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May 1999 arXiv papers — page 22

Showing 2,1012,200 of 2,202 papers

  1. E. D. Davis, G. I. Ghandour

    We observe that, within the effective generating function formalism for the implementation of canonical transformations within wave mechanics, non-trivial canonical transformations which leave invariant the form of the Hamilton function of the classical analogue of a quantum system manifest themselves in an integral equation for its stationary state eigenfun

  2. Don N. Page

    Contrary to an oft-made claim, there can be observational distinctions (say for the expansion of the universe or the cosmological constant) between "single-history" quantum theories and "many-worlds" quantum theories. The distinctions occur when the number of observers is not uniquely predicted by the theory. In single-history theories, each

  3. James Hormuzdiar, Stephen Hsu

    We apply effective field theory and renormalization group techniques to the problem of Cooper pair formation in neutron stars. Simple analytical expressions for the $^1 S_0$ condensate are derived which are free of nuclear potential model dependencies. The condensate is evaluated using phase shift data from neutron-neutron scattering.

  4. Alain Connes, Henri Moscovici

    We associate canonically a cyclic module to any Hopf algebra endowed with a modular pair, consisting of a group-like element and a character, in involution. This provides the key construct allowing to extend cyclic cohomology to Hopf algebras in the non-unimodular case and further to develop a theory of characteristic classes for actions of Hopf algebras com

  5. Cristopher Moore

    We calculate the generating functions for the number of tilings of rectangles of various widths by the right tromino, the $L$ tetromino, and the $T$ tetromino. This allows us to place lower bounds on the entropy of tilings of the plane by each of these. For the $T$ tetromino, we also derive a lower bound from the solution of the Ising model in two dimensions

  6. Marius Crainic, Ieke Moerdijk

    Etale groupoids arise naturally as models for leaf spaces of foliations, for orbifolds, and for orbit spaces of discrete group actions. In this paper we introduce a sheaf homology theory for etale groupoids. We prove its invariance under Morita equivalence, as well as Verdier duality between Haefliger cohomology and this homology. We also discuss the relatio

  7. John B. Etnyre, Robert W. Ghrist

    We prove that any steady solution to the real analytic Euler equations on a Riemannian 3-sphere must possess a periodic orbit bounding an embedded disc. One key ingredient is an extension of Fomenko's work on the topology of integrable Hamiltonian systems to a degenerate case involving stratified integrals. The result on the Euler equations follows from

  8. Ola Bratteli, Akitaka Kishimoto

    Two automorphisms of a simple stable AF algebra with a finite dimensional lattice of lower semicontinuous traces are shown to be outer conjugate if they act in the same way on the K-group and the extremal traces are scaled by numbers which are not equal to 1 and satisfy a certain condition (which always holds if all the scaling factors are less than 1). The

  9. Bong H. Lian, Kefeng Liu, S. T. Yau

    We generalize our theorems in "Mirror Principle I" to a class of balloon manifolds. Many of the results are proved for convex projective manifolds. In a subsequent paper, Mirror Principle III, we will extend the results to projective manifolds without the convexity assumption.

  10. S. Deser

    Before turning to the new result that D=11 supergravity is 2-loop nonrenormalizable, we give a very brief history of the ultraviolet problems of ordinary quantum gravity and of supergravities in general D.

  11. Giorgio Calucci

    The production of electron-positron pairs in a time-dependent magnetic field is estimated in the hypotheses that the magnetic field is uniform over large distances with respect to the pair localization and it is so strong that the spacing of the Landau levels is larger than the rest mass of the particles. This calculation is presented since it has been sugge

  12. A. J. Bordner, E. Corrigan, R. Sasaki

    Calogero-Moser models can be generalised for all of the finite reflection groups. These include models based on non-crystallographic root systems, that is the root systems of the finite reflection groups, H_3, H_4, and the dihedral group I_2(m), besides the well-known ones based on crystallographic root systems, namely those associated with Lie algebras. Uni

  13. F. Hautmann, Z. Kunszt, D. E. Soper

    We describe diffractive hard processes in the framework of QCD factorization and discuss what one can learn from the study of hadronic systems with small transverse size.

  14. Daniel Gomez-Dumm, G. A. Gonzalez-Sprinberg

    The electric and weak electric dipole form factors for heavy fermions are calculated in the context of the most general two-Higgs-doublet model (2HDM). We find that the large top mass can produce a significant enhancement of the electric dipole form factor in the case of the b and c quarks. This effect can be used to distinguish between different 2HDM scenar

  15. Laura Covi, Jihn E. Kim, Leszek Roszkowski

    We show that axinos produced in the early Universe in the decay of the lightest neutralinos are a natural candidate for cold dark matter. We argue that axinos may well provide the main component of the missing mass in the Universe because their relic density is often comparable with the critical density.

  16. A. V. Belitsky, D. Müller

    We provide a complete set of supersymmetric constraints for the anomalous dimensions of the conformal twist-two operators to all orders of perturbation theory. Employing them we derive new relations between the exclusive evolution kernels and apply them in QCD in order to get definite predictions at leading order and beyond.

  17. A. Giovannini, R. Ugoccioni

    Continuing previous work on collective variables properties in full phase space in hadron-hadron collisions in the TeV region our investigation is extended to multiplicity distributions and clan structure analysis in pseudo-rapidity intervals. Total multiplicity distributions (MDs) are considered also here as the weighted superposition of soft and semi-hard

  18. M. A. Ivanov, P. Santorelli, N. Tancredi

    The form factors of the weak currents, which appear in the semileptonic decays of the heavy pseudoscalar mesons, are calculated within the quark confinement model by taking into account, for the first time, the structure of heavy meson vertex and the finite quark mass contribution in the heavy quark propagators. The results are in quite good agreement with t

  19. T. Paul, J. Swain, Z. Was

    We briefly describe a library that may be used with any e+ e- --> tau+ tau- (n gamma) Monte Carlo program to account for the effects of anomalous tau-tau-gamma couplings. The implementation of this library in KORALZ version 4.04 is discussed.

  20. S. Jadach, B. F. L. Ward, Z. Was

    Brief information on new features of KORALZ version 4.04 with respect to version 4.0 is given. The main difference is that the new version could be used at LEP2 energies, i.e. up to 240 GeV centre-of-mass system energy. The possibility to switch on different classes of anomalous couplings is also included.

  21. G. Lazarides

    The shortcomings of the Standard Big Bang Cosmological Model as well as their resolution in the context of inflationary cosmology are discussed. The inflationary scenario and the subsequent oscillation and decay of the inflaton field are then studied in some detail. The density perturbations produced during inflation and their evolution during the matter dom

  22. J. Engels, F. Karsch, T. Scheideler

    We use two non-perturbative methods to obtain the anisotropy derivatives of the coupling constants (the anisotropy coefficients) of SU(3) lattice gauge theory. These coefficients appear in the derivative formulae for the energy density and the pressure. We calculate them for the standard Wilson and two improved actions, the 2x2 and the Square Symanzik action

  23. SELEX Collaboration, F. G. Garcia, S. Y. Jun

    We present preliminary results on various aspects of charm baryon studies at the 1996-1997 fixed target experiment of Fermilab studying charm produced from incident Sigma, proton, and pion beams at 600 GeV. First results include the comparison of hadroproduction asymmetries for $Lambda_c^+$ production from the 3 beams as well x_F distributions and the first

  24. F. Darabi, H. R. Sepangi

    We consider an empty (4+1) dimensional Kaluza-Klein universe with a negative cosmological constant and a Robertson-Walker type metric. It is shown that the solutions to Einstein field equations have degenerate metric and exhibit transitioins from a Euclidean to a Lorentzian domain. We then suggest a mechanism, based on signature transition which leads to com

  25. C. C. Briggs

    General expressions are given for the coefficients of Chern forms up to the 13th order in curvature in terms of the Riemann-Christoffel curvature tensor and some of its concomitants (e.g., Pontrjagin's characteristic tensors) for n-dimensional differentiable manifolds having a general linear connection.

  26. C. C. Briggs

    Some general expressions are given for the coefficient of the 14th Chern form in terms of the Riemann-Christoffel curvature tensor and some of its concomitants (e.g., Pontrjagin's characteristic tensors) for n-dimensional differentiable manifolds having a general linear connection.

  27. Yuval Oreg, Bertrand I. Halperin

    The transresistance and the Hall transresistance of dirty two-dimensional bi-layer systems in the presence of tunneling bridges (pinholes) are studied theoretically. We find, at weak magnetic field, a non-zero Hall transresistance. In a geometry where the pinholes are concentrated in the middle of the sample, a quantum process gives the dominant contribution

  28. Giuliano Benenti, Xavier Waintal, Jean-Louis Pichard

    For intermediate Coulomb energy to Fermi energy ratios $r_s$, spinless fermions in a random potential form a new quantum phase which is different from the Fermi glass and the Wigner crystal. From a numerical study of small clusters, we show that this phase is characterized by an ordered flow of enhanced persistent currents and occurs for $r_s$ values where a

  29. J. Demsar, B. Podobnik, V. V. Kabanov, D. Mihailovic

    The low-energy electronic excitation spectrum and gap structure in optimally doped and overdoped Y_{1-x}Ca_{x}Ba_{2}Cu_{3}O_{7-δ} single crystals are investigated by real-time measurements of the quasiparticle relaxation dynamics with femtosecond optical spectroscopy. From the amplitude of the photoinduced reflectivity as a function of time, temperature and

  30. D. E. Feldman, I. F. Lyuksyutov, V. L. Pokrovsky

    We consider a superconducting film, placed upon a magnetic dot array. Magnetic moments of the dots are normal to the film and randomly oriented. We determine how the concentration of the vortices in the film depends on the magnetic moment of a dot at low temperatures. The concentration of the vortices, bound to the dots, is proportional to the density of the

  31. Patrick Bruno

    This paper contains the notes of lectures on the theory of interlayer exchange coupling presented at the 30-th Ferienschule of the Institut fuer Festkoerperforschung, Forschungszentrum Juelich, March 1999.

  32. V. Cataudella, G. De Filippis, G. Iadonisi

    The normal state conductivity of a system of interacting large polarons is calculated within the Random Phase approximation and some numerical results are presented. The behaviour of the optical absorption as a function of the charge carrier density and of the temperature is analyzed for different values of the electron-phonon coupling constant. It is shown

  33. K. -V. Pham, M. Gabay, P. Lederer

    Standard bosonization techniques lead to phonon-like excitations in a Luttinger liquid (LL), reflecting the absence of Landau quasiparticles in these systems. Yet in addition to the above excitations some LL are known to possess solitonic states carrying fractional quantum numbers (e.g. the spin 1/2 Heisenberg chain). We have reconsidered the zero modes in t

  34. M. Letz, F. Marsiglio

    A system of equations resulting from an approximation of the equation of motion of Green functions for correlated electron systems is usually solved using Matsubara technique. In this work we propose an alternative method which works entirely along the real frequency axis. Using the example of the attractive Hubbard model studied in the T-matrix approximatio

  35. M. Letz

    The understanding of an electron gas with short coherence length pairs formed by an attractive interaction is believed to be one of the major keys to our theoretical knowledge of the high-T_c-superconductors. Mainly the deviations of the cuprates from usual metallic Fermi liquid behaviour already in the normal state like e.g. a linear resistivity or the obse

  36. Dietmar Weinmann, Jean-Louis Pichard, Peter Schmitteckert, Rodolfo A. Jalabert

    We consider the ground state reorganization driven by an increasing nearest neighbor repulsion U for spinless fermions in a strongly disordered ring. When U -> 0, the electrons form a glass with Anderson localized states. At half filling, a regular array of charges (Mott insulator) is pinned by the random substrate when U -> \infty. Between those two insulat

  37. V. A. Schweigert, F. M. Peeters

    The nucleation field for surface superconductivity, $H_{c3}$, depends on the geometrical shape of the mesoscopic superconducting sample and is substantially enhanced with decreasing sample size. As an example we studied circular, square, triangular and wedge shaped disks. For the wedge the nucleation field diverges as $H_{c3}/H_{c2}=\sqrt{3}/α$ with decreasi

  38. Qimiao Si, J. Lleweilun Smith, Kevin Ingersent

    This article briefly reviews three topics related to the quantum critical behavior of certain heavy-fermion systems. First, we summarize an extended dynamical mean-field theory for the Kondo lattice, which treats on an equal footing the quantum fluctuations associated with the Kondo and RKKY couplings. The dynamical mean-field equations describe an effective

  39. M. J. Bünner

    We present the control of the high-dimensional chaos, with possibly a large number of positive Lyapunov-exponents, of unknown time-delay systems to an arbitrary goal dynamics. We give an existence-and-uniqueness theorem for the control force. In the case of an unknown system, a formula to compute a model-based control force is derived. We give an example by

  40. William E. Wiesel

    The problem of formulating self-consistent local and global stability exponents is shown to require global separation of variables. Posing the separation of variable problem, we see that many such separations are possible, but only one is consistent with both Hamiltonian dynamics and the boundedness requirement for a Lyapunov transform: the determinant of th

  41. C. Mathiazhagan

    A simple technique for decoding an unknown modulated chaotic time-series is presented. We point out that, by fitting a polynomial model to the modulated chaotic signal, the error in the fit gives sufficient information to decode the modulating signal. For analog implementation, a lowpass filter can be used for fitting. This method is simple and easy to imple

  42. Robert E. Shirey, Alan M. Levine, Hale V. Bradt

    We show that dramatic spectral evolution associated with dips occurring near phase zero in RXTE observations of Cir X-1 is well-fit by variable and at times heavy absorption (N_H > 10^24 cm^-2) of a bright component, plus an underlying faint component which is not attenuated by the variable column and whose flux is ~10% of that of the unabsorbed bright compo

  43. Luis C. Ho, Andrew Ptak, Yuichi Terashima, Hideyo Kunieda

    We obtained observations of NGC 4639 with ASCA in order to investigate its mildly active Seyfert 1 nucleus at hard X-ray energies. Koratkar et al. (1995) have previously shown that the nucleus is a pointlike source in the ROSAT soft X-ray band. We detected in the 2-10 keV band a compact central source with a luminosity of 8.3E+40 erg/s. Comparison of the ASC

  44. Luis C. Ho

    As a step toward elucidating the physical conditions in nearby active galaxies, this paper presents spectral energy distributions (SEDs) of a sample of seven low-luminosity active galactic nuclei (AGNs). SEDs for four objects are presented for the first time (NGC 4261, NGC 4579, NGC 6251, and M84); the data for the remaining three (M81, M87, and NGC 4594) ha

  45. J. Greiner, G. H. Tovmassian, S. Komossa, M. Rosado

    We report on optical imaging and spectroscopic observations of the Wolf-Rayet candidate star MLA 1159 and the surrounding ionization nebula BA 1-642 in the Andromeda Galaxy. Though both objects have been known for many years, our observations (1) confirm the Wolf-Rayet nature of MLA 1159, (2) allow one to determine the nebula as an ionization nebula, and (3)

  46. S. Pal, M. Hanauske, I. Zakout, H. Stöcker

    The effects of internal quark structure of baryons on the composition and structure of neutron star matter with hyperons are investigated in the quark-meson coupling (QMC) model. The QMC model is based on mean-field description of nonoverlapping spherical bags bound by self-consistent exchange of scalar and vector mesons. The predictions of this model are co

  47. M. Hattori, J. -P. Kneib, N. Makino

    Gravitational lensing in clusters of galaxies is an efficient tool to probe the mass distribution of galaxies and clusters, high redshift objects thanks to the gravitational amplification, and the geometry of the universe. We review some important aspects of cluster lensing and related issues in observational cosmology.

  48. L. O'C Drury, J. P. Meyer, D. C Ellison

    Detailed composition measurements can be a very powerful means of tracing origins, a fact used regularly by forensic scientists and art historians. One of the main motivating factors for making detailed observations of cosmic rays was always the hope that a unique compositional signature could be found which pointed unambiguously to a particular source. This

  49. Ennio Poretti

    The lower part of the classical instability strip and the surrounding main sequence are populated by a large variety of pulsating variable stars. In the past years a great effort was made by the stellar group of Brera Observatory to collect a large amount of photometric and spectroscopic data on Delta Sct stars, the more numerous class. In this paper I will

  50. R. Morganti, Z. I. Tsvetanov, J. Gallimore, M. G. Allen

    We present radio observations for 29 southern Seyfert galaxies selected from a volume limited sample with cz<3600 km s^-1, and declination delta<0degr. Objects with declination -30degr<delta<0degr were observed with the Very Large Array (VLA) at 6 cm (4.9 GHz) and objects with delta<-30degr were observed with the Australia Telescope Compact Array (ATCA) at 3

  51. Atsunori Yonehara

    In the case of gravitationally-lensed quasars, it is well-known that there is a time delay between occurrence of the intrinsic variabilities in each split image. Generally, the source of variabilities has a finite size, and there are time delays even in one image. If the origin of variabilities is widely distributed, say over $\gsim 100 pc$ as whole, variabi

  52. F. N. Owen, M. J. Ledlow, W. C. Keel, G. E. Morrison

    We report a detailed optical study of the clusters Abell 2125 and 2645. Both clusters have z=0.25 and richness class 4, yet contrast strongly in blue fraction and radio galaxy population. We find 27 spectroscopically confirmed radio galaxies in the blue cluster, A2125 and only four in A2645. The excess radio population in A2125 occurs entirely at L(20cm) < 1

  53. A. Lerda, R. Russo

    We present a pedagogical review of the stable non-BPS states in string theory which have recently attracted some attention in the literature. In particular, following the analysis of A. Sen, we discuss in detail the case of the stable non-BPS D-particle of Type I theory whose existence is predicted (and required) by the heterotic/Type I duality. We show that

  54. K. Held, C. Huscroft, R. T. Scalettar, A. K. McMahan

    The single band Hubbard and the two band Periodic Anderson Hamiltonians have traditionally been applied to rather different physical problems - the Mott transition and itinerant magnetism, and Kondo singlet formation and scattering off localized magnetic states, respectively. In this paper, we compare the magnetic and charge correlations, and spectral functi

  55. D. A. Garanin

    The integral relaxation time for the difference of populations of the two potential wells for double-well classical spin systems is introduced. For the uniaxial symmetry, it is given by a quadrature. Unlike the previously introduced integral relaxation time for the magnetization, the former at low temperatures describes the rate of crossing the barrier under

  56. D. Anselmi

    Some recent ideas are generalized from four dimensions to the general dimension n. In quantum field theory, two terms of the trace anomaly in external gravity, the Euler density G_n and Box^{n/2-1}R, are relevant to the problem of quantum irreversibility. By adding the divergence of a gauge-invariant current, G_n can be extended to a new notion of Euler dens

  57. W. Chen

    One of strengths in the finite element (FE) and Galerkin methods is their capability to apply weak formulations via integration by parts, which leads to elements matching at lower degree of continuity and relaxes requirements of choosing basis functions. However, when applied to nonlinear problems, the methods of this type require a great amount of computing

  58. K. Hosomichi, Y. Sugawara

    We analyze the Coulomb branch of Matrix string theory in the presence of NS5-branes. If we regard the components of U(1) gauge fields as the dualized longitudinal coordinates, we obtain the symmetric product of AdS_3 x S^3 x R^4 as the geometry of Coulomb branch. We observe that the absence or presence of the nonzero electric flux determines whether the stri

  59. Ian J. R. Aitchison, Dominic J. Lee, Georgios Metikas

    We extend to finite temperature the time-dependent effective theory for the Goldstone field (the phase of the pair field) $ θ$ which is appropriate for a superfluid containing one species of fermions with s-wave interactions, described by the BCS Lagrangian. We show that, when Landau damping is neglected, the effective theory can be written as a local time-d

  60. Shin-itiro Goto, Yuji Masutomi, Kazuhiro Nozaki

    The Lie-group approach to the perturbative renormalization group (RG) method is developed to obtain an asymptotic solutions of both autonomous and non-autonomous ordinary differential equations. Reduction of some partial differetial equations to typical RG equations is also achieved by this approach and a simple recipe for providing RG equations is presented

  61. Alexander Chervov

    Intertwiners between representations of Lie groups can be used to obtain relations for matrix elements. We apply this technique to obtain different identities for the wave functions of the open Toda chain, in particular raising operators and bilinear relations for the wave functions at different energy levels. We also recall the group theory approach to the

  62. C. Q. Geng, C. C. Lih, T. H. Wu

    We study the lepton polarization asymmetries in the radiative leptonic B decays of $B^+\to l^+ν_{l}γ$ and $B^+_{c}\to l^+ν_{l}γ$. We concentrate on the transverse component of the $τ$ lepton asymmetries in the tau decay modes due to CP violation in theories beyond the standard model to search T violating effect.

  63. Mark D. Roberts

    Static spherically symmetric uncoupled scalar space-times have no event horizon and a divergent Kretschmann singularity at the origin of the coordinates. The singularity is always present so that non-static solutions have been sought to see if the singularities can develop from an initially singular free space-time. In flat space-time the Klein-Gordon equati

  64. Mark D. Roberts

    A method for finding the world function of Robertson-Walker spacetimes is presented. It is applied to find the world function for the $k=0, \ga=2$, solution. The close point approximation for the Robertson-Walker world function is calculated upto fourth order.

  65. Rebecca Hwa

    Corpus-based grammar induction generally relies on hand-parsed training data to learn the structure of the language. Unfortunately, the cost of building large annotated corpora is prohibitively expensive. This work aims to improve the induction strategy when there are few labels in the training data. We show that the most informative linguistic constituents

  66. M. Bengrine, A. Benyoussef, F. Mhirech, S. D. Zhang

    We propose a one-dimensional rice-pile model which connects the 1D BTW sandpile model (Phys. Rev. A 38, 364 (1988)) and the Oslo rice-pile model (Phys. Rev. lett. 77, 107 (1997)) in a continuous manner. We found that for a sufficiently large system, there is a sharp transition between the trivial critical behaviour of the 1D BTW model and the self-organized

  67. Steven V. W. Beckwith

    This article is a tutorial on deriving physical properties from the spectral energy distributions of circumstellar disks. It includes a new derivation of disk mass from millimeter-wave flux density using recent disk model parameters. The energetics for most disks are dominated by radiative heating and cooling, and almost any spectral energy distribution may

  68. J. Skuljan, J. B. Hearnshaw, P. L. Cottrell

    A two-dimensional velocity distribution in the UV-plane has been obtained for stars in the solar neighbourhood, using the Hipparcos astrometry for over 4000 survey stars with parallaxes greater than 10 mas and radial velocities found in the Hipparcos Input Catalogue. In addition to the already known grouping characteristics (field stars plus young moving gro

  69. Qaisar Shafi, Zurab Tavartkiladze

    We suggest a new mechanism for naturally suppressing dimension five baryon number violating in supersymmetric SU(5+N) (N=0, 1,...) GUTs. The mechanism is realized through suppression of qqT type couplings, and is implemented by introducing new `matter&#39; multiplets belonging to symmetric representations of SU(5+N). Together with the suppression of nucleon

  70. Jinwu Ye, Yong Baek Kim, A. J. Millis, P. Majumdar

    We show that the Anomalous Hall Effect (AHE) observed in Colossal Magnetoresistance Manganites is a manifestation of Berry phase effects caused by carrier hopping in a non-trivial spin background. We determine the magnitude and temperature dependence of the Berry phase contribution to the AHE, finding that it increases rapidly in magnitude as the temperature

  71. S. J. Childs, B. D. Reddy

    In this work a finite element simulation of the motion of a rigid body in a fluid, with free surface, is described. A completely general referential description (of which both Lagrangian and Eulerian descriptions are special cases) of an incompressible, Newtonian fluid is used. Such a description enables a distorting finite element mesh to be used for the de

  72. Oleg Andreev

    We consider some unitary representations of infinite dimensional Lie algebras motivated by string theory on AdS_3. These include examples of two kinds: the A,D,E type affine Lie algebras and the N=4 superconformal algebra. The first presents a new construction for free field representations of affine Lie algebras. The second is of a particular physical inter

  73. I. Ichinose, K. Nagao

    We investigate chiral properties of the overlap lattice fermion by using solvable model in two dimensions, the gauged Gross-Neveu model. In this model, the chiral symmetry is spontaneously broken in the presence of small but finite fermion mass. We calculate the quasi-Nambu-Goldstone(NG) boson mass as a function of the bare fermion mass and two parameters in

  74. Raymond Y. Chiao, Jack Boyce

    The Bogoliubov dispersion relation for the elementary excitations of the weakly-interacting Bose gas is shown to hold for the case of the weakly-interacting photon gas (the ``photon fluid&#39;&#39;) in a nonlinear Fabry-Perot cavity. This relation, which is also derived by means of a linearized fluctuation analysis in classical nonlinear optics, implies the

  75. W. B. Atwood, S. Ritz, P. Anthony, E. D. Bloom

    A beam test of GLAST (Gamma-ray Large Area Space Telescope) components was performed at the Stanford Linear Accelerator Center in October, 1997. These beam test components were simple versions of the planned flight hardware. Results on the performance of the tracker, calorimeter, and anti-coincidence charged particle veto are presented.

  76. Mihai Putinar, Florian-Horia Vasilescu

    The first part of this paper is devoted to an analysis of moment problems in R^n with supports contained in a closed set defined by finitely many polynomial inequalities. The second part of the paper uses the representation results of positive functionals on certain spaces of rational functions developed in the first part, for decomposing a polynomial which

  77. Fang-Hua Lin

    For stationary harmonic maps between Riemannian manifolds, we provide a necessary and sufficient condition for the uniform interior and boundary gradient estimates in terms of the total energy of maps. We also show that if analytic target manifolds do not carry any harmonic S^2, then the singular sets of stationary maps are m \leq n - 4 rectifiable. Both of

  78. Elon Lindenstrauss, David Meiri, Yuval Peres

    Given ergodic p-invariant measures {μ_i} on the 1-torus T=R/Z, we give a sharp condition on their entropies, guaranteeing that the entropy of the convolution \muon converges to \log p. We also prove a variant of this result for joinings of full entropy on \T^\N. In conjunction with a method of Host, this yields the following. Denote \sig_q(x) = qx\pmod{1}. T

  79. J. C. Léger

    For a Borel set E in R^n, the total Menger curvature of E, or c(E), is the integral over E^3 (with respect to 1-dimensional Hausdorff measure in each factor of E) of c(x,y,z)^2, where 1/c(x,y,z) is the radius of the circle passing through three points x, y, and z in E. Let H^1(X) denote the 1-dimensional Hausdorff measure of a set X. A Borel set E in R^n is

  80. Mattias Kreck

    Surgery, as developed by Browder, Kervaire, Milnor, Novikov, Sullivan, Wall and others is a method for comparing homotopy types of topological spaces with diffeomorphism or homeomorphism types of manifolds of dimension >= 5. In this paper, a modification of this theory is presented, where instead of fixing a homotopy type one considers a weaker information.

  81. Michel Hilsum

    We construct analytically the signature operator for a new family of topological manifolds. This family contains the quasi-conformal manifolds and the topological manifolds modeled on germs of homeomorphisms of R^n possessing a derivative which is in L^p, with p > n(n+1)/2. We obtain an unbounded Fredholm module which defines a class in the K-homology of the

  82. Mark Feighn, Michael Handel

    The mapping torus of an endomorphism Φof a group G is the HNN-extension G*_G with bonding maps the identity and Φ. We show that a mapping torus of an injective free group endomorphism has the property that its finitely generated subgroups are finitely presented and, moreover, these subgroups are of finite type.

  83. Henri Darmon

    It is believed that any p-adic Galois representation which is potentially semistable arises from a modular form. The main theorem of Wiles establishes this modularity when the representation in question satisfies various technical restrictions, together with the key hypothesis that its reduction modulo p arises itself from a modular form. This article explai

  84. Kevin Buzzard, Richard Taylor

    In this paper we prove the following theorem. Let L/\Q_p be a finite extension with ring of integers O_L and maximal ideal lambda. Theorem 1. Suppose that p >= 5. Suppose also that ρ:G_\Q -> GL_2(O_L) is a continuous representation satisfying the following conditions. 1. ρramifies at only finitely many primes. 2. ρmod λis modular and absolutely irreducible.

  85. Hari Bercovici, Vittorino Pata, Philippe Biane

    In this paper we determine the distributional behavior of sums of free (in the sense of Voiculescu) identically distributed, infinitesimal random variables. The theory is shown to parallel the classical theory of independent random variables, though the limit laws are usually quite different. Our work subsumes all previously known instances of weak convergen

  86. Luis Barreira, Yakov Pesin, Jörg Schmeling

    We prove that every hyperbolic measure invariant under a C^{1+α} diffeomorphism of a smooth Riemannian manifold possesses asymptotically ``almost&#39;&#39; local product structure, i.e., its density can be approximated by the product of the densities on stable and unstable manifolds up to small exponentials. This has not been known even for measures supporte

  87. Semyon Alesker

    The famous Hadwiger theorem classifies all rigid motion invariant continuous valuations on convex sets as linear conbinations of quermassintegrals. We prove much more general result. We classify continuous valuations which are invariant with respect to the orthogonal (or special orthogonal) group. Some applications to integral geometry are given.

  88. Masakazu Kojima, Levent Tuncel

    General Successive Convex Relaxation Methods (SRCMs) can be used to compute the convex hull of any compact set, in an Euclidean space, described by a system of quadratic inequalities and a compact convex set which is not very complicated. Linear Complementarity Problems (LCPs) make an interesting and rich class of structured nonconvex optimization problems.

  89. Joaquim Roe

    Let Z be a zero-dimensional subscheme of the projective plane consisting of the union of r>5 double points, I its defining ideal sheaf. It is known that I has the expected cohomology when the points are distinct and in general position (Hirschowitz &#39;85). We extend this result by allowing infinitely near points, one of them having bigger multiplicity. As

  90. Jason Fulman

    The adjoint action of a finite group of Lie type on its Lie algebra is studied. A simple formula is conjectured for the number of split semisimple orbits of a given genus. This conjecture is proved for type A, and partial results are obtained for other types. For type A a probabilistic interpretation is given in terms of card shuffling.

  91. Mark Adler, Pierre van Moerbeke

    The study of the spectrum of coupled random matrices has received rather little attention. To the best of our knowledge, coupled random matrices have been studied, to some extent, by Mehta. In this work, we explain how the integrable technology can be brought to bear to gain insight into the nature of the distribution of the spectrum of coupled Hermitean ran

  92. L. P. Fulcher, J. Rafelski, R. L. Thews

    We investigate the fate of bottom quarks produced in heavy-ion collisions at RHIC. Examining both the direct capture of a charmed quark, and multi-step processes, where the B_c meson is formed in a sequence of quark capture and exchange reactions, we find: a) that a sufficiently high number of B_c&#39;s will be produced to generate a detectable tri-lepton si

  93. V. Dorofeev, VES Collaboration

    The results of the patial wave analysis(PWA) of the pi+pi-pi- and omegapi-pi0 systems are presented. The a3 and a4(2040) signals are observed in the rho(770)pi and f2(1270)pi channels. Indications of the a1&#39; meson existence was found in the 1+0+ rhopi S-wave. The decay branching ratio of the a2(1320)- to omegapi-pi0 was measured. The 2+1+ wave shows a br

  94. V. Dorofeev, D. Bugg, VES Collaboration

    Results of the ethapi+pi- and omegaomega final state partial wave analysis(PWA) are presented. The mass-independent and the mass-dependent PWA were performed. The ethapi+pi- system PWA results in the observation of the resonances in the JPC=1--,3--,2++ and 4++ waves. The results of the omegaomega system PWA confirms the existence of the f2(1565) and f4(2050)

  95. C. C. Briggs

    General expressions are given for Chern forms up to the 13th order in curvature in terms of simple polynomial concomitants of the curvature 2-form for n-dimensional differentiable manifolds having a general linear connection.

  96. C. C. Briggs

    A general expression is given for the 14th Chern form in terms of simple polynomial concomitants of the curvature 2-form for n-dimensional differentiable manifolds having a general linear connection.

  97. Shi-Jian Gu, You-Quan Li, Hai-Qing Lin

    On the basis of Bethe ansatz solution of one dimensional Kondo model with electronic interaction, the thermodynamics equilibrium of the system in finite temperature is studied in terms of the strategy of Yang and Yang. The string hypothesis in the spin rapidity is discussed extensively. The thermodynamics quantities, such as specific heat and magnetic suscep

  98. Yu. E. Lozovik, O. L. Berman, V. G. Tsvetus

    Superfluidity of spatially separated electrons and holes and unbalanced two-layer electron system in high magnetic field is considered. The temperature of the Kosterlitz-Thouless transition to a superfluid state is obtained as a function of magnetic field and interlayer separation. The equation of state for magnetoexciton system in quasi-classical regime is

  99. R. Reigada, A. H. Romero, A. Sarmiento, K. Lindenberg

    All systems in thermal equilibrium exhibit a spatially variable energy landscape due to thermal fluctuations. Thus at any instant there is naturally a thermodynamically driven localization of energy in parts of the system relative to other parts of the system. The specific characteristics of the spatial landscape such as, for example, the energy variance, de

  100. Ian Affleck, Masaki Oshikawa

    Recent experiments on the S=1/2 antiferromagnetic chain compound, Cu benzoate, discovered an unexpected gap scaling as approximately the 2/3 power of an applied magnetic field. A theory of this gap, based on an effective staggered field, orthogonal to the applied uniform field, resulting from a staggered gyromagnetic tensor and a Dzyaloshinskii-Moriya intera