May 2002 arXiv papers — page 14

P. K. Panda, M. E. Bracco, M. Chiapparini, E. Conte

Excluded volume effects are incorporated in the quark meson coupling model to take into account in a phenomenological way the hard core repulsion of the nuclear force. The formalism employed is thermodynamically consistent and does not violate causality. The effects of the excluded volume on in-medium nucleon properties and the nuclear matter equation of sta

D. Blaschke, D. Sedrakian

We investigate magnetic properties of color superconducting quark matter within a Ginzburg-Landau approach. The simultaneous coupling of the quark fields to gluonic and electromagnetic gauge fields leads to rotated electromagnetism with a massive (Higgsed) and a massless photon-gluon field. We derive the Ginzburg-Landau equations for superconducting quark ma

Daniel Smania

In this short note, we give a sketch of a new proof of the exponential contraction of the Feigenbaum renormalization operator in the hybrid class of the Feigenbaum fixed point. The proof uses the non existence of invariant line fields in the Feigenbaum tower (C. McMullen), the topological convergence (D. Sullivan), and a new infinitesimal argument, different

Gene Cooperman

This work presents a new, simple O(log^2|G|) algorithm, the Fibonacci cube algorithm, for producing random group elements in black box groups. After the initial O(log^2|G|) group operations, epsilon-uniform random elements are produced using O((log 1/epsilon)log|G|) operations each. This is the first major advance over the ten year old result of Babai [Babai

Masaki Kashiwara, Teresa Monteiro Fernandes, Pierre Schapira

Using a result of J-M. Bony, we prove the weak involutivity of truncated microsupports. More precisely, given a sheaf $F$ on a real manifold and an integer $k$, if two functions vanish on the truncated microsupport $Ss_k(F)$, then so does their Poisson bracket.

Davoud Kamani

In this paper we study U(1) gauge transformations on the space-time coordinates and on the background fields $g_{μν}$ and $ϕ$. For some special gauge functions, gauged coordinates and gauged U(1) field are equivalent to the rotated coordinates and rotated gauge field. We find gauge transformations that are symmetries of the string action. Also we obtain gene

V. V. Braguta, A. E. Chalov, A. A. Likhoded

The muon transverse polarization in the $K^+ \to μ^+ νγ$ process induced by the electromagnetic final state interaction is calculated in the framework of Standard Model. It is shown that one loop contributions lead to a nonvanihing muon transverse polarization. The value of the muon transverse polarization averaged over the kinematical region of $E_γ\geq 20$

E. Iancu, K. Itakura, L. McLerran

Geometric scaling is a novel scaling phenomenon observed in deep inelastic scattering at small x: the total virtual photon-proton cross section depends upon the two kinematical variables Q^2 and x only via their combination Q^2 R_0^2(x), with R_0^2(x) \propto x^λ. At sufficiently low Q^2, below the saturation scale Q_s^2(x) (a few GeV^2), this phenomenon fin

Lars Andersson

I describe the conformal method for constructing solutions of the hyperboloidal constraint equations as well as the conditions needed on the free data in order to have regularity up to boundary for the solutions to the constraint equations. A brief discussion of the Einstein evolution equations in the unphysical setting is given.

Brian D. Baker

We propose a method of determining solutions to the constraint equations of General Relativity approximately describing binary black holes in quasi-stationary circular orbits. Black holes with arbitrary linear momenta are constructed in the manner suggested by Brandt and Brugmann. The quasi-stationary circular orbits are determined by local minima in the ADM

S. Fekete, S. Khuller, M. Klemmstein, B. Raghavachari

The problem considered is the following. Given a graph with edge weights satisfying the triangle inequality, and a degree bound for each vertex, compute a low-weight spanning tree such that the degree of each vertex is at most its specified bound. The problem is NP-hard (it generalizes Traveling Salesman (TSP)). This paper describes a network-flow heuristic

Mordecai Golin, Neal E. Young

Describes a near-linear-time algorithm for a variant of Huffman coding, in which the letters may have non-uniform lengths (as in Morse code), but with the restriction that each word to be encoded has equal probability. [See also ``Huffman Coding with Unequal Letter Costs'' (2002).]

Samir Khuller, Balaji Raghavachari, Neal E. Young

This paper give a simple linear-time algorithm that, given a weighted digraph, finds a spanning tree that simultaneously approximates a shortest-path tree and a minimum spanning tree. The algorithm provides a continuous trade-off: given the two trees and epsilon > 0, the algorithm returns a spanning tree in which the distance between any vertex and the root

Neal E. Young

This paper has two results. The first is based on the surprising observation that the well-known ``least-recently-used'' paging algorithm and the ``balance'' algorithm for weighted caching are linear-programming primal-dual algorithms. This observation leads to a strategy (called ``Greedy-Dual'') that generalizes them both and has an

Samir Khuller, Balaji Raghavachari, Neal E. Young

The degree-d spanning tree problem asks for a minimum-weight spanning tree in which the degree of each vertex is at most d. When d=2 the problem is TSP, and in this case, the well-known Christofides algorithm provides a 1.5-approximation algorithm (assuming the edge weights satisfy the triangle inequality). In 1984, Christos Papadimitriou and Umesh Vazirani

S. L. Hakimi, E. Schmeichel, Neal E. Young

The paper focuses on two problems: (i) how to orient the edges of an undirected graph in order to maximize the number of ordered vertex pairs (x,y) such that there is a directed path from x to y, and (ii) how to orient the edges so as to minimize the number of such pairs. The paper describes a quadratic-time algorithm for the first problem, and a proof that

Neal Young, Robert Tarjan, James Orlin

The parametric shortest path problem is to find the shortest paths in graph where the edge costs are of the form w_ij+lambda where each w_ij is constant and lambda is a parameter that varies. The problem is to find shortest path trees for every possible value of lambda. The minimum-balance problem is to find a ``weighting'' of the vertices so that ad

Samir Khuller, Balaji Raghavachari, Neal E. Young

The MEG (minimum equivalent graph) problem is, given a directed graph, to find a small subset of the edges that maintains all reachability relations between nodes. The problem is NP-hard. This paper gives an approximation algorithm with performance guarantee of pi^2/6 ~ 1.64. The algorithm and its analysis are based on the simple idea of contracting long cyc

Neal E. Young

Mixed packing and covering problems are problems that can be formulated as linear programs using only non-negative coefficients. Examples include multicommodity network flow, the Held-Karp lower bound on TSP, fractional relaxations of set cover, bin-packing, knapsack, scheduling problems, minimum-weight triangulation, etc. This paper gives approximation algo

Amos Fiat, Richard Karp, Mike Luby, Lyle McGeoch

The paging problem is that of deciding which pages to keep in a memory of k pages in order to minimize the number of page faults. This paper introduces the marking algorithm, a simple randomized on-line algorithm for the paging problem, and gives a proof that its performance guarantee (competitive ratio) is O(log k). In contrast, no deterministic on-line alg

Samir Khuller, Uzi Vishkin, Neal Young

The paper describes a simple deterministic parallel/distributed (2+epsilon)-approximation algorithm for the minimum-weight vertex-cover problem and its dual (edge/element packing).

Neal E. Young

Randomized rounding is a standard method, based on the probabilistic method, for designing combinatorial approximation algorithms. In Raghavan's seminal paper introducing the method (1988), he writes: "The time taken to solve the linear program relaxations of the integer programs dominates the net running time theoretically (and, most likely, in prac

Richard Lipton, Neal E. Young

Von Neumann's Min-Max Theorem guarantees that each player of a zero-sum matrix game has an optimal mixed strategy. This paper gives an elementary proof that each player has a near-optimal mixed strategy that chooses uniformly at random from a multiset of pure strategies of size logarithmic in the number of pure strategies available to the opponent. For e

Robert Lupton, Miller Maley, Neal Young

The goal of the Sloan Digital Sky Survey is ``to map in detail one-quarter of the entire sky, determining the positions and absolute brightnesses of more than 100 million celestial objects''. The survey will be performed by taking ``snapshots'' through a large telescope. Each snapshot can capture up to 600 objects from a small circle of the s

Neal E. Young

In the on-line file-caching problem problem, the input is a sequence of requests for files, given on-line (one at a time). Each file has a non-negative size and a non-negative retrieval cost. The problem is to decide which files to keep in a fixed-size cache so as to minimize the sum of the retrieval costs for files that are not in the cache when requested.

Laszlo Lovasz, Neal E. Young

This report presents notes from the first eight lectures of the class Many Models of Complexity taught by Laszlo Lovasz at Princeton University in the fall of 1990. The topic is evasiveness of graph properties: given a graph property, how many edges of the graph an algorithm must check in the worst case before it knows whether the property holds.

A. V. Nikolaev, K. H. Michel

Starting from a multipole expansion of intra- molecular Coulomb interactions, we present configuration interaction calculations of the molecular energy terms of the hole configurations hu^m, m=2-5, of C60^{m+} cations, of the electron configurations t1u^n, n=2-4, of the C60^{n-} anions, and of the exciton configurations (hu^+ t1u^-), (hu^+ t1g^-) of the neut

S. Yoshida, N. Ihara, K. Wada

The path probability method (PPM) in the tetrahedron-cactus approximation is applied to the Slater-Takagi model with dipole-dipole interaction for KH2PO4-type hydrogen-bonded ferroelectric crystals in order to derive a small dip structure in the real part of dynamical susceptibility observed at the transition temperature Tc. The dip structure can be ascribed

A. G. Groshev, S. G. Novokshonov

The spatial non-locality (dispersion) of the transport equations results in a nonlinear dependence of the voltage drop $U$ on the distance between the points of measuring. Therefore the results of the usual two-probe measurements of the conductivity depend essentially on the relation between the sample linear size $L$ and the spatial dispersion scale $R$ of

Giorgio Parisi

In this talk I will presente the physical meaning of replica symmetry breaking stressing the physical concepts. After introducing the theoretical framework and the experimental evidence for replica symmetry breaking, I will describe some of the basic ideas using a probabilistic language. The predictions for off-equilibrium dynamics will be shortly outlined.

M. J. Stock, J. Stock, J. Garcia, N. Sanchez

The method developed by Stock and Stock (1999) for stars of spectral types A to K to derive absolute magnitudes and intrinsic colors from the equivalent widths of absorption lines in stellar spectra is extended to B-type stars. Spectra of this type of stars for which the Hipparcos Catalogue gives parallaxes with an error of less than 20% were observed with t

N. Kleeorin, I. Rogachevskii

The evolution of the magnetic helicity tensor for a nonzero mean magnetic field and for large magnetic Reynolds numbers in an anisotropic turbulence is studied. It is shown that the isotropic and anisotropic parts of the magnetic helicity tensor have different characteristic times of evolution. The time of variation of the isotropic part of the magnetic heli

I. Aretxaga, D. H. Hughes, E. L. Chapin, E. Gaztanaga

In this paper we apply our Monte-Carlo photometric-redshift technique, introduced in paper I (Hughes et al. 2002), to the multi-wavelength data available for 77 galaxies selected at 850um and 1.25mm. We calculate a probability distribution for the redshift of each galaxy, which includes a detailed treatment of the observational errors and uncertainties in th

R. C. Lamb, D. W. Fox, D. J. Macomb, T. A. Prince

We report the serendipitous detection of a previously unreported pulsar from the direction of the Small Magellanic Cloud using data from the CHANDRA X-Ray Observatory. Because of the luminosity of about 1.5x10^35 ergs/s, its near lack of variability for more than 20 years, and its soft spectrum we propose that it is an anomalous X-ray pulsar (AXP). Data from

Simon C. O. Glover, Peter W. J. L. Brand

The first generation of stars (commonly known as population III) are expected to form in low-mass protogalaxies in which molecular hydrogen is the dominant coolant. Radiation from these stars will rapidly build up an extragalactic ultraviolet background capable of photodissociating H2, and it is widely believed that this background will suppress further star

A. R. P. Rau, R. A. Wendell

Dissipation and decoherence, and the evolution from pure to mixed states in quantum physics are handled through master equations for the density matrix. By embedding elements of this matrix in a higher-dimensional Liouville-Bloch equation, the methods of unitary integration are adapted to solve for the density matrix as a function of time, including the non-

Oren Bergman, Matthias R. Gaberdiel, Michael B. Green

The cylinder diagrams that determine the static interactions between pairs of Dp-branes in the type IIB plane wave background are evaluated. The resulting expressions are elegant generalizations of the flat-space formulae that depend on the value of the Ramond-Ramond flux of the background in a non-trivial manner. The closed-string and open-string descriptio

Christopher R. Gelino, Mark S. Marley, Jon A. Holtzman, Andrew S. Ackerman

We report on the results of an I-band photometric variability survey of eighteen L dwarfs. We find that seven exhibit statistically significant variations above the 95.4% confidence level with root-mean-square scatter (including photometric errors) between 0.010 and 0.083 mag. Another five targets have variability probabilities ~80%, suggesting that these ar

F. Baldovin, A. Robledo

We uncover the dynamics at the chaos threshold $μ_{\infty}$ of the logistic map and find it consists of trajectories made of intertwined power laws that reproduce the entire period-doubling cascade that occurs for $μ<μ_{\infty}$. We corroborate this structure analytically via the Feigenbaum renormalization group (RG) transformation and find that the sensitiv

Katherine Freese, William H. Kinney

The ultimate fate of life in a universe with accelerated expansion is considered. Previous work showed that life cannot go on indefinitely in a universe dominated by a cosmological constant. In this paper we consider instead other models of acceleration (including quintessence and Cardassian expansion). We find that it is possible in these cosmologies for li

Alan J. Bray, Richard A. Blythe

We consider a diffusing particle, with diffusion constant D&#39;, moving in one dimension in an infinite sea of noninteracting mobile traps with diffusion constant D and density rho. We show that the asymptotic behavior of the survival probability, P(t), is given by P(t) ~ exp[-4 rho(Dt/pi)^{1/2}], independent of D&#39;. The result comes from obtaining upper

Sergei Maslov, Kim Sneppen, Alexei Zaliznyak

A general scheme for detecting and analyzing topological patterns in large complex networks is presented. In this scheme the network in question is compared with its properly randomized version that preserves some of its low-level topological properties. Statistically significant deviation of any measurable property of a network from this null model likely r

Sudipta Mukherji, Marco Peloso

We consider a D3-brane as boundary of a five dimensional charged anti de Sitter black hole. We show that the charge of the black hole induces a regular cosmological evolution for the scale factor of the brane, with a smooth transition between a contracting and an eventual expanding phase. Simple analytical solutions can be obtained in the case of a vanishing

Charles Frohman, Joanna Kania-Bartoszynska

A new state-sum formula for the evaluation of the Yang-Mills measure in the Kauffman bracket skein algebra of a closed surface is derived. The formula extends the Kauffman bracket to diagrams that lie in surfaces other than the plane. It also extends Turaev&#39;s shadow world invariant of links in a circle bundle over a surface away from roots of unity. The

L. L. Salcedo

The multiscattering problem is studied in the matrix density formalism. We study how to isolate the quasi-classical degrees of freedom in order to connect with a cascade approach. The different problems that arise, as well as their possible solutions, are discussed and exemplified with a pion-nucleus model.

Fiorenzo Bastianelli, Andrea Zirotti

We analyze the worldline formalism in the presence of a gravitational background. In the worldline formalism a path integral is used to quantize the worldline coordinates of the particles. Contrary to the simpler cases of scalar and vector backgrounds, external gravity requires a precise definition of the ultraviolet regularization of the path integral. Taki

V. K. Dubrovich, A. T. Bajkova

The CMBR spectral-spatial fluctuations (SSF) formed in early Universe during the Dark Ages are considered. Main attention is focused on the narrow-band spectral properties of the SSF. Based on these properties we propose to use a differential method in order to search for these fluctuations. Description of the method is given.

Steen H. Hansen, Sergio Pastor, Dmitry V. Semikoz

We discuss a new method of finding the cluster temperatures which is independent of distance and therefore very useful for distant clusters. The hot gas of electrons in clusters of galaxies scatters and distorts the cosmic microwave background radiation in a well determined way. This Sunyaev-Zel&#39;dovich (SZ) effect is a useful tool for extracting informat

A. T. Alan, A. Senol, A. T. Tasci

CP violating effects in the single top quark production via flavour changing neutral current (FCNC) reactions $e^+e^- ->t bar{q}$ and $e^+e^- ->bar{t}q$ (here $q$ refers to charm and up quarks) are studied. The effective Lagrangian description of the FCNC interactions is used. A numerical analysis is performed for some next linear colliders. CP violating asy

C. Ospelkaus, U. Rasbach, A. Weis

We have measured the strongly suppressed electric tensor polarizability of the Cs ground state using an optical pump-probe technique in a thermal atomic beam. The result agrees with a previous measurement and confirms the long-standing discrepancy with a theoretical value. The anticipated future reduction of the total uncertainty to the 1% level makes this q

Heinrich Päs, Thomas J. Weiler

Absolute neutrino masses provide a key to physics beyond the standard model. We discuss the impact of absolute neutrinos masses on physics beyond the standard model, the experimental possibilities to determine absolute neutrinos masses, and the intriguing connection with the Z-burst model for extreme-energy cosmic rays.

J. Zimanyi, P. Levai, T. S. Biro

Based on an analysis in the framework of a coalescence hadronization model (ALCOR) we conclude that in heavy ion collisions at CERN SPS and RHIC energies a new type of matter, the massive quark-antiquark matter is produced.

M. Sami, Pravabati Chingangbam, Tabish Qureshi

We consider issues related to tachyonic inflation with exponential potential. We find exact solution of evolution equations in the slow roll limit in FRW cosmology. We also carry out similar analysis in case of Brane assisted tachyonic inflation. We investigate the phase space behavior of the system and show that the dust like solution is a late time attract

Nobuhiro Maekawa, Toshifumi Yamashita

Recently, a new mechanism, which explains why the three gauge coupling constants meet at a certain scale in the minimal supersymmetric standard model, has been proposed in a scenario of grand unified theories with anomalous $U(1)_A$ gauge symmetry. It is a non-trivial result that although there are many superheavy fields whose mass scales are below the unifi

Sibasish Ghosh, Guruprasad Kar, Anirban Roy, Debasis Sarkar

In $2 \otimes 2$, more than 2 orthogonal Bell states with single copy can never be discriminated with certainty if only local operations and classical communication (LOCC) are allowed. More than $d$ orthogonal maximally entangled states in $d \otimed d$, which are in cannonical form, used by Bennett et. al. [Phys. Rev. Lett. 70 (1993) 1895] can never be disc

L. Sudheendra, A. R. Raju, C. N. R. Rao

Electrical and magnetic properties of four series of manganates LnxCa1-xMnO3 (Ln=La, Nd, Gd and Y) have been studied in the electron doped regime (x=0.02-0.25) in order to investigate the various inter-dependent phenomena such as ferromagnetism, phase separation and charge ordering. The general behavior of all the four series of manganates is similar, with s

R. G. Vishwakarma

Einstein believed that Mach&#39;s principle should play a major role in finding a meaningful spacetime geometry, though it was discovered later that his field equations gave some solutions which were not Machian. It is shown, in this essay, that the kinematical $Λ$ models, which are invoked to solve the cosmological constant problem, are in fact consistent w

K. Shima, Y. Tanii, M. Tsuda

We investigate for the N = 2 supersymmetry (SUSY) a relation between a vector supermultiplet of the linear SUSY and the Volkov-Akulov model of the nonlinear SUSY. We express component fields of the vector supermultiplet in terms of Nambu-Goldstone fermion fields at the leading orders in a SUSY invariant way, and show the vector nature of the U(1) gauge field

Sergiu I. Vacaru, Nadejda A. Vicol

We present an introduction to the geometry of higher order vector and co--vector bundles (including higher order generalizations of the Finsler geometry and Kaluza--Klein gravity) and review the basic results on Clifford and spinor structures on spaces with generic local anisotropy modeled by higher order nonlinear connections. Geometric applications in loca

Pisin Chen, Toshiki Tajima, Yoshiyuki Takahashi

A cosmic acceleration mechanism is introduced which is based on the wakefields excited by the Alfven shocks in a relativistically flowing plasma, where the energy gain per distance of a test particle is Lorentz invariant. We show that there exists a threshold condition for transparency below which the accelerating particle is collision-free and suffers littl

David G. d&#39;Enterria

Hard processes in nucleus-nucleus interactions at relativistic energies are reviewed with emphasis on recent PHENIX results from the first run of the Relativistic Heavy-Ion Collider at BNL. The observed suppression of moderately high $p_T$ hadrons ($p_T$ = 2 - 5 GeV/c) in $\sqrt{s_{NN}}$ = 130 GeV $Au+Au$ central collisions with respect to the scaled $pp$ da

F. L. Barkov, D. V. Shantsev, T. H. Johansen, P. E. Goa

Using magneto-optical imaging the phenomenon of dendritic flux penetration in superconducting films was studied. Flux dendrites were abruptly formed in a 300 nm thick film of MgB2 by applying a perpendicular magnetic field. Detailed measurements of flux density distributions show that there exists a local threshold field controlling the nucleation and termin

Luis P. Chimento, Alejandro S. Jakubi, Diego Pavon

In this paper we show that the claims in [Class. Quantum Grav. 19 (2002) 3067, gr-qc/0203081] related to our analysis in [Phys. Rev. D 62, 063508 (2000), astro-ph/0005070] are wrong.

Huirong Yan, A. Lazarian

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for substantial revisions in our understanding of cosmic ray transport. In this paper we use gyroresonance recently obtained scaling laws for MHD modes to calculate the scattering frequency for cosmic rays in the ISM. We consider gyroresonance with MHD modes (Alfvenic, slow and fas

B. C. Travaglione, G. J. Milburn

Recently a scheme has been proposed for constructing quantum error-correcting codes that embed a finite-dimensional code space in the infinite-dimensional Hilbert space of a system described by continuous quantum variables. One of the difficult steps in this scheme is the preparation of the encoded states. We show how these states can be generated by couplin

A. Bramon, G. Garbarino

We propose the use of entangled pairs of neutral kaons, considered as a promising tool to close the well known loopholes affecting generic Bell&#39;s inequality tests, in a specific Hardy-type experiment. Hardy&#39;s contradiction without inequalities between Local Realism and Quantum Mechanics can be translated into a feasible experiment by requiring ideal

Andrzej Grudka, Antoni Wojcik

Generalization of quantum information splitting protocol from qubits to qudits (quantum d-dimensional systems) is presented.

S. Leble, S. Yalunin

The method of zero-range potentials is generalized to account for the molecular electron excitation process. It is made by a matrix formulation in which a state vector components are associated with a scattering channel. The multi-center target is considered and the model is applied to the example of $e + H_2$ low energy scattering. The results of evaluation

K. J. Resch, J. S. Lundeen, A. M. Steinberg

We present an experimental realization of a two-photon conditional-phase switch, related to the ``$c$-$ϕ$&#39;&#39; gate of quantum computation. This gate relies on quantum interference between photon pairs, generating entanglement between two optical modes through the process of spontaneous parametric down-conversion (SPDC). The interference effect serves t

Walter T. Strunz, Fritz Haake

Environment induced decoherence entails the absence of quantum interference phenomena from the macroworld. The loss of coherence between superposed wave packets depends on their separation. The precise temporal course depends on the relative size of the time scales for decoherence and other processes taking place in the open system and its environment. We us

Katarzyna Krajewska, Jerzy Z. Kaminski

A two-dimensional electron system interacting with an impurity and placed in crossed magnetic and electric fields is under investigation. Since it is assumed that an impurity center interacts as an attractive $δ$-like potential a renormalization procedure for the retarded Green&#39;s function has to be carried out. For the vanishing electric field we obtain

A. Bouda, F. Hammad

For a one-dimensional stationary system, we derive a third order equation of motion representing a first integral of the relativistic quantum Newton&#39;s law. We then integrate this equation in the constant potential case and calculate the time spent by a particle tunneling through a potential barrier.

S. Sarg

The physical models of a successful unified theory about the Universe must operate in different phase of matter evolution and different fields of physics. The attempts to build such wide range theory as a bunch of theories developed for different fields of physics are not quite successful. The accumulated knowledge from experiments and observations leads to

U. I. Safronova, W. R. Johnson, M. S. Safronova, J. R. Albritton

Excitation energies, oscillator strengths, and transition rates are calculated for (5d2+5d6s+6s2)--(5d6p+5d5f+6s6p) electric dipole transitions in Yb-like ions with nuclear charges Z ranging from 72 to 100. Relativistic many-body perturbation theory (RMBPT), including the retarded Breit interaction, is used to evaluate retarded E1 matrix elements in length a

Kevin L. Haglin

We establish the extent to which photons and dileptons are penetrating probes of hot hadronic matter by computing mean free paths. Absorption is indeed negligible for real photons as mean free paths are roughly tenths of \AAngströms. However, vector dominance effects, which provide rich structure in virtual photon mass spectra, introduce nonnegligible reabso

Kevin L. Haglin

We apply a confining q\bar{q} potential to charmonium and open charm in order to model wave functions and to begin studying structure. Results (in momentum space) provide form-factor input to a four-flavor effective chiral Lagrangian which models dynamics of charmonium in hot hadronic matter. Estimates are made for J/ψdissociation cross sections and rates wi

J. J. Zach, A. StJ. Murphy, D. Marriott, R. N. Boyd

A Monte Carlo code has been developed to simulate the operation of the planned detectors in OMNIS, a supernova neutrino observatory. OMNIS will detect neutrinos originating from a core collapse supernova by the detection of spalled neutrons from Pb- or Fe-nuclei. This might be accomplished using Gd-loaded liquid scintillator. Results for the optimum configur

M. F. Rivet, N. Bellaize, B. Borderie, R. Bougault

The dynamics and thermodynamics of phase transition in hot nuclei are studied through experimental results on multifragmentation of heavy systems (A>200) formed in central heavy ion collisions. Different signals indicative of a phase transition studied in the INDRA collaboration are presented and their consistency is stressed.

J. A. Gonzalez, A. Bellorin, L. E. Guerrero

We investigate the dynamics of the sine-Gordon solitons perturbed by spatiotemporal external forces. We prove the existence of internal (shape) modes of sine-Gordon solitons when they are in the presence of inhomogeneous space-dependent external forces, provided some conditions (for these forces) hold. Additional periodic time-dependent forces can sustain os

R. Florido, J. M. Martin-Gonzalez, J. M. Gomez Llorente

A class of numerical methods to determine Pollicott-Ruelle resonances in chaotic dynamical systems is proposed. This is achieved by relating some existing procedures which make use of Pade approximants and interpolating exponentials to both the memory function techniques used in the theory of relaxation and the filter diagonalization method used in the harmo

Ricardo Lopez-Ruiz, Yves Pomeau

A model for the symmetric coupling of two self-oscillators is presented. The nonlinearities cause the system to vibrate in two modes of different symmetries. The transition between these two regimes of oscillation can occur by two different scenarios. This might model the release of vortices behind circular cylinders with a possible transition from a symmetr

Adam J. Przezdziecki

Our main motivation for the work presented in this paper is to construct a localization functor, in a certain sense dual to the f-localization of Bousfield and Farjoun, and to study some of its properties. We succeed in a case which is related to the Sullivan profinite completion. As a corollary we prove the existence of certain cohomological localizations.

J. F. Alves, S. Luzzatto, V. Pinheiro

We consider non-uniformly expanding maps on compact Riemannian manifolds of arbitrary dimension, possibly having discontinuities and/or critical sets, and show that under some general conditions they admit an induced Markov tower structure for which the decay of the return time function can be controlled in terms of the time generic points need to achieve so

Elizabeth L. Wilmer

By proving a local limit theorem for higher-order transitions, we determine the time required for necklace chains to be close to stationarity. Because necklace chains, built by arranging identical smaller chains around a directed cycle, are not reversible, have little symmetry, do not have uniform stationary distributions, and can be nearly periodic, prior g

Corrado Mascia, Kevin Zumbrun

We establish sharp pointwise Green&#39;s function bounds and consequent linearized and nonlinear stability for smooth traveling front solutions, or relaxation shocks, of general hyperbolic relaxation systems of dissipative type, under the necessary assumptions ([G,Z.1,Z.4]) of spectral stability, i.e., stable point spectrum of the linearized operator about t

Chris Judge

We prove the existence of limits of real-analytic Laplace eigenvalue branches for real-analytic families of metrics that degenerate along a compact hypersurface.

Miloslav Znojil, Frantisek Gemperle, Omar Mustafa

For the PT symmetric potential of Dorey, Dunning and Tateo we show that in the large angular momentum (i.e., strongly spiked) limit the low-lying eigenstates of this popular non-Hermitian problem coincide with the shifted Hermitian harmonic oscillators calculated at the zero angular momentum. This type of an approximate Hermitization is valid in all the doma

Raphael Bousso

This is my contribution to the Festschrift honoring Stephen Hawking on his 60th birthday. Twenty-five years ago, Gibbons and Hawking laid out the semi-classical properties of de Sitter space. After a summary of their main results, I discuss some further quantum aspects that have since been understood. The largest de Sitter black hole displays an intriguing p

R. M. Godbole, A. Grau, G. Pancheri

We examine the energy dependence of total cross-sections for photon processes and discuss the QCD contribution to the rising behaviour

R. M. Godbole, A. Grau, G. Pancheri, Y. N. Srivastava

We discuss the high energy behaviour of total cross-sections for protons and photons, in a QCD based framework with particular emphasis on the role played by soft gluons

S. M. Troshin, N. E. Tyurin

Unitarity and geometrical effects are discussed for photon--photon scattering.

M. F. McDermott

Both of my talks at DIS2002, on Generalised Parton Distributions and Nuclear Shadowing are presented. In an appendix I summarise some of the discussions which followed the talks.

Francisco J. Herranz

Two new quantum anti-de Sitter so(4,2) and de Sitter so(5,1) algebras are presented. These deformations are called either time-type or space-type according to the dimensional properties of the deformation parameter. Their Hopf structure, universal R matrix and differential-difference realization are obtained in a unified setting by considering a contraction

Junpei Harada

We investigate the symmetry breaking pattern of the democratic mass matrix model, which leads to the small flavor mixing in quark sector and bi-large mixing in lepton sector. We present the symmetry breaking matrices in quark sector which are determined by alternative ways instead of conventional ansatz. These matrices might be useful for understanding the o

N. G. Kelkar

We evaluate the time delay in some of the established resonance regions of $πN$ elastic scattering. In addition to the positive peaks corresponding to resonances, we identify broad regions of negative time delay or time advancement which restrict the energy ranges within which the resonances can be located.

Ph. Boucaud, F. De Soto, A. Donini, A. Le Yaouanc

The running coupling constant can be estimated by computing gluon two- and three-point Green functions from the lattice. Computing in lattice implies working in a fixed gauge sector (Landau). An source of systematic uncertainty is then the contribution of non gauge-invariant condensates, as $<A^2 >$, generating power corrections that might still be important

S. Mallik, Sourav Sarkar

A recently proposed scheme is used to saturate the spectral side of the QCD sum rules derived from the thermal, two-point correlation functions of the vector and the axial-vector currents. At low temperature, it constructs the spectral representation from all the one-loop Feynman diagrams for the two-point functions. The old saturation scheme treats incorrec

H1 Collaboration, C. Adloff

The leptoproduction of J/psi mesons is studied in inelastic reactions for four momentum transfers 2<Q^2<100GeV^2. The data were taken with the H1 detector at the electron proton collider HERA and correspond to an integrated luminosity of 77 pb-1. Single differential and double differential cross sections are measured with increased precision compared with pr

H1 Collaboration, C. Adloff

An analysis of inelastic photoproduction of J/Psi mesons is presented using data collected at the ep collider HERA corresponding to an integrated luminosity of above 80pb-1. Differential and double differential cross sections are measured in a wide kinematic region: 60<W_gammap<260 GeV, 1<p_t^2< 60 GeV^2 and 0.05<z<0.9, where z is the fraction of the energy

E. Craig Dukes

The Fermilab HyperCP collaboration is making precision studies of charged hyperon and kaon decays, as well as searches for rare and forbidden hyperon and kaon decays. We report here on measurements of the branching ratios of the flavor-changing neutral-current decays: K+/- -> pi+/- mu+ mu-, and compare our results to theoretical predictions. This is the firs