January 2000 arXiv papers — page 2

Nevin Weinberg, M. Coleman Miller, Donald Q. Lamb

The discovery of high-amplitude brightness oscillations during type I X-ray bursts from six low-mass X-ray binaries has provided a powerful new tool to study the properties of matter at supranuclear densities, the effects of strong gravity, and the propagation of thermonuclear burning. There is substantial evidence that these brightness oscillations are prod

Michael R. Meyer, Steven V. W. Beckwith

A question central to understanding the origin of our solar system is: how do planets form in circumstellar disks around young stars? Because of the complex nature of the physical processes involved, multi-wavelength observations of large samples will be required in order to obtain a complete answer to this question. Surveys undertaken with ISO have helped t

A. Konopelko, A. Plyasheshnikov

Ground-based atmospheric Cherenkov telescopes are proven to be effective instruments for observations of very high energy (VHE) gamma-radiation from celestial objects. For effective use of such technique one needs detailed Monte Carlo simulations of gamma-ray- and proton/nuclei-induced air showers in Earth atmosphere. Here we discuss in detail the algorithms

A. Broderick, M. Prakash, J. M. Lattimer

We study the effects of very strong magnetic fields on the equation of state (EOS) in multicomponent, interacting matter by developing a covariant description for the inclusion of the anomalous magnetic moments of nucleons. For the description of neutron star matter, we employ a field-theoretical approach which permits the study of several models which diffe

Patrick Slane, Yang Chen, Norbert S. Schulz, Frederick Seward

Chandra observations of the Crab-like supernova remnant G21.5-0.9 reveal a compact central core and spectral variations indicative of synchrotron burn-off of higher energy electrons in the inner nebula. The central core is slightly extended, perhaps indicating the presence of an inner wind-shock nebula surrounding the pulsar. No pulsations are observed from

Keith A. Olive

Our understanding of the evolution of He4 and Li7 depends critically on the available data for these two elements at low metallicity. In particular, the degree to which there is a slope in an abundance vs metallicity regression can help determine the evolution of He, C, N, and O in dwarf galaxies in the case of He, and cosmic-ray induced nucleosynthesis of L

H. W. Duerbeck, W. Liller, C. Sterken, S. Benetti

CCD UBVRi photometry of the final helium flash object V4334 Sgr (Sakurai's Object), carried out during 1997 - 1999, is presented, and the light curve from its pre-discovery rise to the dust obscuration phase is constructed. The optical light curve can be divided into four sections, the rise to maximum, the maximum, the dust onset, and the massive dust sh

L. V. E. Koopmans, A. G. de Bruyn, E. Xanthopoulos, C. D. Fassnacht

We present Very Large Array (VLA) 8.5-GHz light curves of the two lens images of the Cosmic Lens All Sky Survey (CLASS) gravitational lens B1600+434. We find a nearly linear decrease of 18-19% in the flux densities of both lens images over a period of eight months (February-October) in 1998. Additionally, the brightest image A shows modulations up to 11% pea

M. C. Bottorff, G. J. Ferland

In this paper, we show that if the broad line region clouds are in approximate energy equipartition between the magnetic field and gravity, as hypothesized by Rees, there will be a significant effect on the shape and smoothness of broad emission line profiles in active galactic nuclei. Line widths of contributing clouds or flow elements are much wider than t

Daniel Schaerer, Natalia G. Guseva, Yuri I. Izotov

Young super star clusters and young compact massive star forming regions can provide useful information on their burst properties (age, burst duration, SFR), the upper end of the IMF and yield new constraints on the evolution of massive stars. Through the study of their stellar populations we can in particular extend our knowledge on massive stars to extreme

M. Orlandini, A. N. Parmar, F. Frontera, N. Masetti

We report on a BeppoSAX observation of the transient X-ray source XTE J0421+560 during quiescence performed ~150 days after the 1998 April outburst. The source had an unabsorbed 0.5-10 keV flux of 6.7x10^{-12} erg/cm2/s and was still remarkably soft with most of the emission below 2 keV. The X-ray spectrum can be fit with the same two-temperature model as th

L. J. Smith, J. S. Gallagher

We present a detailed study of two luminous super star clusters in the starburst galaxy M82. Spectra, covering 3250-8790 A at a resolution of 1.6 A, were obtained at the 4.2 m William Herschel Telescope (WHT) for cluster F and the highly reddened cluster L. We compare the strengths of the observed Balmer absorption lines and the Balmer jump in the blue spect

M. Guainazzi, G. Matt, W. N. Brandt, L. A. Antonelli

We present the results of a BeppoSAX observation of the nearby spiral galaxy NGC4945 in the 0.1-200 keV energy band. The nuclear X-ray emission emerges above ~7 keV, through an absorber with column density N_H ~ a few 10^24/cm/cm. Its remarkable variability (doubling/halving timescale ~10^4 s) is not associated with any appreciable spectral changes, ruling o

Eugenio Carretta, Raffaele Gratton, Gisella Clementini

The discrepancy between a LONG distance scale derived from Hipparcos based distances to globular clusters via main sequence fitting to local subdwarfs, and a SHORT distance scale derived from the absolute magnitude of field RR Lyraes via statistical parallaxes and the Baade-Wesselink method could be accounted for whether an intrinsic difference of about 0.1-

V. S. Dhillon, S. P. Littlefair, S. B. Howell, D. R. Ciardi

We present K-band spectra of the short-period dwarf novae YZ Cnc, LY Hya, BK Lyn, T Leo, SW UMa and WZ Sge, the novalike variables DW UMa, V1315 Aql, RW Tri, VY Scl, UU Aqr and GP Com, and a series of field dwarf stars with spectral types ranging from K2-M6. The spectra of the dwarf novae are dominated by emission lines of HI and HeI. The large velocity and

Frank Stefani, Gunter Gerbeth, Karl-Heinz Rädler

The paper deals with the integral equation approach to steady kinematic dynamo models in finite domains based on Biot-Savart's law. The role of the electric potential at the boundary is worked out explicitly. As an example, a modified version of the simple spherical $α$-effect dynamo model proposed by Krause and Steenbeck is considered in which the $α$-c

M. A. Garrett, G. de Bruyn, W. Baan, R. T. Schilizzi

We present WSRT 1.38 GHz observations of the Hubble Deep Field (and flanking fields). 72 hours of data were combined to produce the WSRT's deepest image yet, achieving an r.m.s. noise level of 8 microJy per beam. We detect radio emission from galaxies both in the HDF and HFF which have not been previously detected by recent MERLIN or VLA studies of the f

Yoshiaki Taniguchi, Yasuhiro Shioya

We propose a new model for the extended Ly alpha blobs found recently at high redshift z ~ 3. The observational properties of these blobs are; 1) the observed Ly alpha luminosities are ~ 10^{43} h^{-2} ergs s^{-1}, 2) they appear elongated morphologically, 3) their sizes amount to ~ 100 kpc, 4) the observed line widths amount to ~ 1000 km s^{-1}, and 5) they

Kazuhiro Shimasaku

We derive the ratio of total blue luminosity to total baryon mass, LB/Mb, for massive (Mgas at the Abell radius is \ge 1 \times 10^{13} h^{-2.5} \Msolar) clusters of galaxies up to z \simeq 1 from the literature. Twenty-two clusters in our sample are at z > 0.1. Assuming that the relative mix of hot gas and galaxies in clusters does not change during cluster

M. J. Drinkwater, S. Phillipps, J. B. Jones, M. D. Gregg

The Fornax Spectroscopic Survey will use the Two degree Field spectrograph (2dF) of the Anglo-Australian Telescope to obtain spectra for a complete sample of all 14000 objects with 16.5<=Bj<=19.7 in a 12 square degree area centred on the Fornax Cluster. By selecting all objects---both stars and galaxies---independent of morphology, we cover a much larger ran

Tao Han, Danny Marfatia, Ren-Jie Zhang

We consider the Kaluza-Klein scenario in which gravity propagates in the $4+n$ dimensional bulk of spacetime and the Standard Model particles are confined to a 3-brane. We calculate the gauge boson self-energy corrections arising from the exchange of virtual gravitons and present our results in the $STU$-formalism. We find that the new physics contributions

Adrian Dragulescu, Victor M. Yakovenko

In a closed economic system, money is conserved. Thus, by analogy with energy, the equilibrium probability distribution of money must follow the exponential Gibbs law characterized by an effective temperature equal to the average amount of money per economic agent. We demonstrate how the Gibbs distribution emerges in computer simulations of economic models.

G. W. Carter, D. Diakonov

Color superconductivity in QCD breaks the SU(3) color gauge group down to SU(2), inducing masses in five of the eight gluons. This is a dynamical Higgs effect, in which the diquark condensate acts as the vacuum expectation value of a composite scalar field. In order to analyze this effect at low quark density, when gaps are large and generated nonperturbativ

A. K. Svinin

The Volterra and Toda chains equations are considered. A class of special reductions for these equations are derived.

Arthur O. Pittenger, Morton H. Rubin

Great progress has been made recently in establishing conditions for separability of a particular class of Werner densities on the tensor product space of $n$ $d$--level systems (qudits). In this brief note we complete the process of establishing necessary and sufficient conditions for separability of these Werner densities by proving the sufficient conditio

Wai Bong Yeung

We show that the quantum mechanical momentum and angular momentum operators are fixed by the Noether theorem for the classical Hamiltonian field theory we proposed.

I. Arad, I. Procaccia

The problem of anomalous scaling in passive scalar advection, especially with $δ$-correlated velocity field (the Kraichnan model) has attracted a lot of interest since the exponents can be computed analytically in certain limiting cases. In this paper we focus, rather than on the evaluation of the exponents, on elucidating the {\em physical mechanism} respon

Henrique Bursztyn, Stefan Waldmann

In this paper we consider algebras with involution over a ring C which is given by the quadratic extension by i of an ordered ring R. We discuss the *-representation theory of such *-algebras on pre-Hilbert spaces over C and develop the notions of Rieffel induction and formal Morita equivalence for this category analogously to the situation for C^*-algebras.

Anvar R. Mavlyutov

We study the geometry and cohomology of semiample hypersurfaces in toric varieties. Such hypersurfaces generalize the MPCP-desingularizations of Calabi-Yau ample hypersurfaces in the Batyrev mirror construction. We study the topological cup product on the middle cohomology of semiample hypersurfaces. In particular, we obtain a complete algebraic description

Yucai Su, Xiaoping Xu, Hechun Zhang

We classify all the pairs of a commutative associative algebra with an identity element and its finite-dimensional commutative locally-finite derivation subalgebra such that the commutative associative algebra is derivation-simple with respect to the derivation subalgebra over an algebraically closed field with characteristic 0. Such pairs are the fundamenta

Mircea Mustata, Hal Schenck

For an essential, central hyperplane arrangement A in V=k^{n+1}, we show that Ω^1(A) (the module of logarithmic one forms with poles along A) gives rise to a locally free sheaf on P^n if and only if for all X in L_A with rank X<dim V, the module Ω^1(A_X) is free. Our main result is that in this case the Poicare polynomial of A is essentially the Chern polyno

Dmitrij V. Shirkov, Vladimir F. Kovalev

Evolution of the concept known in the theoretical physics as the Renormalization Group (RG) is presented. The corresponding symmetry, that has been first introduced in QFT in mid-fifties, is a continuous symmetry of a solution with respect to transformation involving parameters (e.g., of boundary condition) specifying some particular solution. After short de

Joseph D. Lykken

Contents: 1. Prologomena to any meta future physics 1.1 Physics needs for building future accelerators 1.2 Physics needs for funding future accelerators 2. Physics questions for future accelerators 2.1 Crimes and misapprehensions 2.1.1 Organized religion 2.1.2 Feudalism 2.1.3 Trotsky was right 2.2 The Standard Model as an effective field theory 2.3 What is t

C. B. Yang, X. Cai

The scaled factorial moments $F_q$ are studied for a second-order quark-hadron phase transition within the Ginzburg-Landau description. The role played by the ground state of the system under low temperature is emphasized. After a local shift of the order parameter the fluctuations are around the ground state, and a perturbative calculation for $F_q$ can be

Xiao-Gang He

In this talk I discuss three different methods, using B_d to J/psi K_S, J/psi K_s pi^o, B_d to K^- pi^+, pi^+ pi^- and B_u to K^- pi^0, bar K^0 pi^- pi^- pi^0, to extract hadronic model independent information about new physics.

Michael Melles

The potential between infinitely heavy quarks in a color singlet state is of fundamental importance in QCD. While the confining long distance part is inherently non-perturbative, the short-distance (Coulomb-like) regime is accessible through perturbative means. In this paper we present new results of the short distance potential in coordinate space with quar

Robert D. Mawhinney

The QCDSP computer (Quantum Chromodynamics on Digital Signal Processors) is an inexpensive, massively parallel computer intended primarily for simulations in lattice gauge theory. Currently, two large QCDSP machines are in full-time use: an 8,192 processor, 0.4 Teraflops machine at Columbia University and an 12,288 processor, 0.6 Teraflops machine at the RIK

Robert D. Mawhinney

One of the major frontiers of lattice field theory is the inclusion of light fermions in simulations, particularly in pursuit of accurate, first principles predictions from lattice QCD. With dedicated Teraflops-scale computers currently simulating QCD, another step towards precision full QCD simulations is underway. In addition to ongoing staggered and Wilso

D. V. Livanov, G. Savona, A. A. Varlamov

The theory of fluctuation conductivity for an arbitrary impurity concentration including ultra-clean limit is developed. It is demonstrated that the formal divergency of the fluctuation density of states contribution obtained previously for the clean case is removed by the correct treatment of the non-local ballistic electron scattering. We show that in the

Frank Kuehnel, Leonid P. Pryadko, M. I. Dykman

We study the frequency-dependent magnetoconductivity of a strongly correlated nondegenerate 2D electron system in a quantizing magnetic field. We first restore the single-electron conductivity from calculated 14 spectral moments. It has a maximum for omega ~ gamma (hbar gamma is the disorder-induced width of the Landau level), and scales as a power of omega

L. L. Kiss, J. R. Thomson

Low- and medium resolution spectra of the fast nova, Nova (V1494) Aql 1999 No.2 obtained approximately 6, 7, 19 and 28 days after the maximum brightness are presented and discussed. The spectrum covering the whole optical range at day 6 shows the principal plus diffuse-enhanced spectrum. The presence of strong Fe II multiplets with P-Cyg profiles suggest tha

Hang Bae Kim

We provide the cosmological solutions for Randall-Sundrum models with the bulk energy-momentum $\hat T^5_5$ incorporated. It alters the Friedmann equation for the brane scale factor. We make a specific choice of $\hat T^5_5$ which is adjusted to stabilize the extra dimension. This makes it possible to compactify the extra dimension with a single positive ten

Gunnar S. Bali

The present knowledge of QCD confining forces between static test charges is summarised, with an emphasis on lattice results. Recent developments in relating QCD potentials to quarkonium properties by use of effective field theory methods are presented. The validity of non-relativistic QCD and the adiabatic approximation with respect to heavy quark bound sta

Igor Rivin, Jean-Marc Schlenker

he celebrated formula of Schlafli relates the variation of the dihedral angles of a smooth family of polyhedra in a space form and the variation of volume. We give a smooth analogue of this classical formula -- our result relates the variation of the volume bounded by a hypersurface moving in a general Einstein manifold and the integral of the variation of t

K. R. S. Balaji, Amol S. Dighe, R. N. Mohapatra, M. K. Parida

We provide a model independent criterion which would guarantee a large flavor mixing of two quasi-degenerate Majorana neutrinos at the low scale, irrespective of the mixing at the high scale. We also show that such a situation is realizable for a phenomenologically interesting range of parameters of the weak scale theory. We further show that for a similar c

Nadia Fettes, Ulf-G. Meißner, Martin Mojzis, Sven Steininger

We construct the minimal effective chiral pion-nucleon SU(2) Lagrangian at fourth order in the chiral expansion. The Lagrangian contains 118 in principle measurable terms. We develop both the relativistic as well as the heavy baryon formulation of the effective field theory. For the latter, we also work out explicitly all 1/m corrections at fourth order. We

N. Pinamonti, M. Toller

We study the positive-operator-valued measures on the projective real line covariant with respect to the projective group, assuming that the energy is a positive operator. This problem is similar to the more complicated problem of finding the positive-operator-valued measures on the compactified Minkowski space-time covariant with respect to the conformal gr

V. P. Ruban

The interaction of a small vortex ring with the free surface of a perfect fluid is considered. In the frame of the point ring approximation the asymptotic expression for the Fourier-components of radiated surface waves is obtained in the case when the vortex ring comes from infinity and has both horizontal and vertical components of the velocity. The non-con

M. I. Levchuk, M. Schumacher, F. Wissmann

Neutral pion photoproduction on the deuteron in the inelastic channel is studied in the threshold region from 142 to 160 MeV. The calculation is based on the use of the diagrammatic approach. Contributions from the pole diagrams, one-loop diagrams both with $n$-$p$ and $π$-$N$ rescattering as well as two-loop diagrams with simultaneous inclusion of these res

M. Matsuo, T. Nakatsukasa, K. Matsuyanagi

An adiabatic approximation to the selfconsistent collective coordinate method is formulated in order to describe large amplitude collective motions in superconducting nuclei on the basis of the time-dependent Hartree-Fock-Bogoliubov equations of motion. The basic equations are presented in a local harmonic form which can be solved in a similar way as the qua

Anirban Sain

We observe oscillatory decay in the two-point, non-equal time, velocity correlation function of homogeneous, isotropic turbulence. We found this through a direct numerical simulation (DNS) of the three dimensional Navier-Stokes ($3-D$ NS) equation. We give an approximate analytic theory which explains this oscillatory behaviour. The wave-number and frequency

V. Abramov, N. Bazunova

In this work, we construct the algebra of differential forms with the cube of exterior differential equal to zero on one-dimensional space. We prove that this algebra is a graded q-differential algebra where q is a cubic root of unity. Since the square of differential is not equal to zero the algebra of differential forms is generated not only by the first o

Ashok Kumar Mittal, Ashok Kumar Gupta

The roots of any polynomial of degree m with complex integer coefficients can be computed by manipulation of sequences made from distinct symbols and counting the different symbols in the sequences. This method requires only primitive operations like replacement of sequences and counting of symbols. No calculations using advanced operations like multiplicati

Daniel C. Cohen, Peter Orlik

Motivated by the Milnor fiber of a central arrangement, we study the cohomology of a family of cyclic covers of the complement of an arbitrary arrangement. We give an explicit proof of the polynomial periodicity of the Betti numbers of the members of this family of cyclic covers.

V. Braun, P. Candelas, X de la Ossa, A. Grassi

We study issues related to F-theory on Calabi-Yau fourfolds and its duality to heterotic theory for Calabi-Yau threefolds. We discuss principally fourfolds that are described by reflexive polyhedra and show how to read off some of the data for the heterotic theory from the polyhedron. We give a procedure for constructing examples with given gauge groups and

Giovanni Amelino-Camelia

I consider the implications for brane-world scenarios of the rather robust quantum-gravity expectation that there should be a quantum minimum limit on the uncertainty of all physical length scales. In order to illustrate the possible significance of this issue, I observe that, according to a plausible estimate, the quantum limit on the length scales that cha

S. M. Bilenky

These are lectures given at the CERN-JINR school on high energy physics. The possibilities of the mixing of massive Dirac and Majorana neutrinos are discussed. The theory of neutrino oscillations in vacuum is presented. The trasitions between differen flavor neutrinos in matter are discussed. A short review of the results of the neutrino oscillation experime

A. Bottino, F. Donato, N. Fornengo, S. Scopel

We analyze the annual-modulation effect, measured by the DAMA Collaboration with the new implementation of a further two-years running, in the context of a possible interpretation in terms of relic neutralinos. We impose over the set of supersymmetric configurations, selected by the annual-modulation data, the constraints derived from WIMP indirect measureme

M. Anselmino, M. Boglione, F. Murgia

We consider the polarization of Lambda + Lambda-bar baryons produced in polarized Deep Inelastic Scattering at leading order, with various spin configurations: longitudinally polarized leptons and unpolarized nucleon; unpolarized leptons and longitudinally or transversely polarized nucleons; longitudinally polarized leptons and nucleons. We show how the diff

Morimitsu Tanimoto

We have investigated phenomenological implications on the neutrino flavor mixings in the $S_{3L}\times S_{3R}$ symmetric mass matrices including symmetry breaking terms. We have shown how to get the large mixing angle MSW solution, $\sin^2 2 þ_\odot=0.65\sim 0.97$ and $Δm_{\odot}^2= 10^{-5}\sim 10^{-4}\eV^2$, in this model. It is found that the structure of

I. Schmelzer

The paper is an introduction into General Ether Theory (GET). We start with few assumptions about an universal ``ether&#39;&#39; in a Newtonian space-time which fulfils \partial_t ρ+ \partial_i (ρv^i) = 0 \partial_t (ρv^j) + \partial_i(ρv^i v^j + p^{ij}) = 0 For an ``effective metric&#39;&#39; $g_{μν}$ we derive a Lagrangian where the Einstein equivalence pr

Giovanni Amelino-Camelia

I develop a phenomenological approach to the description of the noise levels that the space-time foam of quantum gravity could induce in modern gravity-wave detectors. Various possibilities are considered, including white noise and random-walk noise. In particular, I find that the sensitivity level expected for the planned LIGO and VIRGO interferometers and

Cosma Rohilla Shalizi, James P. Crutchfield

Computational mechanics is a method for discovering, describing and quantifying patterns, using tools from statistical physics. It constructs optimal, minimal models of stochastic processes and their underlying causal structures. These models tell us about the intrinsic computation embedded within a process---how it stores and transforms information. Here we

K. A. Matveev, L. I. Glazman, A. I. Larkin

Spin-orbit scattering suppresses Zeeman splitting of individual energy levels in small metal particles. This suppression becomes significant when the spin-orbit scattering rate τ_{so}^{-1} is comparable with the quantum level spacing δ. The g-factor exhibits mesoscopic fluctuations; at small δτ_{so} it is distributed according to the Maxwell distribution. At

J. Eroles, G. Ortiz, A. V. Balatsky, A. R. Bishop

Starting from a t-J model, we introduce inhomogeneous terms to mimic stripes. We find that if the inhomogeneous terms break the SU(2) spin symmetry the binding between holes is tremendously enhanced in the thermodynamic limit. In any other model (including homogeneous models) the binding in the thermodynamic limit is small or neglible. By including these inh

Henrik Rydberg, Bengt I. Lundqvist, David C. Langreth, Maxime Dion

A systematic approach for the construction of a density functional for van der Waals interactions that also accounts for saturation effects is described, i.e. one that is applicable at short distances. A very efficient method to calculate the resulting expressions in the case of flat surfaces, a method leading to an order reduction in computational complexit

Chetan Nayak

We consider the O(4) symmetric point in the phase diagram of an electron system in which there is a transition between d_{x^2 - y^2} density-wave order and d_{x^2 - y^2} superconductivity. If the pseudospin $SU(2)\subset O(4)$ symmetry is disordered by quantum fluctuations, the Nodal Liquid can result. In this context, we (1) construct a pseudospin $σ$-model

A. C. A. Boogert, P. Ehrenfreund, P. A. Gerakines, A. G. G. M. Tielens

We present observations of the stretching mode of 13CO2 ice along 13 lines of sight in the Galaxy, using the Short Wavelength Spectrometer on board of the Infrared Space Observatory. Remarkable variations are seen in the absorption band profile in the different lines of sight. The main feature is attributed to 13CO2 mixed with polar molecules such as H2O, an

P. J. Huggins

Molecular gas plays an important role in the structure of planetary nebulae: it is a major component of the equatorial tori of bipolar nebulae, it forms the cores of globules and related mircostructures, and is the likely origin of multiple arcs. It is also a key component during the early stages of formation where interactions with outflows or jets provide

B. G. Elmegreen, Y. N. Efremov, S. Larsen

A globular cluster ~15 My old that contains 5x10^5 Msun of stars inside an 11 pc radius has been found in the nearby spiral galaxy NGC 6946, surrounded by clouds of dust and smaller young clusters inside a giant circular bubble 300 pc in radius. At the edge of the bubble is an arc of regularly-spaced clusters that could have been triggered during the bubble&

Xavier Bertou, Murat Boratav, Antoine Letessier-Selvon

Over the last third of the century, a few tens of events, detected by ground-based cosmic ray detectors, have opened a new window in the field of high-energy astrophysics. These events have macroscopic energies, unobserved sources, an unknown chemical composition and a production and transport mechanism yet to be explained. With a flux as low as one particle

A. Abrassart, B. Czerny

We propose an explanation of the variability of AGN based on a cloud model of accretion onto a black hole. These clouds, present at a distance of 10-100 Schwarzschild radii, possibly come from the disrupted innermost disk and they can partially obscure the central X-ray source due to their extreme Compton optical depth. We consider the implications of this s

Mark Bottorff, Kirk Korista, Isaac Shlosman

A hydromagnetic (MHD) wind from a clumpy molecular accretion disk is invoked to explain observations of warm absorbing (WA) gas in UVX from Sy galaxies. This paper focuses on two issues: (1) compatibility of kinematics and dynamics of MHD wind with the observed properties of WAs; and (2) relationship between the UVX absorptions. We provide an in-depth compar

J. Bezecourt, H. Hoekstra, M. E. Gray, H. M. AbdelSalam

We present a gravitational lensing study of the massive galaxy cluster A2219 (redshift 0.22). This investigation is based on multicolour images from U through H, which allows photometric redshifts to be estimated for the background sources. The redshifts provide useful extra information for the lensing models: we show how they can be used to identify a new m

Roger Blandford, Gabriela Surpi, Tomislav Kundic

In order to use a gravitational lens to measure the Hubble constant accurately, it is necessary to derive a reliable model of the lens surface potential. If the analysis is restricted to the locations and magnifications of point images, the derived Hubble constant depends upon the class of mass models used to fit the data. However, when there is extended emi

Kenneth Intriligator

We point out that the low energy theory of 6d, N=(2,0) field theories, when away from the origin of the moduli space of vacua, necessarily includes a new kind of Wess-Zumino term. The form of this term is related to the Hopf invariant associated with π_7 (S^4). The coefficient of the Wess-Zumino term is fixed by an anomaly matching relation for a global flav

Nadav Drukker, David J. Gross, Arkady Tseytlin

A systematic approach to the study of semiclassical fluctuations of strings in AdS_5 x S^5 based on the Green-Schwarz formalism is developed. We show that the string partition function is well defined and finite. Issues related to different gauge choices are clarified. We consider explicitly several cases of classical string solutions with the world surface

Z. Duan, P. S. Rodrigues da Silva, F. Sannino

Recently it has been proposed that the physical spectrum of a vector-like gauge field theory may exhibit an enhanced global symmetry near a chiral/conformal phase transition. The new symmetry is related to the possibility, supported by various investigations, that a parity-doubled spectrum develops as the number of fermions Nf is increased to a critical valu

Marko B. Popovic, Elizabeth H. Simmons

We employ data from precision electroweak tests and collider searches to derive constraints on the possibility that weak-singlet fermions mix with the ordinary Standard Model fermions. Our findings are presented within the context of a theory with weak-singlet partners for all ordinary fermions and theories in which only third-generation fermions mix with we

D. J. Broadhurst, D. Kreimer

The renormalization of quantum field theory twists the antipode of a noncocommutative Hopf algebra of rooted trees, decorated by an infinite set of primitive divergences. The Hopf algebra of undecorated rooted trees, ${\cal H}_R$, generated by a single primitive divergence, solves a universal problem in Hochschild cohomology. It has two nontrivial closed Hop

J. I. Collar, J. Puibasset, T. A. Girard, D. Limagne

We report on the fabrication aspects and calibration of the first large active mass ($\sim15$ g) modules of SIMPLE, a search for particle dark matter using Superheated Droplet Detectors (SDDs). While still limited by the statistical uncertainty of the small data sample on hand, the first weeks of operation in the new underground laboratory of Rustrel-Pays d&

Sacha Davidson, Marta Losada, Antonio Riotto

We note that the maximum temperature during reheating can be much greater than the reheating temperature $T_r$ at which the Universe becomes radiation dominated. We show that the Standard Model anomalous $(B+L)$-violating processes can therefore be in thermal equilibrium for 1 GeV $\simlt T_{r}\ll 100$ GeV. Electroweak baryogenesis could work and the traditi

Washington Taylor

Open string field theory is considered as a tool for deriving the effective action for the massless or tachyonic fields living on D-branes. Some simple calculations are performed in open bosonic string field theory which validate this approach. The level truncation method is used to calculate successive approximations to the quartic terms ϕ^4, (A^μA_μ)^2 and

Jaume Gomis

We find the orbifold analog of the topological relation recently found by Freed and Witten which restricts the allowed D-brane configurations of Type II vacua with a topologically non-trivial flat $B$-field. The result relies in Douglas proposal -- which we derive from worldsheet consistency conditions -- of embedding projective representations on open strin

A. Khodjamirian, R. Rückl, S. Weinzierl, C. W. Winhart

The $f^+$ form factors of the $B\to π$, $D\to π$ and $D\to K$ transitions are calculated from QCD light-cone sum rules (LCSR) and used to predict the widths and differential distributions of the exclusive semileptonic decays $B\to π\bar{l}ν_l$, $D \toπ\bar{l}ν_l$ and $D \to K \bar{l}ν_l$, where $l=e,μ$. The current theoretical uncertainties are estimated. Th

Eung Jin Chun, Sin Kyu Kang

We bring the theoretical issue of whether two important cosmological demands, baryon asymmetry and degenerate neutrinos as hot dark matter, can be compatible in the context of the seesaw mechanism. To realize leptogenesis with almost degenerate Majorana neutrinos without severe fine-tuning of parameters, we propose the hybrid seesaw mechanism with a heavy Hi

Vanina Ruhlmann-Kleider

This review presents recent results on new particle searches achieved at Tevatron, Hera and LEP. After a brief outline of the searches on exotic particles, results on supersymmetric particles and Higgs bosons are detailed. Near future prospects are also given.

M. Bargiotti, A. Bertin, M. Bruschi, M. Capponi

A complete review of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and of the experimental methods for their determination is presented. A critical analysis of the relevant experimental results, and in particular of the most recent ones, allows to improve the accuracies of all the matrix elements. A chi-square minimization with the three-family unitari

Axel G. Rossberg

Patterns forming spontaneously in extended, three-dimensional, dissipative systems are likely to excite several homogeneous soft modes ($\approx$ hydrodynamic modes) of the underlying physical system, much more than quasi one- and two-dimensional patterns are. The reason is the lack of damping boundaries. This paper compares two analytic techniques to derive

Véronique Bernard, Thomas R. Hemmert, Ulf-G. Meißner

We calculate ordinary and radiative muon capture on the proton in an effective field theory of pions, nucleons and delta isobars, working to third and second order in the small scale expansion respectively. Preceding calculations in chiral effective field theories only employed pion and nucleon degrees of freedom and were not able to reproduce the photon spe

Christian R. Kaiser, Rashid Sunyaev, Henk C. Spruit

We present a model for the radio outbursts of microquasars based on the assumption of quasi-continuous jet ejection. The jets are `lit up&#39; by shock fronts traveling along the jets during outbursts. The observed comparatively flat decay light curves combined with gradually steepening spectral slopes are explained by a superposition of the radiation of the

Arata Hayashigaki

We evaluate the mass shift of isospin-averaged D-meson in the nuclear medium. Borel-transformed QCD sum rules are used to describe an interaction between the D-meson and a nucleon by taking into account all the lowest dimension-4 operators in the operator product expansion (OPE). We find at normal matter density the D-meson mass shift is about 10 times (\sim

Frederick Green, Mukunda P Das

We analyze high-field current fluctuations in degenerate conductors by mapping the electronic Fermi-liquid correlations at equilibrium to their semiclassical non-equilibrium form. Our resulting Boltzmann description is applicable to diffusive mesoscopic wires. We derive a non-equilibrium connection between thermal fluctuations of the current and resistive di

J. D. Bashford, P. D. Jarvis

The systematics of indices of physico-chemical properties of codons and amino acids across the genetic code are examined. Using a simple numerical labelling scheme for nucleic acid bases, data can be fitted as low-order polynomials of the 6 coordinates in the 64-dimensional codon weight space. The work confirms and extends recent studies by Siemion of amino

Shin&#39;ichi Nojiri, Sergei D. Odintsov, Sergio Zerbini

Stability of dilatonic AdS spaces due to quantum effects of dilaton coupled conformal matter is considered. When such spaces do not exist on classical level, their dynamical generation occurs. Explicit examples corresponding to quantum creation of d4 dilatonic AdS Universe and of d2 dilatonic AdS Black Hole (BH) are presented. Motivated by holographic RG, in

C. L. Henley, N. G. Zhang

Spinless fermions on a lattice with nearest-neighbor repulsion serve as a toy version Hubbard model, and have a symmetry-broken even/odd superlattice at half-filling. At infinite repulsion, doped holes form charged stripes which are antiphase walls (as noted by Mila in 1994). Exact-diagonalization data for systems up to 36 sites around 1/4 filling, and also

Rob Clifton, Hans Halvorson

Entanglement has long been the subject of discussion by philosophers of quantum theory, and has recently come to play an essential role for physicists in their development of quantum information theory. In this paper we show how the formalism of algebraic quantum field theory (AQFT) provides a rigorous framework within which to analyze entanglement in the co

Edward Farhi, Jeffrey Goldstone, Sam Gutmann, Michael Sipser

We give a quantum algorithm for solving instances of the satisfiability problem, based on adiabatic evolution. The evolution of the quantum state is governed by a time-dependent Hamiltonian that interpolates between an initial Hamiltonian, whose ground state is easy to construct, and a final Hamiltonian, whose ground state encodes the satisfying assignment.

Y. T. Pashayan, G. G. Grigoryan

We investigate propagation of a pulse pair in a three-level medium under the adiabatic following condition for the general case of unequal oscillator strengths. Exact analytical solutions to the propagation equations have been obtained. It is shown that propagation dynamics strongly depends on the relationship between oscillator strengths. The adiabaticity c

Sebastiano Tosto

The relativistic angular momentum is introduced as an extension of the non-relativistic analysis of allowed states in the phase space for a quantum particle. The paper shows the conceptual basis of the approach. An interesting feature of the present point of view is that the indistinguishability of identical particles and the Pauli principle are found as cor