July 2003 arXiv papers — page 16

Alex Grishin, Igor V. Yurkevich, Igor V. Lerner

We use a functional integral formalism developed earlier for the pure Luttinger liquid (LL) to find an exact representation for the electron Green function of the LL in the presence of a single backscattering impurity. This allows us to reproduce results (well known from the bosonization techniques) for the suppression of the electron local density of states

V. Hardy, M. R. Lees, A. Maignan, S. Hebert

Specific heat measurements were carried out on the closely related spin-chain oxides Ca3Co2O6 and Ca3CoRhO6. Both compounds consist of Ising magnetic chains that are arranged on a triangular lattice. The spin coupling along and between the chains are ferromagnetic and antiferromagnetic, respectively. Geometrical frustration is expected from the combination o

J. E. Villegas, E. M. Gonzalez, M. I. Montero, Ivan K. Schuller

Rectangular pinning arrays of Ni dots define a potential landscape for vortex motion in Nb films. Magnetotransport experiments in which two in-plane orthogonal electrical currents are injected simultaneously allow selecting the direction and magnitude of the Lorentz force on the vortex-lattice, thus providing the angular dependence of the vortex motion. The

C. Weber, L. Capriotti, G. Misguich, F. Becca

We study the thermal properties of the classical antiferromagnetic Heisenberg model with both nearest ($J_1$) and next-nearest ($J_2$) exchange couplings on the square lattice by extensive Monte Carlo simulations. We show that, for $J_2/J_1 > 1/2 $, thermal fluctuations give rise to an effective $Z_2$ symmetry leading to a {\it finite-temperature} phase tran

V. Hardy, S. Lambert, M. R. Lees, D. McK. Paul

Specific heat and magnetization measurements have been carried out under a range of magnetic fields on single crystals of Ca3Co2O6. This compound is composed of Ising magnetic chains that are arranged on a triangular lattice. The intrachain and interchain couplings are ferromagnetic and antiferromagnetic, respectively. This situation gives rise to geometrica

F. A. Pinheiro, M. Rusek, A. Orlowski, B. A. van Tiggelen

We have studied the distribution of resonant widths $P (Γ)$ in one-, two- and three dimensional multiple light scattering systems. $P (Γ)$ should follow a universal power law $P (Γ) \sim Γ^{-1}$ in the localized regime as confirmed by extensive numerical calculations. This behavior can be interpreted as an unambiguous signature of exponential Anderson locali

P. Pisarski, G. Haran

We study a single impurity effect on the local density of states in a d-wave superconductor accounting for the momentum-dependent impurity potential. We show that the anisotropy of the scattering potential can alter significantly the spatial dependence of the quasiparticle density of states in the vicinity of the impurity.

V. Garzo, J. W. Dufty

Many features of granular media can be modeled by a fluid of hard spheres with inelastic collisions. Under rapid flow conditions, the macroscopic behavior of grains can be described through hydrodynamic equations accounting for dissipation among the interacting particles. A basis for the derivation of hydrodynamic equations and explicit expressions appearing

P. Pieri, G. C. Strinati

The present manuscript concerns the calculation of the boson-boson scattering length for the composite bosons that form as bound-fermion pairs in the strong-coupling limit of the BCS-BEC crossover. The material presented in this manuscript was already published as a part of a longer paper on the BCS-BEC crossover problem (P. Pieri and G.C. Strinati, Phys. Re

P. Gegenwart, C. Langhammer, R. Helfrich, N. Oeschler

Non-Fermi liquid (NFL) behavior in the normal state of the heavy-fermion superconductor UBe13 is studied by means of low-temperature measurements of the specific heat, C, and electrical resistivity, ρ, on a high-quality single crystal in magnetic fields up to 15.5 T. At B=0, unconventional superconductivity forms at Tc=0.9 K out of an incoherent state, chara

Tatsuaki Wada

The thermodynamic stability conditions (TSC) of nonadditive and composable entropies are discussed. Generally the concavity of a nonadditive entropy with respect to internal energy is not necessarily equivalent to the corresponding TSC. It is shown that both the TSC of Tsallis' entropy and that of the $κ$-generalized Boltzmann entropy are equivalent to t

A. Hernandez-Cabrera, P. Aceituno, F. T. Vasko

Ultrafast intersubband excitation of electrons in tunnell-coupled wells is studied depending on the structure parameters, the duration of the infrared pump and the detuning frequency. The temporal dependencies of the photoinduced concentration and dipole moment are obtained for two cases of transitions: from the single ground state to the tunnel-coupled exci

R. Asgari, M. Polini, B. Davoudi, M. P. Tosi

We calculate the correlation energy of a two-dimensional homogeneous electron gas using several available approximations for the exchange-correlation kernel $f_{\rm xc}(q,ω)$ entering the linear dielectric response of the system. As in the previous work of Lein {\it et al.} [Phys. Rev. B {\bf 67}, 13431 (2000)] on the three-dimensional electron gas, we give

A. Sorkin, Joan Adler, R. Kalish

We present tight-binding molecular dynamics simulations of the structural modifications that result from the "thermal spike" that occurs during the passage of a heavy fast ion through a thin diamond or amorphous carbon layer, and the subsequent regrowth upon cooling. The thermal spike and cooling down are simulated by locally heating and then quenchi

F. G. Aliev, R. Schad, A. Volodin, K. Temst

For antiferromagnetically coupled Fe/Cr multilayers the low field contribution to the resistivity, which is caused by the domain walls, is strongly enhanced at low temperatures. The low temperature resistivity varies according to a power law with the exponent about 0.7 to 1. This behavior can not be explained assuming ballistic electron transport through the

D. S. Golubovic, W. V. Pogosov, M. Morelle, V. V. Moshchalkov

We have studied the nucleation of superconductivity in a mesoscopic Al disk wit a Co/Pd magnetic dot placed on the top by measuring the normal superconducting phase boundary Tc(B). The measurements have revealed a pronounced asymmetry with respect to the direction of the applied magnetic field, indicating an enhancement of the critical field when an applied

J. Javier Brey, M. J. Ruiz-Montero

The departure of a granular gas in the instable region of parameters from the initial homogeneous cooling state is studied. Results from Molecular Dynamics and from Direct Monte Carlo simulation of the Boltzmann equation are compared. It is shown that the Boltzmann equation accurately predicts the low density limit of the system. The relevant role played by

Keshav N. Shrivastava

Usually the Landau levels are given by (n+1/2)\hbarω_c with \hbarω_c=eB/mc. We find that there are clusters of electrons with localization so that the orbital angular momentum is not zero. There are interactions which transfer the electrons from {\it l}=0 to {\it l}\ne 0 so that there is doubling in the Landau levels with \hbarω_c= (1/2)g_\pmeB/mc where (1/2

Tatsuya Kawae, Tatsuharu Yamamoto, Kenji Yurue, Naoyuki Tateiwa

We have studied the low-temperature properties of Pr$_{x}$La$_{1-x}$Pb$_{3}$ with non-Kramers $Γ_{3}$ quadrupolar moments of the crystal-electric-field ground state, for a wide concentration range of Pr ions. For $x$$\le$0.05, the specific heat $C/T$ increases monotonically below $T$=1.5 K, which can be scaled with a characteristic temperature $T^{*}$ define

O. Flomenbom, J. Klafter

We study voltage driven translocation of a single stranded (ss) DNA through a membrane channel. Our model, based on a master equation (ME) approach, investigates the probability density function (pdf) of the translocation times, and shows that it can be either double or mono-peaked, depending on the system parameters. We show that the most probable transloca

A. A. Katsnelson, A. Yu. Lavrenov, I. A. Lubashevsky

In binary metallic systems like the Pd--Er alloys charged with hydrogen the observed structure evolution exhibits complex dynamics. It is characterized by non-monotonic time variations in an Er-rich fraction respect with an Er-poor fraction observed experimentally. The present paper proposes a qualitative model for this non-monotonic structure relaxation. We

D. Belitz, T. R. Kirkpatrick

We comment on various incorrect claims made in a recent paper by Grosu et al. (cond-mat/0101392).

David W. Hogg, Michael R. Blanton, Jarle Brinchmann, Daniel J. Eisenstein

The distribution in color and absolute magnitude is presented for 55,158 galaxies taken from the Sloan Digital Sky Survey in the redshift range $0.08<z<0.12$, as a function of galaxy number overdensity in a line-of-sight cylinder of transverse radius $1 h^{-1} \mathrm{Mpc}$. In all environments, bulge-dominated galaxies (defined to be those with radial profi

HEGRA Collaboration, in particular, :, N. Goetting

This preprint encompasses thirteen individual contributions of the HEGRA collaboration to the 28th International Cosmic Ray conference in Tsukuba, Japan. The papers report on results on M87, M31, H1426+428, Mkn421, 1ES1959+650, Scan of the TeV sky, Performance of the system, GeV sources, 54 AGN, and SN1006

Marek Gierlinski, Chris Done

Disc spectra from highly luminous black hole binaries are observed to be rather simple, despite theoretical predictions to the contrary. We collate the disc-dominated spectra from multiple observations of 10 separate sources, and show that these overwhelmingly follow a multi-temperature disc blackbody spectrum with luminosity proportional to T^4, and that su

A. Fontana, I. Donnarumma, E. Vanzella, E. Giallongo

We use a deep K(AB)<25 galaxy sample in the Hubble Deep Field South to trace the evolution of the cosmological stellar mass density from z~ 0.5 to z~3. We find clear evidence for a decrease of the average stellar mass density at high redshift, 2<z<3.2, that is 15^{+25}_{-5}% of the local value, two times higher than what observed in the Hubble Deep Field Nor

J. Hjorth, P. Møller, J. Gorosabel, J. P. U. Fynbo

We present optical and near-infrared observations of the dim afterglow of GRB 020124, obtained between 2 and 68 hours after the gamma-ray burst. The burst occurred in a very faint (R > 29.5) Damped Ly-alpha Absorber (DLA) at a redshift of z = 3.198 +- 0.004. The derived column density of neutral hydrogen is log(N_H) = 21.7 +- 0.2 and the rest-frame reddening

Rainer Beck, Anvar Shukurov, Dmitry Sokoloff, Richard Wielebinski

Faraday rotation of the polarization plane in magnetized thermal plasma provides one of the most efficient methods to deduce regular magnetic fields from radio astronomical observations. Since the Faraday rotation measure RM is proportional to an integral, along the line of sight, of magnetic field weighted with thermal electron density, RM is believed to yi

Maurizio Salaris, Susan Percival, Leo Girardi

We present a detailed analysis of the uncertainty on the theoretical population corrections to the LMC Red Clump (RC) absolute magnitude, by employing a population synthesis algorithm to simulate theoretically the photometric and spectroscopic properties of RC stars, under various assumptions about the LMC Star Formation Rate (SFR) and Age Metallicity Relati

Nicolas Rambaux, Eric Bois

The 3:2 spin-orbit resonance between the rotational and orbital motions of Mercury results from a functional dependance on a tidal friction adding to a non-zero eccentricity with a permanent asymmetry in the equatorial plane of the planet. The upcoming space missions, MESSENGER and BepiColombo with onboard instrumentation capable of measuring the Mercury&#39

Th. Boller, R. Keil, G. Hasinger, E. Costantini

We report on an XMM-Newton observation of the ultraluminous infrared galaxy NGC 6240. The 0.3-10 keV spectrum can be successfully modelled with: (i) three collisionally ionized plasma components with temperatures of about 0.7, 1.4, and 5.5 keV; (ii) a highly absorbed direct power-law component; and (iii) a neutral Fe K_alpha and K_beta line. We detect a sign

Nicola Cabibbo, Earl C. Swallow, Roland Winston

Using a technique that is not subject to first-order SU(3) symmetry breaking effects, we determine the $V_{us}$ element of the CKM matrix from data on semileptonic hyperon decays. We obtain $V_{us}$ =0.2250(27). This value is of similar precision to the one derived from $K_{l3}$, but higher and in better agreement with the unitarity requirement, $|V_{ud}|^2+

Agnes Helmstetter, Didier Sornette

The empirical Bath&#39;s law states that the average difference in magnitude between a mainshock and its largest aftershock is 1.2, regardless of the mainshock magnitude. Following Vere-Jones [1969] and Console et al. [2003], we show that the origin of Bath&#39;s law is to be found in the selection procedure used to define mainshocks and aftershocks rather t

Harald P. Pfeiffer, Dong Lai

The inner region of the accretion disk around a magnetized star (T Tauri star, white dwarf or neutron star) is subjected to magnetic torques that induce warping and precession of the disk. These torques arise from the interaction between the stellar field and the induced electric currents in the disk. We carry out numerical simulations of the nonlinear evolu

Joel David Hamkins

If an extension Vbar of V satisfies the delta approximation and cover properties for classes and V is a class in Vbar, then every suitably closed embedding j:Vbar to Nbar in Vbar with critical point above delta restricts to an embedding j|V:V to N amenable to the ground model V. In such extensions, therefore, there are no new large cardinals above delta. Thi

A. Freund, M. Strikman

In this paper we analyze nuclear medium effects on DVCS amplitudes in the $\Bx$ range of $0.1-0.0001$ for a large range of $Q^2$ and four different nuclei. We use our nucleon GPD model capable of describing all currently available DVCS data on the proton and extend it to the nuclear case using two competing parameterizations of nuclear effects. The two param

B. E. Light, Ravhi S. Kumar, A. L. Cornelius, P. G. Pagliuso

In heavy fermion materials superconductivity tends to appear when long range magnetic order is suppressed by chemical doping or applying pressure. Here we report heat capacity measurements on diluted alloyes of the heavy fermion superconductor CeRhIn_5;. Heat capacity measurements have been performed on CeRh_{1-y}Ir_{y}In_5; (y <= 0.10) and Ce_{1-x}La_{x}Rh_

S. Fossier, S. Salaun, J. Mangin, O. Bidault

Lithium thioindate (LiInS$_{2}$) is a new nonlinear chalcogenide biaxial material transparent from 0.4 to 12 $μ$m, that has been successfully grown in large sizes and good optical quality. We report on new physical properties that are relevant for laser and nonlinear optics applications. With respect to AgGaS(e)$_2$ ternary chalcopyrite materials, LiInS$_{2}

Vittorio Giovannetti, Seth Lloyd, Lorenzo Maccone, Jeffrey H. Shapiro

We calculate the communication capacity of a broadband electromagnetic waveguide as a function of its spatial dimensions and input power. We analyze the two cases in which either all the available modes or only a single directional mode are employed. The results are compared with those for the free space bosonic channel.

Marija Dimitrijevic, Larisa Jonke, Lutz Möller, Efrossini Tsouchnika

A general formalism is developed that allows the construction of a field theory on quantum spaces which are deformations of ordinary spacetime. The symmetry group of spacetime (Poincar\&#39; e group) is replaced by a quantum group. This formalism is demonstrated for the kappa-deformed Poincaré algebra and its quantum space. The algebraic setting is mapped to

Meesoon Ha, Jussi Timonen, Marcel den Nijs

Stochastic driven flow along a channel can be modeled by the asymmetric simple exclusion process. We confirm numerically the presence of a dynamic queuing phase transition at a nonzero obstruction strength, and establish its scaling properties. Below the transition, the traffic jam is macroscopic in the sense that the length of the queue scales linearly with

Daw-Wei Wang, Mikhail D. Lukin, Eugene Demler

We analyze effects of a random magnetic potential in a microfabricated waveguide for ultra-cold atoms. We find that the shape and position fluctuations of a current carrying wire induce strongly disordered potential that is quasiperiodic with a lengthscale set by the atom-wire separation. The theory is used to explain quantitatively the experimentally observ

R. S. Chivukula, H. -J. He, J. Howard, E. H. Simmons

This paper studies models with extended electroweak gauge sectors of the form SU(2) x SU(2) x U(1) x [SU(2) or U(1)]. We establish the general behavior of corrections to precision electroweak observables in this class of theories and connect our results to previous work on specific models whose electroweak sectors are special cases of our extended group.

H. J. de Vega, N. Sanchez

We develop the cluster expansion and the Mayer expansion for the self-gravitating thermal gas and prove the existence and stability of the thermodynamic limit N, V to infty with N/V^{1/3} fixed. The essential (dimensionless) variable is here eta = [G m^2 N]/[V^{1/3} T] (which is kept fixed in the thermodynamic limit). We succeed in this way to obtain the exp

ZEUS Collaboration

Cross sections for e^+p charged current deep inelastic scattering at a centre-of-mass energy of 318 GeV have been determined with an integrated luminosity of 60.9pb^-1 collected with the ZEUS detector at HERA. The differential cross sections dsigma/dQ^2, dsigma/dx and dsigma/dy for Q^2>200 GeV^2 are presented. In addition, d^2sigma/dxdQ^2 has been measured i

Boaz Tsaban, Tomasz Weiss

We describe a simple machinery which translates results on algebraic sums of sets of reals into the corresponding results on their cartesian product. Some consequences are: 1. The product of a meager/null-additive set and a strong measure zero/strongly meager set in the Cantor space has strong measure zero/is strongly meager, respectively. 2. Using Scheepers

Boaz Tsaban

We construct several topological groups with very strong combinatorial properties. In particular, we give simple examples of subgroups of the real line R (thus strictly o-bounded) which have the Hurewicz property but are not sigma-compact, and show that the product of two o-bounded subgroups of R^N may fail to be o-bounded, even when they satisfy the stronge

C. Panagopoulos, A. P. Petrovic, A. D. Hillier, J. L. Tallon

We have studied the spin glass behaviour of non-superconducting La$_{2-x}$Sr$_x$Cu$_{0.95}$Zn$_{0.05}$O$_4$ ($x=0.10-0.22$). As in the superconducting analogues of these samples the spin glass transition temperature $T_g$ decreases with increasing $x$, and vanishes at $x=0.19$. A local enhancement in $T_g$ at $x=0.12$ is also observed and attributed to strip

Glennys R. Farrar, P. J. E. Peebles

We discuss models for the cosmological dark sector in which the energy density of a scalar field approximates Einstein&#39;s cosmological constant and the scalar field value determines the dark matter particle mass by a Yukawa coupling. A model with one dark matter family can be adjusted so the observational constraints on the cosmological parameters are clo

Shaul Mukamel

Computing response functions by following the time evolution of superoperators in Liouville space (whose vectors are ordinary Hilbert space operators) offers an attractive alternative to the diagrammatic perturbative expansion of many-body equilibrium and nonequilibrium Green functions. The bookkeeping of time ordering is naturally maintained in real (physic

Valerio Scarani, Nicolas Gisin, Sandu Popescu

We present a proposal for the experimental observation of energy-time entanglement of quasi-particles in mesoscopic physics. This type of entanglement arises whenever correlated particles are produced at the same time and this time is uncertain in the sense of quantum uncertainty, as has been largely used in photonics. We discuss its feasibility for electron

Kyung-Seok Cha, Bum-Hoon Lee, Hyun Seok Yang

We study intersecting D-branes in a type IIB plane wave background using Green-Schwarz worldsheet formulation. We consider all possible $D_\pm$-branes intersecting at angles in the plane wave background and identify their residual supersymmetries. We find, in particular, that $D_\mp - D_\pm$ brane intersections preserve no supersymmetry. We also present the

C. Wetterich

We investigate a possible unified theory of all interactions which is based only on fundamental spinor fields. The vielbein and metric arise as composite objects. The effective quantum gravitational theory can lead to a modification of Einstein&#39;s equations due to the lack of local Lorentz-symmetry. We explore the generalized gravity with global instead o

Anthony Lasenby, Chris Doran

We present a new approach to constructing inflationary models in closed universes. Conformal embedding of closed-universe models in a de Sitter background suggests a quantisation condition on the available conformal time. This condition implies that the universe is closed at no greater than the 10% level. When a massive scalar field is introduced to drive an

E. Papantonopoulos, V. Zamarias

Using the AdS/CFT correspondence we study the holographic principle and the CFT/FRW relations in the near-horizon AdS(5)xS(5) geometry with a probe D3-brane playing the role of the boundary to this space. The motion of the probe D3-brane in the bulk, induces a cosmological evolution on the brane. As the brane crosses the horizon of the bulk black hole, it pr

R. Neri, R. Genzel, R. J. Ivison, F. Bertoldi

We report IRAM Plateau de Bure, millimeter interferometry of three z=~2.4 to 3.4, SCUBA deep field galaxies. Our CO line observations confirm the rest-frame UV/optical redshifts, thus more than doubling the number of confirmed, published redshifts of the faint submillimeter population and proving their high-z nature. In all three sources our measurements of

D. Controzzi, G. Mussardo

Form Factor Perturbation Theory is applied to study the spectrum of the O(3) non--linear sigma model with the topological term in the vicinity of $θ= π$. Its effective action near this value is given by the non--integrable double Sine--Gordon model. Using previous results by Affleck and the explicit expressions of the Form Factors of the exponential operator

A. Ferroglia, G. Ossola, A. Sirlin

Gauge independent form factors ρ^(e; e) and \hatκ^(e; e)(q^2) for Moller scattering at s << m_W^2 are derived. It is pointed out that \hatκ^(e; e) is very different from its counterparts in other processes. The relation between the effective parameter \hatκ^(e; e)(q^2,μ) \sin^2 \hatθ_W(μ) and \sin^2 θ_eff is derived in a scale-independent manner. A gauge and

Somendra M. Bhattacharjee

We develop a propagating front analysis, in terms of a local probability of zipping, for the helicase activity of opening up a double stranded DNA (dsDNA). In a fixed-distance ensemble (conjugate to the fixed-force ensemble) the front separates the zipped and unzipped phases of a dsDNA and a drive acts locally around the front. Bounds from variational analys

T. Kato, R. Stubbings, B. Monard, N. D. Butterworth

We observed long-term behavior of the helium dwarf nova V803 Cen, and clarified the existence of at least two distinct states (state with 77-d supercycles and standstill-like state) which interchangeably appeared with a time-scale of 1--2 yr. We also conducted a time-resolved CCD photometry campaign during the bright outburst in 2003 June. The overall appear

Michail P. Rekalo, Egle Tomasi-Gustafsson

We derive from first principles, as the C-invariance of the electromagnetic interaction and the crossing symmetry, the general properties of two-photon exchange in electron-proton elastic scattering. We show that the presence of this mechanism destroys the linearity of the Rosenbluth separation.

Yoshiaki Kato, Shin Mineshige, Kazunari Shibata

We present three-dimensional (3-D) magnetohydrodynamical (MHD) simulations of radiatively inefficient accretion flow around black holes. General relativistic effects are simulated by using the pseudo-Newtonian potential. We start calculations with a rotating torus threaded by localized poloidal magnetic fields with plasma beta, a ratio of the gas pressure to

Zhangbu Xu

In this report, we discuss the measurement of the hadronic decay modes of resonances in relativistic heavy-ion collisions, emphasizing on RHIC results. The study of resonances can provide: (1) the yield and spectra of more particles with different properties to study whether the system is in thermal equilibrium; (2) an independent probe of the time evolution

Ramin G. Daghigh, Yutaka Hosotani

We investigate gravitating lumps with a false vacuum core surrounded by the true vacuum in a scalar field potential. Such configurations become possible in the Einstein gravity in the presence of fermions at the core. Gravitational interactions as well as Yukawa interactions are essential for such lumps to exist. The mass and size of gravitating lumps sensit

Hiroshi Watabe, Takashi Torii

We study the stability of a spherically symmetric black hole with a global monopole hair. Asymptotically the spacetime is flat but has a deficit solid angle which depends on the vacuum expectation value of the scalar field. When the vacuum expectation value is larger than a certain critical value, this spacetime has a cosmological event horizon. We investiga

Dragan Huterer, Chung-Pei Ma

Strong gravitational lensing is a useful probe of both the intrinsic properties of the lenses and the cosmological parameters of the universe. The large number of model parameters and small sample of observed lens systems, however, have made it difficult to obtain useful constraints on more than a few parameters from lensing statistics. Here we examine how t

Chris Lomont

There are quantum circuit identities that simplify quantum circuits, reducing the effort needed physically to implement them. This paper constructs all identities made from 3 or fewer operations taken from a common set of one qubit operations, and explains how they may be used to simplify the cost of constructing quantum circuit identities.

Alexander A. Klyachko, Alexander S. Shumovsky

We discuss maximum entangled states of quantum systems in terms of quantum fluctuations of all essential measurements responsible for manifestation of entanglement. Namely, we consider maximum entanglement as a property of states, for which quantum fluctuations come to their extreme.

Tarek Khalil, Jean Richert

The energies of low-lying bound states of a microscopic quantum many-body system of particles can be worked out in a reduced Hilbert space. We present here and test a specific non-perturbative truncation procedure. We also show that real exceptional points which may be present in the spectrum can be identified as fixed points of coupling constants in the tru

Peter Nicoletopoulos

The variation with energy of the total cross section for elastic electron scattering from atoms of several elements is caused primarily by shape resonances corresponding to the formation of temporary negative ions. It is shown that such cross sections are expressible analytically in terms of a constant background added to a &#34;generalized Fano profile&#34;

A. Brotas, J. C. Fernandes

The simultaneous study of deformation and heat transmission in a bar was ignored for about 150 years. The traditional Fourier equation just allows to study the evolution of temperature in a undeformable bar. The search for its relativistic variant is a task which must fail because in Relativity there are no undeformable bars. Rigid bodies, in the sense as ri

Jesper Laegsgaard, Niels Asger Mortensen, Jesper Riishede, Anders Bjarklev

The waveguiding properties of two silica-based airguiding photonic bandgap fiber designs are investigated with special emphasis on material effects. The nonlinear coefficients are found to be 1-2 orders of magnitude smaller than those obtained in index-guiding microstructured fibers with large mode areas. The material dispersion of silica makes a significant

Jesper Laegsgaard, Niels Asger Mortensen, Anders Bjarklev

The field energy distributions and effective mode areas of silica-based photonic bandgap fibers with a honeycomb airhole structure in the cladding and an extra airhole defining the core are investigated. We present a generalization of the common effective area definition, suitable for the problem at hand, and compare the results for the photonic bandgap fibe

Ken Sekimoto, Jacques Prost, Frank Julicher, Hakim Boukellal

It has been observed experimentally that the actin gel grown from spherical beads coated with polymerization enzymes spontaneously breaks the symmetry of its spherical shape, and yields a ``comet&#39;&#39; pushing the bead forward. We propose a mechano-chemical coupling mechanism for the initialization of this symmetry breaking. Key assumptions are that the

Wei-Mou Zheng

Simple hidden Markov models are proposed for predicting secondary structure of a protein from its amino acid sequence. Since the length of protein conformation segments varies in a narrow range, we ignore the duration effect of length distribution, and focus on inclusion of short range correlations of residues and of conformation states in the models. Confor

A. Bahaoui, C. Fayard, T. Mizutani, B. Saghai

$\Kbar N$ interactions are investigated {\it via} an effective non-linear chiral meson-baryon Lagrangian. The adjustable parameters are determined by a fitting procedure on the $K^-p$ threshold branching ratios and total cross-section data for $p^{lab}_K\le$ 250 MeV/c. We produce predictions for the $Σπ$ mass spectrum, and scattering lenghts $a_{K^-p}$, $a_n

Egle Tomasi-Gustafsson, Michail P. Rekalo

QCD gives definite predictions for hadron electromagnetic form factors in space-like and time-like momentum transfer regions, such as the quark counting rules, the hypothesis of hadron helicity conservation, and the relations between nucleon and deuteron form factors in the formalism of reduced nuclear matrix elements. Recent precise data about these form fa

L. Gerland, L. Frankfurt, M. Strikman, H. Stocker

We discuss the new data for the production of the $ψ&#39;$ meson in pA collisions at 450 GeV at CERN-SPS (of the NA50-collaboration) [1]. We extract from the CERN data $σ(ψ&#39; N)\approx 8$ mb under the assumption that the $ψ&#39;$ is produced as a result of the space-time evolution of a point-like $c\bar c$ pair which expands with time to the full size of

A. Rose

We present the design and performance analysis of a new integrated track reconstruction code developed for the STAR experiment at RHIC. The code is meant to replace multiple previous tracking codes written in FORTRAN many years ago, and to readily enable the integration of new and varied detector components. The new tracker is written from the ground up in C

Michel Planat

We describe a new model of massless thermal bosons which predicts an hyperbolic fluctuation spectrum at low frequencies. It is found that the partition function per mode is the Euler generating function for unrestricted partitions $p(n)$. Thermodynamical quantities carry a strong arithmetical structure: they are given by series with Fourier coefficients equa

Serge Perrine

The text deals with generalizations of the Markoff equation in number theory, arising from continued fractions. It gives the method for the complete resolution of such new equations, and their interpretation in algebra and algebraic geometry. This algebraic approach is completed with an analytical development concerning fuchsian groups. The link with the Tei

Martin Scharlemann

An updated proof of a 1933 theorem of Goeritz, exhibiting a finite set of generators for the group of automorphisms of the 3-sphere that preserve a genus two Heegaard splitting. The group is analyzed via its action on a certain connected 2-complex. (The analogous problem for higher genus Heegaard splittings appears to remain unresolved.)

Jaap Top, Noriko Yui

We present explicit equations of semi-stable elliptic surfaces (i.e., having only type $I_n$ singular fibers) which are associated to the torsion-free genus zero congruence subgroups of the modular group as classified by A. Sebbar.

R. Exel, J. Renault

Given a Bratteli diagram D we consider the compact topological space formed by all infinite paths on D. Two such path are said to be tail-equivalent when they &#34;have the same tail&#34;, i.e. when they eventually coincide. This equivalence relation is approximately proper and hence one may consider the C*-algebra associated to it according to a procedure r

Sara Billey, Victor Guillemin, Etienne Rassart

We use Gelfand-Tsetlin diagrams to write down the weight multiplicity function for the Lie algebra sl_k(C) (type A_{k-1}) as a single partition function. This allows us to apply known results about partition functions to derive interesting properties of the weight diagrams. We relate this description to that of the Duistermaat-Heckman measure from symplectic

Jürgen Herzog, Takayuki Hibi, Xinxian Zheng

By using Alexander duality on simplicial complexes we give a new and algebraic proof of Dirac&#39;s theorem on chordal graphs.

Attila Wiebe

For standard graded Artinian $K$-algebras defined by componentwise linear ideals and Gotzmann ideals, we give conditions for the weak Lefschetz property in terms of numerical invariants of the defining ideals.

Juergen Herzog, Takayuki Hibi, Xinxian Zheng

In this paper we consider graded ideals in a polynomial ring over a field and ask when such an ideal has the property that all of its powers have a linear resolution. In particular it is shown that all powers of a monomial ideal with 2-linear resolution have again a linear resolution.

Manfred K&#34;\uhleitner, Werner Georg Nowak

This paper provides asymptotics with a sharp error term for the Dirichlet summatory function of a certain class of arithmetic functions. The result applies, e.g., to the sums over r^2(n) and r(n^3), where r(m) denotes the number of ways to write m as a sum of two squares of integers.

M. Kuenzer, E. Wirsing

Let p > 2 be a prime, let n > m > 0. Let pi_n be the norm of zeta_{p^n} - 1 under C_{p-1}, so that Z_(p)[pi_n] | Z_(p) is a purely ramified extension of discrete valuation rings of degree p^{n-1}. The minimal polynomial of pi_n over Q(pi_m) is an Eisenstein polynomial; we give lower bounds for its coefficient valuations at pi_m. The function field analogue,

Manuel Ritoré, César Rosales

We study the problem of existence of regions separating a given amount of volume with the least possible perimeter inside a Euclidean cone. Our main result shows that nonexistence for a given volume implies that the isoperimetric profile of the cone coincides with the one of the half-space. This allows us to give some criteria ensuring existence of isoperime

James D. E. Grant, Emilio Musso

In this article we study constrained variational problems in one independent variable defined on the space of integral curves of a Frenet system in a homogeneous space G/H. We prove that if the Lagrangian is G-invariant and coisotropic then the extremal curves can be found by quadratures. Our proof is constructive and relies on the reduction theory for coiso

Luis Baez-Duarte

We give a new equivalent condition for the Riemann hypothesis consisting in an order condition for certain finite rational combinations of the values of the Riemann zeta-function at even positive integers.

Luis Baez-Duarte

A rigorous proof is given of the hypergeometric-like representation of the Riemann-zeta function discovered by K. Maslanka.

Craig Huneke, Graham Leuschke

In studying Nakayama&#39;s 1958 conjecture on rings of infinite dominant dimension, Auslander and Reiten proposed the following generalization: Let Lambda be an Artin algebra and M a Lambda-generator such that Ext^i_Lambda(M,M)=0 for all i \geq 1; then M is projective. This conjecture makes sense for any ring. We establish Auslander and Reiten&#39;s conjectu

Tobias H. Colding, William P. Minicozzi

This is a survey of our work on embedded minimal disks.

Marco Scandurra

The casimir pressure on a non ideal conducting slab is calculated. Using a simple model for the conductivity according to which the slab is perfectly conducting at frequencies below plasma frequency omega_p and perfectly transparent above such frequency, it is found that the vacuum pressure on each surface of the slab is (h omega_p^4)/(24 pi^2 c^3) which is

A. P. Contogouris, P. K. Papachristou

Recently obtained NNLO exact corrections for Higgs and Pseudoscalar Higgs boson production in hadron colliders are compared with approximate ones. As shown before, it is found that there is a range of a proper variable where these corrections differ little.

A. Wereszczynski, M. Slusarczyk

SU(2) Yang-Mills theory coupled in a non-minimal way to two scalar fields is discussed. For the massless scalar fields a family of finite energy solutions generated by an external, static electric charge is found. Additionally, there is a single solution which can be interpreted as confining one. Similar solutions have been obtained in the magnetic sector. I

S. Iyer Dutta, I. Mocioiu, M. H. Reno, I. Sarcevic

Astrophysical sources of ultrahigh energy neutrinos yield tau neutrino fluxes due to neutrino oscillations. At neutrino energies in the EeV range, radio Cherenkov detection methods show promise for detecting these fluxes. We quantify the tau neutrino contributions to the signal in, for example, a detector like the Radio Ice Cherenkov Experiment (RICE) for a