March 2002 arXiv papers — page 11

Pranab Ghosh

I summarize X-ray diagnostic studies of cosmic star formation in terms of evolutionary schemes for X-ray binary evolution in normal galaxies with evolving star formation. Deep X-ray imaging studies by CHANDRA and XMM-NEWTON are beginning to constrain both the X-ray luminosity evolution of galaxies and the log N - log S diagnostics of the X-ray background: I

K. Motohara, F. Iwamuro, T. Maihara, S. Oya

This paper describes a Cooled Infrared Spectrograph and Camera for OHS (CISCO), mounted on the Nasmyth focus of the Subaru telescope. It is primarily designed as a back-end camera of the OH-Airglow Suppressor (OHS), and is also used as an independent, general-purpose near-infrared camera/spectrograph. CISCO is based on a single 1024x1024 format HgCdTe HAWAII

Igor O. Cherednikov

The contribution of the ground state energy of quantum fields to the cosmological constant is estimated from the point of view of the standard Casimir energy calculation scheme. It is shown that the requirement of the renormalization group invariance leads to the value of the effective $Ł$-term which is of 11 orders higher than the result extracted from the

P. N. Best

Deep sub-millimetre observations using SCUBA are presented of the central regions of four high redshift clusters which have been extensively studied optically: CL0023+0423 (z=0.84), J0848+4453 (z=1.27), CL1604+4304 (z=0.90) and CL1604+4321 (z=0.92). 10 sub-millimetre sources are securely detected towards these four clusters at 850 microns, with two further t

Sandip Pakvasa, Probir Roy

All existing data on neutrino oscillations (including those from the LSND experiment) imply a four neutrino scheme with six different allowed mass patterns. Some of the latter are shown to be disfavored by using a conservative upper bound on the $βbeta 0 ν$ nuclear decay rate, if neutrinos are assumed to be Majorana particles. Comparisons are also made with

W. Kluzniak, M. A. Abramowicz

Non-linear acoustic coupling of modes in accretion disks allows a parametric resonance between epicyclic motions. In black hole disks, such a resonance first occurs, and is strongest, when the radial and vertical epicyclic frequencies are approximately in a 2:3 ratio, in agreement with the 300 and 450 Hz frequencies reported in GRO J1655-40 and the 184 and 2

L. M. Voigt, R. W. Schmidt, A. C. Fabian, S. W. Allen

Chandra and XMM-Newton observations have confirmed the presence of large temperature gradients within the cores of many relaxed clusters of galaxies. Here we investigate whether thermal conduction operating over those gradients can supply sufficient heat to offset radiative cooling. Narayan & Medvedev (2001) and Gruzinov (2002) have noted, using published re

K. Huitu, J. Laamanen, P. N. Pandita

We study in detail the particle spectrum in anomaly mediated supersymmetry breaking models in which supersymmetry breaking terms are induced by the super-Weyl anomaly. We investigate the minimal anomaly mediated supersymmetry breaking models, gaugino assisted supersymmetry breaking models, as well as models with additional residual nondecoupling D-term contr

J. D. Vergados, D. Owen

Exotic dark matter together with the vacuum energy (associated with the cosmological constant) seem to dominate the Universe. Thus its direct detection is central to particle physics and cosmology. Supersymmetry provides a natural dark matter candidate, the lightest supersymmetric particle (LSP). One essential ingredient in obtaining the direct detection rat

R. Salvaterra, C. Burigana

We have compared the absolute temperature data of the CMB spectrum with models for CMB spectra distorted by a single or two heating processes at different cosmic times. The constraints on the fractional energy injected in the radiation field, DE/E, are mainly provided by the FIRAS instrument aboard the COBE satellite. Under the hypothesis that two heating pr

Darren S. Madgwick, Paul C. Hewett, Daniel J. Mortlock, Ofer Lahav

The 100,000 spectra from the 2 degree Field Galaxy Redshift Survey (2dFGRS) in the 100k Public Data Release represent the largest single compilation of galaxy spectra available. By virtue of its sheer size and the properties of the photometric catalogue that defines the sample, the 2dFGRS is expected to contain a number of potentially interesting objects oth

W. T. Buttler, S. K. Lamoreaux, J. R. Torgerson, G. H. Nickel

We describe a new error reconciliation protocol {\it Winnow} based on the exchange of parity and Hamming's ``syndrome'' for $N-$bit subunits of a large data set. {\it Winnow} was developed in the context of quantum key distribution and offers significant advantages and net higher efficiency compared to other widely used protocols within the quantum cryptogra

Charles B. Thorn

We extend previous work by developing a worldsheet description of non-abelian gauge theory (Yang-Mills). This task requires the introduction of Grassmann variables on the world sheet analogous to those of the Neveu-Schwarz-Ramond formulation of string theory. A highlight of our construction is that once the three gluon vertices of Yang-Mills Feynman diagrams

Antal Jevicki, Jesse Thaler

We consider the process of black hole formation in particle collisions in the exactly solvable framework of 2+1 dimensional Anti de Sitter gravity. An effective Hamiltonian describing the near horizon dynamics of a head on collision is given. The Hamiltonian exhibits a universal structure, with a formation of a horizon at a critical distance. Based on it we

Hans J. Pirner, Feng Yuan

We discuss deep inelastic scattering at high energies as a critical phenomenon in 2+1 space - time dimensions. In the limit of Bjorken $x \to 0$, $QCD$ SU(3) with quark fields becomes a critical theory with a diverging correlation length $ξ(x) \propto x^{-\frac{1}{2 λ_2}}$ where the exponent $λ_2=2.52$ is obtained from the center group Z(3) of SU(3). We conj

H. Bruntt, C. Catala, R. Garrido, E. Rodriguez

One of the goals of the ground-based support program for the COROT and MONS/Roemer satellite missions is to select and characterise suitable target stars for the part of the missions dedicated to asteroseismology. While the global atmospheric parameters may be determined with good accuracy from the Stromgren indices, careful abundance analysis must be made f

M. R. Ahmady, F. A. Chishtie, V. Elias, A. H. Fariborz

For any perturbative series that is known to $k$-subleading orders of perturbation theory, we utilise the process-appropriate renormalization-group (RG) equation in order to obtain all-orders summation of series terms proportional to $α^n \log^{n-k}(μ^2)$ with $k = {0,1,2,3}$, corresponding to the summation to all orders of the leading and subsequent-three-s

Yeinzon Rodriguez, Carlos Quimbay

We study the behaviour of the flavour changing neutral currents in the Left-Right Symmetric Model related to the presence of spontaneous CP phases. To do this, we explore four cases corresponding to combinations of maximal and no CP violation in both the lepton and quark sector. We find that we can constrain the flavour changing neutral currents to the exper

M. De Petris, L. D'Alba, L. Lamagna, F. Melchiorri

We have measured the Sunyaev-Zeldovich effect towards the Coma cluster (A1656) with the MITO experiment, a 2.6-m telescope equipped with a 4-channel 17 arcminute (FWHM) photometer. Measurements at frequency bands 143+/-15, 214+/-15, 272+/-16 and 353+/-13 GHz, were made during 120 drift scans of Coma. We describe the observations and data analysis that involv

Danny Calegari, Nathan M. Dunfield

If M is an atoroidal 3-manifold with a taut foliation, Thurston showed that pi_1(M) acts on a circle. Here, we show that some other classes of essential laminations also give rise to actions on circles. In particular, we show this for tight essential laminations with solid torus guts. We also show that pseudo-Anosov flows induce actions on circles. In all ca

C. Quesne, N. Vansteenkiste

Order-$p$ parasupersymmetric and orthosupersymmetric quantum mechanics are shown to be fully reducible when they are realized in terms of the generators of a generalized deformed oscillator algebra and a ${\rm Z}_{p+1}$-grading structure is imposed on the Fock space. The irreducible components provide $p+1$ sets of bosonized operators corresponding to both u

C. Quesne, N. Vansteenkiste

Pseudosupersymmetric quantum mechanics (PsSSQM), based upon the use of pseudofermions, was introduced in the context of a new Kemmer equation describing charged vector mesons interacting with an external constant magnetic field. Here we construct the complete explicit solution for its realization in terms of two superpotentials, both equal or unequal. We pro

Anjan S. Joshipura, Rishikesh D. Vaidya, Sudhir K. Vempati

We perform a general analytic study of feasibility of obtaining a combined explanation for the deficits in the solar and the atmospheric neutrino fluxes with two large mixing angles in supersymmetric model with bilinear R parity violations. The required hierarchy among the solar and atmospheric neutrino mass scales follows in this framework in the presence o

Amit Sever, Assaf Shomer

We derive the general formula, at a finite cutoff, for the change in the boundary condition of a scalar field in AdS under a Multiple-trace deformation of the dual CFT. Our analysis suggests that fluctuations around the classical solution in AdS should not be constrained by boundary conditions.

H. W. Diehl, M. Krech, H. Karl

The dynamic critical behavior of isotropic Heisenberg ferromagnets with a planar free surface is investigated by means of field-theoretic renormalization group techniques and high-precision computer simulations. An appropriate semi-infinite extension of the stochastic model J is constructed. The relevant boundary terms of the action of the associated dynamic

D. Martinez-Delgado, R. Zinn, R. Carrera, C. Gallart

Photometry of a large field around the young globular cluster Palomar 12 has revealed the main-sequence of a low surface-brightness stellar system. This main-sequence is indicative of a stellar population that varies significantly in metallicity and/or age, but in the mean is more metal poor than Pal 12. Under different assumptions for the properties of this

Yvonne Y. Y. Wong

A recent numerical study by A. D. Dolgov, S. H. Hansen, S. Pastor, S. T. Petcov, G. G. Raffelt, and D. V. Semikoz (DHPPRS) [hep-ph/0201287] found that complete or partial equilibrium between all active neutrino flavours can be achieved before the big bang nucleosynthesis epoch via flavour oscillations, if the oscillation parameters are those inferred from th

Guillaume Duchateau, Eric Cormier, Robert Gayet

In conditions where the interaction betweeen an atom and a short high-frequency extreme ultraviolet laser pulse is a perturbation, we show that a simple theoretical approach, based on Coulomb-Volkov-type states, can make reliable predictions for ionization. To avoid any additional approximation, we consider here a standard case : the ionization of hydrogen a

Kousuke Yakubo, Yshai Avishai, Doron Cohen

Relation between the geometry of a two-dimensional sample and its equilibrium physical properties is exemplified here for a system of non-interacting electrons on a Moebius strip. Dispersion relation for a clean sample is derived and its persistent current under moderate disorder is elucidated, using statistical analysis pertinent to a single sample experime

Graciela Gelmini, Alexander Kusenko, Shmuel Nussinov

We show that direct dark matter detection experiments can distinguish between pointlike and non-pointlike dark-matter candidates. The shape of the nuclear recoil energy spectrum from pointlike dark-matter particles, e.g., neutralinos, is determined by the velocity distribution of dark matter in the galactic halo and by nuclear form factors. In contrast, typi

Shailesh Chandrasekharan

A cluster algorithm is constructed and applied to study the chiral limit of the strongly coupled lattice Schwinger model involving staggered fermions. The algorithm is based on a novel loop representation of the model. Finite size scaling of the chiral susceptibility based on data from lattices of size up to $64\times 64$ indicates the absence of long range

L. R. G. Fontes, M. Isopi, C. M. Newman, K. Ravishankar

Arratia, and later Tóth and Werner, constructed random processes that formally correspond to coalescing one-dimensional Brownian motions starting from every space-time point. We extend their work by constructing and characterizing what we call the {\em Brownian Web} as a random variable taking values in an appropriate (metric) space whose points are (compact

A. Kinkhabwala, M. Sako, E. Behar, S. M. Kahn

We present the first high-resolution, soft-X-ray spectrum of the prototypical Seyfert 2 galaxy, NGC 1068. This spectrum was obtained with the XMM-Newton Reflection Grating Spectrometer. Emission lines from H-like and He-like low-Z ions (from C to Si) and Fe-L-shell ions dominate the spectrum. Strong, narrow radiative recombination continua (RRC) for several

Roland Netz, David Andelman

Chain-like macromolecules (polymers) show characteristic adsorption properties due to their flexibility and internal degrees of freedom, when attracted to surfaces and interfaces. In this review we discuss concepts and features that are relevant to the adsorption of neutral and charged polymers at equilibrium, including the type of polymer/surface interactio

Matteo G. A. Paris

We suggest an interferometric scheme assisted by squeezing and linear feedback to realize the whole class of field-quadrature quantum nondemolition measurements, from Von Neumann projective measurement to fully non-destructive non-informative one. In our setup, the signal under investigation is mixed with a squeezed probe in an interferometer and, at the out

D. B. Horoshko, S. Ya. Kilin

We perform a comparison of two protocols for generating a cryptographic key composed from d-valued symbols: one exploiting a string of independent qubits and another one utilizing d-level systems prepared in states belonging to d+1 mutually unbiased bases. We show that the protocol based on qubits is optimal for quantum cryptography, since it provides higher

J. Tworzydlo, C. W. J. Beenakker

We study the competing effects of stimulated and spontaneous emission on the information capacity of an amplifying disordered waveguide. At the laser threshold the capacity reaches a "universal" limit, independent of the degree of disorder. Whether or not this limit is larger or smaller than the capacity without amplification depends on the disorder,

Li-Xiang Cen, Nan-Jian Wu, Fu-Hua Yang, Jun-Hong An

The optimal entanglement manipulation for a single copy of mixed states of two qubits is to transform it to a Bell diagonal state. In this paper we derive an explicit form of the local operation that can realize such a transformation. The result obtained is universal for arbitrary entangled two-qubit states and it discloses that the corresponding local filte

Fabio Raciti, Giovanni Salesi

In this paper we calculate the analytic expression of the phase time for the scattering of an electron off a complex square barrier. As is well known the (negative) imaginary part of the potential takes into account, phenomenologically, the absorption. We investigate the so-called Hartman-Fletcher effect, and find that it is suppressed by the presence of a (

Matej Pavsic, Erasmo Recami, Waldyr A. Rodrigues, G. Daniele Maccarrone

The recent literature shows a renewed interest, with various independent approaches, in the classical models for spin. Considering the possible interest of those results, at least for the electron case, we purpose in this paper to explore their physical and mathematical meaning, by the natural and powerful language of Clifford algebras (which, incidentally,

Pi-Gang Luan, Yee-Mou Kao

Reflection of a normal incident matter wave by a perfectly reflecting wall moving with a constant velocity is investigated. A surprising phenomenon is found-that if the the wall moves faster than the phase velocity of the incident wave, both the reflected and incident waves propagate in the same direction. This counter-intuitive result is an example which sh

P. Caban, J. Rembielinski, K. A. Smolinski, Z. Walczak

A description of destruction of states on the grounds of quantum mechanics rather than quantum field theory is proposed. Several kinds of maps called supertraces are defined and used to describe the destruction procedure. The introduced algorithm can be treated as a supplement to the von Neumann-Lueders measurement. The discussed formalism may be helpful in

Stephen D. Bartlett, Barry C. Sanders

Although universal continuous-variable quantum computation cannot be achieved via linear optics (including squeezing), homodyne detection and feed-forward, inclusion of ideal photon counting measurements overcomes this obstacle. These measurements are sometimes described by arrays of beam splitters to distribute the photons across several modes. We show that

Troy D. Mackay, Stephen D. Bartlett, Leigh T. Stephenson, Barry C. Sanders

We analyze the quantum walk in higher spatial dimensions and compare classical and quantum spreading as a function of time. Tensor products of Hadamard transformations and the discrete Fourier transform arise as natural extensions of the quantum coin toss in the one-dimensional walk simulation, and other illustrative transformations are also investigated. We

Bin Zhou

Evidence implies that basic laws of thermodynamics must be tested by experiments. In this paper, an experiment is designed to measure the entropy of a system with at least one known (measurable) equation of state, especially the gas systems. Since the entropy can be measured now, the formulae related to the second law of thermodynamics can be examined by oth

A. P. Potylitsyn

For a number of physical studies which are planned to be made with the next generation colliders, it is necessary to use polarized beams of both electrons and positrons. The problem of producing and acceleration of polarized electrons may be considered to be solved, but the existing approaches to create polarized positron beams do not ensure the parameters r

Frank X. Lee, Xinyu Liu

The masses of octet baryons are calculated by the method of QCD sum rules. Using generalized interpolating fields, three independent sets of QCD sum rules are derived which allow the extraction of low-lying N* states with spin-parity 1/2+, 1/2- and 3/2- in both the non-strange and strange channels. The predictive ability of the sum rules is examined by a Mon

A. Chernomoretz, P. Balenzuela, C. O. Dorso

The phase diagram, ($T,ρ$), of a finite, constrained, and classical system is built from the analysis of cluster distributions in phase and configurational space. The obtained phase diagram can be split in three regions. One, low density limit, in which first order phase transition features can be observed. Another one, corresponding to the high density regi

M. Ison, P. Balenzuela, A. Bonasera, C. O. Dorso

In this communication we analyze the behavior of excited drops contained in spherical volumes. We study different properties of the dynamical systems i.e. the maximum Lyapunov exponent MLE, the asymptotic distance in momentum space $d_{\infty}$ andthe normalized variance of the maximum fragment NVM. It is shown that the constrained systems behaves as undergo

T. Frick, H. Müther, A. Sedrakian

Effects of spin polarization on the structure of symmetric nuclear matter and pure neutron matter are investigated. We show that the spin polarization induces a deformation of the Fermi spheres for nucleons with spin parallel and opposite to the polarization axes. This feature can be related to the structure of the one pion exchange contribution to a realist

LSND Collaboration

Charged current scattering of ν_μon ^{12}C has been studied using a π^+ decay-in-flight ν_μbeam at the Los Alamos Neutron Science Center. A sample of 66.9+-9.1 events satisfying criteria for the exclusive reaction ^{12}C(ν_μ,μ^-)^{12}N_{g.s.} was obtained using a large liquid scintillator neutrino detector. The observed flux-averaged cross section (5.6+-0.8+

Y. G. Ma, R. Wada, K. Hagel, M. Murray

Momentum widths of the primary fragments and observed final fragments have been investigated within the framework of an Antisymmetrized Molecular Dynamics transport model code (AMD-V) with a sequential decay afterburner (GEMINI). It is found that the secondary evaporation effects cause the values of a reduced momentum width, $σ_0$, derived from momentum widt

Kunihiko Kaneko

In the first half of the paper, some recent advances in coupled dynamical systems, in particular, a globally coupled map are surveyed. First, dominance of Milnor attractors in partially ordered phase is demonstrated. Second, chaotic itinerancy in high-dimensional dynamical systems is briefly reviewed, with discussion on a possible connection with a Milnor at

Matthias Baaz, Richard Zach

Bernays introduced a method for proving underivability results in propositional calculi by truth tables. In general, this motivates an investigations of how to find, given a propositional logic, a finite-valued logic which has as few tautologies as possible, but which has all the valid formulas of the given logic as tautologies. It is investigated how far th

A. Khovanskii, D. Novikov

We define a class of L-convex-concave subsets of $\Bbb{R}P^n$, where L is a projective subspace of dimension l in $\Bbb{R}P^n$. These are sets whose sections by any (l+1)-dimensional space L' containing L are convex and concavely depend on L'. We introduce an L-duality for these sets, and prove that the L-dual to an L-convex-concave set is an $L^*$-c

A. Khovanskii, D. Novikov

Consider a closed connected hypersurface in $\mathbb{R}^n$ with constant signature (k,l) of the second quadratic form, and approaching a quadratic cone at infinity. This hypersurface divides $\mathbb{R}^n$ into two pieces. We prove that one of them contains a k-dimensional subspace, and another contains a l-dimensional subspace, thus proving an affine versio

A. M. Gavrilik, A. U. Klimyk

Deformed orthogonal and pseudo-orthogonal Lie algebras are constructed which differ from deformations of Lie algebras in terms of Cartan subalgebra and root vectors and which make it possible to construct representations by operators acting according to Gel'fand--Tsetlin-type formulas. Unitary representations of the q-deformed algebras U_q(so_{n,1}) are

A. Khovanskii, D. Novikov

We define a class of $L$-convex-concave subsets of $\mathbb{R}P^3$, where $L$ is a projective line in $\mathbb{R}P^3$. These are sets whose sections by any plane containing $L$ are convex and concavely depend on this plane. We prove a version of Arnold hypothesis for these sets, namely we prove that each such set contains a line.

Volker Runde

We define a Banach algebra A to be dual if $A = (A_\ast)^\ast$ for a closed submodule $A_\ast$ of $A^\ast$. The class of dual Banach algebras includes all $W^\ast$-algebras, but also all algebras M(G) for locally compact groups G, all algebras L(E) for reflexive Banach spaces E, as well as all biduals of Arens regular Banach algebras. The general impression

Andre Diatta, Alberto Medina

Let G be a Lie group with Lie algebra $ \Cal G: = T_εG$ and $T^*G = \Cal G^* \rtimes G$ its cotangent bundle considered as a Lie group, where G acts on $\Cal G^*$ via the coadjoint action. We show that there is a 1-1 correspondance between the skew-symmetric solutions $r\in \wedge^2 \Cal G$ of the Classical Yang-Baxter Equation in G, and the set of connected

Volker Runde

It is an open problem whether an infinite-dimensional amenable Banach algebra exists whose underlying Banach space is reflexive. We give sufficient conditions for a reflexive, amenable Banach algebra to be finite-dimensional (and thus a finite direct sum of full matrix algebras). If $A$ is a reflexive, amenable Banach algebra such that for each maximal left

Claudio Gorodski, Gudlaugur Thorbergsson

Several classes of irreducible orthogonal representations of compact Lie groups that are of importance in Differential Geometry have the property that the second osculating spaces of all of their nontrivial orbits coincide with the representation space. We say that representations with this property are of class O^2. Our approach in the present paper will be

Yves André

This is an introduction to $p$-adic geometry and $p$-adic analysis focusing on the theme of $p$-adic period mappings. We follow as closely as possible the development of the classical theory of complex period mappings, blending differential equations, group theory and geometry. The text ends with a detailed discussion of $p$-adic triangle groups.

Paul S. Muhly, Baruch Solel

We study the structure of quantum Markov Processes from the point of view of product systems and their representations.

Joachim Hilgert, Dieter H. Mayer

We investigate the location of zeros and poles of a dynamical zeta function arizing in a class of lattice spin models introduced in the 60-ties by M. Kac. The transfer operator method allows us to prove the xistence of infinitely nontrivial zeros of this function on the real line. For certain parameter values there exist also infinitely many trivial equally

Massimiliano Berti, Luca Biasco, Philippe Bolle

We consider a nearly integrable, non-isochronous, a-priori unstable Hamiltonian system with a (trigonometric polynomial) $O(μ)$-perturbation which does not preserve the unperturbed tori. We prove the existence of Arnold diffusion with diffusion time $T_d = O((1/ μ) \log (1/ μ))$ by a variational method which does not require the existence of ``transition cha

Mario M. Graca

A neutral fixed point of a real iteration map $u$ becomes a super attracting fixed point using a suitable double newtonisation. The map $u$ is so transformed into a map $w$ which is here called the standard accelerator of $u$. The map $w$ provides a unifying process to deal with a large set of fixed point sequences which are not convergent or converge slowly

R. Exel, A. Vershik

We show that certain C*-algebras which have been studied among others by Arzumanian, Vershik, Deaconu, and Renault in connection to a measure preserving transformation of a measure space and/or to a covering map of a compact space are special cases of the endomorphism crossed-product construction recently introduced by the first named author. As a consequenc

L. J. P. Kilford

This paper answers a question of Gross and others, by exhibiting specific examples of Hecke algebras where mod 2 multiplicity one fails for some modular forms, and the associated Hecke algebras are not Gorenstein. It shows that the methods of Wiles, Gross, Edixhoven, Buzzard, Mazur and others have an upper bound to their applicability.

Ernesto Lupercio, Bernardo Uribe

In this paper we construct an explicit geometric model for the group of gerbes over an orbifold $X$. We show how from its curvature we can obtain its characteristic class in $H^3(X)$ via Chern-Weil theory. For an arbitrary gerbe $\LL$, a twisting $\Korb{\LL}(X)$ of the orbifold $K$-theory of $X$ is constructed, and shown to generalize previous twisting by Ro

Fausto Ongay, Jeffrey M. Rabin

We obtain the existence of a cohomological obstruction to expressing N=2 line bundles as tensor products of N=1 bundles. The motivation behind this paper is an attempt at understanding the N=2 super KP equation via Baker functions, which are special sections of line bundles on supercurves.

Vyacheslav A. Soroka

Recollections on how the basic concepts and ingredients of supergravity were formulated by Dmitrij V. Volkov and the present author in 1973-74.

John March-Russell, Frank Wilczek

At a formal level, there appears to be no difficulty involved in introducing a chemical potential for a globally conserved quantum number into the partition function for space-time including a black hole. Were this possible, however, it would provide a form of black hole hair, and contradict the idea that global quantum numbers are violated in black hole eva

N. Kitanine, J. M. Maillet, N. A. Slavnov, V. Terras

Using multiple integral representations, we derive exact expressions for the correlation functions of the spin-1/2 Heisenberg chain at the free fermion point.

W. Lerche, P. Mayr

We study the open string extension of the mirror map for N=1 supersymmetric type II vacua with D-branes on non-compact Calabi-Yau manifolds. Its definition is given in terms of a system of differential equations that annihilate certain period and chain integrals. The solutions describe the flat coordinates on the N=1 parameter space, and the exact disc insta

David Rainwater, Michael Spira, Dieter Zeppenfeld

We review the theoretical status of signal and background calculations for Higgs boson production at hadron colliders. Particular emphasis is given to missing NLO results, which will play a crucial role for the Tevatron and the LHC.

Alexander L. Bondarev

We propose to use the modified Gram -- Schmidt orthonormalization process in Minkowski space for construction of orthonormal bases from the vectors of the problem.

Anjan S. Joshipura, Eduard Masso, Subhendra Mohanty

We examine the constraints on non-radiative decay of neutrinos from the observations of solar neutrino experiments. The standard oscillation hypothesis among three neutrinos solves the solar and atmospheric neutrino problems. Decay of a massive neutrino mixed with the electron neutrino results in the depletion of the solar neutrino flux. We introduce neutrin

S. R. Slabospitsky

CMS potential for study of the s-channel $H^{\pm}$-boson production via light quark annihilation is investigated for large values of $\tanβ$ ($=20÷50$) and relatively light charge Higgs boson ($M_H = 200 ÷400$ GeV). An appropriate parameterisation for $M_{\top}(j, \ETM)$-distributions of the signal and background events is proposed, which provides the determ

V. V. Kiselev

We construct a Lagrangian of Weyl spinors and gauge fields, which is invariant under the action of equivalent local transformations on the spinor algebra representations. A model of vacuum with a nontrivial gauge strength-tensor setting a scale and spontaneously breaking the gauge symmetry is suggested, so that the leading approximation at low energies is de

R. A. Briere

We determine the weak coupling |Vcb| between the b and c quarks using a sample of 3 million BB-bar events in the CLEO detector at the Cornell Electron Storage Ring. We determine the yield of reconstructed B --> D* l nu decays as a function of w, the boost of the D* in the B rest frame, and from this we obtain the differential decay rate dGamma/dw. By extrapo

The FOCUS Collaboration

Using a large sample of charm semileptonic decays collected by the FOCUS photoproduction experiment at Fermilab, we present evidence for a small, even spin K- π+ amplitude that interferes with the dominant K*0 component in the K-pi+ mu- nu final state. Although this interference significantly distorts the decay angular distributions, the new amplitude create

G. Brandenburg

Using 13.53/fb of CLEO data, we have measured the ratios of the branching fractions R+(e) = BF(D+ --> K*0bar e+ nu_e) / BF(D+ --> K- pi+ pi+), R+(mu) = BF(D+ --> K*0bar mu+ nu_mu) / BF(D+ --> K- pi+ pi+) and the combined branching fraction ratio R+(l) = BF(D+ --> K*0bar l+ nu_l) / BF(D+ --> K- pi+ pi+). We find R+(e) = 0.74 +- 0.04 +- 0.05, R+(mu) = 0.72 +-

Pierre Van Mechelen

A new, very forward, proton spectrometer with large acceptance will be installed in the proton beam line of the H1 experiment in 2003. The spectrometer, located 220 m downstream of the interaction point, is based on the Roman Pot technique and consists of two stations in the cold section of the proton beam line. A brief description of this new device and exp

Gilvan A. Alves

This Paper summarize the present status and near term perspectives for Diffractive Physics at Tevatron. We describe the new detectors that are being installed around the CDF and D0 interaction regions, and discuss he physics topics accessible in view of these upgrades.

K. Abe, The Belle Collaboration

We report the results of a search for the rare baryonic decays $B^0 \to p\bar{p}$, $Λ\barΛ$, and $B^+ \to p\barΛ$. The analysis is based on a data set of $31.7\times 10^6 B\bar{B}$ events collected by the Belle detector at the KEKB $e^+e^-$ collider. No statistically significant signals are found, and we set branching fraction upper limits ${\mathcal B}(B^0

Sergio Dain, Osvaldo M. Moreschi, Reinaldo J. Gleiser

We point out the relation between the photon rocket spacetimes and the Robinson Trautman geometries. This allows a discussion of the issues related to the distinction between the gravitational and matter energy radiation that appear in these metrics in a more geometrical way, taking full advantage of their asymptotic properties at null infinity to separate t

W. Rudnicki, R. J. Budzynski, W. Kondracki

A new definition of a strong curvature singularity is proposed. This definition is motivated by the definitions given by Tipler and Krolak, but is significantly different and more general. All causal geodesics terminating at these new singularities, which we call generalized strong curvature singularities, are classified into three possible types; the classi

G S Khadekar, Bavana Butey

Lee. et.al. (1976) analysed the bimetric theory with the help of parameterized post Newtonian (PPN) formalism. They found that the post Newtonian limit of the theory is identical with that of general theory of relativity except for their PPN parameter $α_{2}$, on the basis of cosmological considerations. In the present paper it is pointed out that feasibilit

David Lyback, Magnus Boman

New services based on the best-effort paradigm could complement the current deterministic services of an electronic financial exchange. Four crucial aspects of such systems would benefit from a hybrid stance: proper use of processing resources, bandwidth management, fault tolerance, and exception handling. We argue that a more refined view on Quality-of-Serv

Clara Saluena, Thorsten Poeschel

In horizontally shaken granular material different types of pattern formation have been reported. We want to deal with the convection instability which has been observed in experiments and which recently has been investigated numerically. Using two dimensional molecular dynamics we show that the convection pattern depends crucial on the inelastic properties

L. I. Korovin, I. G. Lang, D. A. Contreras-Solorio, S. T. Pavlov

The reflection, transmission and absorption of a symmetric electromagnetic pulse, which carrying frequency is close to the frequency of an interband transition in a QW (QW), are obtained. The energy levels of a QW are assumed discrete, one exited level is taken into account. The case of a wide QW is considered when a length of the pulse wave, appropriate to

Denis Boyer, Jorge Vinals

We study the motion of a grain boundary separating two otherwise stationary domains of hexagonal symmetry. Starting from an order parameter equation appropriate for hexagonal patterns, a multiple scale analysis leads to an analytical equation of motion for the boundary that shares many properties with that of a crystalline solid. We find that defect motion i

Douglas F. de Albuquerque, A. S. de Arruda

By using the differential operator technique and the effective field theory scheme we study the tricritical behavior of Heisenberg classical model of spin-1/2 in a random field. The phase diagram in the T-h plane on a square and simple cubic lattice for a cluster with two spins is obtained when the random field is bimodal distributed.

M. V. Cheremisin

We calculate the zero magnetic field resistivity, taking into account the degeneracy of the 2D electron (hole) gas and the thermal correction due to the combined Peltier and Seebeck effects. The resistivity is found to be universal function of temperature, expressed in units of $\frac{h}{e^{2}}% (k_{F}l)^{-1}$.

Viviane M. de Oliveira, J. F. Fontanari

Complementarity among species with different traits is one of the basic processes affecting biodiversity, defined as the number of species in the ecosystem. We present here a soluble model ecosystem in which the species are characterized by binary traits and their pairwise interactions follow a complementarity principle. Manipulation of the species compositi

R. Currat, E. I. Kats, I. Luk'yanchuk

We propose a simple phenomenological model describing composite crystals, constructed from two parallel sets of periodic inter-penetrating chains. In the harmonic approximation and neglecting thermal fluctuations we find the eigenmodes of the system. It is shown that at high frequencies there are two longitudinal sound modes with standard attenuation, while

B. Biswal, C. Dasgupta

A neural network model that exhibits stochastic population bursting is studied by simulation. First return maps of inter-burst intervals exhibit recurrent unstable periodic orbit (UPO)-like trajectories similar to those found in experiments on hippocampal slices. Applications of various control methods and surrogate analysis for UPO-detection also yield resu

M. S. Shell, P. G. Debenedetti, A. Z. Panagiotopoulos

The present investigation examines the relationship between structural order, diffusivity anomalies, and density anomalies in liquid silica by means of molecular dynamics simulations. We use previously defined orientational and translational order parameters to quantify local structural order in atomic configurations. Extensive simulations are performed at d

J. Lopez, O. F. de Lima, P. N. Lisboa-Filho, F. M. Araujo-Moreira

We studied the magnetization as a function of temperature and magnetic field in the compounds Nd0.5Sr0.5MnO3, Nd0.5Ca0.5MnO3 and Ho0.5Ca0.5MnO3. It allowed us to identify the ferromagnetic, antiferromagnetic and charge ordering phases in each case. The intrinsic magnetic moments of Nd3+ and Ho3+ ions experienced a short range order at low temperatures. We al