric tensor gauge theories in arbitrary space-time dimensions to include topological defects. We show explicitly that the condensation of these defects leads, in 4 dimensions, to confinement of electric strings in the two dual models. The dual phase, in which magnetic strings are confin

Dietmar Klemm, Silvia Penati, Laura Tamassia

We investigate the most general non(anti)commutative geometry in N=1 four-dimensional superspace, invariant under the classical (i.e., undeformed) supertranslation group. We find that a nontrivial non(anti)commutative superspace geometry compatible with supertranslations exists with non(anti)commutation parameters which may depend on the spinorial coordinate

Abdesslam Arhrib, Seungwon Baek

We consider the contribution of a two-loop Barr-Zee type diagram to $(g-2)_μ$ in the minimal supersymmetric standard model (MSSM). At relatively large $\tanβ$, we show that the contribution of light third generation scalar fermions and neutral CP-even Higgs, $h^0(H^0)$, can easily explain the very recent BNL experimental data. In our analysis $(g-2)_μ$ prefe

Bodo Geyer, Petr Lavrov, Armen Nersessian

We show that the specific operators V^a appearing in the triplectic formalism can be viewed as the anti-Hamiltonian vector fields generated by a second rank irreducible Sp(2) tensor. This allows for an explicit realization of the triplectic algebra being constructed from an arbitrary Poisson bracket on the space of the fields only, equipped by the flat Poiss

Elena Cuoco, Giovanni Losurdo, Giovanni Calamai, Leonardo Fabbroni

We report the analysis we made on data taken by Caltech 40-meter prototype interferometer to identify the noise power spectral density and to whiten the sequence of noise. We concentrate our study on data taken in November 1994, in particular we analyzed two frames of data: the 18nov94.2.frame and the 19nov94.2.frame. We show that it is possible to whiten th

A. S. Joshipura, E. A. Paschos, W. Rodejohann

The masses and mixing of the light left-handed neutrinos can be related to those of the heavy right-handed neutrinos in left-right symmetric theories. Properties of the light neutrinos are measured in terrestrial experiments and the CP-violating decays of their heavy counterparts produce a baryon asymmetry via the well-known leptogenesis mechanism. The left-

Nariya Uchida

We study fluctuation-induced interaction in confined fluids above the isotropic-lamellar transition. At an ideal continuous transition, the disjoining pressure has the asymptotic form $Π(d\to\infty)\approx -C k_BT q_0^2/d$, where $d$ is the interwall distance, $q_0$ is the wavenumber of the scattering peak, and $C= 1/(4π)$ in the strong anchoring limit. The

Yoshio Koide

The eigenvalues and mixing angles in the Zee model are investigated parameter-independently. When we require |Δm^2_{12}/Δm^2_{23}| \ll 1 in order to understand the solar and atmospheric data simultaneously, the only solution is one which gives bi-maximal mixing. It is pointed out that the observed values \sin^2 2θ_{solar} \simeq 0.66 in the MSW LMA solution

M. R. Grasselli

We construct an infinite-dimensional information manifold based on exponential Orlicz spaces without using the notion of exponential convergence. We then show that convex mixtures of probability densities lie on the same connected component of this manifold, and characterize the class of densities for which this mixture can be extended to an open segment con

S. Boffi, M. Radici, L. Glozman, R. F. Wagenbrunn

The proton and neutron electromagnetic form factors and the nucleon axial form factor have been calculated in the Goldstone-boson exchange constituent-quark model within the point-form approach to relativistic quantum mechanics. The results, obtained without any adjustable parameter nor quark form factors, are, due to the dramatic effects of the boost requir

B. Binz, D. Baeriswyl, B. Doucot

The weak coupling instabilities of a two dimensional Fermi system are investigated for the case of a square lattice using a Wilson renormalization group scheme to one loop order. We focus on a situation where the Fermi surface passes through two saddle points of the single particle dispersion. In the case of perfect nesting, the dominant instability is a spi

Shinji Mukohyama

Cosmological perturbations in the brane-world cosmology with a positive tension brane in the AdS background bulk geometry is analyzed by using the doubly gauge-invariant formalism. We derive four independent equations for scalar perturbations in the plane symmetric (K=0) background. Three of these equations are differential equations written in terms of gaug

Kiyoshi Higashijima, Tetsuji Kimura, Muneto Nitta

We propose a class of N=2 supersymmetric nonlinear sigma models on the Ricci-flat Kahler manifolds with O(n) symmetry.

J. J. M. in &#39;t Zand, L. Kuiper, L. Amati, L. A. Antonelli

We analyze the BeppoSAX measurements of the prompt and afterglow emission of the gamma-ray burst GRB010222. Among 45 GRBs detected with the Wide Field Cameras on BeppoSAX, the 40-700 keV fluence of (9.3+/-0.3)E-5 erg cm-2 is only surpassed by GRB990123. In terms of the isotropic 20-2000 keV energy output of 7.8E53 erg, it ranks third of all GRBs with measure

Semyon Alesker

We recall known and establish new properties of the Dieudonné and Moore determinants of quaternionic matrices.Using these linear algebraic results we develop a basic theory of plurisubharmonic functions of quaternionic variables. Then we introduce and briefly discuss quaternionic Monge-Ampére equations.

A. A. Fraerman, S. A. Gusev, L. A. Mazo, I. M. Nefedov

Regular 2D rectangular lattices of permalloy nanoparticles (40 nm in diameter) were prepared by the method of the electron lithography. The magnetization curves were studied by Hall magnetometry with the compensation technique for different external field orientations at 4.2K and 77K. The shape of hysteresis curves indicates that there is magnetostatic inter

U. K. Yang, T. Adams, A. Alton, C. G. Arroyo

We report on the extraction of R=sigma_L/sigma_T from CCFR nu_mu-Fe and nubar_mu-Fe differential cross sections. The CCFR differential cross sections do not show the deviations from the QCD expectations that are seen in the CDHSW data at very low and very high x. R as measured in nu_mu scattering is in agreement with R as measured in muon and electron scatte

W. P. Bowen, P. K. Lam, T. C. Ralph

We consider pure continuous variable entanglement with non-equal correlations between orthogonal quadratures. We introduce a simple protocol which equates these correlations and in the process transforms the entanglement onto a state with the minimum allowed number of photons. As an example we show that our protocol transforms, through unitary local operatio

S. Shresta

A variation to the usual formulation of Grassmann representation path integrals is presented. Time-indexed anticommuting partners are introduced for each Grassmann coherent state variable and a general method for handling the effect of these introduced Grassmann partners is also developed. These Grassmann partners carry the nilpotency and anticommutivity of

Gyula Bene

Analytical and numerical arguments are presented in case of a pair of two-state systems in a singlet state that the threshold visibility for testing Bell&#39;s theorem on the entire range of measurement settings is 33.3%. It is also shown that no lower treshold exists.

Nguyen Ba An

Fan-even K-quantum nonlinear coherent states are introduced and higher-order amplitude squeezing is investigated in such states. It is shown that for a given K the lowest order in which an amplitude component can be squeezed is 2K and the squeezing appears simultaneously in K directions separated successively in phase by π/K.

D. Felbacq, B. Guizal, F. Zolla

The starting point of the article is the puzzling fact that one cannot recover the Fresnel coefficients by letting tend the width of a slab to infinity. Without using the so-called limiting absorption principle, we show by a convenient limit analysis that it is possible to define rigorously the field diffracted by a semi-infinite periodic medium.

A. V. Nikulov

A contradiction of the Little-Parks experiment with the Ohm&#39;s law and other fundamental laws is explained. This explanation shows that the Little-Parks oscillations of the loop resistance are an experimental evidence of a direct (non-chaotic) Brownian motion. The Langevin force is connected with a change of the momentum circulation of superconducting pai

G. N. Throumoulopoulos, H. Tasso

It is found that the ideal magnetohydrodynamic equilibrium of an axisymmetric gravitating magnetically confined plasma with incompressible flows is governed by a second-order elliptic differential equation for the poloidal magnetic flux function containing five flux functions coupled with a Poisson equation for the gravitation potential, and an algebraic rel

D. Geschke, T. Bastug, T. Jacob, S. Fritzsche

We report on results of a theoretical study of the adsorption process of a single carbon oxide molecule on a Platinum (111) surface. A four-component relativistic density functional method was applied to account for a proper description of the strong relativistic effects. A limited number of atoms in the framework of a cluster approach is used to describe th

E. L. Afraimovich, A. B. Beletsky, L. A. Leonovich, O. S. Lesyuta

Basic properties of the mid-latitude large-scale traveling ionospheric disturbances (LS TIDs) during the maximum phase of a strong magnetic storm of 6-8 April 2000 are shown. Total electron content (TEC) variations were studied by using data from GPS receivers located in Russia and Central Asia. The nightglow response to this storm at mesopause and termosphe

The Cloud Collaboration

This report is the first of two addenda to the CLOUD proposal at CERN (physics/0104048), which aims to test experimentally the existence a link between cosmic rays and cloud formation, and to understand the microphysical mechanism. The document provides further details on the detector design, scientific motivation and experimental programme.

C. Tannous, R. Davies, A. Angus

Multipath propagation of radio waves in indoor/outdoor environments shows a highly irregular behavior as a function of time. Typical modeling of this phenomenon assumes the received signal is a stochastic process composed of the superposition of various altered replicas of the transmitted one, their amplitudes and phases being drawn from specific probability

A. Deloff

The pi-N s-wave scattering lengths have been inferred from a joint analysis of the pionic hydrogen and the pionic deuterium x-ray data using a non-relativistic approach in which the pi-N interaction is simulated by a short-ranged potential. The pi-d scattering length has been calculated exactly by solving the Faddeev equations and also by using a static appr

C. Adler

We report results on the ratio of mid-rapidity anti-proton to proton yields in Au+Au collisions at $\rts = 130$ GeV per nucleon pair as measured by the STAR experiment at RHIC. Within the rapidity and transverse momentum range of $|y|<0.5$ and 0.4 $<p_t<$ 1.0 GeV/$c$, the ratio is essentially independent of either transverse momentum or rapidity, with an ave

Nu Xu, Masashi Kaneta

Systematic trend of the hadron freeze-out conditions from AGS/SPS to RHIC is discussed. The most interesting results from collisions at RHIC are that the system is indeed approaching net-baryon free and the transverse expansion is much stronger than that from collisions at AGS/SPS energies. In order to understand the trend of the collective velocity, an ener

S. C. Johnson

First identical-pion correlations measured at RHIC energies by PHENIX are presented. Two analyses with separate detectors, systematics, and statistics provide consistent results. The resulting HBT radii are moderately larger than those measured at lower energies. The $k_t$ dependence of the Bertsch-Pratt HBT radii is also similar to previous measures and is

P. Sapienza, R. Coniglione, M. Colonna, E. Migneco

The energetic proton emission has been investigated as a function of the reaction centrality for the system 58Ni + 58Ni at 30A MeV. Extremely energetic protons (EpNN > 130 MeV) were measured and their multiplicity is found to increase almost quadratically with the number of participant nucleons thus indicating the onset of a mechanism beyond one and two-body

Miguel Onorato, Alfred R. Osborne, Marina Serio, Serena Bertone

Freak waves are very large, rare events in a random ocean wave train. Here we study the numerical generation of freak waves in a random sea state characterized by the JONSWAP power spectrum. We assume, to cubic order in nonlinearity, that the wave dynamics are governed by the nonlinear Schroedinger (NLS) equation. We identify two parameters in the power spec

Surendra Singh Negi, Ramakrishna Ramaswamy

The discrete Schrödinger equation with a quasiperiodic dichotomous potential specified by the Fibonacci sequence is known to have a singular continuous eigenvalue spectrum with all states being critically localized. This equation can be transformed into a quasiperiodic skew product dynamical system. In this iterative mapping which is entirely equivalent to t

T. Ioannidou, J. Pouget, E. Aifantis

This paper proposes a one-dimensional lattice model with long-range interactions which, in the continuum, keeps its nonlocal behaviour. In fact, the long-time evolution of the localized waves is governed by an asymptotic equation of the Benjamin-Ono type and allows the explicit construction of moving kinks on the lattice. The long-range particle interaction

Newton C. A. da Costa, Adonai S. Sant&#39;Anna

We use Padoa&#39;s principle of independence of primitive symbols in axiomatic systems in order to show that time is dispensable in continuum thermodynamics, according to the axiomatic formulation of Gurtin and Williams. We also show how to define time by means of the remaining primitive concepts of Gurtin and Williams system. Finally, we introduce thermodyn

L. Chiantini, A. F. Lopez

In this article we apply the classical method of focal loci of families to give a lower bound for the genus of curves lying on general surfaces. First we translate and reprove Xu&#39;s result that any curve C on a general surface in P^3 of degree d>4 has geometric genus g > 1 + deg(C)(d - 5)/2. Then we prove a similar lower bound for the curves lying on a ge

Carlos Florentino

We study a natural map from representations of a free group of rank g in GL(n,C), to holomorphic vector bundles of degree 0 over a compact Riemann surface X of genus g, associated with a Schottky uniformization of X. Maximally unstable flat bundles are shown to arise in this way. We give a necessary and sufficient condition for this map to be a submersion, w

Cinzia Casagrande

We announce a factorization result for equivariant birational morphisms between toric 4-folds whose source is Fano: such a morphism is always a composite of blow-ups along smooth invariant centers. Moreover, we show with a counterexample that, differently from the 3-dimensional case, even if both source and target are Fano, the intermediate varieties can not

Michela Varagnolo, Eric Vasserot

We define a quantum analogue of the Grothendieck ring of finite dimensional modules of a quantum affine algebra of simply laced type. The construction is based on perverse sheaves on a variety related to quivers. We get also a new geometric construction of the tensor category of finite dimensional modules of a finite dimensional simple Lie algebra of type A-

Antoine Chambert-Loir, Yuri Tschinkel

We prove asymptotic formulas for the number of rational points of bounded height on smooth equivariant compactifications of the affine space. (Nous établissons un développement asymptotique du nombre de points rationnels de hauteur bornée sur les compactifications équivariantes lisses de l&#39;espace affine.)

Orlando Alvarez, I. M. Singer

Given a Riemann surface and a riemannian manifold M with certain restrictions, we construct a cobordism invariant of M. This invariant is a generalization of the elliptic genus and it shares some similar properties.

L. Castellani, L. Sommovigo

1-brane nonmaximally supersymmetric solutions of D=10 chiral supergravity are discussed. In the dual frame, their near brane geometry is the product of a 3-dimensional domain wall spacetime and a 7-dimensional homogeneous Einstein space G/H.

Ashok Das

In this talk, I summarize the status of our understanding of the puzzle of large gauge invariance at finite temperature.

Ashok Das, Ziemowit Popowicz

The super Moyal-Lax representation and the super Moyal momentum algebra are introduced and the properties of simple and extended supersymmetric integrable models are systematically investigated. It is shown that, much like in the bosonic cases, the super Moyal-Lax equation can be interpreted as a Hamiltonian equation and can be derived from an action. Simila

Bodo Geyer, Dietmar Mülsch

We study the renormalizability of (massive) topological QCD based on the algebraic BRST technique by adopting a non-covariant Landau type gauge and making use of the full topological superalgebra. The most general local counter terms are determined and it is shown that in the presence of central charges the BRST cohomology remains trivial. By imposing an add

V. Akulov

In this report I give the short historical review some of the first steps that were done to the invention of SUSY in Kharkov team headed by D.Volkov. This paper is dedicated to the memory of Prof. Yu. Gol&#39;fand, whose ideas of SUSY inspired the most active developments in High Energy Physics over thirty years.

Kiyonori Gomi

We formulate the Chern-Simons action for any compact Lie group using Deligne cohomology. This action is defined as a certain function on the space of smooth maps from the underlying 3-manifold to the classifying space for principal bundles. If the 3-manifold is closed, the action is a function with values in complex numbers. If the 3-manifold is not closed,

Leonid D. Lantsman

The aim of this work is to show, on the example of the behaviour of the spinless charged particle in the homogeneous electric field, that one can quantized the velocity of particle by the special gauge fixation. The work gives also the some information about the theory of second quantisation in the space of Hilbert- Fock and the theory of projectors in the H

Simeon Hellerman, Nemanja Kaloper, Leonard Susskind

We discuss the obstacles for defining a set of observable quantities analogous to an S-matrix which are needed to formulate string theory in an accelerating universe. We show that the quintessence models with the equations of state $-1 < w <-1/3$ have future horizons and may be no better suited to an S-matrix or S-vector description. We also show that in a c

M. Scandurra

An extension of the fundamental laws of thermodynamics and of the concept of entropy to the ground state fluctuations of the quantum fields is studied and some new results are found. At the end a device to extract energy from the vacuum recently proposed by an author is critically analyzed. It is found that no energy can be extracted cyclically from the vacu

Elias Gravanis, Nick E. Mavromatos

In a previous study we showed that D0-branes (particles) can operate as sources of very-high-energy radiation, as a result of an unstable spacetime distortion that follows a D0-particle/closed string state scattering. The effect can happen only if the energy of the incident particle/closed string state exceeds a certain threshold, which is of order of the su

She-Sheng Xue

We quantitatively compute the rate and spectrum of spontaneous photon emissions, caused by the vacuum decaying when an external magnetic field is introduced. The spectrum of spontaneous photon emissions shows the energy-momentum-dependency in the low-energy region and in the high energy region, is respectively similar to the Rayleigh-Jeans part and the Wien

V. A. Khoze, A. D. Martin, M. G. Ryskin

We show that the broad transverse momentum distribution of the Higgs boson produced by WW fusion can provide a viable way to identify H --> b anti-b decays at the LHC, if particular kinematical configurations with large rapidity gaps are selected. We estimate the event rate of the signal and of the QCD b anti-b background. We also discuss Higgs boson detecti

Oliver Schwindt, Niels R. Walet

We discuss calculations of the phase diagram of the baby-Skyrme model, a two-dimensional version of the model that has been so successful in the description of baryons. Contact is made with the sine Gordon model in 1D, and relations with the Skyrme model used in the quantum-Hall effect are pointed out. It is shown that at finite temperature the phase diagram

Alan Kostelecky

This talk outlines some recent theoretical developments in Lorentz and CPT violation.

G. L. Fogli, E. Lisi, A. Marrone, D. Montanino

We perform a global three generation analysis of the current solar and atmospheric evidence in favor of neutrino oscillations. We also include the negative results coming from CHOOZ to constrain the nu_e mixing. We study the zones of mass-mixing oscillations parameters compatible with all the data. It is shown that almost pure nu_mu <--> nu_tau oscillations

M. Aoki, K. Hagiwara, Y. Hayato, T. Kobayashi

In this paper, we discuss physics potential of the Very Long Base-Line (VLBL) Neutrino-Oscillation Experiments with the High Intensity Proton Accelerator (HIPA), which is planned to be built by 2006 in Tokaimura, Japan. We propose to use conventional narrow-band ν_μbeams (NBB) from HIPA for observing the ν_μ\to ν_e transition probability and the ν_μsurvival

L. Giusti, M. L. Paciello, C. Parrinello, S. Petrarca

We review many topics and results about numeric gauge fixing in lattice QCD.

B. I. Eisenstein, CLEO Collaboration

Using 12.7 $fb^{-1}$ of data collected with the CLEO detector at CESR, we observed two-photon production of the $c \bar c$ states $χ_{c0}$ and $χ_{c2}$ in their decay to $π^+ π^- π^+ π^-$. We measured $Γ_{γγ}(χ_{c}) \times {\mathcal B}(χ_{c} \to π^+π^-π^+π^-)$ to be 75 +- 13 (stat) +- 8 (syst) eV for the $χ_{c0}$ and 6.4 +- 1.8 (stat) +- 0.8 (syst) eV for th

A. Bozek

Using the data sample of 10.5 fb-1 collected by the Belle detector, we searched for two-body charmless decays involving vector mesons. The clear signal signature of B+ -> phi K+ is seen and its branching fraction is measured to be (1.39+.32-.30 +- 0.2) X 10-5. The evidence for B+ -> rho pi+, B0 -> rho- pi+ and B+ -> phi K*+ is reported and their branching fr

Anzhong Wang

Studies of black hole formation from gravitational collapse have revealed interesting non-linear phenomena at the threshold of black hole formation. In particular, in 1993 Choptuik studied the collapse of a massless scalar field with spherical symmetry and found some behaviour, which is quite similar to the critical phenomena well-known in {\em Statistical M

Martin Bojowald

Loop quantum cosmology is shown to provide both the dynamical law and initial conditions for the wave function of a universe by one discrete evolution equation. Accompanied by the condition that semiclassical behavior is obtained at large volume, a unique wave function is predicted.

B. Coll, J. Llosa, D. Soler

Any three-dimensional Riemannian metric can be locally obtained by deforming a constant curvature metric along one direction. The general interest of this result, both in geometry and physics, and related open problems are stressed.

M. Vasilic

Geometric sigma models are purely geometric theories of scalar fields coupled to gravity. Geometrically, these scalars represent the very coordinates of space-time, and, as such, can be gauged away. A particular theory is built over a given metric field configuration which becomes the vacuum of the theory. Kaluza-Klein theories of the kind have been shown to