October 1999 arXiv papers — page 2

Kenneth M. Lanzetta, Hsiao-Wen Chen, Alberto Fernandez-Soto, Sebastian Pascarelle

We report on some aspects of our efforts to establish properties of the extremely faint galaxy population by applying our photometric redshift technique to the HDF and HDF-S WFPC2 and NICMOS fields. We find that cosmological surface brightness dimming effects play a dominant role in setting what is observed at redshifts z > 2, that the comoving number densit

Arlin P. S. Crotts

The volume around the SN 1987A contains a variety of structures, not just the three rings glowing in recombination lines. Many of these are revealed by light echoes, so are mapped in three dimensions by our optical imaging of the SN environs. The rings reside in a bipolar nebula containing them at its waist and crowns, and which is itself contained in a larg

A. P. S. Crotts, R. Uglesich, G. Gyuk

We detail how microlensing internal to M31 could be used to test whether a large fraction of the matter in spiral galaxy haloes is composed of dark objects with masses comparable to those of stars, and in the process show how the microlensing matter is distributed in space and as a function of mass. A survey of small fields in M31 has revealed several such c

Nick Gorkavyi, Leonid Ozernoy, John Mather, Tanya Taidakova

We develop a physical model of the zodiacal cloud incorporating the real dust sources of asteroidal, cometary, and kuiperoidal origin. Using the inferred distribution of the zodiacal dust, we compute its thermal emission and scattering at several wavelengths (1.25, 5, and 20 $μ$m) as a function of NGST location assumed to be at 1 AU or 3 AU. Areas on the sky

Gareth Leyshon

This thesis reports the K-band polarizations of a representative sample of nine radio galaxies: seven 3C objects at 0.7 < z < 1.3, and two other distinctive sources. Careful consideration is given to the accurate measurement and `debiasing&#39; of faint polarizations, with recommendations for the function of polarimetric software. 3C 22 and 3C 41 both have 3

J. E. McEnery, R. Atkins, W. Benbow, D. Berley

Milagrito, a detector sensitive to gamma-rays at TeV energies, monitored the northern sky during the period February 1997 through May 1998. With a large field of view and high duty cycle, this instrument was used to perform a search for TeV counterparts to gamma-ray bursts. Within the Milagrito field of view 54 gamma-ray bursts at keV energies were observed

S. B. Kraemer, D. M. Crenshaw

The physical conditions near the optical continuum peak (``hot spot&#39;&#39;) in the inner narrow line region (NLR) of the Seyfert 2 galaxy, NGC 1068. Spectra were taken with HST/STIS through the 0.1X52 arcsec slit, covering the full STIS 1200 to 10000 Angstrom waveband, and are from a region that includes the hot spot, extending 0.2, or ~ 14 pc (for H= 75

D. M. Crenshaw, S. B. Kraemer

We present the first long-slit spectra of the Seyfert 2 galaxy NGC 1068 obtained by the Space Telescope Imaging Spectrograph (STIS); the spectra cover the wavelength range 1150 - 10,270 Angstroms at a spatial resolution of 0.05 - 0.1 arcsec and a spectral resolving power of 1000. In this first paper, we concentrate on the far-UV to near-IR continuum emission

David Merritt

Supermassive binary black holes and their influence on the structure and evolution of galaxies is reviewed.

Jordi Miralda-Escude

This review presents a brief discussion of the theory of Cold Dark Matter of structure formation in the universe, describing the main processes determining the power spectrum, the non-linear gravitational collapse, the formation of galaxies and the evolution of the intergalactic medium. Recent advances in the observations of high redshift galaxies, and their

Peter J. Wheatley

Symbiotic stars are thought to show distinct X-ray emission from the accreting object and from the colliding winds of the two stars. I show that the colliding wind component is unnecessary. Instead, the spectra can be interpreted as emission only from the compact object that is strongly absorbed by the partially-ionised wind of the red giant. There remains n

K. S. Cheng, J. H. Fan, L. Zhang

In this paper, a method is proposed to determine the basic properties of $γ$-ray loud blazars, among them the central black hole mass, M, the Doppler factor, $δ$, the propagation angle of the $γ$-rays with respect to the symmetric axis of a two-temperature accretion disk, $Φ$, and the distance (i.e. the height above the accretion disk), d at which the $γ$-ra

Nami Mowlavi

[condensed] A new scenario is presented for the production of Na23 in asymptotic giant branch (AGB) stars. The scenario takes advantage of the periodic third dredge-up episodes characterizing those stars, which mix primary C12 from their intershell layers to their surface. Two successive interpulse/pulse/dredge-up sequences are then required to produce Na23.

P. Kretschmar, I. Kreykenbohm, J. Wilms, R. Staubert

We present results from a 20 h RXTE observation of Vela X-1, ncluding a peculiar low state of a few hours duration, during which the pulsation of the X-ray emission ceased, while significant non-pulsed emission remained. This ``quiescent state&#39;&#39; was preceded by a ``normal state&#39;&#39; without any unusual signs and followed by a ``high state&#39;&#

F. Poli, E. Giallongo, N. Menci, S. D&#39;Odorico

The sizes of the field galaxies with I<25 have been measured in the NTT Deep Field. Intrinsic sizes have been obtained after deconvolution of the PSF with a multigaussian method. The reliability of the method has been tested using both simulated data and HST observations of the same field. The distribution of the half light radii is peaked at r_{hl} 0.3 arcs

Alexander K. Konopelko

We discuss an effect of the intergalactic absorption of the TeV gamma-rays in time-averaged spectrum of Mkn 501 measured by the HEGRA Collaboration. Analysis of the spectral behavior, variability time scale and relevant calculations of TeV gamma-ray emission allow to conclude the presence of a noticeable absorption of the TeV gamma-rays in the Mkn 501 energy

Nils Bergvall, Goran Ostlin, Josefa Masegosa, Erik Zackrisson

The effects of mergers in low mass galaxies are poorly understood. In this paper we analyze different observational evidences which support the view that mergers can trigger starbursts in dwarf galaxies. We discuss the relationships between blue compact galaxies (BCGs), dIs, dEs and low surface brightness galaxies (LSBGs) and present some evidences which fav

T. Douvion, P. O. Lagage, C. J. Cesarsky

Thanks to mid-infrared observations, we provide new clues to the element mixing during a supernova explosion by probing the mixing between three adjacent layers: the oxygen burning products layer (sulfur, argon,...), the silicate layer and the neon layer. The silicate and neon layers are both contaminated by sulfur and argon in a macroscopic way, but appear

D. K. Galloway, K. Wu

Pulse profiles from X-ray pulsars often exhibit strong energy dependence and both periodic and aperiodic variations with time. The great variety of profiles observed in various sources, and even from individual sources, makes it difficult to separate the numerous factors influencing the phase-dependence of the X-ray emission. These factors include the system

Paolo Padoan, Raul Jimenez, James Dunlop

The first stars to form in protogalaxies must have primordial chemical composition. We refer to a protogalaxy that is forming stars of primordial composition, or very low metallicity ($Z\le 0.01 Z_{\odot}$), as ``Primordial Proto-Galaxy&#39;&#39; (PPG). PPGs contain little or no dust, and therefore their spectral energy distribution can be modelled from the

Andrei Ya. Maltsev

We consider the $m$-phase Whitham's averaging method and propose a procedure of "averaging" of non-local Hamiltonian structures. The procedure is based on the existence of a sufficient number of local commuting integrals of a system and gives a Poisson bracket of Ferapontov type for the Whitham's system. The method can be considered as a generalization of th

M. Bertolini, M. Trigiante

We show in a precise group theoretical fashion how the generating solution of regular BPS black holes of N=8 supergravity, which is known to be a solution also of a simpler N=2 STU model truncation, can be characterized as NS-NS or R-R charged according to the way the corresponding STU model is embedded in the original N=8 theory. Of particular interest is t

M. Khodas, S. Fishman, O. Agam

The relaxation rates to the invariant density in the chaotic phase space component of the kicked rotor (standard map) are calculated analytically for a large stochasticity parameter, $K$. These rates are the logarithms of the poles of the matrix elements of the resolvent, $ \hat{R}(z)=(z-\hat{U})^{-1} $, of the classical evolution operator $\hat{U} $. The re

Antonio O. Bouzas

We give a complete analytical computation of three and two-point loop integrals occurring in heavy-particle theories, involving a velocity change, for arbitrary real values of the external masses and residual momenta.

M. Bocquet, D. Serban, M. R. Zirnbauer

Disordered noninteracting quasiparticles that are governed by a Majorana-type Hamiltonian -- prominent examples are dirty superconductors with broken time-reversal and spin-rotation symmetry, or the fermionic representation of the 2d Ising model with fluctuating bond strengths -- are called class D. In two dimensions, weakly disordered systems of this kind m

Frederic Piron

The Very High Energy (VHE) gamma-ray emission of the BL Lacertae objects Markarian 501 and Markarian 421 has been observed by the CAT Imaging Atmospheric Cherenkov Telescope in 1997 and 1998. The spectrum extraction method is presented, and the spectral properties of both sources are compared in different activity states. Theoretical implications for jet ast

Frederic Piron

Due to the lack of test-beams in ground-based gamma-ray astronomy, detector calibration has been a major challenge in this field. However, with the use of Cherenkov ring-images due to cosmic-ray muons and of strong gamma-ray signals, the CAT telescope could be rather well monitored and understood. Here we present a few oustanding aspects of this work.

A. D. Dolgov

Cosmological arguments proving that the universe is dominated by invisible non-baryonic matter are reviewed. Possible physical candidates for dark matter particles are discussed. A particular attention is paid to non-compensated remnants of vacuum energy, to the question of stability of super-heavy relics, cosmological mass bounds for very heavy neutral lept

S. Gieseke, C. -F. Qiao

The light-cone Photon wave function in explicit helicity states, valid for massive quarks and in both momentum and configuration space, is presented by considering the leading order photon-proton hard scattering, i.e., the splitting quark pair scatters with the proton in the Regge limit. Further we apply it to the diffractive scattering at nonzero momentum t

E. Ruiz Arriola, L. L. Salcedo

The anomalies of a very general class of non local Dirac operators are computed using the $\zeta$-function definition of the fermionic determinant and an asymmetric version of the Wigner transformation. For the axial anomaly all new terms introduced by the non locality can be brought to the standard minimal Bardeen's form. Some extensions of the present tech

Vidar Gudmundsson, Sigurdur I. Erlingsson, Andrei Manolescu

We calculate the magnetization of the two-dimensional electron gas in a short-period lateral superlattice, with the Coulomb interaction included in Hartree and Hartree-Fock approximations. We compare the results for a finite, mesoscopic system modulated by a periodic potential, with the results for the infinite periodic system. In addition to the expected st

Massimo Bianchi, Jose&#39; F. Morales, Gianfranco Pradisi

We discuss some Z_N^L x Z_N^R orbifold compactifications of the type IIB superstring to D= 4,6 dimensions and their type I descendants. Although the Z_N^L x Z_N^R generators act asymmetrically on the chiral string modes, they result into left-right symmetric models that admit sensible unorientable reductions. We carefully work out the phases that appear in t

Vahid Rezania, M. Jahan-Miri

The loss of angular momentum through gravitational radiation, driven by the excitation of r-modes, is considered in neutron stars having rotation frequencies smaller than the associated critical frequency. We find that for reasonable values of the initial amplitudes of such pulsation modes of the star, being excited at the event of a glitch in a pulsar, the

P. F. L. Maxted, C. K. J. Moran, T. R. Marsh, A. A. Gatti

We have used the radial velocity variations of two sdB stars previously reported to be binaries to establish their orbital periods. They are PG0940+068, (P=8.33d) and PG1247+554 (P=0.599d). The minimum masses of the unseen companions, assuming a mass of 0.5 solar masses for the sdB stars, are 0.090 +/- 0.003 solar masses for PG1247+554 and 0.63 +/- 0.02 sola

Oliver Rudolph

The basic mathematical framework for super Hilbert spaces over a Grassmann algebra with a Grassmann number-valued inner product is formulated. Super Hilbert spaces over infinitely generated Grassmann algebras arise in the functional Schroedinger representation of spinor quantum field theory in a natural way.

M. Khorrami, M. Alimohammadi

Using the collective field theory approach of large-N generalized two-dimensional Yang-Mills theory on cylinder, it is shown that the classical equation of motion of collective field is a generalized Hopf equation. Then, using the Itzykson-Zuber integral at the large-N limit, it is found that the classical Young tableau density, which satisfies the saddle-po

A. Campillo, J. I. Farran

We present an algorithm to compute the Weierstrass semigroup at a point P together with functions for each value in the semigroup, provided P is the only branch at infinity of a singular plane model for the curve. As a byproduct, the method also provides us with a basis for the spaces L(mP) and the computation of the Feng-Rao distance for the corresponding a

Alessio Guglielmi

This paper introduces a logical system, called BV, which extends multiplicative linear logic by a non-commutative self-dual logical operator. This extension is particularly challenging for the sequent calculus, and so far it is not achieved therein. It becomes very natural in a new formalism, called the calculus of structures, which is the main contribution

A. Campillo, J. I. Farran

We present an algorithm to compute bases for the spaces L(G), provided G is a rational divisor over a non-singular absolutely irreducible algebraic curve, and also another algorithm to compute the Weierstrass semigroup at P together with functions for each value in this semigroup, provided P is a rational branch of a singular plane model for the curve. The m

Jun-ichiro Kishine

We study the low-energy asymptotics of the half-filled Hubbard model with a circular Fermi surface in $d=1+ε$ continuous dimensions, based on the one-loop renormalization-group (RG) method. Peculiarity of the $d=1+ε$ dimensions is incorporated through the mathematica structure of the elementary particle-partcile (PP) and particle-hole (PH) loops: infrared lo

Yuji Hara

Integral formulae for the correlation functions of the XYZ model with a boundary are calculated by mapping the model to the bosonized boundary SOS model. The boundary K-matrix considered here coincides with the known general solution of the boundary Yang-Baxter equation. For the case of diagonal K-matrix, our formulae reproduce the one-point function previou

H. J. Kim, H. J. Ahn, S. K. Kim, E. Won

Searches for weakly interacting massive particles(WIMP) can be based on the dete ction of nuclear recoil energy in CsI(Tl) crystals. We demonstrate that low energy gamma rays down to few keV is detected with CsI(Tl) crystal detector. A clear peak at 6 keV is observed using X-ray source. Good energy resolution and linearity have been achieved down to X-ray re

David Sudarsky, Adam Burrows, Philip Pinto

We generate theoretical albedo and reflection spectra for a full range of extrasolar giant planet (EGP) models, from Jovian to 51-Pegasi class objects. Our albedo modeling utilizes the latest atomic and molecular cross sections, a Mie theory treatment of extinction by condensates, a variety of particle size distributions, and an extension of the Feautrier ra

Ue-Li Pen

We present a general linear algorithm for measuring the surface mass density 1-κfrom the observable reduced shear g=γ/(1-κ) in the strong lensing regime. We show that in general, the observed polarization field can be decomposed into ``electric&#39;&#39; and ``magnetic&#39;&#39; components, which have independent and redundant solutions, but perfectly orthog

H. Furutsu, T. Kojima, Y. -H. Quano

The SU(2) invariant massive Thirring model with a boundary is considered on the basis of the vertex operator approach. The bosonic formulae are presented for the vacuum vector and its dual in the presence of the boundary. The integral representations are also given for form factors of the present model.

Nistor Nicolaevici

We consider the vacuum fluctuations contribution to the mass of a mirror in an exactly soluble partially reflecting moving mirror model. Partial reflectivity is accounted for by a repulsive delta-type potential localized along the mirror trajectory. The mirror&#39;s mass is explicitly found as an integral functional of the mirror&#39;s past trajectory.

Konrad Banaszek

In this thesis we present a direct scheme for measuring quasidistribution functions of light. This scheme, based on photon counting, is derived from a simple relation linking the Wigner function with photon statistics. We develop a full multimode theory of the scheme, and show that the principle of the measurement can be straightforwardly generalized to the

Guihua Zeng, Xinmei Wang

The security of the previous quantum key distribution (QKD) protocols, which is guaranteed by the nature of physics law, is based on the legitimate users. However, impersonation of the legitimate communicators by eavesdroppers, in practice, will be inevitable. In fact, the previous QKD protocols is unsecure without authentication in practical communication.

Alex A. Samoletov

A model of chemical synapse as an electric junction is proposed. Estimations and analysis of the model show that the junction has unique physical characteristics reminding the Josephson junction.

J. C. R. Bloch, C. D. Roberts, S. M. Schmidt

We study the evolution of a strong field plasma using a quantum Vlasov equation with a non-Markovian source term and a simple collision term, and calculate the time dependence of the energy- and number-density, and the temperature. The evolution of a plasma produced with RHIC-like initial conditions is well described by a low density approximation to the sou

B. Krippa

The effective field theory of NN interactions in nuclear matter is considered. Due to the Pauli principle the effective NN amplitude is not affected by the shallow bound states. We show that the next-to-leading order terms in the chiral expansion of the effective NN potential can be interpreted as corrections so the expansion is systematic. The value of pote

A. Mengoni, T. Otsuka

We show examples of neutron capture, photo dissociation and Coulomb dissociation processes, relevant for studying nuclear structure properties of some light nuclei. In the case of the neutron capture, we show how interference effects among the direct and resonance processes can be accounted for. The same interference effect is shown to play an important role

V. G. Kartavenko, A. Sandulescu, W. Greiner

A static scission configuration in cold ternary fission has been considered in the framework of mean field approach. The inverse scattering method is applied to solve single-particle Schroedinger equation, instead of constrained selfconsistent Hartree-Fock equations. It is shown, that it is possible to simulate one-dimensional three-center system via inverse

Steven Duplij

The thesis is devoted to abstract, geometric and symmetric aspects of modern elementary particle theories. A new direction in constructing supersymmetric and superstring models based on consequent and strong consideration and inclusion of semigroups, ideals and noninvertible properties into their mathematical structure is proposed. A theory of semisupermanif

A. Rennie

In [1], Connes presented axioms governing noncommutative geometry. He went on to claim that when specialised to the commutative case, these axioms recover spin or spin^c geometry depending on whether the geometry is &#39;&#39;real&#39;&#39; or not. We attempt to flesh out the details of Connes&#39; ideas. As an illustration we present a proof of his claim, p

N. J. Kalton, C. Le Merdy

We answer a question of Peller by showing that for any c>1 there exists a power-bounded operator T on a Hilbert space with the property that any operator S similar to T satisfies $\sup_n\|S^n\|>c.$

Oren Kolman, Saharon Shelah

The classes of slender and cotorsion-free abelian groups are axiomatizable in the infinitary logics L_{infty,omega_1} and L_{infty,omega}, respectively. The Baer-Specker group Z^omega is not L_{infty,omega_1}-equivalent to a slender group.

Ruediger Goebel, Saharon Shelah

Let R be a subring of the rationals. We want to investigate self splitting R-modules G that is Ext_R(G,G)=0 holds. For simplicity we will call such modules splitters. Our investigation continues math.LO/9910159. In math.LO/9910159, we answered an open problem by constructing a large class of splitters. Classical splitters are free modules and torsion-free, a

Y. Brudnyi, N. J. Kalton

Let K be a closed bounded convex subset of $\Bbb R^n$; then by a result of the first author, which extends a classical theorem of Whitney there is a constant $w_m(K)$ so that for every continuous function f on K there is a polynomial $ϕ$ of degree at most m-1 so that $$ |f(x)-ϕ(x)|\le w_m(K)\sup_{x,x+mh\in K} |Δ_h^m(f;x)|.$$ The aim of this paper is to study

Ruediger Goebel, Saharon Shelah

Let R be a subring of the rationals. We want to investigate self splitting R-modules G that is Ext_R(G,G)=0 holds and follow Schultz to call such modules splitters. Free modules and torsion-free cotorsion modules are classical examples for splitters. Are there others? Answering an open problem by Schultz we will show that there are more splitters, in fact we

Saharon Shelah

This is a non-standard paper, containing some problems, mainly in model theory, which I have, in various degrees, been interested in. Sometimes with a discussion on what I have to say; sometimes, of what makes them interesting to me, sometimes the problems are presented with a discussion of how I have tried to solve them, and sometimes with failed tries, ane

Claude Sabbah

We show the compatibility between the moderate or nearby cycle functor for regular holonomic $\mathcal{D}$-modules, as defined by Beilinson, Kashiwara and Malgrange, and the Hermitian duality functor, as defined by Kashiwara.

Moshe Rozali

We establish a relation, conjectured recently by E. Witten, between the hypermultiplet moduli space in compactifications of the heterotic string on an A-D-E singularities, and the moduli spaces of three dimensional pure gauge theories with the corresponding A-D-E gauge groups. It is possible to add a bounded number of heterotic fivebranes sitting in the sing

Ori J. Ganor

In a previous paper we conjectured that the structure of various gauge theories as well as M-theory on $T^8$ is encoded in a unique function $Ξ$ on the coset $E_{10}(Z)\backslash E_{10}(R)/K$ and that this function is harmonic with respect to the $E_{10}(R)$ invariant metric. In this paper we elaborate on the conjecture. We discuss various mass deformations

Jean-Loup Gervais

In a recent paper (hep-th/9811108), Saveliev and the author showed that there exits an on-shell light cone gauge where the non-linear part of the field equations reduces to a (super) version of Yang&#39;s equations which may be solved by methods inspired by the ones previously developed for self-dual Yang-Mills equations in four dimensions. Later on (hep-th/

Alexei A. Abrikosov

The multi-instanton solutions by &#39;tHooft and Jackiw, Nohl & Rebbi are generalized to curvilinear coordinates. Expressions can be notably simplified by the appropriate gauge transformation. This generates the compensating addition to the gauge potential of pseudoparticles. Singularities of the compensating connection are irrelevant for physics but affect

Henrique Boschi-Filho, Nelson R. F. Braga

We discuss how the variational principle can be used as a criterion for choosing, among scalar field actions implying the same equation of motion, the appropriate one for the AdS/CFT correspondence.

R. Loll, J. Ambjorn, K. N. Anagnostopoulos

In two space-time dimensions, there is a theory of Lorentzian quantum gravity which can be defined by a rigorous, non-perturbative path integral and is inequivalent to the well-known theory of (Euclidean) quantum Liouville gravity. It has a number of appealing features: i) its quantum geometry is non-fractal, ii) it remains consistent when coupled to matter,

Marek Rogatko

We presented the proof of the positive mass theorem for black holes in Einstein-Maxwell axion-dilaton gravity being the low-energy limit of the heterotic string theory. We show that the total mass of a spacetime containing a black hole is greater or equal to the square root of the sum of squares of the adequate dilaton-electric and dilaton-axion charges.

A. Gorsky, K. Selivanov

It is argued that there are states (quasiparticles) with masses ranging over the scales $ΛN_{c}^{1/3} ÷ΛN_{c}$ in N=1 supersymmetric multicolor gluodynamics. These states exist in the form of quantum bubbles made out of the BPS domain walls. Analogous states are likely to exist in non-supersymmetric case as well.

V. A. Dolgushev

An open bosonic string is considered with the aim to construct a general gauge invariant, being a polynomial of Fubini-Veneziano (FV) fields. The FV fields are transformed as 1-forms on $S^1$, that allows to formulate the problem in geometric terms. We introduce a most general anzats for these invariants and explicitly resolve the invariance conditions in th

Mariano Cadoni, Salvatore Mignemi

We show that the arguments proposed by Park and Yee against our recent derivation of the statistical entropy of 2D black holes do not apply to the case under consideration

Heinrich Saller

The linear particle-antiparticle conjugation $\ty C$ and position space reflection $\ty P$ as well as the antilinear time reflection $\ty T$ are shown to be inducable by the selfduality of representations for the operation groups $\SU(2)$, $\SL(\C^2)$ and $\R$ for spin, Lorentz transformations and time translations resp. The definition of a colour compatible

Ori J. Ganor

We propose that the structure of gauge theories, the $(2,0)$ and little-string theories is encoded in a unique function on the real group manifold $E_{10}(R)$. The function is invariant under the maximal compact subgroup $K$ acting on the right and under the discrete U-duality subgroup $E_{10}(Z)$ on the left. The manifold $E_{10}(Z)\backslash E_{10}(R) /K$

Luca Girlanda

The possibility of detecting the S-wave of the decays tau -> 3 pi + nu(tau) in the threshold region is explored, with emphasis on the sensitivity to the size of the quark antiquark condensate <qq>.

Sebastien Descotes, Luca Girlanda, Jan Stern

We argue that light quark loops produce a paramagnetic suppression of infrared-sensitive order parameters such as <qq>, as the number N_f of light fermions increases. The possibly strong dependence of <qq> on N_f is related to the observed Zweig rule violation in the scalar channel. Presuming the existence of a chiral phase transition for not too large N_f,

Michael Joyce, Kimmo Kainulainen, Tomislav Prokopec

We derive quantum Boltzmann equations from Schwinger-Dyson equations in gradient expansion for a weakly coupled scalar field theory with a spatially varying mass. We find that at higher order in gradients a full description of the system requires specifying not only an on shell distribution function but also a finite number of its derivatives, or equivalentl

M. Beneke

The present theoretical status of top quark pair production near threshold at (future) $e^+ e^-$ ($μ^+μ^-$) colliders is summarized.

A. Gomez Nicola

We analyse the extension of Chiral Perturbation Theory to describe a meson gas out of thermal equilibrium. For that purpose, we let the pion decay constant be a time-dependent function and work within the Schwinger-Keldysh contour technique. A useful connection with curved space-time QFT allows to consistently renormalise the model, introducing two new low-e

Matthias Neubert

Various strategies for extracting or constraining the weak phase gamma with controlled theoretical uncertainties are reviewed. Measurements of the rates for the hadronic decays B^+- -> pi K provide largely model-independent information on gamma. Hadronic uncertainties enter only at the level of nonfactorizable contributions to the decay amplitudes that are p

P. Zenczykowski

Main theoretical approaches to weak radiative hyperon decays are briefly reviewed. It is emphasized that only approaches with great predictive power should be seriously considered when seeking a resolution of the puzzle presented by observed large negative asymmetry alpha (Sigma ^+ --> p gamma). In such cases, asymmetry in the Xi ^0 --> Lambda gamma decay is

C. Blöchinger, H. Fraas

With the process $e^-γ\to \tildeχ_1^0 \tilde{e}_{L/R}^- \to e^- \tildeχ_1^0 \tildeχ_1^0$ it is possible to constrain selectron masses above the kinematical limit of the pair production process in $e^+e^-$ colliders. We investigate these mass ranges and discuss the possibility to test the renormalization group equations for the selectron masses.

J. Gegelia, G. Japaridze, A. Tkabladze, A. Khelashvili

The different schemes for the definition of the Z boson mass are analyzed. It is shown that the scheme, defining the mass as pole of the real part of the Z boson propagator and the width as the imaginary part of the propagator at the same point results in the gauge dependent results for these parameters in a two-loop approximation. On the other hand, the sch

X. Song

The quark spin and flavor structure of the nucleon is discussed in the SU(4) symmetry breaking chiral quark model. The spin and flavor contents for charm quarks and anti-charm quarks are predicted and compared with the results given by other models. The intrinsic charm quark contribution to the Ellis-Jaffe sum rule is discussed.

R. Escribano, J. -M. Frere, D. Monderen, V. Van Elewyck

We study the lensing of neutrinos by astrophysical objects. At the difference of photons, neutrinos can cross a stellar core; as a result the lens quality improves. While Saturnians alone would benefit from this effect in the Sun, similar effects could be considered for binary systems.

F. J. Yndurain

Bound states of heavy $\bar{q}q$ quarks are reviewed within the context of QCD. First of all, we consider the calculations which can be performed {\sl ab initio}, which includes $\bar{t}t$ with principal quantum number $n$ up to four, $\bar{b}b$ states with $n=1$ and (to a lesser extent) $\bar{b}b$ with $n=2$ and $\bar{c}c$ for $n=1$. Among the results, we r

F. Knechtli

The static potential in the confinement ``phase&#39;&#39; of the SU(2) Higgs model is studied. In particular, the observation of the screening (called string breaking) of the static quarks by the dynamical light quarks leading to the formation of two static-light mesons was not observed before my work in non-Abelian gauge theories. The tool that I employ is

A. Airapetian

Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle phi of the pion relative to the lepton scattering plane was observed for pi+ electro-production on a longitudinally polarized hydrogen target. The corresp

David E. Jaffe

Recent experimental results on charmless rare b decays are reviewed.

Ulrich H. Gerlach

The geometrical and quantum mechanical basis for Davies&#39; and Unruh&#39;s acceleration temperature is traced to a type of quantum mechanical (``achronal&#39;&#39;) spin. Its existence and definition are based on pairs of causally disjoint accelerated frames. For bosons the expected spin vector of monochromatic particles is given by the ``Planckian power&#

J. P. Mbelek, M. Lachièze-Rey

We suggest an explanation of the &#34;Pioneer effect&#34; based on the interaction of the spacecraft with a long-range scalar field, $ϕ$. The scalar field under consideration is external to gravity, coupled to the ordinary matter and undergoes obedience to the weak equivalence principle. In the weak fields limit it result a long-range acceleration $a_{P}$, a

Martin Bojowald

Volume operators measuring the total volume of space in a loop quantum theory of cosmological models are constructed. In the case of models with rotational symmetry an investigation of the Higgs constraint imposed on the reduced connection variables is necessary, a complete solution of which is given for isotropic models; in this case the volume spectrum can

Martin Bojowald

The framework of quantum symmetry reduction is applied to loop quantum gravity with respect to transitively acting symmetry groups. This allows to test loop quantum gravity in a large class of minisuperspaces and to investigate its features - e.g. the discrete volume spectrum - in certain cosmological regimes. Contrary to previous studies of quantum cosmolog

T. Sakai, A. Widom, Y. N. Srivastava

The notion of inflation (past or present) in standard cosmological models is shown to be a consequence of a sufficiently high second law entropy production from the internal heating of the universal expansion. The longitudinal viscous internal heating of matter requires neither ``inflaton&#39;&#39; fields nor ``quintessence&#39;&#39; fields which in theory m

A. A. Kiselev, K. W. Kim

We have investigated spatio-temporal kinetics of electron spin polarization in semiconductor narrow 2D strip and explored the ability to manipulate spin relaxation. Information about spin of the conduction electrons and mechanisms of spin rotation is incorporated into transport Monte Carlo simulation program. A model problem, involving linear-in-k splitting

Andrew Schwartz, Marc Scheffler, Steven M. Anlage

Employing a broadband microwave reflection configuration, we have measured the complex surface impedance, $Z_S(ω,T)$, of single crystal La$_{0.8}$Sr$_{0.2}$MnO$_3$, as a function of frequency (0.045-45 GHz) and temperature (250-325 K). Through the dependence of the microwave surface impedance on the magnetic permeability, $\hatμ(ω,T)$, we have studied the lo

Guy Trambly de Laissardiere, Didier Mayou

We analyze the criterion for the appearance of magnetic moments in quasicrystals approximants and liquids Al-Mn. In a Hartree-Fock scheme, it is shown that the Stoner criterion (Un_d(E_F) > 1) does not apply to these systems due to the presence of the pseudogap in the density of states. We give an generalized criterion that can take into account the particul

Michael Krech, Erik Luijten

We discuss an efficient approach to the calculation of the internal energy in numerical simulations of spin systems with long-range interactions. Although, since the introduction of the Luijten-Blöte algorithm, Monte Carlo simulations of these systems no longer pose a fundamental problem, the energy calculation is still an O(N^2) problem for systems of size

Walter Kob, Jean-Louis Barrat, Francesco Sciortino, Piero Tartaglia

Using molecular dynamics computer simulations we investigate the out-of-equilibrium dynamics of a Lennard-Jones system after a quench from a high temperature to one below the glass transition temperature. By studying the radial distribution function we give evidence that during the aging the system is very close to the critical surface of mode-coupling theor

A. Malinowski, R. T. Harley

The significance of nuclear spin polarisation in time-resolved optical studies of III-V semiconductors is addressed. Electron Larmor beats in pump-probe reflectivity from a GaAs/AlGaAs quantum well show Overhauser shift of 0.7 T due to accumulated nuclear polarisation <I>/I=0.065. This leads to precision values of electron g-factor, elucidates nuclear spin p