March 1999 arXiv papers — page 14

V. Vedral

Classical and quantum error correction are presented in the form of Maxwell's demon and their efficiency analyzed from the thermodynamic point of view. We explain how Landauer's principle of information erasure applies to both cases. By then extending this principle to entanglement manipulations we rederive upper bounds on purification procedures the

Koji Hashimoto

In models inspired by non-commutative geometry, patterns of gauge symmetry breaking are analyzed, and SU(5) models are found to naturally favor a vacuum preserving SU(3) X SU(2) X U(1). A more realistic model is presented, and the possibility of D-brane interpretation is discussed.

Bihn Zhou, Chuan-Jie Zhu

In this paper, we use only the equation of motion for an interacting system of gravity, dilaton and antisymmetric tensor to study the soliton solutions by making use of a Poincar\'e invariant ansatz. We show that the system of equations are completly integrable and the solution is unique with appropriate boundary conditions. Some new class of solutions are a

T. Csorgo

A fully developed Bose-Einstein condensate, containing macroscopically large number of bosons can under certain conditions be considered as a generalized vacuum state. Applying the annihilation operator to the condensate, hole states can be defined. Infinite ladders of such hole states can be considered as generalized coherent states of the creation operator

A. N. Leznov

A method to construct in explicit form the generators of the simple roots of an arbitrary finite-dimensional representation of a quantum or standard semisimple algebra is found. The method is based on general results from the global theory of representations of semisimple groups. The rank two algebras $A_2$, $B_2=C_2$, $D_2$ and $G_2$ are considered as examp

Mark J. Gotay, Janusz Grabowski

We prove an algebraic ``no-go theorem'' to the effect that a nontrivial Poisson algebra cannot be realized as an associative algebra with the commutator bracket. Using this, we show that there is an obstruction to quantizing the Poisson algebra of polynomials generated by a nilpotent basic algebra on a symplectic manifold. Finally, we explicitly cons

Gregery T. Buzzard, Stephen Lu

Using the Kodaira dimension and the fundamental group of X, we succeed in classifying algebraic surfaces which are dominable by C^2 except for certain cases in which X is an algebraic surface of Kodaira dimension zero and the case when X is rational without any logarithmic 1-form. More specifically, in the case when X is compact (namely projective), we need

Milind V. Diwan

We have observed 1 event consistent with the signature expected of the rare decay of a positive kaon to a positive pion and a neutrino anti-neutrino pair. In the examined momentum region of 211 to 230 MeV/c in the center of mass of the kaon we estimated the backgrounds to be about $0.08 \pm 0.03$ events. From this observation we estimate the branching ratio

Andy Hocker

The most recently available results from searches conducted by the four LEP experiments at 189 GeV center-of-mass energy for Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) are presented. No evidence for a signal has been observed, and the null result is used by the experiments, both individually and collectively, to exclude regions of the M

Ren-yuan Zhu

Crystal Calorimetry is widely used in high energy physics because of its precision. Recent development in crystal technology identified two key issues to reach and maintain crystal precision: light response uniformity and calibration in situ. Crystal radiation damage is understood. While the damage in alkali halides is found to be caused by the oxygen/hydrox

B. G. Sidharth

In this brief communication we show why superclusters would naturally arise in the universe.

Marco Raberto, Enrico Scalas, Gianaurelio Cuniberti, Massimo Riani

We study the volatility of the MIB30-stock-index high-frequency data from November 28, 1994 through September 15, 1995. Our aim is to empirically characterize the volatility random walk in the framework of continuous-time finance. To this end, we compute the index volatility by means of the log-return standard deviation. We choose an hourly time window in or

Gianaurelio Cuniberti, Marco Raberto, Enrico Scalas

We analyze the time series of overnight returns for the bund and btp futures exchanged at LIFFE (London). The overnight returns of both assets are mapped onto a one-dimensional symbolic-dynamics random walk: The `bond walk'. During the considered period (October 1991 - January 1994) the bund-future market opened earlier than the btp-future one. The cross

Kihong Kim

We study the superfluid-insulator transition of a particle-hole symmetric system of long-range interacting bosons in a time-dependent random potential in two dimensions, using the momentum-shell renormalization-group method. We find a new stable fixed point with non-zero values of the parameters representing the short- and long-range interactions and disorde

K. A. Kikoin, M. N. Kiselev, A. S. Mishchenko, A. de Visser

Detailed experimental and theoretical studies of the low-temperature specific heat, magnetic susceptibility, thermal expansion and magnetostriction of the orthorhombic compound CeNiSn are presented. All anomalies observed in the thermodynamic and magnetic properties of CeNiSn are explained in a framework of a model of metallic Kondo lattice with well develop

P. Cinzano, H. -W. Rix, M. Sarzi, E. M. Corsini

We present the kinematics and photometry of the stars and of the ionized gas near the centre of the S0 galaxy NGC4036. Dynamical models based on the Jeans Equation have been constructed from the stellar data to determine the gravitational potential in which the ionized gas is expected to orbit. Inside 10'', the observed gas rotation curve falls well

C. Alcock, R. A. Allsman, D. Alves, T. S. Axelrod

This is a preliminary report on the application of Difference Image Analysis (DIA) to galactic bulge images. The aim of this analysis is to increase the sensitivity to the detection of gravitational microlensing. We discuss how the DIA technique simplifies the process of discovering microlensing events by detecting only objects which have variable flux. We i

S. Veilleux

This paper reviews the results from recent optical and near-infrared spectroscopic studies of ultraluminous infrared galaxies.

Christopher F. McKee, John H. Holliman, II

Molecular clouds are supported by thermal pressure, magnetic pressure, and turbulent pressure. Each of these can be modeled with a polytropic equation of state, so that overall the total pressure is the sum of the individual components. We model the turbulent pressure as being due to a superposition of Alfven waves. The theory of polytropes is generalized to

Cenalo Vaz

The canonical quantization of a Schwarzschild black hole yields a picture of the black hole that is shown to be equivalent to a collection of oscillators whose density of levels is commensurate with that of the statistical bootstrap model. Energy eigenstates of definite parity exhibit the Bekenstein mass spectrum, $M \sim \sqrt{\cal N} M_p$, where ${\cal N}

F. Derue, C. Afonso, C. Alard, J-N. Albert

We present the analysis of the light curves of 8.5 million stars observed during two seasons by EROS (Experience de Recherche d'Objets Sombres), in the galactic plane away from the bulge. Three stars have been found that exhibit luminosity variations compatible with gravitational microlensing effects due to unseen objects. The corresponding optical depth

Robert A. Herrmann

As of this date of this version, this monograph (part I and II) contains most of the technical results relative to the Robinson-styled nonstandard modeling of natural languages and certain associated linguistic processes such as deduction via consequence operators among other concepts. These results have direct application to the construction of the GGU-mode

Robert A. Herrmann

As of the date of this version, this monograph (parts I and II) contains all of the known technical results relative to the Robinson-styled nonstandard modeling of natural languages and certain associated linguistic processes such as deduction via consequence operators among other concepts. These results have direct application to the construction of the GGU

Yoon-Ho Kim, Maria V. Chekhova, Sergei P. Kulik, Yanhua Shih

We report a two-photon interference effect, in which the entangled photon pairs are generated from two laser pulses well-separated in time. In a single pump pulse case, interference effects did not occur in our experimental scheme. However, by introducing a second pump pulse delayed in time, quantum interference was then observed. The visibility of the inter

Renyue Cen, Jeremiah P. Ostriker

Numerical simulations of standard cosmological scenarios have now reached the degree of sophistication required to provide tentative answers to the fundamental question: Where and when were the heavy elements formed? Averaging globally, these simulations give a metallicity that increases from 1% of the solar value at $z=3$ to 20% at present. This conclusion

Yoon-Ho Kim, R. Yu, S. P. Kulik, Y. H. Shih

This paper reports a "delayed choice quantum eraser" experiment proposed by Scully and Drühl in 1982. The experimental results demonstrated the possibility of simultaneously observing both particle-like and wave-like behavior of a quantum via quantum entanglement. The which-path or both-path information of a quantum can be erased or marked by its ent

Stephen D. H. Hsu

We investigate the effect of the density-dependent proton and neutron gaps on vortex dynamics in neutron stars. We argue that the persistence of neutron star magnetic fields on timescales of $10^9$ y suggests a superconducting gap curve with local maximum at intermediate density. We discuss the implications for exotic core phenomena such as pion/kaon condens

A. B. Balantekin, W. C. Haxton

In these Canberra summer school lectures we treat a number of topical issues in neutrino astrophysics: the solar neutrino problem, including the physics of the standard solar model, helioseismology, and the possibility that the solution involves new particle physics; atmospheric neutrinos; Dirac and Majorana neutrino masses and their consequences for low-ene

J. Stachel

An Overview of the status and results from the relativistic heavy ion program at the AGS and SPS; perspective for future colliders.

F. Bentosela, R. M. Cavalcanti, P. Exner, V. A. Zagrebnov

We consider an electron with an anomalous magnetic moment g>2 confined to a plane and interacting with a nonzero magnetic field B perpendicular to the plane. We show that if B has compact support and the magnetic flux in the natural units is F\ge 0, the corresponding Pauli Hamiltonian has at least 1+[F] bound states, without making any assumptions about the

F. Ardalan

Compactification of Matrix Model on a Noncommutative torus is obtained from strings ending on D-branes with background B field. The BPS spectrum of the system and a novel SL(2,Z) symmetry are discussed.

P. A. Horváthy

The quantized magnetic flux $Φ=-4πN\sk, N=0,\pm1,...$ of non-topological vortices in the non-relativistic Chern-Simons theory is related to the topological degree of the $S^2\to S^2$ mapping defined by lifting the problem to the Riemann spheres. Regular solutions with finite degree only arise for rational functions, whose topological degree, $N$, is the comm

S. C. Bennett, C. E. Wieman

The ratio of the off-diagonal hyperfine amplitude to the tensor transition polarizability (Mhf/beta) for the 6S-7S transition in cesium has been measured. The value of beta=27.024(43)(expt)(67)(theory)a_0^3 is then obtained using an accurate semi-empirical value of Mhf. This is combined with a previous measurement of parity nonconservation in atomic cesium a

Fatimah Shojai, Ali Shojai, Mehdi Golshani

Recently, it was shown that the quantum effects of the matter, could be used to determine the conformal degree of freedom of the space-time metric. So both gravity and quantum are geometrical features. Gravity determines the causal structure of the space-time, while quantum determines the scale of the space-time. In this article, it is shown that it is possi

Fatimah Shojai, Ali Shojai, Mehdi Golshani

Recently\cite{BQG}, it was shown that quantum effects of matter could be identified with the conformal degree of freedom of the space-time metric. Accordingly, one can introduce quantum effects either by making a scale transformation (i.e. changing the metric), or by making a conformal transformation (i.e. changing all physical quantities). These two ways ar

Ali Shojai, Fatimah Shojai, Mehdi Golshani

It is shown explicitly that in the framework of Bohmian quantum gravity, the equations of motion of the space-time metric are Einstein's equations plus some quantum corrections. It is observed that these corrections are not covariant. So that in the framework of Bohmian quantum gravity the general covariance principle breaks down at the individual level.

Fatimah Shojai, Mehdi Golshani

It is shown explicitly that in the framework of Bohmian quantum gravity, the equations of motion of the space-time metric are Einstein's equations plus some quantum corrections. It is observed that these corrections are not covariant. So that in the framework of Bohmian quantum gravity the general covariance principle breaks down at the individual level.

Sergey V. Sushkov

We analyse in details the problems which one faces trying to quantize a scalar field on the spacelike cylinder being the simple example of a spacetime with closed timelike curves. Our analysis brings to light the fact that the usual set of positive and negative frequency solutions of the field equation turns out to be incomplete. The consequence of this fact

A. S. Alexandrov, A. M. Bratkovsky

We show that the current carrier density collapse in doped manganites, which results from bipolaron formation in the paramagnetic phase, leads to a colossal change of the optical conductivity in an external magnetic field at temperatures close to the ferromagnetic transition. As with the colossal magnetoresistance (CMR) itself, the corresponding magnetooptic

Angel Rubio

We present a theoretical study of the role of the local environment in the electronic properties of carbon nanotubes: isolated single- and multi-wall nanotubes, nanotube-ropes, tubes supported on gold and cutted to finite length. Interaction with the substrate or with other tubes does not alter the scanning-tunneling-microscopy (STM) patterns observed for is

Simon Portegies Zwart

A phenomenological model is presented to explain the light curves of gamma-ray bursts. Gamma-rays are produced in a narrow beam which sweeps through space due to the precession of a slaved accretion disc. The light curve expected from such a precessing luminosity cone can explain the complex temporal behavior of bright gamma-ray bursts.

Hugo Martel, Richard Matzner

We have simulated the formation and evolution of large-scale structure in the universe, for 68 different COBE-normalized cosmological models. For each cosmological model, we have performed between 1 and 3 simulations, for a total of 160 simulations. This constitutes the largest database of cosmological simulations ever assembled, and the largest cosmological

M. S. Nanda Kumar, B. G. Anandarao, C. J. Davis

We report the detection of the H2 v=1-0 S(1) line at 2.122um, from RNO91 in the L43 dark cloud, which is known to be a T Tauri star surrounded by a 1700AU disk structure (containing ices) and a weak outflow. The non-detection of the H2 v=2-1 S(1) line at 2.247um suggests shock excitation rather than fluorescence. The emission is extended spatially up to 9arc

L. Tenorio, A. H. Jaffe, S. Hanany, C. H. Lineweaver

We consider wavelets as a tool to perform a variety of tasks in the context of analyzing cosmic microwave background (CMB) maps. Using Spherical Haar Wavelets we define a position and angular-scale-dependent measure of power that can be used to assess the existence of spatial structure. We apply planar Daubechies wavelets for the identification and removal o

W. S. Paciesas, C. A. Meegan, G. N. Pendleton, M. S. Briggs

The Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) has triggered on 1637 cosmic gamma-ray bursts between 1991 April 19 and 1996 August 29. These events constitute the Fourth BATSE burst catalog. The current version (4Br) has been revised from the version first circulated on CD-ROM in September 1997 (4B) to include i

Julian Borrill

Ongoing observations of the Cosmic Microwave Background, such as the MAXIMA and BOOMERanG projects, are providing datasets of unprecedented quality and ever-increasing size. Exact analysis of the data they produce is a serious computational challenge, currently scaling as the number of sky pixels squared in memory and cubed in time. Here we discuss the origi

Tristan Hubsch

The Hilbert spaces of supersymmetric systems admit symmetries which are often related to the topology and geometry of the (target) field-space. Here, we study certain (2,2)-supersymmetric systems in 2-dimensional spacetime which are closely related to superstring models. They all turn out to posess some hitherto unexploited and geometrically and topologicall

Pippa Storey, Maxim Olshanii

A trajectory approach is taken to the hydrodynamical treatment of collective excitations of a Bose-Einstein condensate in a harmonic trap. The excitations induced by linear deformations of the trap are shown to constitute a broad class of solutions that can be fully described by a simple nonlinear matrix equation. An exact closed-form expression is obtained

R. Weht, A. B. Shick, W. E. Pickett

We review the reasons that make superconductivity unlikely to arise in a ferromagnet. Then, in light of the report by Tallon and collaborators that RuSr2GdCu2O8 becomes superconducting at approximately 35 K which is well below the Curie temperature of 132 K, we consider whether the objections really apply to this compound. Our considerations are supported by

N. A. Obers, B. Pioline

We investigate the relevance of Eisenstein series for representing certain $G(Z)$-invariant string theory amplitudes which receive corrections from BPS states only. $G(Z)$ may stand for any of the mapping class, T-duality and U-duality groups $Sl(d,Z)$, $SO(d,d,Z)$ or $E_{d+1(d+1)}(Z)$ respectively. Using $G(Z)$-invariant mass formulae, we construct invarian

J. R. Forshaw, G. Kerley, G. Shaw

We report on a successful attempt to extract the cross-section for the high-energy scattering of colour dipoles of fixed transverse size off protons using electroproduction and photoproduction total cross-section data, subject to the constraint provided by the ratio of the overall photon dissociation cross-section to the total cross-section.

R. Bertle, M. Faber, J. Greensite, S. Olejnik

We investigate the structure of center vortices in maximal center gauge of SU(2) lattice gauge theory at zero and finite temperature. In center projection the vortices (called P-vortices) form connected two dimensional surfaces on the dual four-dimensional lattice. At zero temperature we find, in agreement with the area law behaviour of Wilson loops, that mo

Carlos M. Gutierrez, Rafael Rebolo, Robert A. Watson, Rod D. Davies

The results of the Tenerife Cosmic Microwave Background (CMB) experiments are presented. These observations cover 5000 and 6500 square degrees on the sky at 10 and 15 GHz respectively centred around Dec.~ +35 degrees. The experiments are sensitive to multipoles l=10-30 which corresponds to the Sachs-Wolfe plateau of the CMB power spectra. The sensitivity of

M. Gluck, E. Reya, I. Schienbein

The parton content of real (P^2=0) and virtual (P^2\neq 0) transverse photons γ(P^2) is expressed in terms of perturbative pointlike and nonperturbative hadronic (VMD) components, employing recently updated parton distributions of pions and protons. The resulting parameter-free and perturbatively stable LO and NLO parton densities f^{γ(P^2)}(x,Q^2) are smoot

Thomas Bauer

Seshadri constants are local invariants, introduced by Demailly, which measure the local positivity of ample line bundles. Recent interest in Seshadri constants stems on the one hand from the fact that bounds on Seshadri constants yield, via vanishing theorems, bounds on the number of points and jets that adjoint linear series separate. On the other hand it

Kristinn Johnsen, Antti-Pekka Jauho

We theoretically study nonlinear optics of excitons under intense THz irradiation. In particular, the linear near infrared absorption and resonantly enhanced nonlinear sideband generation are described. We predict a rich structure in the spectra which can be interpreted in terms of the quasienergy spectrum of the exciton, via a remarkably transparent express

Yasunori Nomura, Takashi Sugimoto

We investigate the SO(10) grand unified model with generation flipping. The model contains one extra matter multiplet $ψ(10)$ and it mixes with the usual matter multiplets $ψ_i(16)$ when the SO(10) is broken down to SU(5). We find the parameter region of the model in which the observed quark masses and mixings are well reproduced. The resulting parameter reg

J. R. Buck, S. J. van Enk, Christopher A. Fuchs

We demonstrate superadditivity in the communication capacity of a binary alphabet consisting of two nonorthogonal quantum states. For this scheme, collective decoding is performed two transmissions at a time. This improves upon the previous schemes of Sasaki et al. [Phys. Rev. A 58, 146 (1998)] where superadditivity was not achieved until a decoding of three

S. F. Tuan

The recent BES Collaboration data on $\psi' \ra PV$, particularly the isospin violating mode $\psi' \ra \pi^0 \omega^0$ and finding of a finite number for $B(\psi' \ra K^{*0}\bar{K}^0)$, enable us now to deal more precisely about the challenges to theory concerning this extraordinary and remarkable so called $\rho - \pi$ Puzzle of $J/\psi$ and $\psi'$ Decays

A. Kehagias, K. Sfetsos

We present a new type-IIB supergravity vacuum that describes the strong coupling regime of a non-supersymmetric gauge theory. The latter has a running coupling such that the theory becomes asymptotically free in the ultraviolet. It also has a running theta angle due to a non-vanishing axion field in the supergravity solution. We also present a worm-hole solu

A. A. Suzko

A discrete version of the two-dimensional inverse scattering problem is considered. On this basis, algebraic transformations for the two-dimensional finite-difference Schredinger equation are elaborated.

Anders Sorensen, Klaus Molmer

We show that by displacing two optical lattices with respect to each other, we may produce interactions similar to the ones describing ferro-magnetism in condensed matter physics. We also show that particularly simple choices of the interaction lead to spin-squeezing, which may be used to improve the sensitivity of atomic clocks. Spin-squeezing is generated

S. A. Gurvitz

We show that long standing debates on the collapse and the role of the observer in quantum mechanics can be resolved experimentally via a nondistructive continuous monitoring of a single quantum system. An example of such a system, coupled with the point-contact detector is presented. The detailed quantum mechanical analysis of the entire system (including t

Arno Schindlmayr

We comment on a recent article by H. L. Neal [Am. J. Phys. 66, 512 (1998)], in which an analytic expression for the Hohenberg-Kohn functional was derived for one-dimensional two-particle systems with the harmonic interaction. We argue that the functional given by Neal is not exact but really constitutes an approximation in the same spirit as the local-densit

P. -G. Reinhard, D. J. Dean, W. Nazarewicz, J. Dobaczewski

The phenomenon of shape coexistence is discussed within the self-consistent Hartree-Fock method and the nuclear shell model. The occurrence of the coexisting configurations with different intrinsic shapes is traced back to the properties of the effective Hamiltonian.

M Braun, L L Howell, S A Sofianos, W Sandhas

Differential cross sections for the electro-disintegration process $e + {^4He} \longrightarrow {^3H}+ p + e'$ are calculated, using a model in which the final state interaction is included by means of a nucleon-nucleus (3+1) potential constructed via Marchenko inversion. The required bound-state wave functions are calculated within the integrodifferentia

S. T. Belyaev, A. L. Barabanov

General theory of neutron scattering (elastic and inelastic) is presented. It is applicable for the whole domain of slow neutrons and includes as limiting cases existing theories for thermal and cold neutrons and for elastic scattering of UCN. New expression for inelastic scattering cross section for UCN is proposed. It differs from the usually used by prope

S. A. Coon, H. K. Han, J. Carlson, B. F. Gibson

We calculate the contributions of a particular set of charge asymmetric $ΛN$ interactions to the difference of the separation energies of $^4_Λ$He and $^4_Λ$H. We use perturbation theory with four-body variational Monte Carlo wave functions calculated from a Hamiltonian with two- and three-hadron forces. We compare with the data and with an earlier calculati

Z. S. Wang, C. Fuchs, Amand Faessler, T. Gross-Boelting

The squeeze-out phenomenon of $K^+$ and $K^-$ mesons, i.e. the azimuthal asymmetry of $K^+$ and $K^-$ mesons emitted at midrapidity in heavy ion reactions, is investigated for beam energies of 1-2 A.GeV. It is found that the squeeze-out signal is strongly affected by in-medium potentials of these mesons. The repulsive $K^+$-nucleus potential gives rise to a

WA98 Collaboration, M. M. Aggarwal et al

The multiplicity of inclusive photons has been measured on an event-by-event basis for 158 AGeV Pb induced reactions on Ni, Nb, and Pb targets. The systematics of the pseudorapidity densities at midrapidity (rho_max) and the width of the pseudorapidity distributions have been studied for varying centralities for these collisions. A power law fit to the photo

B. K. Nandi, T. K. Nayak, B. Mohanty, D. P. Mahapatra

A new method to search for localized domains of disoriented chiral condensates (DCC) has been proposed by utilising the (eta-phi) phase space distributions of charged particles and photons. Using the discrete wavelet transformation (DWT) analysis technique, it has been found that the presence of DCC domains broadens the distribution of wavelet coefficients i

A. L. De Paoli, M. A. Estevez, M. C. Rocca, H. Vucetich

In this work we show that it is possible to extend analitically, and with the use of tempered ultradistributions, the pseudonorm defined by T. Berggren for Gamow states. We define this pseudonorm for all states determined by the zeros of the Jost function for any short range potential. As an example we study the s-states corresponding to the square well pote

Romeo Brunetti, Klaus Fredenhagen

We present a perturbative construction of interacting quantum field theories on any smooth globally hyperbolic manifold. We develop a purely local version of the Stueckelberg-Bogoliubov-Epstein-Glaser method of renormalization using techniques from microlocal analysis. As byproducts, we describe a perturbative construction of local algebras of observables, p

N. N. Chaus

Instead of a linear system of equations for a free electromagnetic field, we propose a nonlinear system of equations. The classical electrodynamics is preseved. The appeared solutions (the electromagnetic fields) having photon properties. The theory posits the vacuum is a physical medium. The most important problems of relativistic interaction of interpenetr

N. N. Chaus

We construct a general relativity formula for the law of gravity for material bodies. The formula contains three numeric parameters that are to be determined experimentally. If they are chosen from symmetry considerations, then the theory that appears is close to the theory of electrodynamics: the gravitational field is given by two vector fields, one can wr

Hanno Hammer

We generalize the concept of global moment maps to local moment maps, whose different branches are labelled by the elements of the fundamental group of the underlying symplectic manifold. These branches can be smoothly glued together by employing fundamental-group-valued \u Cech cocycles on the phase space. In the course of this work we prove a couple of the

Martin Scharlemann, Jennifer Schultens

We analyze how a family of essential annuli in a compact 3-manifold will induce, from a strongly irreducible generalized Heegaard splitting of the ambient manifold, generalized Heegaard splittings of the complementary components. There are specific applications to the subadditivity of tunnel number of knots, improving somewhat bounds of Kowng. For example, i

Arjeh M. Cohen, Anja Steinbach, Rosane Ushirobira, David B. Wales

We study Lie algebras generated by extremal elements (i.e., elements spanning inner ideals of L) over a field of characteristic distinct from 2. We prove that any Lie algebra generated by a finite number of extremal elements is finite dimensional. The minimal number of extremal generators for the Lie algebras of type An, Bn (n>2), Cn (n>1), Dn (n>3), En (n=6

James W. Anderson, Richard D. Canary

Troels Jorgensen conjectured that the algebraic and geometric limits of an algebraically convergent sequence of isomorphic Kleinian groups agree if there are no new parabolics in the algebraic limit. We prove that this conjecture holds in 'most' cases. In particular, we show that it holds when the domain of discontinuity of the algebraic limit of suc

James W. Anderson, Richard D. Canary

We introduce the notion of the visual core of a hyperbolic 3-manifold N and explore its basic properties. The visual core can be thought of as a harmonic analysis analogue of the convex core. We investigate circumstances in which the visual core of a cover N' of N embeds under the covering map from N' to N. We apply this analysis to convergent sequen

J. -M. Drézet

Let E,F be algebraic vector bundles on a projective algebraic variety. Let G=Aut(E)XAut(F), acting on W=Hom(E,F). In this paper new methods of construction of algebraic quotients of open G-invariant subsets of W are studied. This is done by associating to W a new space of morphisms W'=Hom(E',F') (with group G'=Aut(E')XAut(F')) in such

J. Ginibre, G. Velo

We study the theory of scattering for a class of Hartree type equations with long range interactions in space dimension n > 2, including Hartree equations with potential V(x) = lambda |x|^{- gamma}. For 0 < gamma < or =1 we prove the existence of modified wave operators with no size restriction on the data and we determine the asymptotic behaviour in time of

A. Beauville

We discuss a particular class of rational Gorenstein singularities, which we call symplectic. A normal variety V has symplectic singularities if its smooth part carries a closed symplectic 2-form whose pull-back in any resolution X --> V extends to a holomorphic 2-form on X . Our main result is the classification of isolated symplectic singularities with smo

Boris Tsirelson

A two-dimensional array of independent random signs produces coalescing random walks. The position of the walk, starting at the origin, after N steps is a highly nonlinear, noise sensitive function of the signs. A typical term of its Fourier-Walsh expansion involves the product of about square roof of N signs.

Su-Win Yang

For an integral homology 3-sphere embedded asymptotically flatly in an Euclidean space, we find a natural framing extending the standard trivialization on the asymptotically flat part.

Kazuhiko Yamaki

In this paper, we prove the Effective Bogomolov&#39;s Conjecture for hyperelliptic curves defined over function fields.

C. Klimcik

It is shown that noncommutative geometry is a nonperturbative regulator which can manifestly preserve a space supersymmetry and a supergauge symmetry while keeping only a finite number of degrees of freedom in a theory. The simplest N=1 case of an U(1) supergauge theory on the sphere is worked out in detail.

K. Koepsell, H. Nicolai, H. Samtleben

We present the algebraic framework for the quantization of the classical bosonic charge algebra of maximally extended (N=16) supergravity in two dimensions, thereby taking the first steps towards an exact quantization of this model. At the core of our construction is the Yangian algebra $Y(e_8)$ whose RTT presentation we discuss in detail. The full symmetry

S. F. Tuan

Recent preliminary evidence for a $D \bar{D}$ state $χ(3.86)$ raises extremely interesting implications for theoretical models, particularly those currently in vogue, e.g. the flux tube model and a molecular charmonium picture. We examine the experimental consequences as well as the possible unveiling of a strata of C-exotic states in heavy quarkonia systems

T. Blazek, S. Raby, K. Tobe

In this letter we present a predictive SO(10) SUSY GUT with flavor symmetry U(2) \times U(1) which has several nice features. We are able to fit fermion masses and mixing angles, including recent neutrino data, with 9 parameters in the charged fermion sector and 4 in the neutrino sector. The flavor symmetry plays a preeminent role -- (i) The model is &#34;na

M. Bergmann, W. Schroers, N. G. Stefanis

The anomalous dimensions of trilinear-quark operators are calculated at leading twist $t=3$ by diagonalizing the one-gluon exchange kernel of the renormalization-group type evolution equation for the nucleon distribution amplitude. This is done within a symmetrized basis of Appell polynomials of maximum degree $M$ for $M\gg 1$ (up to order 400) by combining

A. Capella, E. G. Ferreiro, A. B. Kaidalov

We apply dynamical string models of heavy-ions collisions at high energies to the analysis of event-by-event fluctuations. Main attention is devoted to a new variable proposed to study &#34;equilibration&#34; in heavy-ions collisions. Recent results of the NA49 collaboration at CERN SPS are compared with predictions of the Quark-Gluon String Model (QGSM), wh

Sergey L. Cherkas

It is shown that two ways of the description of the 1/2-spin precession in a circularly polarized electromagnetic wave: on the basis of the Bargmann-Michel-Telegdi equation and on the basis of the Dirac equation with Pauli term give the same result in the second order on the wave&#39;s field for arbitrary wave length.

Howard Baer, P. G. Mercadante, Xerxes Tata, Yili Wang

We examine signals for sparticle production at the Tevatron within the framework of gauge mediated supersymmetry breaking models for four different model lines, each of which leads to qualitatively different signatures. We identify cuts to enhance the signal above Standard Model backgrounds, and use ISAJET to evaluate the SUSY reach of experiments at the Fer

Ting-Wai Chiu, Tung-Han Hsieh

We evaluate the axial anomaly for the general Ginsparg-Wilson fermion operator $D = D_c (\Id + R D_c)^{-1}$ with $R = r \Id$. For any chirally symmetric $D_c$ which in the free fermion limit, is free of species doubling and behaves like $i γ_μp_μ$ as $p \to 0$, the axial anomaly $\tr[γ_5 (R D) (x,x)]$ for U(1) lattice gauge theory with single fermion flavor

J. William Gary

A summary is given of some recent QCD results from LEP. For LEP-2, the topics include event shape measurements, determinations of the strong coupling constant, and measurements of the charged particle multiplicity distribution at the recently completed run at 189 GeV. For LEP-1, the topics presented are a test of the flavor independence of the strong couplin

Y. A. Kulchitsky, V. B. Vinogradov

The analytical representation of the longitudinal hadronic shower development from the face of a calorimeter is presented and compared with experimental data. The suggested formula is particularly useful at designing, testing and calibration of huge calorimeter complex like in ATLAS at LHC.

R. Coxe

A search for CP(T) violation is performed and the fractional difference between the $b$ and $\bar b$ hadron lifetimes is measured using reconstructed secondary vertices in inclusive B hadron decays culled from 3.1 million $Z^0 \to q \bar q$ events. The data were collected by the OPAL experiment at the LEP collider at CERN at $\sqrt{s} \approx 91$ GeV from 19

Carlo Rovelli

This is a contribution to a book on quantum gravity and philosophy. I discuss nature and origin of the problem of quantum gravity. I examine the knowledge that may guide us in addressing this problem, and the reliability of such knowledge. In particular, I discuss the subtle modification of the notions of space and time engendered by general relativity, and

H. -J. Schmidt, F. Homann

We discuss numerical solutions of Einstein&#39;s field equation describing static, spherically symmetric conglomerations of a photon gas. These equations imply a back reaction of the metric on the energy density of the photon gas according to Tolman&#39;s equation. The 3-fold of solutions corresponds to a class of physically different solutions which is para