September 2000 arXiv papers — page 4

A. C. Davis, T. W. B. Kibble, A. Rajantie, H. Shanahan

We present a non-perturbative formalism for measuring defect free energies (monopole mass or vortex tension) in three-dimensional SU(2)+adjoint Higgs models. Starting from twisted, translation invariant boundary conditions, we perform a change of variables that allows us to express the defect free energies in terms of 't Hooft loops. We propose that the

J. M. Isidro

Following a suggestion by Vafa, we present a quantum-mechanical model for S-duality symmetries observed in the quantum theories of fields, strings and branes. Our formalism may be understood as the topological limit of Berezin's metric quantisation of the upper half-plane H, in that the metric dependence has been removed. Being metric-free, our prescript

A. Balbi, C. Baccigalupi, S. Matarrese, F. Perrotta

Prompted by the recent MAXIMA-1 and BOOMERANG-98 measurements of the cosmic microwave background (CMB) anisotropy power spectrum, and motivated by the results from the observation of high-redshift Type Ia supernovae, we investigate CMB anisotropies in quintessence models in order to characterize the nature of the dark energy today. We perform a Bayesian like

Hiroshi Suzuki

The Weyl fermion belonging to the real representation of the gauge group provides a simple illustrative example for Lüscher's gauge-invariant lattice formulation of chiral gauge theories. We can explicitly construct the fermion integration measure globally over the gauge-field configuration space in the arbitrary topological sector; there is no global ob

Martin Weigt, Alexander K. Hartmann

In this letter, we analytically describe the typical solution time needed by a backtracking algorithm to solve the vertex-cover problem on finite-connectivity random graphs. We find two different transitions: The first one is algorithm-dependent and marks the dynamical transition from linear to exponential solution times. The second one gives the maximum com

David Dooling, Kyungsik Kang

Using the warped extra dimension geometry of the many-brane extension of the Randall-Sundrum solution, we find a natural explanation for the observed quark masses of the three Standard Model (SM) generations. Localizing massless SM matter generations on neighboring 3-branes in an extra dimensional world leads to phenomenologically acceptable effective four d

Kazumi Okuyama

We consider the boundary states which describe D-branes in a constant B-field background. We show that the two-form field Phi, which interpolates commutative and noncommutative descriptions of D-branes, can be interpreted as the invariant field strength in the T-dual picture. We also show that the extended algebra parametrized by theta and Phi naturally appe

N. Suzuki, M. Biyajima

The Fokker-Planck equation is considered, which is connected to the birth and death process with immigration by the Poisson transform. The fractional derivative in time variable is introduced into the Fokker-Planck equation. From its solution (the probability density function), the generating function (GF) for the corresponding probability distribution is de

I. Kakeya, R. Nakamura, T. Wada, K. Kadowaki

Vortex matter phases and phase transitions are investigated by means of Josephson plasma resonance in under-doped Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ single crystals in a microwave frequency range between 19 and 70 GHz. Accompanied by the vortex lattice melting transition, a jump of the interlayer phase coherence extracted from the field dependence of the plasma f

K. Bardakci, A. Konechny

In this paper we investigate the tachyon instability of open bosonic string theory applying methods of boundary conformal field theory. We consider compactifications on maximal tori of various simple Lie algebras with a specific background coupled to the string boundaries. The resulting world-sheet CFT is a free theory perturbed by a boundary term that is ma

Horace P. Yuen

A new cryptographic tool, anonymous quantum key technique, is introduced that leads to unconditionally secure key distribution and encryption schemes that can be readily implemented experimentally in a realistic environment. If quantum memory is available, the technique would have many features of public-key cryptography; an identification protocol that does

P. H. Souto Ribeiro

We report on an experiment showing that the wavelength of a biphoton is clearly dependent on the measurement scheme and on the way it is defined. It is shown that it can take any value, depending on the control of the interferometer phase differences. It is possible to identify the interference of the single and two-photon wavepackets as particular cases of

J. G. Muga, A. D. Baute, J. A. Damborenea, I. L. Egusquiza

An operational arrival-time distribution is defined as the distribution of detection times of the first photons emitted by two level atoms in resonance with a perpendicular laser beam in a time of flight experiment. For ultracold Cesium atoms the simulations are in excellent agreement with the theoretical ideal time-of-arrival distribution of Kijowski.

Hans De Raedt, Anthony Hams, Kristel Michielsen, Seiji Miyashita

We study effects of the physical realization of quantum computers on their logical operation. Through simulation of physical models of quantum computer hardware, we analyse the difficulties that are encountered in programming physical implementations of quantum computers. We discuss the origin of the instabilities of quantum algorithms and explore physical m

G. A. Krafft, J. -C. Denard, R. W. Dickson, R. Kazimi

As compared to electron storage rings, one advantage of recirculating linear accelerators is that the beam properties at target are no longer dominated by the equilibrium between quantum radiative diffusion and radiation damping because new beam is continually injected into the accelerator. This allows the energy spread from a CEBAF-type machine to be relati

Swadesh M. Mahajan, Ryszard Miklaszewski, Kommunela I. Nikol'skaya, Nana L. Shatashvili

An integrated Magneto-Fluid model, that accords full treatment to the Velocity fields associated with the directed plasma motion, is developed to investigate the dynamics of coronal structures. It is suggested that the interaction of the fluid and the magnetic aspects of plasma may be a crucial element in creating so much diversity in the solar atmosphere. I

B. G. Sidharth

Recently a stochastic underpinning for space time has been considered, what may be called Quantized Fractal Space Time. This leads us to a number of very interesting consequences which are testable, and also provides a rationale for several otherwise inexplicable features in Particle Physics and Cosmology. These matters are investigated in the present paper.

B. G. Sidharth

The space time that is used in relativistic Quantum Mechanics and Quantum Field Theory is the Minkowski space time. Yet, as pointed out by several scholars this classical space time is incompatible with the Heisenberg Uncertainity Principle: We cannot go down to arbitrarily small space time intervals, let alone space time points. Infact this classical space

Vladimir S. Vanyashin

A new variational basis with well-behaved local approximation properties and multiple output is proposed for Coulomb systems. The trial function has proper behaviour at all Coulomb centres. Nonlinear asymptotic parameters are introduced softly: they do not destroy the self-optimized local behaviour of the wave function at vanishing interparticle distances. T

G. N. Throumoulopoulos, H. Tasso

It is shown that the magnetohydrodynamic equilibrium states of an axisymmetric toroidal plasma with finite resistivity and flows parallel to the magnetic field are governed by a second-order partial differential equation for the poloidal magnetic flux function $ψ$ coupled with a Bernoulli type equation for the plasma density (which are identical in form to t

C. B. Das, S. Das Gupta

For pedagogical reasons we compute the caloric curve for 11 particles in a $3^3$ lattice. Monte-Carlo simulation can be avoided and exact results are obtained. There is no back-bending in the caloric curve and negative specific heat does not appear. We point out that the introduction of kinetic energy in the nuclear Lattice Gas Model modifies the results of

Victor S. L'vov, Anna Pomyalov, Itamar Procaccia

Extreme events have an important role which is sometime catastrophic in a variety of natural phenomena including climate, earthquakes and turbulence, as well as in man-made environments like financial markets. Statistical analysis and predictions in such systems are complicated by the fact that on the one hand extreme events may appear as "outliers"

Wei G. W

This Letter proposes a rescaled adaptive coupling scheme for the synchronization of spatially extended systems. Coupling and synchronization are analyzed from the point view of image filter construction. A length rescaling technique is introduced based on dimensional argument of control process. Control sensors are adaptively selected according to local info

Mathieu Dutour

Nous étudions dans cette thèse la fonctionnelle de Ginzburg-Landau dans $\R^3$ sur des couples de fonctions $(ϕ, \overrightarrow{A})$ qui vérifient des conditions de périodicité de jauge en $x_3$ et selon un réseau discret de $(x_1,x_2)$. Nous montrons que le problème variationnel est équivalent au problème de la minimisation d'une autre fonctionnelle su

J. Froehlich, M. Griesemer, B. Schlein

In models of (non-relativistic and pseudo-relativistic) electrons interacting with static nuclei and with the (ultraviolet-cutoff) quantized radiation field, the existence of asymptotic electromagnetic fields is established. Our results yield some mathematically rigorous understanding of Rayleigh scattering and of the phenomenon of relaxation of isolated ato

Frank Quinn

Concerns decompositions of smooth 4-manifolds as the union of two handlebodies, each with handles of index <=2 (``Heegard&#39;&#39; decompositions).Sample result: Two 2-complexes are (up to 2-deformation) dual spines of a Heegard decomposition of the 4-sphere if and only if they satisfy the conclusions of the Alexander-Lefshetz duality theorem ($H_1K\simeq H

S. Marmi

This is an introduction to small divisors problems. The material treated in this book was brought together for a PhD course I tought at the University of Pisa in the spring of 1999. Here is a Table of Contents: Part I One Dimensional Small Divisors. Yoccoz&#39;s Theorems 1. Germs of Analytic Diffeomorphisms. Linearization 2. Topological Stability vs. Analyti

Hiraku Nakajima

Frenkel-Reshetikhin introduced $q$-characters of finite dimensional representations of quantum affine algebras. We give a combinatorial algorithm to compute them for all simple modules. Our tool is $t$-analogue of the $q$-characters, which is similar to Kazhdan-Lusztig polynomials, and our algorithm has a resemblance with their definition.

M. Porrati, A. Starinets

We study monotonicity and other properties of the canonical c-function (defined through the correlator of the energy-momentum tensor) in some holographic duals of 4-d quantum field theories. The canonical c-function and its derivatives are related to the 5-d Green&#39;s function of the dual supergravity theory. While positivity of the canonical c-function is

Louise Dolan, Chiara R. Nappi

We derive the worldsheet propagator for an open string with different magnetic fields at the two ends, and use it to compute two distinct noncommutativity parameters, one at each end of the string. The usual scaling limit that leads to noncommutative Yang-Mills can be generalized to a scaling limit in which both noncommutativity parameters enter. This corres

Kirill A. Kazakov

The problem of consistent definition of the quantum corrected gravitational field is considered in the framework of the $S$-matrix method. Gauge dependence of the one-particle-reducible part of the two-scalar-particle scattering amplitude, with the help of which the potential is usually defined, is investigated at the one-loop approximation. The $1/r^2$-term

V. B. Petkova, J. -B. Zuber

The study of boundary conditions in rational conformal field theories is not only physically important. It also reveals a lot on the structure of the theory ``in the bulk&#39;&#39;. The same graphs classify both the torus and the cylinder partition functions and provide data on their hidden ``quantum symmetry&#39;&#39;. The Ocneanu triangular cells -- the 3j

I. B. Khriplovich

The motion of spinning relativistic particles in external electromagnetic and gravitational fields is considered. Covariant equations for this motion are demonstrated to possess pathological solutions, when treated nonperturbatively in spin. A self-consistent approach to the problem is formulated, based on the noncovariant description of spin and on the usua

P. Heslop, P. S. Howe

Representations of four-dimensional superconformal groups on harmonic superfields are discussed. It is argued that any representation can be given as a superfield on many superflag manifolds. Representations on analytic superspaces do not require constraints. We discuss short representations and how to obtain them as explicit products of fundamental fields.

A. Nersessian

We propose the model of $D-$dimensional massless particle whose Lagrangian is given by the $N-$th extrinsic curvature of world-line. The system has $N+1$ gauge degrees of freedom constituting $W-$like algebra; the classical trajectories of the model are space-like curves which obey the conditions $k_{N+a}=k_{N-a}$, $k_{2N}=0$, $a=1,...,N-1$, $N\leq[(D-2)/2]$

A. Szczurek, V. Uleshchenko, J. Speth

We investigate unambiguities in the extraction of the $\bar d - \bar u$ asymmetry from semi-inclusive production of pions in DIS. The role of several effects beyond the quark-parton model (QPM) which lead to $N_p^{π^+} \ne N_n^{π^+}$ and $N_p^{π^-} \ne N_n^{π^-}$ and may therefore cloud such an extraction is studied. The results are discussed in the context

M. C. Banuls

The problem of indirect violation of discrete symmeties CP, T and CPT in a neutral meson system can be described using two complex parameters epsilon and delta, which are invariant under rephasing of meson and quark fields. For the Bd system, where the width difference between the physical states is negligible, only Re(delta) and Im(epsilon) survive. As a co

J. Taron

We consider departures from hamiltonian dynamics in the evolution of neutral kaons due to their interactions with the environment that generate entanglement among them.

Colin Morningstar

Recent lattice simulation studies of heavy-quark hybrid mesons in which the quark and antiquark are bound together by an excited gluon field are summarized.

J. Kalinowski

The Higgs search strategies in minimal non-supersymmetric extensions of the SM are discussed.

D. Ebert, R. N. Faustov, V. O. Galkin, H. Toki

The exclusive rare radiative B meson decay to the orbitally excited tensor K_2^*(1430) meson is investigated in the framework of the relativistic quark model based on the quasipotential approach in quantum field theory. The calculated branching ratio BR(B --> K_2^*(1430)γ)=(1.7\pm 0.6)\times 10^{-5} as well as the ratio BR(B --> K_2^*(1430)γ)/BR(B --> K^*(89

G. S. Asanov

The Finsler-relativistic metric function $F(g;R)$ and the associated Hamiltonian function $H(g;P)$, being considered together with explicit Finslerian special-relativistic kinematic transformations, give rise to a self-consistent and rigorous framework upon which corrections to Lorentz-relativistic quantities can properly be evaluated. The concomitant relati

A. Geiser

Future experiments focusing on atmospheric neutrino detection are reviewed. One of the main goals of these experiments is the detection of an unambiguous oscillation pattern (nu_mu reappearance) to prove the oscillation hypothesis. Further goals include the discrimination of nu_mu - nu_tau and nu_mu - nu_sterile oscillations, and the detection of a potential

ZEUS Collaboration, J. Breitweg

A study of the antineutrino-jet mass spectrum in e^+p -> antineutrino+X events at center-of-mass energy 300 GeV has been performed with the ZEUS detector at HERA using an integrated luminosity of 47.7 pb^-1. The mass spectrum is in good agreement with that expected from Standard Model processes over the antineutrino -jet mass range studied. No significant ex

ALEPH Collaboration

The decay B0 -> J/psi K0_S is reconstructed with J/psi -> e+ e- or mu+ mu- and K0_S -> pi+ pi-. From the full ALEPH dataset at LEP1 of about 4 million hadronic Z decays, 23 candidates are selected with an estimated purity of 71%. They are used to measure the CP asymmetry of this decay, given by sin 2beta in the Standard Model, with the result sin 2beta = 0.8

D. C. Srivastava, S. K. Sahay

We present the Fourier Transform of continuous gravitational wave for arbitrary location of detector and source and for any duration of observation time in which both rotational motion of earth about its spin axis and orbital motion around sun has been taken into account. We also give the method to account the spin down of continuous gravitational wave.

A. De Felice, E. Fabri

We develop an evolution scheme, based on Sorkin algorithm, to evolve the most complex regular tridimensional polytope, the 600-cell. This application has been already studied before and all authors found a stop point for the evolution of the spatial section. In our opinion a clear and satisfactory meaning to this behaviour has not been given. In this paper w

Rens Bod

We present an LFG-DOP parser which uses fragments from LFG-annotated sentences to parse new sentences. Experiments with the Verbmobil and Homecentre corpora show that (1) Viterbi n best search performs about 100 times faster than Monte Carlo search while both achieve the same accuracy; (2) the DOP hypothesis which states that parse accuracy increases with in

Rens Bod

Common wisdom has it that the bias of stochastic grammars in favor of shorter derivations of a sentence is harmful and should be redressed. We show that the common wisdom is wrong for stochastic grammars that use elementary trees instead of context-free rules, such as Stochastic Tree-Substitution Grammars used by Data-Oriented Parsing models. For such gramma

Jorge Iniguez, S. Ivantchev, J. M. Perez-Mato, Alberto Garcia

We have studied the Devonshire-Landau potential underlying the phase transition sequence of BaTiO3 using the first-principles effective Hamiltonian of Zhong, Vanderbilt, and Rabe [Phys. Rev. Lett. 73, 1861 (1994)], which has been very successful in reproducing the phase transitions and the dielectric and piezoelectric properties of this compound. The configu

A. Kunold, M. Hernandez, A. Myszkowki, J. L. Cardoso

A phenomenological theory to describe the electromagnetic properties of granular superconductors, based on known bulk superconductors expressions and conventional Josephson&#39;s junctions tunneling currents, is presented and succesfully used to fit distinct experimental results for the magnetic susceptibility as a function of the temperature and the applied

C. Villagonzalo, R. A. Roemer, M. Schreiber, A. MacKinnon

The scaling behavior of the thermoelectric transport properties in disordered systems is studied in the energy region near the metal-insulator transition. Using an energy-dependent conductivity $σ$ obtained experimentally, we extend our linear-response-based transport calculations in the three-dimensional Anderson model of localization. Taking a dynamical sc

David Hochberg, Carmen Molina-Paris, Matt Visser

The presence of fluctuations and non-linear interactions can lead to scale dependence in the parameters appearing in stochastic differential equations. Stochastic dynamics can be formulated in terms of functional integrals. In this paper we apply the heat kernel method to study the short distance renormalizability of a stochastic (polynomial) reaction-diffus

Assa Auerbach, Ehud Altman

The projected SO(5) (pSO(5)) Hamiltonian incorporates the quantum spin and superconducting fluctuations of underdoped cuprates in terms of four bosons moving on a coarse grained lattice. A simple mean field approximation can explain some key feautures of the experimental phase diagram: (i) The Mott transition between antiferromagnet and superconductor, (ii)

Reinhold Brueckner

We give a brief account on the importance of surface effects from homogeneous background charge and assess the role of numerical work for Wigner cristal transitions. We signal work from the 1960s on the impossibility of a Wigner Cristal thermodynamic phase and suggest a possible research direction for investigation of cristalline electron behaviour.

S. Flach, V. Fleurov, A. A. Ovchinnikov

We consider the tunneling of localized excitations (many boson bound states) in the presence of a bosonic bath. We show both analytically and numerically that the bath influence results in a dramatical enhancement of the amplitude of the excitation tunneling. The order of the bosonic flow in the course of the tunneling process is obtained. On the background

Marc Mezard, Giorgio Parisi

So far the problem of a spin glass on a Bethe lattice has been solved only at the replica symmetric level, which is wrong in the spin glass phase. Because of some technical difficulties, attempts at deriving a replica symmetry breaking solution have been confined to some perturbative regimes, high connectivity lattices or temperature close to the critical te

Reinhold Brueckner

It is shown that the description of the FQHE as condensation of the electron system into a ground state with fractionally charged excitations is incompatible with experimental observations. The nature of the Hall voltage in fractional plateaux as a chemical potential difference eliminates the condensate as current carrier and the temperature dependence of lo

Nicolas Combe, Hernán Larralde

We present a precise microscopic description of the limiting step for low temperature shape relaxation of two dimensional islands in which activated diffusion of particles along the boundary is the only mechanism of transport allowed. In particular, we are able to explain why the system is driven irreversibly towards equilibrium. Based on this description, w

Steven S. Plotkin

Perturbing a Go model towards a realistic protein Hamiltonian by adding non-native interactions, we find that the folding rate is in general enhanced as ruggedness is initially increased, as long as the protein is sufficiently large and flexible. Eventually the rate drops rapidly towards zero when ruggedness significantly slows conformational transitions. En

Steven S. Plotkin, Jose N. Onuchic

A general theoretical framework is developed using free energy functional methods to understand the effects of heterogeneity in the folding of a well-designed protein. Native energetic heterogeneity arising from non-uniformity in native stability, as well as entropic heterogeneity intrinsic to the topology of the native structure are both investigated as to

Craig L. Sarazin, Jimmy A. Irwin, Joel N. Bregman

Chandra observations of the X-ray faint elliptical galaxy NGC 4697 resolve much of the X-ray emission (61% within one effective radius) into ~80 point sources, of which most are low mass X-ray binaries (LMXBs). These LMXBs provide the bulk of the hard emission and much of the soft emission as well. Of the remaining unresolved emission, it is likely that abou

E. Athanassoula, A. Garijo, C. Garcia

We present N-body simulations of galaxy groups embedded in a common halo of matter. We study the influence of the different initial conditions upon the evolution of the group and show that denser configurations evolve faster, as expected. We then concentrate on the influence of the initial radial density profile of the common halo and of the galaxy distribut

Y. Tanaka, K. Koyama, Y. Maeda, T. Sonobe

The X-ray spectrum in a $1^{\circ}\times1^{\circ}$ region of the Galactic center observed with the ASCA satellite is examined in detail, following the first report by Koyama et al. (1996, AAA 65.155.208). The observed spectrum contains prominent emission lines from helium-like and hydrogen-like ions of various elements, and is essentially the same all over t

Antoine Letessier-Selvon

The cosmic ray spectrum has been shown to extend well beyond 10^20 eV. With nearly 20 events observed in the last 40 years, it is now established that particles are accelerated or produced in the universe with energy near 10^21 eV. In all production models neutrinos and photons are part of the cosmic ray flux. In acceleration models (bottom-up models), they

C. P. Haines, R. G. Clowes, L. E. Campusano

We report significant associated clustering in the field of a z=1.226 quasar from the Clowes-Campusano LQG in the form of both a factor ~11 overdensity of I-K>3.75 galaxies and red sequences of 15-18 galaxies at I-K~4.3, V-K~6.9 indicative of a population of massive ellipticals at the quasar redshift. The quasar is located between two groups of these galaxie

Gopal-Krishna, Paul J. Wiita

We provide observational and theoretical perspectives on the currently much debated issue of the Fanaroff-Riley (FR) morphological dichotomy of extragalactic radio sources. In this context we introduce a new, albeit rare, class of double radio sources in which the two lobes exhibit clearly different FR morphologies. It is argued that such `HYbrid MOrphology

Victor Zubko, Moshe Elitzur

We construct a self-consistent model for the wind around W Hya by solving the coupled equations describing the hydrodynamics and dust radiative transfer problems. The model matches simultaneously the observed continuum radiation and wind velocity profile. The water line emission is calculated next using the water abundance as the only free parameter, fitted

R. Bachiller, F. Gueth, S. Guilloteau, M. Tafalla

New, high-sensitivity interferometric CO J=2-1 observations of the HH 7-11 outflow show that despite previous doubts, this system is powered by the Class I source SVS 13. The molecular outflow from SVS 13 is formed by a shell with a large opening angle at the base, which is typical of outflows from Class I sources, but it also contains an extremely-high-velo

J. Knapik, M. Soida, R. -J. Dettmar, R. Beck

Two flocculent galaxies NGC 3521 and NGC 5055 has been observed at 10.55GHz with the Effelsberg 100m telescope. In both cases polarized emission reveals substantial radial component of regular magnetic field - similar to that in grand-designed spirals. Comparison with H_alpha distribution obtained at Lowell Observatory is presented. Polarization models discu

Yan-Jie Xue, Xiang-Ping Wu

In this Letter we present the radial temperature profiles of three X-ray clusters (A119, A2255 and A2256) reconstructed from a combination of the X-ray surface brightness measurements and the universal density profile as the underlying dark matter distribution. Our algorithm is based on the hydrostatic equilibrium for intracluster gas and the universality of

Xiang-Ping Wu, Tzihong Chiueh

In this paper we have made an attempt to derive the radial profiles of density and temperature of intracluster gas based on the two well-established facts at present: the X-ray observed surface brightness of clusters described by the standard beta model and the (NFW) universal density profile as the underlying dark matter distribution. We have numerically so

T. Yaqoob, P. J. Serlemitsos

The Fe-K line, an important physical diagnostic in the X-ray spectra of AGN, has been notoriously difficult to measure in the high-luminosity, radio-loud quasar 3C 273 (z=0.158). On the few occasions that it has been detected its intrinsic width has been thought to be narrow (FWHM < 10,000 km/s) with an equivalent width (EW) of a few tens of eV.This was cons

T. Di Salvo, L. Stella, N. R. Robba, M. van der Klis

We report results of a BeppoSAX (0.1-200 keV) observation of the Z-type low mass X-ray binary GX 17+2. The source was on the so-called Horizontal and Normal branches. Energy spectra were selected based on the source position in the X-ray hardness-intensity diagram. The continuum could be fairly well described by the sum of a ~0.6 keV blackbody, contributing

Vincent Le Brun, Alain Smette, Jean Surdej, Jean-Francois Claeskens

Le Brun et al. (1997) presented the first identifications of the galaxies giving rise to 7 intermediate redshift damped Ly-alpha (DLA) absorption systems. Here, we study the gravitational lensing properties of these foreground galaxies based on their observed optical appearance and on the absence of any secondary lensed quasar image. We consider the possibil

S. Andreon, J. -C. Cuillandre, R. Pello

[Abridged] The Coma cluster luminosity function (LF) from ultraviolet (2000 AA) to the near-infrared (H band) is summarized. In the UV the LF is very steep, much steeper than in the optical. The steep Coma UV LF implies that faint and bright galaxies give similar contributions to the total UV flux and to the total metal production rate. The Coma UV LF is dom

J. Greiner, R. Schwarz, S. Zharikov, M. Orio

We have discovered a transient X-ray source, RX J1420.4+5334, which displays a ROSAT flux variation of >150 between the ROSAT All-Sky-Survey in 1990 and a preceding pointed ROSAT observations in July 1990. Optical observations suggest a non-active galaxy as the only visible counterpart. We therefore tentatively identify RX J1420.4+5334 as a tidal disruption

Leticia Carigi

Chemical evolution models for the Galactic disk under an inside-out formation scenario are presented for seven sets of stellar yields, all of them metal dependent. In particular, the effects of yields from massive and low-and-intermediate-mass stars on the C/O chemical history of the solar neighborhood and on abundance gradients are discussed comparing the p

Roberto Gomez, Sascha Husa, Jeffrey Winicour

We present an algorithm for calculating the complete data on an event horizon which constitute the necessary input for characteristic evolution of the exterior spacetime. We apply this algorithm to study the intrinsic and extrinsic geometry of a binary black hole event horizon, constructing a sequence of binary black hole event horizons which approaches a si

M. J. Duff, James T. Liu, W. A. Sabra

A supersymmetric Randall-Sundrum brane-world demands that not merely the graviton but the entire supergravity multiplet be trapped on the brane. To demonstrate this, we present a complete ansatz for the reduction of (D=5,N=4) gauged supergravity to (D=4,N=2) ungauged supergravity in the Randall-Sundrum geometry. We verify that it is consistent to lowest orde

Mariana Graña, Joseph Polchinski

We consider warped type IIB supergravity solutions with three-form flux and ${\cal N}=1$ supersymmetry, which arise as the supergravity duals of confining gauge theories. We first work in a perturbation expansion around $AdS_5 \times S^5$, as in the work of Polchinski and Strassler, and from the ${\cal N}=1$ conditions and the Bianchi identities recover thei

David Berenstein, Robert G. Leigh

We discuss aspects of the algebraic geometry of compact non-commutative Calabi-Yau manifolds. In this setting, it is appropriate to consider local holomorphic algebras which can be glued together into a compact Calabi-Yau algebra. We consider two examples: a toroidal orbifold T^6/Z_2 x Z_2, and an orbifold of the quintic in CP_4, each with discrete torsion.

Takahiko Matsubara, Bhuvnesh Jain

The topology of weak lensing fields is studied using the 2-dimensional genus statistic. Simulated fields of the weak lensing convergence are used to focus on the effect of nonlinear gravitional evolution and to model the statistical errors expected in observational surveys. For large smoothing angles, the topology is in agreement with the predictions from li

S. Ulrych

A representation of the quadratic Dirac equation and the Maxwell equations in terms of the three-dimensional universal complex Clifford algebra is given. The investigation considers a subset of the full algebra, which is isomorphic to the Baylis algebra. The approach is based on the two Casimir operators of the Poincare group, the mass operator and the spin

V. Baran, M. Colonna, M. Di Toro, V. Greco

We derive stability conditions of Asymmetric Nuclear Matter ($ANM$) and discuss the relation to mechanical and chemical instabilities of general two-component systems. We show that the chemical instability may appear as an instability of the system against isoscalar-like rather than isovector-like fluctuations if the interaction between the two constituent s

D. Drinen, M. Tomforde

To an arbitrary directed graph we associate a row-finite directed graph whose C*-algebra contains the C*-algebra of the original graph as a full corner. This allows us to generalize results for C*-algebras of row-finite graphs to C*-algebras of arbitrary graphs: the uniqueness theorem, simplicity criteria, descriptions of the ideals and primitive ideal space

S. K. Bogner, T. T. S. Kuo

Lee-Suzuki similarity transformations and Krencigowa-Kuo folded diagrams are two common methods used to derive energy independent model space effective interactions for nuclear many-body systems. We demonstrate that these methods are equivalent to a Renormalization Group (RG) analysis of a separable potential model. The effective low-momentum potentials V_{e

Daniel J. Rolfe, Carole A. Haswell, Joseph Patterson

We use the hot spot eclipse times of the newly discovered deeply-eclipsing dwarf nova IY UMa to trace out the shape of its disc during the late superhump era. We find an eccentric disc. We show that the brightness of the stream-disc impact region varies as expected with |deltaV|^2, where deltaV is the differential velocity of the stream with respect to the v

Anna Sanpera, Dagmar Bruss, Maciej Lewenstein

The Schmidt number of a mixed state characterizes the minimum Schmidt rank of the pure states needed to construct it. We investigate the Schmidt number of an arbitrary mixed state by constructing a Schmidt number witness that detects it. We present a canonical form of such witnesses and provide constructive methods for their optimization. Finally, we present

B. O. Kerbikov

Final state hyperon-nucleon interaction in strangeness photoproduction of the deuteron is investigated making use of the covariant reaction formalism and the P-matrix approach to the YN system. Remarkably simple analytical expression for the amplitude is obtained. Pronounced effects due to final state interaction are predicted including the manifestation of

Stefan Giller, Cezary Gonera

A method of fundamental solutions has been used to investigate transitions in two energy level systems with no level crossing in a real time. Compact formulas for transition probabilities have been found in their exact form as well as in their adiabatic limit. No interference effects resulting from many level complex crossings as announced by Joye, Mileti an

L. Popa, C. Burigana, F. Finelli, N. Mandolesi

The imprint of neutrino oscillations on the Cosmic Microwave Background (CMB) anisotropy and polarization power spectra is evaluated in a $Λ$CHDM model with two active neutrino flavors, consistent with the structure formation models and the atmospheric neutrino oscillations data. We show the existence of a significant overlap between the region of the oscill

G. L. Fogli, E. Lisi, A. Marrone

In the context of neutrino scenarios characterized by four (three active plus one sterile) neutrino species and by mass spectra with two separated doublets, we analyze solutions to the atmospheric neutrino anomaly which smoothly interpolate between ν_μ-->ν_τand ν_μ-->ν_s oscillations. We show that, although the Super-Kamiokande data disfavor the pure ν_μ-->ν

Jean Alexandre

The one-loop vacuum polarization tensor is computed in QED with an external constant, homogeneous magnetic field at finite temperature. The Schwinger proper-time formalism is used and the computations are done in Euclidian space. The well-known results are recovered when the temperature and/or the magnetic field are switched off and the effect of the magneti

S. Kadlecek, T. Walker, D. K. Walter, C. Erickson

We present calculations of spin-relaxation rates of alkali-metal atoms due to the spin-axis interaction acting in binary collisions between the atoms. We show that for the high-temperature conditions of interest here, the spin relaxation rates calculated with classical-path trajectories are nearly the same as those calculated with the distorted-wave Born app

V. G. Bornyakov, D. A. Komarov, M. I. Polikarpov

We present results of the careful study of the Gribov copies problem in SU(2) lattice gauge theory for the direct maximal center projection widely used in confinement studies. Applying simulated annealing algorithm we demonstrate that this problem is more severe than it was thought before. The projected (gauge noninvariant) string tension is not in the agree

Bo-Qiang Ma, Ivan Schmidt, Jian-Jun Yang

The azimuthal asymmetry observed by the HERMES collaboration in semi-inclusive pion production in deep inelastic scattering of unpolarized positron on the longitudinally polarized proton target, can provide information of the quark transversity distributions of the nucleon. We show that the quark transversity distributions predicted both by the light-cone qu

Richard Grimm, Carl Herrmann, Annamaria Kiss

A concise geometrical formulation of N=4 supergravity containing an antisymmetric tensor gauge field is given in central charge superspace: graviphotons are identified in the super-vielbein on the same footing as the vierbein and the Rarita-Schwinger fields. As a consequence of superspace soldering, Chern-Simons terms in the fieldstrength of the antisymmetri

Yasuhide Sota, Osamu Iguchi, Masahiro Morikawa, Takayuki Tatekawa

Fractal structures and non-Gaussian velocity distributions are characteristic properties commonly observed in virialized self-gravitating systems such as galaxies or interstellar molecular clouds. We study the origin of these properties using the one-dimensional ring model which we newly propose in this paper. In this simple model, $N$ particles are moving,

Igor G. Korepanov

An invariant of three-dimensional orientable manifolds is built on the base of a solution of pentagon equation expressed in terms of metric characteristics of Euclidean tetrahedra.