October 1998 arXiv papers — page 21

D. Vretenar, P. Ring, G. A. Lalazissis

We present a review of recent applications of the relativistic mean-field theory to the structure of nuclei close to the drip-lines. For systems with extreme isospin values, the relativistic Hartree-Bogoliubov model provides a unified and self-consistent description of mean-field and pairing correlations. The model has been applied in studies of structure ph

M. Bouwhuis, R. Alarcon, T. Botto, J. F. J. van den Brand

We report on a measurement of the tensor-analyzing power T20 in elastic electron-deuteron scattering in the range of four-momentum transfer from 1.8 to 3.2 fm-1. Electrons of 704 MeV were scattered from a polarized deuterium internal target. The tensor polarization of the deuterium nuclei was determined with an ion-extraction system, allowing an absolute mea

Nantel Bergeron, Frank Sottile

We give the formula for multiplying a Schubert class on an odd orthogonal or symplectic flag manifold by a special Schubert class pulled back from a Grassmannian of maximal isotropic subspaces. This is also the formula for multiplying a type $B$ (respectively, type $C$) Schubert polynomial by the Schur $P$-polynomial $p_m$ (respectively, the Schur $Q$-polyno

Ethan M. Coven, William Geller, Sylvia Silberger, William P. Thurston

A finite collection $P$ of finite sets tiles the integers iff the integers can be expressed as a disjoint union of translates of members of $P$. We associate with such a tiling a doubly infinite sequence with entries from $P$. The set of all such sequences is a sofic system, called a tiling system. We show that, up to powers of the shift, every shift of fini

John McCuan, Lafe Spietz

We describe decomposition formulas for rotations of $R^3$ and $R^4$ that have special properties with respect to stereographic projection. We use the lower dimensional decomposition to analyze stereographic projections of great circles in $S^2 \subset R^3$. This analysis provides a pattern for our analysis of stereographic projections of the Clifford torus $

Roman Gielerak, Robert Ralowski

The notion of anyonic Wick algebras is introduced and the corresponding second quantisation procedure is discussed. Applications to the physics of 2D anyonic matter are presented. In particular the existence of thermodynamics in the infinite volume for the case of Leinaas-Myrheim potentials is presented. Additionally a new class of states corresponding to qu

Michael Farber

It is shown that the signature of a manifold with a symplectic circle action having only isolated fixed points, equals the alternating sum of the Novikov numbers corresponding to the cohomology class of the generalized moment map. The same is true for more general fixed point sets.

Theresia Eisenkölbl

We compute the number of rhombus tilings of a hexagon with sides n, n, N, n, n, N, where two triangles on the symmetry axis touching in one vertex are removed. The case of the common vertex being the center of the hexagon solves a problem posed by Propp.

S. Ole Warnaar

We obtain connection coefficients between $q$-binomial and $q$-trinomial coefficients. Using these, one can transform $q$-binomial identities into a $q$-trinomial identities and back again. To demonstrate the usefulness of this procedure we rederive some known trinomial identities related to partition theory and prove many of the conjectures of Berkovich, Mc

Anastasia Doikou, Rafael I. Nepomechie

We formulate the notion of parity for the periodic XXZ spin chain within the Quantum Inverse Scattering Method. We also propose an expression for the eigenvalues of the charge conjugation operator. We use these discrete symmetries to help classify low-lying S^z=0 states in the critical regime, and we give a direct computation of the S matrix.

M. V. Cougo-Pinto, C. Farina, M. R. Negrao, A. Tort

The Casimir effect for Dirac as well as for scalar charged particles is influenced by external magnetic fields. It is also influenced by finite temperature. Here we consider the Casimir effect for a charged scalar field under the combined influence of an external magnetic field and finite temperature. The free energy for such a system is computed using Schwi

Rafael I. Nepomechie

This is a very elementary introduction to the Heisenberg (XXX) quantum spin chain, the Yang-Baxter equation, and the algebraic Bethe Ansatz.

A. Morozov

Review of some old and relatively new ideas surrounding the subjects of AdS/CFT correspondence, generalized tau-functions and possible equivalences between a priori different quantum field theories.

M. I. Gorenstein, V. P. Shelest, Yu. A. Sitenko, G. M. Zinovjev

Statistical method is applied to Neveu and Schwartz model for obtaining the average characteristics of the heavy resonances: spin distribution, decay widths etc. The properties of the dual model spectrum of states constructed of both commuting and anticommuting operators are considered. In this case the spin characteristics coincide with the results of the s

Lubomir Martinovic, James P. Vary

The massive Schwinger model in bosonic representation is quantized on the light front using the Dirac--Bergmann method. The non-perturbative theta- vacuum in terms of coherent states of the gauge-field zero mode is derived and found to coincide with the massless case. On the other hand, the mass term becomes highly non-linear due to the constrained zero mode

Juri Rolf

This Ph.D. thesis pursues two goals: The study of the geometrical structure of two-dimensional quantum gravity and in particular its fractal nature. To address these questions we review the continuum formalism of quantum gravity with special focus on the scaling properties of the theory. We discuss several concepts of fractal dimensions which characterize th

Patrick Dorey

Notes on exact S-matrices in 1+1 dimensions, based on lectures given at the 1996 Eotvos Graduate School, Budapest, and at the Institut Henri Poincare, Paris.

A. Marshakov, A. Mironov

We briefly review the Whitham hierarchies and their applications to integrable systems of the Seiberg-Witten type. The simplest example of the N=2 supersymmetric SU(2) pure gauge theory is considered in detail and the corresponding Whitham solutions are found explicitely.

Randy Lewis, Nader Mobed

The effects of isospin violation on the neutral weak magnetic form factor of the proton are studied using two-flavour chiral perturbation theory. The first nonzero contributions appear at O(p^4) in the small-momentum expansion, and the O(p^5) corrections are also calculated. The leading contributions from an explicit Delta(1232) isomultiplet are included as

M. Krawczyk, A. Zembrzuski

The NLO calculation of the DIC process with the isolated photon is presented and the comparison is made with the other NLO calculation and with recent measurement at HERA. The satisfactory agreement was found.

Tonguc Rador

We calculate the rates for lepton number violating processes via the exchange of the Z' boson occuring in top-color assisted technicolor. The current experimental limits on muon electron conversion in Ti nuclei allow for a mass of the new gauge boson around 1 TeV and the magnitudes of the mixing angles turn out to lie roughly between the analogous elemen

L. Afanasyev, A. Tarasov, O. Voskresenskaya

It is shown that $α^2$-term of sum rules for the total cross sections of interaction of elementary atoms with matter ones, obtained in ref.[Denisenko K. and Mrowczynski S., Phys. Rev. D36 (1987) 1529] is wrong. New sum rules valid up to terms of order $α^2$ are derived.

L. Afanasyev, O. Voskresenskaya

The ratio of productions of pi+pi- atoms to free pi+pi- pairs is calculated with account of the strong interaction in final states. It is shown that this ratio is expressed via a squared ratio of the well-known Coulomb wave functions and thus can be calculated with a high accuracy.

Utpal Sarkar

The most promising scenarios of baryogenesis seems to be the one through lepton number violation. Lepton number violation through a Majarana mass of the right-handed neutrinos can generate a lepton asymmetry of the universe when the right-handed neutrinos decay. The left-handed neutrinos get small Majorana masses through see-saw mechanism in these models. A

A. Barducci, R. Casalbuoni, R. Gatto, M. Modugno

The composite operator formalism is applied to QCD at finite temperature to calculate the masses of scalar and pseudoscalar mesons. In particular the ratio of the sigma mass to the pion mass is an interesting measure of the degree of chiral symmetry breaking at different temperatures. We calculate the temperature T* at which M_sigma(T) < 2M_pi(T), above whic

V. Ch. Zhukovskii, K. G. Levtchenko, T. L. Shoniya, P. A. Eminov

The radiation shift of the quark mass in a constant chromomagnetic field at finite temperature and density was calculated. The limiting cases of a weak and a strong chromomagnetic field were considered. It was shown that in a strong field there is no imaginary part in the contribution of the finite density effects to the quark mass shift, and its real part c

Owe Philipsen

The physics of electric and magnetic screening in non-Abelian finite temperature field theory is closely related to the non-perturbative properties of the corresponding three-dimensional effective theories which are confining. I discuss recent lattice results obtained for the mass spectrum, string tension and the static potential in SU(2) pure gauge theory a

W. Bietenholz, H. Dilger

We construct a new perfect action for free staggered fermions, which is more local than the one obtained from the standard block average scheme. This pays off in superior properties after a short ranged truncation. This action is ``gauged by hand&#39;&#39; and tested in Schwinger model simulations by means of a new variant of hybrid MC. Using ``fat links&#39

Guido Martinelli

In this review, three subjects are discussed: a phenomenological application of lattice predictions to $K^0$--$\bar K^0$ mixing in Super Symmetry; a discussion of the non-perturbative renormalization methods for four-fermion operators and a new approach to extract weak matrix elements in effective theories denoted as OPE without OPE (operator product expansi

E. Pallante

The ultraviolet behaviour of the generating functional for hadronic weak interactions with $|ΔS| =1, 2$ is investigated to one loop for a generic number of flavours and in the quenched approximation. New quenched chiral logarithms generated by the weak interactions can be accounted for via a redefinition of the weak mass term in the $ΔS=\pm 1$ weak effective

Stefan Soldner-Rembold

The total hadronic photon-photon cross-section measured by L3 and OPAL and the apparent discrepancy between the results are discussed. OPAL measurements of jet and charged hadron production in photon-photon scattering and preliminary H1 results on neutral pion production in photon-proton scattering are also presented. The mechanism of baryon number transfer

D. Muller

We present new studies of 3-jet final states from hadronic $Z^0$ decays recorded by the SLD experiment, in which jets are identified as quark, antiquark or gluon. Our gluon energy spectrum, measured over the full kinematic range, is consistent with the predictions of QCD, and we derive a limit on an anomalous chromomagnetic $bbg$ coupling. We measure the par

M. A. Negodaev, B. N. Lomonosov, S. K. Kotelnikov, A. V. Bagulya

The gas electron multiplier produced with the polyimide film 100 um thick. The maximum gas gain obtained with gas mixture Ar/CH4(91/9) was 5000. No decrease of gas gain with rates up to 2\cdot10^4 1/(mm^2 s) was observed. The possibility of operation of GEM with and without MSGC is discussed

M. Chaves, G. Padilla

The inflaton field is assumed to possess electric charge. The effect of the charge upon inflation is studied using a parameter ω_0 that acts as a measure of the quantity of inflaton present. It is shown that at the end of inflation the charged inflaton should produce a fractal electromagnetic structure, which could act as a seed for the development of macros

Simonetta Frittelli, Ezra T. Newman

We first define what we mean by gravitational lensing equations in a general space-time. A set of exact relations are then derived that can be used as the gravitational lens equations in all physical situations. The caveat is that into these equations there must be inserted a function, a two-parameter family of solutions to the eikonal equation, not easily o

Kip S. Thorne, Carolee J. Winstein

Among all forms of routine human activity, the one which produces the strongest gravity-gradient noise in interferometric gravitational-wave detectors (e.g. LIGO) is the beginning and end of weight transfer from one foot to the other during walking. The beginning and end of weight transfer entail sharp changes (timescale tau ~ 20msec) in the horizontal jerk

Edward M. Murphy

Anderson, et al. (gr-qc/9808081) have recently reported the discovery of an apparent anomalous, weak, long-range acceleration in the Pioneer 10/11 and Ulysses spacecraft. I believe that this result can be explained by non-isotropic radiative cooling of the spacecraft electronics through passive radiators on the spacecraft surface. These radiators are prefere

Ilja Schmelzer

One way the ultraviolet problem may be solved is explicit physical regularization. In this scenario, QFT is only the long distance limit of some unknown non-Poincare-invariant microscopic theory. One can ask how complex and contrived such microscopic theories should be. We show that condensed matter in standard Newtonian framework is sufficient to obtain gra

Nick McKeown, Martin Izzard, Adisak Mekkittikul, Bill Ellersick

The objective is to design and build a small, high-bandwidth switch.

Tuomas Sandholm, Kate Larson, Martin Andersson, Onn Shehory

Coalition formation is a key topic in multiagent systems. One would prefer a coalition structure that maximizes the sum of the values of the coalitions, but often the number of coalition structures is too large to allow exhaustive search for the optimal one. But then, can the coalition structure found via a partial search be guaranteed to be within a bound f

Joerg Schmalian

Feedback effects due to spin fluctuation induced precursors in the fermionic quasiparticle spectrum are taken into account in the description of a quantum critical point of itinerant spin systems. A correlation length dependent spin damping occurs, leading to a dynamical scaling with z\approx 1 which non-trivially competes with the conventional spin wave beh

M. J. de Ruijter, J. De Coninck, G. Oshanin

We study the time evolution of a sessile liquid droplet, which is initially put onto a solid surface in a non-equilibrium configuration and then evolves towards its equilibrium shape. We adapt here the standard approach to the dynamics of mechanical dissipative systems, in which the driving force, i.e. the gradient of the system&#39;s Lagrangian function, is

P. Tegzes, T. Vicsek, D. C. Rapaport

Motivated by recent advances in the investigation of fluctuation-driven ratchets and flows in excited granular media, we have carried out experimental and simulational studies to explore the horizontal transport of granular particles in a vertically vibrated system whose base has a sawtooth-shaped profile. The resulting material flow exhibits novel collectiv

Alexander K. Hartmann

Large numbers of ground states of two-dimensional Ising spin glasses with periodic boundary conditions in both directions are calculated for sizes up to 40^2. A combination of a genetic algorithm and Cluster-Exact Approximation is used. For each quenched realization of the bonds up to 40 independent ground states are obtained. For the infinite system a groun

H. -J. Schmidt, J. Schnack

A remarkable thermodynamic fermion-boson symmetry is found for the canonical ensemble of ideal quantum gases in harmonic oscillator potentials of odd dimensions. The bosonic partition function is related to the fermionic one extended to negative temperatures, and vice versa.

K. Takenaka, K. Iida, Y. Sawaki, S. Sugai

Optical reflectivity spectra of La(1-x)Sr(x)MnO(3) (0<=x<=0.30) were measured on cleavage surfaces of single crystals. The optical conductivity $σ(w) of ferromagnetic-metal La(0.70)Sr(0.30)MnO(3) is characterized by a Drude-like - but not simple Drude - component with large spectral weight below 1.6 eV, which yields a large effective carrier number N*_eff co

I. Tifrea, I. Grosu, M. Crisan

We investigate the fluctuation contribution to the specific heat of a two-dimensional superconductor with a non-Fermi normal state described by a Anderson Green&#39;s function $G(k,iω)=ω_c^{-α}/(iω-ε_k)^{1-α}$. The specific heat corrections contain a term proportional to $(T^{2α-T_c^{2α}})^{-1}$ and another logarithmic one. We defined a coherence length as f

Guang-Ming Zhang, Lu Yu

We consider the symmetric single-impurity Anderson model in the presence of pairing fluctuations. In the isotropic limit, the degrees of freedom of the local impurity are separated into hybridizing and non-hybridizing modes. The self-energy for the hybridizing modes can be obtained exactly, leading to two subbands centered at $\pm U/2$. For the non-hybridizi

G. Khaliullin, R. Kilian, S. Krivenko, P. Fulde

We present a theory of magnetic (Ni) and nonmagnetic (Zn) impurities substituted into planar Cu sites in the normal state of underdoped cuprates exhibiting a spin gap. Both types of impurities induce magnetic moments on neighboring Cu sites. In the case of Ni these moments partially screen the inherent impurity spin, resulting in an effective S=1/2 moment. T

D. Pogosyan, J. R. Bond, L. Kofman, J. Wadsley

Simple analytic arguments are used to understand the predominantly filamentary web in the large-scale distribution of galaxies. Numerical simulations of superclusters are performed to assess the feasibility of directly mapping the intracluster webbing, in particular with weak gravitational lensing using Wide Field Cameras.

J. E. Gizis, I. N. Reid

We present results of a study of very low mass halo stars. Using a sample of proper motion stars identified from plate material taken as part of the first and second Palomar Sky Surveys, we measure the space density, metallicity distribution, and kinematics of the Population II M subdwarfs. Our overall luminosity function is in good agreement with previous a

Mario Mateo

The Local Group (LG) dwarf galaxies offer a unique window to the detailed properties of the most common type of galaxy in the Universe. In this review, I update the census of LG dwarfs based on the most recent distance and radial velocity determinations. I then discuss the detailed properties of this sample, including (a) the integrated photometric parameter

Dennis Zaritsky

We review the various techniques used to constrain the Galactic halo mass profile for radii > 20 kpc with particular emphasis on identifying a self-consistent halo model and resolving the apparent discrepancies present in the literature on this subject. We collate published results and demonstrate that they are all consistent with a Galactic halo that is nea

H. Papathanassiou

I present a computationally efficient way to account for synchrotron and its inverse Compton scattered emission along with the resulting radiative losses, in a self-consistent way, for a relativistic distribution of electrons continuously injected in an expanding region. This approach permits the exploration of the wide parameter space of the physical proces

Robert Antonucci

Optical/UV observations provide many constraints on accretion disk models of AGN which aren&#39;t always appreciated by modelers of the X-ray emission (or sometimes even of the optical/UV emission). The spectral behavior at the Ly edge, the polarization, the continuum slopes and breaks, and the variability timescales and phasing all conflict with simple mode

Mariangela Bernardi, Alvio Renzini, Luiz N. da Costa, Gary Wegner

Using new observations for a sample of 931 early-type galaxies we investigate whether the \mg2--\so relation shows any dependence on the local environment. The galaxies have been assigned to three different environments depending on the local overdensity: clusters, groups, and field, having used our completeredshift database to guide the assignment of galaxi

H. M. P. Couchman, Andrew J. Barber, Peter A. Thomas

We have developed a new three-dimensional algorithm, based on the standard P$^3$M method, for computing deflections due to weak gravitational lensing. We compare the results of this method with those of the two-dimensional planar approach, and rigorously outline the conditions under which the two approaches are equivalent. Our new algorithm uses a Fast Fouri

Sonja Vrielmann, Axel D. Schwope

We present a new mapping algorithm, the Accretion Stream Mapping, which uses the complete emission-line light curve to derive spatially resolved intensity distributions along the stream on a surface created as a duodecadon shaped tube. We successfully test this method on artificial data and then applied it to emission line light curves in Hbeta, Hgamma and H

Axel D. Schwope, Robert Schwarz, Andreas Staude, Claus Heerlein

We are reviewing the power of Doppler tomography for detailed investigations of polars (magnetic cataclysmic binaries without accretion disk). Using high-resolution spectroscopy in combination with tomography as analytic tool, the structure and extent of the accretion flows and accretion curtains in the binaries can be uncovered and the irradiated and non-ir

Wolfgang Kundt

Seventy-nine physical problems are listed and explained with whose proposed solutions I do not agree. Such disagreements -- even though some of them may simply reflect our preliminary insight into the laws of nature -- have occasionally caused deplorable damage to personal relationships.

H. -Th. Janka

Multi-dimensional hydrodynamic simulations of the post-bounce evolution of collapsed stellar iron cores have demonstrated that convective overturn between the stalled shock and the neutrinosphere can have an important effect on the neutrino-driven explosion mechanism. Whether a model yields a successful explosion or not, however, still depends on the power o

H. -Th. Janka, M. Ruffert, T. Eberl

Hydrodynamic simulations were performed of the dynamical phase of the merging of binary neutron stars (NS-NS) and of neutron star black hole binaries (NS-BH), using the physical nuclear equation of state of Lattimer and Swesty (1991) and taking into account the emission of gravitational waves and neutrinos.

Takuji Tsujimoto, Toshikazu Shigeyama

The supernova yields of several heavy elements including alpha-, iron-group, and r-process elements are obtained as a function of the mass of their progenitor main-sequence stars M_ms from the abundance patterns of extremely metal-poor stars with a procedure recently proposed by Shigeyama and Tsujimoto (1998). The ejected masses of alpha- and iron-group elem

Matthew A. Malkan

It is well established in the local Universe that regions of high star-formation rate are dusty. As a result of this physical causal link, galaxies of increasing current star formation activity emit a larger proportion of their bolometric luminosity via dust absorption and re-radiation in the thermal mid- to far-infrared. Several new observations indicate th

Daniel Schaerer, Thierry Contini, Daniel Kunth

We report the detection of WC stars in 5 Wolf-Rayet (WR) galaxies: He 2-10, NGC 3049, NGC 3125, NGC 5253 and Tol 89. The faint broad CIV5808 line requires sufficiently high S/N to be detected explaining the non-detection of this WC feature in previous observations. From the WR emission lines we conclude that all regions (except NGC 3049) contain a mixed popu

Orfeu Bertolami, Ricardo Schiappa

We study solutions of the Wheeler-DeWitt equation corresponding to an S-modular invariant N=1 supergravity model and a closed homogeneous and isotropic Friedmann-Robertson-Walker spacetime. The issues of inflation and of the cosmological constant problem are addressed with the help of the relevant wave functions. We find that topological type inflation is co

Wu Zhong Chao

For a spherically symmetric vacuum model with a negative cosmological constant, a complex constrained instanton is considered as the seed for the quantum pair creation of Schwarzschild-anti-de Sitter black holes. The relative creation probability is found to be the exponential of the negative of the black hole entropy. The black hole entropy is known to be o

M. Ardehali

Einstein&#39;s locality is invoked to derive a correlation inequality. In the case of ideal experiments, this inequality is equivalent to Bell&#39;s original inequality of 1965 which, as is well known, is violated by a maximum factor of 1.5. The crucial point is that even in the case of real experiments where polarizers and detectors are non-ideal, the prese

A. M. Steinberg, S. Myrskog, Han Seb Moon, Hyun Ah Kim

We describe a series of atom optics experiments underway at Toronto for investigating tunnelling interaction times of various sorts. We begin by discussing some outstanding issues and confusions related to the question of whether or not superluminal tunnelling can be construed as true faster-than-light ``signal propagation,&#39;&#39; a question which we answ

E. A. Kolganova, A. K. Motovilov

A mechanism of disappearance and formation of the Efimov levels of the helium ^4He_3 trimer is studied when the force of interatomic interaction is changed. The resonances including virtual levels are calculated by the method based on the solving the boundary value problem, at complex energies, for the Faddeev differential equations describing the (2+1 --> 2

Tom Leinster

A concise guide to very basic bicategory theory, from the definition of a bicategory to the coherence theorem.

Amnon Yekutieli

Let k be a field and A a noetherian (noncommutative) k-algebra. The rigid dualizing complex of A was introduced by Van den Bergh. When A = U(g), the enveloping algebra of a finite dimensional Lie algebra g, Van den Bergh conjectured that the rigid dualizing complex is (U(g) \otimes \wedge^{n} g)[n], where n = dim g. We prove this conjecture, and give a few a

Grigori Olshanski

The matrix Whittaker kernel has been introduced by A. Borodin in Part IV of the present series of papers. This kernel describes a point process -- a probability measure on a space of countable point configurations. The kernel is expressed in terms of the Whittaker confluent hypergeometric functions. It depends on two parameters and determines a $J$-symmetric

Ichiro Oda

It is shown that a supersymmetric and $κ$-symmetric D3-brane action on $AdS_5 \times S^5$ is mapped into itself by a duality transformaion, thereby verifying the $SL(2,Z)$ invariance of the D3-brane action in the $AdS_5 \times S^5$ background as in the flat background. To this end, we fix the $κ$-symmetry in a gauge which simplifies the classical action in o

Alan Kostelecky

A brief summary is given of recent developments concerning a Lorentz-violating extension of the standard model and its implications for experiments testing Lorentz and CPT symmetry.

John D. Stack, William Tucker

We study the heavy quark potential in the SU(2) positive plaquette model using monopoles in the maximum abelian gauge, and vortices. Monopoles give a quantitative description of the string tension. Vortices approximately reproduce the entire heavy quark potential.

E. -M. Ilgenfritz, S. Thurner

Using the renormalization group motivated smoothing technique we study the semiclassical structure of the pure Yang-Mills vacuum. We carefully check that identified clusters of topological charge behave like instantons around their centers. Looking at distance distributions of clusters we find instanton-antiinstanton pair formation in the deconfined phase. W

Jiseong Park

The paper is concerned with the Einstein equations for a spherically symmetric static distribution of anisotropic matter. The equations are cast into a system of Fuchsian type ODE for certain scalar invariants of the strain. And then the existence and regularity of this ODE is studied under general constitutive relation. In the case the constitutive relation

V. Kurasov

The contradiction between the stationary aproach to the density profile and the avalanche character of the metastable phase consumption is investigated. The exact solution for the metastable phase profile is obtained. The reconsidered value for the special parameter responsible for the hierarchy in the structure of the density profile around the droplet is p

Piero Rosati

I review recent observational progress in the search for and study of distant galaxy clusters in the X-ray band, with particular emphasis on the evolution of the abundance of X-ray clusters out to z~1. Several on-going deep X-ray surveys have led to the discovery of a sizeable population of clusters at z>0.5 and have the sensitivity to detect clusters beyond

Kailash C. Sahu, M. S. Sahu

More than a dozen microlensing events have been detected so far towards the LMC and 2 towards the SMC. If all the lenses are in the Galactic halo, both the LMC and the SMC events are expected to have similar time scales. However, the first event towards the SMC, MACHO 97-SMC-1, had a time scale of 123 days which is much larger than the typical time scale for

Hiroyuki Fukuda, Asao Habe, Keiichi Wada

In our previous paper, we have shown that a gas disk in the nuclear region of a barred galaxy which contains a central supermassive black hole (SMBH) rapidly evolves into a nuclear gas ring by the effect of an additional inner Lindblad resonance caused by the SMBH. In this paper, we investigate the fate of the gas ring, involving self-gravity of gas, using t

Chi-Sheng Niu, Robert B. Griffiths

We study the mapping which occurs when a single qubit in an arbitrary state interacts with another qubit in a given, fixed state resulting in some unitary transformation on the two qubit system which, in effect, makes two copies of the first qubit. The general problem of the quality of the resulting copies is discussed using a special representation, a gener

Dirk Kreimer

Using set-theoretic considerations, we show that the forest formula for overlapping divergences comes from the Hopf algebra of rooted trees.

D. Fargion, M. Yu. Khlopov, R. V. Konoplich, R. Mignani

Considering heavy stable neutrinos of 4th generation we calculate the relic density of such neutrinos in the Universe. Taking into account the condensation of heavy neutrinos in the Galaxy and applying the results of calculations to experimental data from underground experiments on search for WIMPs in elastic neutral current scattering on nuclei we found an

Nga le Tran, Jeong-Man Park, Michael W. Deem

We explore the regime of ``superfast&#39;&#39; reactivity that has been predicted to occur in turbulent flow in the presence of potential disorder. Computer simulation studies confirm qualitative features of the previous renormalization group predictions, which were based on a static model of turbulence. New renormalization group calculations for a more real

Dik Bouwmeester, Jian-Wei Pan, Matthew Daniell, Harald Weinfurter

Braunstein and Kimble observe correctly that, in the Innsbruck experiment, Nature 390, 575 (1997), one does not always observe a teleported photon conditioned on a coincidence recording at the Bell-state analyser. However, when a teleported photon appears, it has all the properties required by the teleportation protocol.

M. Kibler, G. -H. Lamot, P. Winternitz

This paper deals with the classical trajectories for two super-integrable systems: a system known in quantum chemistry as the Hartmann system and a system of potential use in quantum chemistry and nuclear physics. Both systems correspond to ring-shaped potentials. They admit two maximally super-integrable systems as limiting cases, viz, the isotropic harmoni

Alexei Borodin, Grigori Olshanski

We give a summary of the results from Parts I-V (math.RT/9804086, math.RT/9804087, math.RT/9804088, math.RT/9810013, math.RT/9810014). Our work originated from harmonic analysis on the infinite symmetric group. The problem of spectral decomposition for certain representations of this group leads to a family of probability measures on an infinite-dimensional

Alexei Borodin

We study a 2-parametric family of probability measures on the space of countable point configurations on the punctured real line (the points of the random configuration are concentrated near zero). These measures (or, equivalently, point processes) have been introduced in Part II (A. Borodin, math.RT/9804087) in connection with the problem of harmonic analys

Ulrich Hermisson

A method of constructing covariant differential calculi on a quantum homogeneous space is devised. The function algebra X of the quantum homogeneous space is assumed to be a left coideal of a coquasitriangular Hopf algebra H and to contain the coefficients of any matrix over H which is the two-sided inverse of one with entries in X. The method is based on pa

H. Arthur Weldon

A nonperturbative proof is given that the chirally-invariant quark propagator contains both particle and hole singularities with different dispersion relations. Mesons made of a quark and a hole will produce dilepton pairs at masses characteristic of the plasma and with a distinct energy dependence.

Chung-I Tan

The most important consequence of Pomeron being a pole is the factorization property. However, due to Pomeron intercept being greater than 1, the extrapolated single diffraction dissociation cross section based on a classical triple-Pomeron formula is too large leading to a potential unitarity violation at Tevatron energies, which has been referred to as &#3

Bruce R. Childers, James P. Cohoon, Jack W. Davidson, Peter Valle

Teaching object-oriented programming in an introductory programming course poses considerable challenges to the instructor. An often advocated approach to meeting this challenge is the use of a simple, object-oriented graphics library. We have developed a simple, portable graphics library for teaching object-oriented programming using C++. The library, EzWin

R. Kilian, G. Khaliullin

We discuss the role of orbital degeneracy in the transport properties of perovskite manganites, focusing in particular on the optical conductivity in the metallic ferromagnetic phase at low temperatures. Orbital degeneracy and strong correlations are described by an orbital t-J model which we treat in a slave-boson approach. Employing the memory-function for

Debashis Gangopadhyay, Ranjan Chaudhury

Van der Waerden&#39;s (VDW) colouring theorem in combinatoric number theory [1] has scope for physical applications.The solution of the two colour case has enabled the construction of an explicit mapping of an infinite, one dimensional antiferromagnetic Ising system to an effective pseudo- ferromagnetic one with the coupling constants in the two cases becomi

M. W. Wu, H. Haug

We investigate the femtosecond kinetics of optically excited 2D magneto-plasma. We calculate the femtosecond dephasing and relaxation kinetics of the laser pulse excited magneto-plasma due to bare Coulomb potential scattering, because screening is under these conditions of minor importance. By taking into account four Landau subbands in both the conduction b

M. R. Zapatero Osorio, R. Rebolo, E. L. Martin, S. T. Hodgkin

We present the results of a deep CCD-based IZ photometric survey of a ~1 sq. deg area in the central region of the Pleiades Galactic open cluster. The magnitude coverage of our survey (from I~17.5 down to 22) allows us to detect substellar candidates with masses between 0.075 and 0.03 Msol. Details of the photometric reduction and selection criteria are give

G. Dubus, P. A. Charles, K. S. Long, P. J. Hakala

Using our extensive ROSAT X-ray observations of M33, we confirm a 3.45 day eclipse period for the Einstein source X-7 (Larson & Schulman, 1997) and discover evidence for a 0.31-s pulse period. The orbital period, pulse period and observed X-ray luminosity are remarkably similar to SMC X-1. We therefore suggest M33 X-7 is a neutron star high mass X-ray binary

Jesus Pando, Li-Zhi Fang

We present an analysis of the non-Gaussianity in the distribution of Ly$α$ forest lines in the QSO absorption spectra. Statistical tests performed on this data indicate that there may be large scale structure even though the power spectrum of the Ly$α$ line distribution on large scales is found to be flat. It is apparent that higher (than two) order statisti