Skip to content

April 2002 arXiv papers — page 6

Showing 501–600 of 2,793 papers

  1. V. A. Kulbachinskii, R. A. Lunin, V. A. Rogozin, V. G. Mokerov

    We have investigated the optical and transport properties of MBE grown short-period superlattices of InAs/GaAs with different numbers of periods (3 <= N <= 24) and a total thickness 14 nm. Bandstructure calculations show that these superlattices represent a quantum well with average composition In_0.16Ga_0.84As. The electron wave functions are only slightly

  2. M. I. Katsnelson, A. I. Lichtenstein

    In the framework of ab initio dynamical mean field theory for realistic electronic structure calculations a new perturbation scheme which combine the T-matrix and fluctuating exchange approximations has been proposed. This method is less computationally expensive than numerically exact quantum Monte Carlo technics and give an adequate description of the elec

  3. Nguyen Quoc Hung, Nguyen Vu Nhan, Nguyen Quang Bau

    Based on the quantum transport equation for the electron-phonon system, the absorption coefficient of sound (acoustic phonons) by absorption of laser radiation in cylindrical quantum wires is calculated for the case of monophoton absorption process and the case of multiphoton absorption process. Analytical expressions and conditions for the absorption of sou

  4. Nicole Y. Morgan, C. A. Leatherdale, M. Drndic, Mirna Vitasovic

    We present results for electronic transport measurements on large three-dimensional arrays of CdSe nanocrystals. In response to a step in the applied voltage, we observe a power-law decay of the current over five orders of magnitude in time. Furthermore, we observe no steady-state dark current for fields up to 10^6 V/cm and times as long as 2x10^4 seconds. A

  5. H. Wilhelm, D. Jaccard

    The influence of pressure on the magnetically ordered CePd_{2.02}Ge_{1.98} has been investigated by a combined measurement of electrical resistivity, $ρ(T)$, and ac-calorimetry, C(T), for temperatures in the range 0.3 K<T<10 K and pressures, p, up to 22 GPa. Simultaneously CePd_2Ge_2 has been examined by $ρ(T)$ down to 40 mK. In CePd_{2.02}Ge_{1.98} and CePd

  6. Eugene Kogan, Mark Auslender

    From the double-exchange Hamiltonian with classical localized spins in the limit of large but finit Hund exchange coupling we obtain the $t-J$ model (with classical localized spins).

  7. D. M. Eagles

    A simple model is used to analyse published results on large room-temperature diamagnetism for two films of oxidised atactic polypropylene (OAPP) at low magnetic fields. The model involves induced currents expected in circular closed loops of superconductors in fields below the lower critical field H_{c1} at which flux penetration would first occur if a meta

  8. E. M. Chudnovsky, D. A. Garanin

    We show that crystals of molecular nanomagnets can exhibit giant magnetic relaxation due to the Dicke superradiance of electromagnetic waves. Rigorous treatment of the superradiance induced by a field pulse is presented.

  9. N. Pesheva, G. Oshanin

    We study the spreading kinetics of a monolayer of hard-core particles on a semi-infinite, chemically heterogeneous solid substrate, one side of which is coupled to a particle reservoir. The substrate is modeled as a square lattice containing two types of sites -- ordinary ones and special, chemically active sites placed at random positions with mean concentr

  10. S. N. Taraskin, S. R. Elliott

    The spectral density for vector vibrations in the f.c.c. lattice with force-constant disorder is analysed within the coherent potential approximation. The phase diagram showing the weak- and strong-scattering regimes is presented and compared with that for electrons. The weak-scattering regime for external long-wavelength vibrational plane waves is shown to

  11. Thomas Schwager, Thorsten Poeschel

    A method for the discrete particle simulation of of almost rigid, sharply edged frictional particles, such as railway ballast is proposed. In difference to Molecular Dynamics algorithms, the method does not require knowledge about the deformation-force law of the material. Moreover, the method does not suffer from numerical instability which is encountered i

  12. N. V. Agrinskaya, Yu. L. Ivanov, P. V. Petrov, V. M. Ustinov

    By selective doping (Be) of the well and barrier regions of p-GaAs/AlGaAs structures we have realized the situation where the upper Hubbard band (A+ centers) has been occupied by holes in the equilibrium. We studied temperature behavior of the Hall effect, variable range hopping conductivity and the photoluminescence spectra of the corresponding structures.

  13. Mitsuharu Okazaki, Tomoki Watanabe, Naohito Urakami, Takashi Yamamoto

    Relatively short peptides, such as toxins and antimicrobial-peptides, are known to insert themselves into cell membranes. On the basis of simple bead-spring models for the membrane lipids, the peptide, and water, detailed processes of the peptide insertion is investigated by molecular dynamics simulation; our special concern is in the highly cooperative moti

  14. Todor M. Mishonov, Evgeni S. Penev, Joseph O. Indekeu

    An analytical result for renormalization of the jump of the heat capacity Delta C/C_N by the anisotropy of the order parameter is derived in the framework of the model proposed by Haas and Maki [Phys. Rev. B 65, 020502(R) (2001)], for both prolate and oblate anisotropy. The graph of Delta C/C_N versus the ratio of the gaps on the equator and the pole, Delta_

  15. Fa-Min Liu, J. Q. Li, C. Dong, T. M. Wang

    The tiny Ag diffusion to MgCNi3 has been prepared by solid states reaction. Its structure was characterized by X-ray diffractometer (XRD). The results show that a small mount of Ag substitute for Ni sites, and much of Ag are in vacancy sites of the MgCNi3. We have further studied the surface properties of Ag-MgCNi3 using Raman scattering spectra, and X-ray p

  16. Pooja Shah, Charusita Chakravarty

    Quasi-saddles or inherent saddles of the potential energy surface, $U$, of a liquid are defined as configurations which correspond to absolute minima of the pseudo-potential surface, $W =\wf$, as identified by a multi-dimensional minimisation procedure. The sensitivity of statistical properties of inherent saddles to the convergence criteria of the minimisat

  17. C. K. Law, P. T. Leung, M. C. Chu

    We examine the time-dependent quantum depletion of a trapped Bose condensate arising from a rapid increase of the scattering length. Our solution indicates that a significant buildup of incoherent atoms can occur within a characteristic time short compared with the harmonic trap period. We discuss how the depletion density and the characteristic time depend

  18. I. Terasaki, T. Mizuno, K. Inagaki, Y. Yoshino

    We prepared a set of Pb-substituted Bi_{2-x}Pb_xSr_2ErCu_2O_8 single crystals. The resistivity and the in-plane thermopower decrease with increasing x from 0 to 0.8, which indicates that the Pb substitution supplies holes in the CuO_2 plane. For x=0.8, a tiny resistivity drop (a trace of superconductivity) is seen near 70 K, suggesting that the doping level

  19. M. Franz, Z. Tesanovic, O. Vafek

    In a recent preprint [cond-mat/0204040] Khveshchenko questioned the validity of our computation of the gauge invariant fermion propagator in QED3, which we employed as an effective theory of high-T_c cuprate superconductors [cond-mat/0203333]. We take this opportunity to further clarify our procedure and to show that criticism voiced in the above preprint is

  20. M. M. Hedman, D. Barkats, J. O. Gundersen, J. J. McMahon

    We update the limit from the 90 GHz PIQUE ground-based polarimeter on the magnitude of any polarized anisotropy of the cosmic microwave radiation. With a second year of data, we have now limited both Q and U on a ring of 1 degree radius. The window functions are broad: for E-mode polarization, the effective l is <l> = 191 +143 -132. We find that the E-mode s

  21. David W. Hogg, Michael Blanton, Iskra Strateva

    A complete sample of $7.7\times 10^4$ galaxies with five-band imaging and spectroscopic redshifts from the Sloan Digital Sky Survey is used to determine the fraction of the optical luminosity density of the Local Universe (redshifts $0.02<z<0.22$) emitted by red galaxies. The distribution in the space of rest-frame color, central surface brightness, and conc

  22. Michael W. Regan, Kartik Sheth, Peter J. Teuben, Stuart N. Vogel

    Although inner star-forming rings are common in optical images of barred spiral galaxies, observational evidence for the accompanying molecular gas has been scarce. In this paper we present images of molecular inner rings, traced using the CO (1-0) emission line, from the Berkeley-Illinois-Maryland-Association Survey of Nearby Galaxies (BIMA SONG). We detect

  23. Hector G. Arce, Alyssa A. Goodman

    We present a new set of high-resolution molecular line maps of the gas immediately surrounding various Herbig-Haro (HH) knots of the giant HH flow HH 315, from the young star PV Cephei. The observations, aimed at studying the entrainment mechanism of the 2.6 pc-long HH 315 flow, include IRAM 30m maps of the 12CO(2-1), 12CO(1-0), and 13CO(1-0) lines, with bea

  24. J. J. M. in &#39;t Zand, F. Verbunt, E. Kuulkers, C. Markwardt

    SLX 1737-282 is a persistent moderately bright X-ray source 1.2 deg from the Galactic center. X-ray observations with the Wide Field Cameras on BeppoSAX have for the first time revealed the true nature of SLX 1737-282: a 15-min long thermonuclear flash was detected exposing the source as a neutron star in a binary system. The flash was Eddington-limited cons

  25. E. T. Polehampton, J. -P. Baluteau, C. Ceccarelli, B. M. Swinyard

    The giant molecular cloud Sagittarius B2, located near the Galactic Centre, has been observed in the far-infrared by the ISO Long Wavelength Spectrometer. Wavelengths in the range 47-196 microns were covered with the high resolution Fabry-Perot spectrometer, giving a spectral resolution of 30-40 km/s. The J=1-0 and J=2-1 rotational transitions of HD fall wit

  26. Piet Hut

    Traditionally, a simulation of a dense stellar system required choosing an initial model, running an integrator, and analyzing the output. Almost all of the effort went into writing a clever integrator that could handle binaries, triples and encounters between various multiple systems efficiently. Recently, the scope and complexity of these simulations has i

  27. John M. Carpenter, Lynne A. Hillenbrand, M. F. Skrutskie, Michael R. Meyer

    We present the results of a J, H, and K_s photometric monitoring campaign of a 0.72 x 6 sq deg. area centered on the Chamaeleon I star forming region. Data were obtained on 15 separate nights over a 4 month time interval using the 2MASS South telescope. Out of a total of 34,539 sources brighter than the photometric completeness limits (J=16.0, H=15.2, K_s=14

  28. Yoel Rephaeli, Duane Gruber

    The two nearby starburst galaxies M82 and NGC 253 were observed for 100 ksec over a 10-month period in 1997. An increase of the M82 flux by a factor ~2 was measured during the period July-November, when compared with the flux measured earlier in 1997. The flux measured in the field centered on M82 includes ~38 of the emission from the Seyfert 1 galaxy M81. T

  29. Tim Jenness, Jason A. Stevens, Elese N. Archibald, Frossie Economou

    The Submillimetre Common User Bolometer Array (SCUBA) instrument has been operating on the James Clerk Maxwell Telescope (JCMT) since 1997. The data archive is now sufficiently large that it can be used to investigate instrumental properties and the variability of astronomical sources. This paper describes the automated calibration and reduction scheme used

  30. Hideyuki Enoguchi, Hiroshi Tsunemi, Emi Miyata, Kumi Yoshita

    We report here on the observation of Kes 27, a proto-typical mixed-morphology SNR, using ASCA. It clearly shows a filled-center structure in the X-ray region while a shell structure in the radio region. There are two radio bright regions: one is in the center, while the other is in the east rim. The X-ray intensity peak coincides well with the radio bright r

  31. M. Mouhcine, T. Contini

    We compute chemical evolution models to constrain the mode and the history of star formation in starburst galaxies as a whole, i.e. over a large range of mass and metallicity. To this end, we investigate the origin of the dispersion observed in the evolution of both nitrogen-to-oxygen abundance ratio and galaxy luminosity as a function of metallicity for a l

  32. R. Zamanov, P. Marziani

    We point out an analogy between two accreting white dwarfs with jets (CH Cyg and MWC 560) and powerful quasars. In spite of the enormous difference in the mass of the central object (a factor about 10^7), the emission lines are strikingly similar to those of I Zw1 (the prototype &#34;Narrow Line Seyfert 1&#34; nucleus whose spectrum is widely used as an FeII

  33. II Collaboration, R. Enomoto

    Protons with energies up to 10^15 eV are the main component[1] of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking[2]. Electrons are known to be accelerated to cosmic-ray energies in supernova remnants[3, 4], and the shock waves associated with such remnants, when they hit the surr

  34. S. S. Larsen, J. P. Brodie, M. A. Beasley, D. A. Forbes

    We analyze high signal-to-noise spectra for 14 globular clusters (GCs) in the Sombrero galaxy, NGC 4594 = M104, obtained with the LRIS spectrograph on the Keck I telescope. We find generally good agreement between spectroscopic metallicities and previous photometric metallicities based on V-I colors. Further, we use measurements of various Balmer line indice

  35. Martin Olsson, Jason Starr

    Given a separated and locally finitely-presented Deligne-Mumford stack $\cX$ over an algebraic space $S$, and a locally finitely-presented $\OO_{\cX}$-module $\cF$, we prove that the Quot functor $\text{Quot}(\cF/\cX/S)$ is represented by a separated and locally finitely-presented algebraic space over $S$. Under additional hypotheses, we prove that the conne

  36. Yuzuru Sato, James P. Crutchfield

    Starting with a group of reinforcement-learning agents we derive coupled replicator equations that describe the dynamics of collective learning in multiagent systems. We show that, although agents model their environment in a self-interested way without sharing knowledge, a game dynamics emerges naturally through environment-mediated interactions. An applica

  37. Don N. Page, Sumati Surya, Eric Woolgar

    For n+1 dimensional asymptotically AdS spacetimes which have holographic duals on their n dimensional conformal boundaries, we show that the imposition of causality on the boundary theory is sufficient to prove positivity of mass for the spacetime when n > 2, without the assumption of any local energy condition. We make crucial use of a generalization of the

  38. Abhijit Bandyopadhyay, Sandhya Choubey, Srubabati Goswami, D. P. Roy

    We perform model independent and model dependent analyses of solar neutrino data including the neutral current event rate from SNO. The inclusion of the first SNO NC data in the model independent analysis determines the allowed ranges of $^{8}{B}$ flux normalisation and the $ν_e$ survival probability more precisely than what was possible from the SK and SNO

  39. C. Pruneau, S. Gavin, S. Voloshin

    We discuss various measures of net charge (conserved quantities) fluctuations proposed for the identification of critical phenomena in heavy ion collisions. We show the dynamical component of fluctuations of the net charge can be expressed simply in terms of integrals of two- and single-particle densities. We discuss the dependence of the fluctuation observa

  40. Constantine Yannouleas, Uzi Landman

    A new class of analytic wave functions is derived for two dimensional N-electron (2 <= N < infinity) systems in high magnetic fields. These functions are constructed through breaking (at the Hartree-Fock level) and subsequent restoration (via post-Hartree-Fock methods) of the circular symmetry. They are suitable for describing long-range Coulomb correlations

  41. B. Dittrich, R. Loll

    We formulate a dynamically triangulated model of three-dimensional Lorentzian quantum gravity whose spatial sections are flat two-tori. It is shown that the combinatorics involved in evaluating the one-step propagator (the transfer matrix) is that of a set of vicious walkers on a two-dimensional lattice with periodic boundary conditions and that the entropy

  42. O. Morsch, M. Cristiani, J. H. Müller, D. Ciampini

    We have experimentally investigated the free expansion of a Bose-Einstein condensate in an array of two-dimensional traps created by a one-dimensional optical lattice. If the condensate held in a magnetic trap is loaded adiabatically into the lattice, the increase in chemical potential due to the additional periodic potential is reflected in the expansion of

  43. David C. Page, Douglas J. Smith

    We consider giant gravitons as probes of a class of ten-dimensional solutions of type IIB supergravity which arise as lifts of solutions of U(1)^3 gauged N=2 supergravity in five-dimensions. Surprisingly it is possible to solve exactly for minimum energy configurations of these spherical D3-brane probes in the compact directions, even in backgrounds which pr

  44. K. Miuchi, M. Minowa, A. Takeda, H. Sekiya

    Tokyo group has performed first underground dark matter search experiment in 2001 through 2002 at Kamioka Observatory(2700m.w.e). The detector is eight LiF bolometers with total mass 168g aiming for the direct detection of WIMPs via spin-dependent interaction. With a total exposure of 4.1 kg days, we derived the limits in the a_p-a_n (WIMP-nucleon couplings)

  45. M. Ciafaloni, D. Colferai, G. P. Salam, A. Stasto

    We point out that, in some models of small-x hard processes, the transition to the Pomeron regime occurs through a sudden tunneling effect, rather than a slow diffusion process. We explain the basis for such a feature and we illustrate it for the BFKL equation with running coupling by gluon rapidity versus scale correlation plots.

  46. Elena Rossi, Martin J. Rees

    In models for gamma ray burst afterglows, it is normally assumed that the external shock strongly amplifies the magnetic field and that this field maintains a steady value throughout the shocked region. We discuss the effects of modifying this (probably simplistic) assumption by allowing for a short decay time. The observations are incompatible with a post-s

  47. O. Bertolami, F. M. Nunes

    We consider an extension of the recent experiment with ultracold neutrons and the quantization of its vertical motion in order to test the Weak Equivalence Principle. We show that an improvement on the energy resolution of the experiment may allow to establish a modest limit to the Weak Equivalence Principle and on the gravitational screening constant. We al

  48. J. Donin, A. Mudrov

    Let $G$ be a reductive Lie group, $\g$ its Lie algebra, and $M$ a $G$-manifold. Suppose $\A_h(M)$ is a $\U_h(\g)$-equivariant quantization of the function algebra $\A(M)$ on $M$. We develop a method of building $\U_h(\g)$-equivariant quantization on $G$-orbits in $M$ as quotients of $\A_h(M)$. We are concerned with those quantizations that may be simultaneou

  49. Jan-e Alam, Sanjay K. Ghosh, Pradip Roy, Sourav Sarkar

    We study the effects of in-medium hadronic properties on shadowing in photon-nucleus interactions in Glauber model as well as in the multiple scattering approach. A reasonable agreement with the experimental data is obtained in a scenario of downward spectral shift of the hadrons. Shadowing is found to be insensitive to the broadening of the spectral functio

  50. Debajyoti Choudhury, Debashis Ghoshal, Dileep P. Jatkar, Sudhakar Panda

    We analyse of the effective action of the tachyon field on a D-brane, of both bosonic as well as superstring theory. We find that the non-standard kinetic term of the tachyon field requires a correction to the Born-Infeld type Lagrangian. The cosmological significance of the resulting dynamics is explored. We also examine if the rolling tachyon can provide a

  51. M. Ciafaloni, D. Colferai, G. P. Salam, A. M. Stasto

    We study QCD hard processes at scales of order k^2 > Lambda^2 in the limit in which the beta-function coefficient - b is taken to be small, but alphas(k) is kept fixed. The (nonperturbative) Pomeron is exponentially suppressed in this limit, making it possible to define purely perturbative high-energy Green&#39;s functions. The hard Pomeron exponent acquires

  52. H. Eberl, W. Majerotto, V. C. Spanos

    For energies relevant to future linear colliders, $\sqrt{s} \gsim 500$ GeV, the WW fusion channel dominates the Higgs boson production cross section $e^+ e^- \to \barν νh^0$. We have calculated the one-loop corrections to this process due to fermion and sfermion loops in the context of the MSSM. As a special case, the contribution of the fermion loops in the

  53. Koji Hashimoto

    Using D-brane effective field theories, we study dynamical decay of unstable brane systems : (i) a parallel brane-antibrane pair with separation l and (ii) a dielectric brane. In particular we give explicitly the decay width of these unstable systems, and describe how the decay proceeds after the tunnel effect. The decay (i) is analysed by the use of a tachy

  54. N. Schwartz, R. Cohen, D. ben-Avraham, A. -L. Barabasi

    Many complex networks in nature have directed links, a property that affects the network&#39;s navigability and large-scale topology. Here we study the percolation properties of such directed scale-free networks with correlated in- and out-degree distributions. We derive a phase diagram that indicates the existence of three regimes, determined by the values

  55. A. D. Armour, A. MacKinnon

    We investigate the effect of a quantised vibrational mode on electron tunneling through a chain of three quantum dots. The outer dots are coupled to voltage leads, but the position of the central dot is not rigidly fixed. Motion of the central dot modulates the size of the tunneling barriers in opposite ways so that electron tunneling is correlated with the

  56. Michihiro Naka

    We find out that some unitary minimal models of the N=1 ${\cal SW}(3/2,2)$ superconformal algebra can be realized as the level one coset models based on the Wolf spaces $SU(n)/(SU(n-2)\times SU(2))$. We obtain the expression of the fermionic current with the conformal weight 5/2 in the algebra. Then, these models are twisted to give the topological conformal

  57. E. Kiritsis, C. Kounnas, P. M. Petropoulos, J. Rizos

    Five-brane distributions with no strong coupling problems and high symmetry are studied. The simplest configuration corresponds to a spherical shell of branes with S^3 geometry and symmetry. The equations of motions with delta-function sources are carefully solved in such backgrounds. Various other brane distributions with sixteen unbroken supercharges are d

  58. Takashi Tsuji

    We address the problem of how dust forms and how it could be sustained in the static photospheres of cool dwarfs for a long time. In the cool and dense gas, dust forms easily at the condensation temperature, T_cond, and the dust can be in detailed balance with the ambient gas so long as it remains smaller than the critical radius, r_cr. However, dust will gr

  59. Ryushi Goto

    We shall develop a new deformation theory of geometric structures in terms of closed differential forms. This theory is a generalization of Kodaira -Spencer theory and further we obtain a criterion of unobstructed deformations. We apply this theory to certain geometric structures: Calabi-Yau, HyperKähler, $\G$ and $\Spin$ structures and show that these defor

  60. Yosuke Imamura

    We investigate colliding processes of closed strings with large angular momenta with D-branes. We give explicit CFT calculations for closed string states with an arbitrary number of bosonic excitations and no or one fermion excitation. The results reproduce the correspondence between closed string states and single trace operators in the boundary gauge theor

  61. M. Buballa, J. Hosek, M. Oertel

    The analysis of color-superconducting two-flavor deconfined quark matter at moderate densities is extended to include a particular spin-1 Cooper pairing of those quarks which do not participate in the standard spin-0 diquark condensate. (i) The relativistic spin-1 gap Delta&#39; implies spontaneous breakdown of rotation invariance manifested in the form of t

  62. Donald S. Bethune, William P. Risk

    Quantum cryptographic key distribution (QKD) uses extremely faint light pulses to carry quantum information between two parties (Alice and Bob), allowing them to generate a shared, secret cryptographic key. Autocompensating QKD systems automatically and passively compensate for uncontrolled time dependent variations of the optical fiber properties by coding

  63. K. Audenaert, B. De Moor, K. G. H. Vollbrecht, R. F. Werner

    For a special class of bipartite states we calculate explicitly the asymptotic relative entropy of entanglement $E_R^\infty$ with respect to states having a positive partial transpose (PPT). This quantity is an upper bound to distillable entanglement. The states considered are invariant under rotations of the form $O\otimes O$, where $O$ is any orthogonal ma

  64. T. B. Pittman, B. C. Jacobs, J. D. Franson

    One of the main requirements in linear optics quantum computing is the ability to perform single-qubit operations that are controlled by classical information fed forward from the output of single photon detectors. These operations correspond to pre-determined combinations of phase corrections and bit-flips that are applied to the post-selected output modes

  65. D. Salgado, J. L. Sanchez-Gomez

    A formalism is presented to express decoherence both in the markovian and nonmarkovian regimes and both dissipative and nondissipative in isolated systems. The main physical hypothesis, already contained in the literature, amounts to allowing some internal parameters of the system to evolve in a random fashion. This formalism may also be applicable to open q

  66. K. Schonhammer

    For quantum mechanics on a lattice the position (``particle number&#39;&#39;) operator and the quasi-momentum (``phase&#39;&#39;) operator obey canonical commutation relations (CCR) only on a dense set of the Hilbert space. We compare exact numerical results for a particle in simple potentials on the lattice with the expectations, when the CCR are assumed to

  67. M. S. Torres, J. M. A. Figueiredo

    We study the classical motion of a particle subject to a stochastic force. We then present a perturbative schema for the associated Fokker-Planck equation where, in the limit of a vanishingly small noise source, a consistent dynamical model is obtained. The resulting theory is similar to Quantum Mechanics, having the same field equations for probability meas

  68. Constantin Piron

    En nous laissant guider par la notion de champ qui en fait domine toute la physique nous définissons la nature physique d&#39;un système, ses propriétés et ses états possibles. Nous proposons alors un cadre très générale permettant la description de tels systèmes et la construction de modèles consistants. Nous en donnons des exemples et pour illustrer les co

  69. Constantin Piron

    Dans ce colloque je discute la notion d&#39;espace selon Descartes et Leibniz et j&#39;y oppose le point de vue de Samuel Clarke et Isaac Newton comme solution pour comprendre la réalité du monde physique

  70. Z. Papp, C-. Y. Hu

    Electron-hydrogen scattering is studied in the Faddeev-Merkuriev integral equation approach. The equations are solved by using the Coulomb-Sturmian separable expansion technique. We present $S$- and $P$-wave scattering and reactions cross sections up to the $H(n=4)$ threshold.

  71. V. Capek, J. Bok

    An experimentally inspired model is constructed and rigorously solved from the Hamiltonian level where a dc circular spontaneous flow exists in absence of a magnetic field, irrespective of presence of dissipation causing otherwise proper relaxation. The flow causes a spontaneous unidirectional transfer of heat from one bath to another one, even against tempe

  72. Denes Molnar, Miklos Gyulassy

    We investigate whether it is possible to dynamically generate from classical transport theory the observed surprising Rout ~ Rside in Au+Au at s^1/2 = 130A GeV at RHIC. We obtained covariant solutions to the Boltzmann transport equation via the MPC technique, for a wide range of partonic initial conditions and opacities. We demonstrate that there exist trans

  73. E. Hiyama, M. Kamimura, T. Motoba, T. Motoba

    Energy levels of the double-$Λ$ hypernuclei $_Λ^{}$$_Λ^7$He, $_Λ^{}$$_Λ^7$Li, $_Λ^{}$$_Λ^8$Li, $_Λ^{}$$_Λ^9$Li, $_Λ^{}$$_Λ^9$Be and $_Λ^{}$$_Λ^{10}$Be are predicted on the basis of the $α+x+Λ+Λ$ four-body model with $x=n, p, d, t, ^3$He and $α$, respectively.

  74. Scott Bogner, T. T. S. Kuo, L. Coraggio

    We study a method by which realistic nucleon-nucleon potentials V_NN can be reduced, in a physically equivalent way, to an effective low-momentum potential V-low-k confined within a cut-off momentum k-cut. Our effective potential is obtained using the folded-diagram method of Kuo, Lee and Ratcliff, and it is shown to preserve the half-on-shell T-matrix. Both

  75. K. Sasaki, T. Inoue, M. Oka

    Nonmesonic weak decays of the A=4, and 5 hypernuclei are studied. The short range parts of the hyperon-nucleon weak interactions are described by the direct quark (DQ) weak transition potential, while the longer range interactions are given by the $π$ and $K$ meson exchange processes. Virtual $Σ$ mixings of the coherent type are found to give significant eff

  76. Itzhak Tserruya

    The field of relativistic heavy-ion physics is reviewed with emphasis on new results and highlights from the first run of the Relativistic Heavy-Ion Collider at BNL and the 15 year research programme at the SPS at CERN and the AGS at BNL.

  77. Constantin Piron

    After having explained Samuel Clarke&#39;s conception of the new philosophy of physical reality, we will treat the electron field in this context as a field modifying the void. From this we will be able to derive the so-called quantum rules just from Noether&#39;s theorem on conserved currents. Thus quantum theory appears as a kind of nonlocal field theory,

  78. P. L. Christiansen, A. V. Zolotaryuk, V. N. Ermakov, Y. B. Gaididei

    Exact positive and negative energy solutions for the eigenvalue problem of the Schrödinger equation in one dimension with a $δ^\prime$ interaction are found and analyzed. An infinite series of transparency resonance levels in the strength of this interaction is shown to exist. This result is against the actual belief that the $δ^\prime$ potential acts as a t

  79. Bjorn Poonen

    Let k be a field. Let K_0(V_k) denote the quotient of the free abelian group generated by the geometrically reduced varieties over k, modulo the relations of the form [X]=[X-Y]+[Y] whenever Y is a closed subvariety of X. Product of varieties makes K_0(V_k) into a ring. We prove that if the characteristic of k is zero, then K_0(V_k) is not a domain.

  80. Andrei Okounkov, Rahul Pandharipande

    We establish an explicit equivalence between the stationary sector of the Gromov-Witten theory of a target curve X and the enumeration of Hurwitz coverings of X in the basis of completed cycles. The stationary sector is formed, by definition, by the descendents of the point class. Completed cycles arise naturally in the theory of shifted symmetric functions.

  81. Estelle L. Basor, Torsten Ehrhardt

    In this paper we determine the asymptotics of the determinant of Bessel operators for sufficiently smooth generating functions. These operators are similar to Wiener-Hopf operators with the Fourier transform replaced by the Hankel transform and thus the asymptotics of the determinanst are similar to the well-known Szegö-Akhiezer-Kac formula for truncated Wie

  82. Pavel I. Etingof, Adriano A. Moura

    The category of finite dimensional (type 1) representations of a quantum affine algebra $U_q(\hat{\mathfrak g})$ is not semisimple. However, as any abelian category with finite-length objects, it admits a unique decomposition into a direct sum of indecomposable subcategorie (blocks). We define the elliptic central character of a finite dimensional (type 1) r

  83. Maria J. Cantero, Leandro Moral, Luis Velazquez

    It is shown that monic orthogonal polynomials on the unit circle are the characteristic polynomials of certain five-diagonal matrices depending on the Schur parameters. This result is achieved through the study of orthogonal Laurent polynomials on the unit circle. More precisely, it is a consequence of the five term recurrence relation obtained for these ort

  84. Maria J. Cantero, Maria P. Ferrer, Leandro Moral, Luis Velazquez

    The zeros of semi-orthogonal functions with respect to a probability measure mu supported on the unit circle can be applied to obtain Szego quadrature formulas. The discrete measures generated by these formulas weakly converge to the orthogonality measure mu. In this paper we construct families of semi-orthogonal functions with interlacing zeros, and give a

  85. A. Mudrov

    We list characters (one-dimensional representations) of the reflection equation algebra associated with the fundamental vector representation of the Drinfeld-Jimbo quantum group $\U_q\bigl(gl(n)\bigr)$.

  86. J. Donin, A. Mudrov

    We prove that the reflection equation (RE) algebra $\La_R$ associated with a finite dimensional representation of a quasitriangular Hopf algebra $\Ha$ is twist-equivalent to the corresponding Faddeev-Reshetikhin-Takhtajan (FRT) algebra. We show that $\La_R$ is a module algebra over the twisted tensor square \twist{$\Ha$}{$\Ha$} and the double $\D(\Ha)$. We d

  87. Maria J. Cantero, Maria P. Ferrer, Leandro Moral, Luis Velazquez

    Szego&#39;s procedure to connect orthogonal polynomials on the unit circle and orthogonal polynomials on [-1,1] is generalized to nonsymmetric measures. It generates the so-called semi-orthogonal functions on the linear space of Laurent polynomials L, and leads to a new orthogonality structure in the module LxL. This structure can be interpreted in terms of

  88. J. -M. Fontaine, M. Rapoport

    Let (D,phi) be an isocrystal over an algebraically closed field of characteristic p. Let F^bullet be a filtration on D. If F^bullet is (weakly) admissible, its type vector is greater or equal to the slope vector of (D,phi). We prove that conversely, give a type mu greater or equal to the slope vector of (D,phi), there exists an admissible filtration F^bullet

  89. Paul D. Mitchener

    In this article we give a characterisation of the Baum-Connes assembly map with coefficients. The technical tools needed are the K-theory of C*-categories, and equivariant KK-theory in the world of groupoids.

  90. Oleg Viro

    The multivariable Conway function is generalized to oriented framed trivalent graphs equipped with additional structure (coloring). This is done via refinements of Reshetikhin-Turaev functors based on irreducible representations of quantized gl(1|1) and sl(2). The corresponding face state sum models for the generalized Conway function are presented.

  91. N. V. Krylov, R. Liptser

    Convergence of stochastic processes with jumps to diffusion processes is investigated in the case when the limit process has discontinuous coefficients. An example is given in which the diffusion approximation of a queueing model yields a diffusion process with discontinuous diffusion and drift coefficients.

  92. Hiraku Nakajima

    We prove the Kirillov-Reshetikhin conjecture concerning certain finite dimensional representations of a quantum affine algebra $\Ua$ when $\hat\g$ is an untwisted affine Lie algebra of type $ADE$. We use $t$--analog of $q$--characters introduced by the author in an essential way.

  93. Hiraku Nakajima

    Let $\ag$ be an affine Lie algebra, and let $\Ua$ be the quantum affine algebra introduced by Drinfeld and Jimbo. In [Kas94] Kashiwara introduced a $\Ua$-module $V(λ)$, having a global crystal base for an integrable weight $λ$ of level 0. We call it an {\it extremal weight module}. In [\S13]{Kas00} Kashiwara gave a conjecture on the structure of extremal wei

  94. Apoloniusz Tyszka

    Let ϕ((x_1,...,x_n),(y_1,...,y_n))=(x_1-y_1)^2+...+(x_n-y_n)^2. We say that f:R^n -> C^n preserves distance d>=0 if for each x,y \in R^n ϕ(x,y)=d^2 implies ϕ(f(x),f(y))=d^2. We prove that if x,y \in R^n (n>=3) and |x-y|=(\sqrt{2+2/n})^k \cdot (2/n)^l (k,l are non-negative integers) then there exists a finite set {x,y} \subseteq S(x,y) \subseteq R^n such that

  95. Pavel Etingof, Adriano Moura

    We study a quantum version of the Kazhdan-Lusztig functor. Namely, we prove that there exists a fully faithfull exact tensor functor from the category of finite dimensional representations of the quantum affine algebra Uq(sl(n)) (with extended scalars) to the category of finite dimensional representations of Felder&#39;s elliptic quantum group E_{τ,\gamma2}(

  96. Michael Praehofer, Herbert Spohn

    We establish that the static height fluctuations of a particular growth model, the PNG droplet, converges upon proper rescaling to a limit process, which we call the Airy process A(y). The Airy process is stationary, it has continuous sample paths, its single &#34;time&#34; (fixed y) distribution is the Tracy-Widom distribution of the largest eigenvalue of a

  97. Yoshihiro Ônishi

    In this paper we generalize the formula of Frobenius-Stickelberger and the formula of Kiepert type to the genus-two case.

  98. Alexei Vladimirov

    We outline the proofs of several principal statements in conventional renormalization theory. This may be of some use in the light of new trends and new techniques (Hopf algebras, etc.) recently introduced in the field.

  99. Igor Schnakenburg, Peter West

    A description of the bosonic sector of massive IIA supergravity as a non-linear realisation is given. An essential feature of this construction is that the momentum generators have non-trivial commutation relations with the generators associated with the gauge fields.

  100. S. L. Dubovsky, V. A. Rubakov

    In some models with infinite extra dimensions, gauge fields are localized on a brane by gravity. A generic property of these models is the existence of arbitrarily light bulk modes of charged fields. This property may lead to interesting low-energy effects such as electric charge non-conservation on the brane (decay of electron to nothing). One may worry tha