May 1999 arXiv papers — page 15

R. F. Bikbaev, R. A. Sharipov

The solutions of the Landau-Lifshitz equation with finite-gap behavior at infinity are considered. By means of the inverse scattering method the large-time asymptotics is obtained.

Lajos Diosi

In the past ten-fifteen years, stochastic models of continuous wave function collapse were being proposed to describe the continuous emergence of classicality from quantum. We advocate that the hybrid dynamics of canonically coupled quantum and classical systems is a more basic concept. Continuous collapse formalisms are obtained as special cases. To illustr

Chong-Yu Ruan, Scott Nguyen, Manfred Fink

The electron optics of a 90 degree spherical deflecting analyzer (SDA-90) is investigated with an imaging matrix formalism. As a preanalyzer in the UTA-neutrino experiment, high transmission and reasonable energy resolution are the choices of optimization. The magnification of the source through the analyzer plays the key role in determining the energy resol

Chong-Yu Ruan, Manfred Fink

The emission optics of a Steigerwald type electron gun is re-examined. The virtual and real points of divergence, divergence angles and beam-widths of the electron beams at different telefocusing strength are measured in detail for first time . Two different Wehnelt cylinders are used to establish a contrasting viewpoint. The original `focusing' curves m

K. Schwarzschild

Translation by S. Antoci and A. Loinger of the fundamental memoir, that contains the ORIGINAL form of the solution of Schwarzschild's problem. The solution is regular in the whole space-time, with the only exception of the origin of the spatial co-ordinates; consequently, it leaves no room for the science fiction of the black holes. (In the centuries of

A. A. Fedyanin, N. V. Didenko, N. E. Sherstyuk, A. A. Nikulin

The use of specific symmetry properties of the optical second-harmonic generation (the s,s-exclusion rule) has allowed us to observe high-contrast hyper-Rayleigh interference patterns in a completely diffuse light - an effect having no analog in case of linear (Rayleigh) scattering.

Giuseppe Dito

We show that on the dual of a Lie algebra $\g$ of dimension $d$, the star-product recently introduced by M. Kontsevich is equivalent to the Gutt star-product on $\g^\ast$. We give an explicit expression for the operator realizing the equivalence between these star-products.

Thomas M. Richardson

A Filbert matrix is a matrix whose (i,j) entry is 1/F_(i+j-1), where F_n is the nth Fibonacci number. The inverse of the n by n Filbert matrix resembles the inverse of the n by n Hilbert matrix, and we prove that it shares the property of having integer entries. We prove that the matrix formed by replacing the Fibonacci numbers with the Fibonacci polynomials

Rafe Mazzeo, Frank Pacard, Daniel Pollack

We establish a general `gluing theorem', which states roughly that if two nondegenerate constant mean curvature surfaces are juxtaposed, so that their tangent planes are parallel and very close to one another, but oppositely oriented, then there is a new constant mean curvature surface quite near to this configuration (in the Hausdorff topology), but whi

James Seibert

A linear system of plane curves satisfying multiplicity conditions at points in general position is called special if the dimension is larger than the expected dimension. A (-1) curve is an irreducible curve with self intersection -1 and genus zero. The Harbourne-Hirschowitz Conjecture is that a linear system is special only if a multiple of some fixed (-1)

Michel Dubois-Violette, Ivan T. Todorov

We generalize the BRS method for the (finite-dimensional) quantum gauge theory involved in the zero modes of the monodromy extended SU(2) WZNW model. The generalization consists of a nilpotent operator Q such that $Q^h=0$ ($h=k+2=2,3,...$ being the height of the current algebra representation) acting on an extended state space. The physical subquotient is id

Shu Kawaguchi

Let M be a field of finite type over {\bf Q} and X a variety defined over M. We study when the set {P \in X(K) \mid f^{\circ n} (P) = P for some n \geq 1} is finite for any finite extension fields K of M and for any dominant K-morphisms f : X \to X with deg f \geq 2.

Hiromichi Takagi

We obtain a classification of a Q-factorial Q-Fano 3-fold $X$ with the following properties: the Picard number of $X$ is 1; the Gorenstein index of $X$ is 2; the Fano index of $X$ is 1/2; $h^0 (-K_X) \geq 4$; there exists an index 2 point $P$ such that $(X,P)\simeq (\{xy +f(z^2,u)=0\} / \Bbb Z_2 (1,1,1,0), o)$ with $ord f(Z,U)=1$.

Y. Gaspar

This paper will be replaced later by a revised version.

J. -M. Chung, B. K. Chung

Using the method of renormalization group, we improve the two-loop effective potential of the massive $ϕ^4$ theory to obtain the next-next-to-leading logarithm correction in the $\bar{MS}$ scheme. Our result well reproduces the next-next-to-leading logarithm parts of the ordinary loop expansion result known up to the four-loop order.

B. Eden, P. S. Howe, P. C. West

It is shown that there are no nilpotent invariants in N=4 analytic superspace for $n\leq4$ points. It is argued that there is (at least) one such invariant for n=5 points which is not invariant under U(1)_Y. The consequences of these results are that the n=2 and 3 point correlation functions of the N=4 gauge-invariant operators which correspond to KK multipl

Dmitri Diakonov

We calculate the energy of a Yang-Mills vortex as function of its magnetic flux or, else, of the Wilson loop surrounding the vortex center. The calculation is performed in the 1-loop approximation. A parallel with a potential as function of the Polyakov line at nonzero temperatures is drawn. We find that quantized Z(2) vortices are dynamically preferred thou

R. Banerjee, P. Mukherjee

We compute the spin of both the topological and nontopological solitons of the Chern - Simons - Higgs model by using our approach based on constrained analysis. We also propose an extension of our method to the non - relativistic Chern - Simons models. The spin formula for both the relativistic and nonrelativistic theories turn out to be structurally identic

G. V. Vlasov

We present the general formulation of the relativistic fluid dynamics with vorticity (including relativistic superfluid) on a manifold with boundary. Making use of the Hodge decomposition, we emphasize that the equations of motion include a term due to non-trivial topology, while the pure vortex term introduced by Carter and Langlois will be presented merely

W. Buchmuller, T. Gehrmann, A. Hebecker

Small-x DIS is described as the scattering of a partonic fluctuation of the photon off a superposition of target color fields. Diffraction occurs if the emerging partonic state is in a color singlet. Introducing a specific model for the averaging over all relevant color field configurations, both diffractive and inclusive parton distributions at some low sca

W. Grimus, R. Pfeiffer, T. Schwetz

We take as a starting point the Gelmini -- Roncadelli model enlarged by a term with explicit lepton number violation in the Higgs potential and add a neutrino singlet field coupled via a scalar doublet to the usual leptons. This scenario allows us to take into account all three present indications in favour of neutrino oscillations provided by the solar, atm

Alex Krasnitz, Raju Venugopalan

We discuss a real time, non-perturbative computation of the transverse dynamics of gluon fields at central rapidities in very high energy nuclear collisions.

Chuan-Tsung Chan, Ernest M. Henley, Thomas Meissner

The electric dipole moments of nucleons (NEDM, d_N) are calculated using the method of QCD sum rules. Our calculations are based on the parity and time reversal violating parameter $\thetabar$ in QCD and establish a functional dependence of the NEDM on $\thetabar$, without assuming a perturbative expansion of this symmetry breaking parameter. The results obt

Kenichiro Aoki, Kenji Ito

We analyze a two dimensional model of gauged fermions with quartic couplings in the large-N limit. This combines the 't Hooft model and the Gross-Neveu model where the coupling constants of both theories are arbitrary. Analytic equations describing the meson states of the theory are derived and are solved systematically using various methods. The physics

Hai-Yang Cheng, Kwei-Chou Yang

The QCD-based operator-product-expansion technique is systematically applied to the study of charmed meson lifetimes. We stress that it is crucial to take into account the momentum of the spectator light quark of charmed mesons, otherwise the destructive Pauli-interference effect in $D^+$ decays will lead to a negative decay width for the $D^+$. We have appl

T. D. Bakeyev

Some results of test runs on a $6^3\times 12$ lattice with Wilson quarks and gauge group SU(2) for a previously proposed fermion algorithm by A. Slavnov are presented.

Yu. P. Goncharov

We remark that the standard black hole topology admits twisted configurations of spinor field due to existence of the twisted spinor bundles and analyse them using the Schwarzschild black hole as an example. This is physically linked with the natural presence of Dirac monopoles on black holes and entails marked modification of the Hawking radiation for spino

A. G. Agnese, A. P. Billyard, H. Liu, P. S. Wesson

We extend previous analyses of soliton solutions in (4+1) gravity to new ranges of their defining parameters. The geometry, as studied using invariants, has the topology of wormholes found in (3+1) gravity. In the induced-matter picture, the fluid does not satisfy the strong energy conditions, but its gravitational mass is positive. We infer the possible exi

Michael R. Brent

This paper presents a model-based, unsupervised algorithm for recovering word boundaries in a natural-language text from which they have been deleted. The algorithm is derived from a probability model of the source that generated the text. The fundamental structure of the model is specified abstractly so that the detailed component models of phonology, word-

A. P. Mills,, A. P. Ramirez, L. N. Pfeiffer, K. W. West

The low temperature longitudinal resistance-per-square Rxx(T) in ungated GaAs/AlGaAs quantum wells of high peak hole mobility 1.7x10^6 cm^2/Vs is metallic for 2D hole density p as low as 3.8x10^9 cm-2. The electronic contribution to the resistance, R_{el}(T), is a nonmonotonic function of T, exhibiting thermal activation, R_{el}(T) ~ exp{-E_a/kT}, for kT<<E_

A. H. Romero, David W. Brown, Katja Lindenberg

We analyze electron-phonon correlation functions measured in 1D polaron ground states of the Holstein Hamiltonian using the Global-Local variational method. The spatial collapse of electron-phonon correlations is found to occur in concert with transition behavior in other polaron properties, providing mutually confirming evidence for a self-trapping line in

J. Ashkenazi

Considering both &#34;large-U&#34; and &#34;small-U&#34; orbitals it is found that the high-Tc cuprates are characterized by a striped structure, and three types of carriers: polaron-like &#34;stripons&#34; carrying charge, &#34;quasielectrons&#34; carrying charge and spin, and &#34;svivons&#34; carrying spin and lattice distortion. It is shown that this ele

A. S. Katz, S. I. Woods, E. J. Singley, T. W. Li

We report on infrared studies of the c-axis electrodynamics of Tl-Ba-Cu-O (Tl-2201) crystals. A sum rule analysis reveals spectral weight shifts that can be interpreted as a kinetic energy change at the superconducting transistion. In optimally doped crystals, showing an incoherent normal state response, the kinetic energy is lowered at T < Tc, but no signif

Marc-Etienne Brachet, Erik Taflin, Jean Marcel Tcheou

The price of financial assets are, since Bachelier, considered to be described by a (discrete or continuous) time sequence of random variables, i.e a stochastic process. Sharp scaling exponents or unifractal behavior of such processes has been reported in several works. In this letter we investigate the question of scaling transformation of price processes b

Patrick Grosfils, Jean Pierre Boon, E. G. D. Cohen, L. A. Bunimovich

We show that a signal can propagate in a particular direction through a model random medium regardless of the precise state of the medium. As a prototype, we consider a point particle moving on a one-dimensional lattice whose sites are occupied by scatterers with the following properties: (i) the state of each site is defined by its spin (up or down); (ii) t

D. N. Aristov

We consider the correlation functions in a gas of electrons moving within a thin layer on the surface of nanosize sphere. A closed form of expressions for the RKKY indirect exchange, superconducting Cooper loop and `density-density&#39; correlation function is obtained. The systematic comparison with planar results is made, the effects of spherical geometry

J. Gonzalez, F. Guinea, M. A. H. Vozmediano

A two dimensional electronic system, where the Fermi surface is close to a Van Hove singularity, shows a variety of weak coupling instabilities, and it is a convenient model to study the interplay between antiferromagnetism and anisotropic superconductivity. We present a detailed analysis of the kinematics of the electron scattering in this model. The simili

Diptiman Sen, Siddhartha Lal

We study the spectrum of fermions hopping on a chain with a weak incommensuration close to dimerization; both q, the deviation of the wave number from pi, and delta, the strength of the incommensuration, are small. For free fermions, we use a continuum Dirac theory to show that there are an infinite number of bands which meet at zero energy as q approaches z

Marcel Porta, Eduard Vives, Teresa Castan

A Monte Carlo simulation study of the vacancy-assisted domain-growth in asymmetric binary alloys is presented. The system is modeled using a three-state ABV Hamiltonian which includes an asymmetry term, not considered in previous works. Our simulated system is a stoichiometric two-dimensional binary alloy with a single vacancy which evolves according to the

Edson Sardella, M. M. Doria, P. R. S. Netto

We obtain the vortex configurations, the matching fields and the magnetization of a superconducting film with a finite cross section. The applied magnetic field is normal to this cross section, and we use London theory to calculate many of its properties, such as the local magnetic field, the free energy and the induction for the mixed state. Thus previous s

A. Guarino, S. Ciliberto, A. Garcimartin

The failure time of samples of heterogeneous materials (wood, fiberglass) is studied as a function of the applied stress. It is shown that in these materials the failure time is predicted with a good accuracy by a model of microcrack nucleation proposed by Pomeau. It is also shown that the crack growth process presents critical features when the failure time

A. Depuydt, C. Van Haesendonck, N. S. Maslova, V. I. Panov

We have used a low-temperature scanning tunneling microscope (STM) to study the surface of heavily doped semiconductor InAs crystals. The crystals are cleaved in situ along the (110) plane. Apart from atomically flat areas, we also observe two major types of atomic scale defects which can be identified as S dopant atoms and as As vacancies, respectively. The

V. Shahrezaei, N. Hamedani, M. R. Ejtehadi

The concept of the reduced set of contact maps is introduced. Using this concept we find the ground state candidates for Hydrophobic-Polar lattice model on a two dimensional square lattice. Using these results we exactly enumerate the native states of all proteins for a wide range of energy parameters. In this way, we show that there are some sequences, whic

C. Dziurzik, A. Schadschneider, J. Zittartz

We investigate the stability domains of ground states of generalized Hubbard models with next-nearest neighbour interaction using the optimum groundstate approach. We focus on the $η$-pairing state with momentum P=0 and the fully polarized ferromagnetic state at half-filling. For these states exact lower bounds for the regions of stability are obtained in th

M. Capone, M. Fabrizio, P. Giannozzi, E. Tosatti

We study the unconventional insulating state in A_4C_{60} with a variety of approaches, including density functional calculations and dynamical mean-field theory. While the former predicts a metallic state, in disagreement with experiment, the latter yields a (paramagnetic) Mott-Jahn-Teller insulator. In that state, conduction between molecules is blocked by

P. Sitko

The interaction energy of the two-dimensional electron system in the region of fractional quantum Hall effect is considered within the Chern-Simons composite fermion approach. In the limit when Coulomb interaction is very small comparing to the cyclotron energy the RPA results are obtained for the fillings $ν=1/3, 1/5, 2/3, 2/5, 3/7$ and compared with the ex

L. Vichi, S. Stringari

We calculate the effects of two-body interactions on the low frequency oscillations of a normal Fermi gas confined in a harmonic trap. The mean field contribution to the collective frequencies is evaluated in the collisionless regime using a sum rule approach. We also discuss the transition between the collisionless and hydrodynamic regime with special empha

A. A. Shashkin, V. T. Dolgopolov, E. V. Deviatov, B. Irmer

We study the lateral tunneling through the gate-voltage-controlled barrier, which arises as a result of partial elimination of the donor layer of a heterostructure along a fine strip using an atomic force microscope, between edge channels at the depletion-induced edges of a gated two-dimensional electron system. For a sufficiently high barrier a typical curr

R. Y. Gu, Z. D. Wang, Shun-Qing Shen, D. Y. Xing

We investigate the phase diagram of an extended Kondo lattice model for doped manganese oxides in the presence of strong but finite Hund&#39;s coupling and on-site Coulomb interaction. By means of the Schwinger-boson mean-field approach, it is found that, besides magnetic ordering, there will be non-uniform charge distributions, such as charge ordering and p

A. Depuydt, C. Van Haesendonck, N. S. Maslova, V. I. Panov

We have performed voltage dependent imaging and spatially resolved spectroscopy on the (110) surface of Te doped GaAs single crystals with a low temperature scanning tunneling microscope (STM). A large fraction of the observed defects are identified as Te dopant atoms which can be observed down to the fifth subsurface layer. For negative sample voltages, the

J. P. Rodriguez

In this erratum to my article published in Physical Review B, vol. 51, pg. 9348 (1995), I produce the correct formula for the deconfinement temperature of compact QED in two space dimensions at weak-coupling. The context is anyon superconductivity and chiral spin-liquid physics. (Any claims of priority are welcome.)

Leonid P. Pryadko, Steven A. Kivelson, V. J. Emery, Yaroslaw B. Bazaliy

We analyze the properties of a general Ginzburg-Landau free energy with competing order parameters, long-range interactions, and global constraints (e.g., a fixed value of a total ``charge&#39;&#39;) to address the physics of stripe phases in underdoped high-Tc and related materials. For a local free energy limited to quadratic terms of the gradient expansio

I. Aretxaga

Among the Active Galactic Nuclei (AGN) that have suffered type mutations, the classically classified Seyfert 2 NGC 7582 recently found at a Seyfert 1 stage, is perhaps one of the most puzzling cases, since it defies a well supported case for unification. We investigate the possibility that this type transition, common to other 12 AGN, is driven by supernovae

Ralph E. Pudritz, Jason D. Fiege

We review the physics of star formation, and its links with the state of the ISM in galaxies. Current obervations indicate that the preferred mode of star formation is clustered. Given that OB associations provide the dominant energy input into the ISM, deep links exist between the ISM and star formation. We present a multi-scale discussion of star formation

Itziar Aretxaga, B. Joguet, D. Kunth, J. Melnick

We report the transition towards a type 1 Seyfert experienced by the classical type 2 Seyfert nucleus in NGC 7582. The transition, found at most 20 days from its maximum peak, presents a unique opportunity to study these rare events in detail. At maximum the Ha line width is of about 12000 km/s. We examine three scenarios that could potentially explain the t

Y. C. Lin

In current theoretical models of the blazar subclass of active galaxies, the broadband emission consists of two components: a low-frequency synchrotron component with a peak in the IR to X-ray band, and a high-frequency inverse Compton component with a peak in the gamma-ray band. In such models, the gamma-ray spectral index should be correlated with the loca

Ismael Tereno

The question of the physical reality of the black hole interior is a recurrent one. An objection to its existence is the well known fact that the velocity of a material particle, refered to the stationary frame, tends to the velocity of light as it approaches the horizon. It is shown, using Kruskal coordinates, that a timelike radial geodesic does not become

Emi Miyata, Hiroshi Tsunemi

We observed the North-East (NE) Limb toward the center region of the Cygnus Loop with the ASCA Observatory. We found a radial variation of electron temperature (kTe) and ionization timescale (log(τ)) whereas no variation could be found for the abundances of heavy elements. In this paper, we re-analyzed the same data set and new observations with the latest c

M. V. Smolsky, V. V. Usov

We use 1+1/2 dimensional particle-in-cell plasma simulations to study the interaction of a relativistic, strongly magnetized wind with an ambient medium. Such an interaction is a plausible mechanism which leads to generation of cosmological gamma-ray bursts. We confirm the idea of Meszaros and Rees (1992) that an essential part (about 20%) of the energy that

Cheongho Han

In this paper, we investigate the intrinsic bias in detecting caustic crossings between Galactic halo and self-lensing events in the Magellanic Clouds. For this, we determine the region for optimal caustic-crossing detection in the parameter space of the physical binary separations, $\ell$, and the total binary lens mass, $M$, and find that the optimal regio

Richard Barvainis, Robert Antonucci, George Helou

In a search for lensed infrared galaxies, ISOCAM images have been obtained toward the rich clusters Abell 2218 and Abell 2219 at 15um. Nine galaxies (four in Abell 2218 and five in Abell 2219) were detected with flux levels in the range 530-1100 microJy. Three of the galaxies detected in Abell 2218 have previously known redshifts; of these one is a foregroun

E. Pointecouteau, M. Giard, A. Benoit, F. X. Désert

We have mapped the Sunyaev-Zel&#39;dovich decrement (hereafter SZ) in the direction of the most luminous X-ray cluster known to date, RXJ1347-1145, at z=0.451. This has been achieved with an angular resolution of about 23&#39;&#39; using the Diabolo photometer running on the IRAM 30 meter radio telescope. We present here a map of the cluster central region a

Agostino Martinelli, Francesca Matteucci, Sergio Colafrancesco

We predict the behaviour of the abundances of $α$-elements and iron in the intracluster medium as a function of redshift in poor and rich clusters. In order to do that we calculate the detailed chemical evolution of elliptical galaxies by means of one-zone and multi-zone models and then we integrate the contributions to the total gas and single elements by e

R. De Propris, S. A. Stanford, P. R. Eisenhardt, M. E. Dickinson

We present $K$-band luminosity functions for galaxies in a heterogeneous sample of 38 clusters at $0.1 < z < 1$. Using infrared-selected galaxy samples which generally reach 2 magnitudes fainter than the characteristic galaxy luminosity $L^*$, we fit Schechter functions to background-corrected cluster galaxy counts to determine $K^*$ as a function of redshif

Rosa M. Gonzalez Delgado

Stellar population models to predict the H Balmer and HeI lines in absorption are presented. Models are computed for burst and continuous star formation. It is found that the Balmer and HeI line profiles are sensitive to the age, except during the first 4 Myr of the evolution, when the equivalent widths of these lines are constant. The comparison of these li

H. Hirashita, H. Kamaya, T. T. Takeuchi

We examine the correlation between physical quantities to explore the existence of dark matter (DM) in the Local Group dwarf spheroidal galaxies (dSphs). In order to clarify whether DM exists in the dSphs we compare two extreme models of their internal kinematics: [1] a tidal model (the mass of a dSph is estimated with the luminous mass, since the observed l

Liliya L. R. Williams, Julio F. Navarro, Matthias Bartelmann

We examine gravitational lensing constraints on the structure of galaxy clusters and compare them with the results of cosmological N-body simulations of cluster formation in cold dark matter (CDM) dominated universes. We find that cluster core masses, as measured by the observed location of giant tangential arcs, generally exceed those of dark matter halos o

S. A. Laurent-Muehleisen, R. I. Kollgaard, E. D. Feigelson, W. Brinkmann

Combining newly identified and previously known BL Lacs from the RASS-Green Bank (RGB) catalog, we present a sample of 127 BL Lacs, the largest ever derived from a single uniform survey. A Complete sample of 33 objects brighter than O=18.0 mag is also presented. These samples are compared to other known BL Lac samples and are generally found to exhibit prope

Gabriela Mallen-Ornelas, Simon Lilly, David Crampton, David Schade

We present the results of a study of the internal kinematics of luminous starforming galaxies in the 0 < z < 0.8 range, with the aim of investigating the nature of the blue galaxies which cause the largest changes in the luminosity function at z > 0.5. New kinematic data are analysed for a sample of 24 galaxies from the Canada-France Redshift Survey, most of

Donald A. Smith, Hale V. Bradt, Alan M. Levine

The fourth unambiguously identified Soft Gamma Repeater (SGR), SGR1627-41, was discovered with the BATSE instrument on 1998 June 15 (Kouveliotou et al. 1998). Interplanetary Network (IPN) measurements and BATSE data constrained the location of this new SGR to a 6 deg segment of a narrow (19&#34;) annulus (Hurley et al. 1999; Woods et al. 1998). We present tw

Neil R. Constable, Robert C. Myers

We investigate a family of solutions of Type IIb supergravity which asymptotically approach AdS_5 X S^5 but contain a non-constant dilaton and volume scalar for the five-sphere. These solutions preserve an SO(1,3) X SO(6) symmetry. We discuss the solution in the context of the AdS/CFT correspondence, and we find that as well as running coupling from the nont

S. P. de Alwis

The decay of rotated brane configurations and the corresponding condensation of tachyons is discussed. In a certain IIB orbifold case a heuristic argument about the mass of the state living on the fixed plane is made. When the rotation angle is $π$ this mass agrees with that obtained by Sen.

Luca Amendola, Sandra Savaglio

We investigate the clustering properties of 13 QSO lines of sight in flat space, with average redshifts from z~2 to 4. We estimate the 1-D power spectrum and the integral density of neighbours, and discuss their variation with respect to redshift and column density. We compare the results with standard CDM models, and estimate the power spectrum of Lyman-alp

Ilka Brunner, Rami Entin, Christian Romelsberger

In this note we discuss D-branes on T^4/Z_2 using the boundary states formalism. Explicit formulas for the untwisted boundary states inherited from the underlying T^4 and twisted states corresponding to branes wrapping collapsed 2-cycles at the orbifold singularities are given. The exact CFT description of the orbifold makes it possible to study how the boun

A. L. Kataev, G. Parente, A. V. Sidorov

A detailed next-to-next-to-leading order (NNLO) QCD analysis is performed for the experimental data of the CCFR collaboration for the $xF_3$ structure function. Theoretical ambiguities of the results of our NNLO fits are estimated by application of the Padé resummation technique and variation of the factorization and renormalization scales. The NNLO and N$^3

Giancarlo Franzese

We consider a Potts model diluted by fully frustrated Ising spins. The model corresponds to a fully frustrated Potts model with variables having an integer absolute value and a sign. This model presents precursor phenomena of a glass transition in the high-temperature region. We show that the onset of these phenomena can be related to a thermodynamic transit

Joel H. Kastner, David P. Huenemoerder, Norbert S. Schulz, David A. Weintraub

We present ASCA and ROSAT X-ray observations of the classical T Tauri star TW Hya, the namesake of a small association that, at a distance of ~ 50 pc, represents the nearest known region of recent star formation. Analysis of ASCA and ROSAT spectra indicates characteristic temperatures of ~ 1.7 MK and ~ 9.7 MK for the X-ray emitting region(s) of TW Hya, with

Z. Burda, J. Jurkiewicz, A. Krzywicki

A general method of constructing the Dirac operator for a randomly triangulated manifold is proposed. The fermion field and the spin connection live, respectively, on the nodes and on the links of the corresponding dual graph. The construction is carried out explicitly in 2-d, on an arbitrary orientable manifold without boundary. It can be easily converted i

Horatiu Nastase, Diana Vaman, Peter van Nieuwenhuizen

We show that there exists a consistent truncation of 11 dimensional supergravity to the 'massless' fields of maximal (N=4) 7 dimensional gauged supergravity. We find the complete expressions for the nonlinear embedding of the 7 dimensional fields into the 11 dimensional fields, and check them by reproducing the d=7 susy transformation laws from the d=11 laws

Christopher Haydock, Nenad Juranić, Franklyn G. Prendergast, Slobodan Macura

The cobalt glycyl-leucine dipeptide is a model system for studying the effects of Karplus equation calibration, molecular mechanics accuracy, backbone conformation, and thermal motions on the measurability of side chain rotational isomer populations. We analyze measurements of 8 vicinal coupling constants about the alpha to beta-carbon and beta to gamma-carb

V. Akulov, M. Kudinov

A parametrization of the Hamiltonian of the generalized Witten model of the SUSY QM by a single arbitrary function in d=1 has been obtained for an arbitrary number of the supersymmetries N. Possible applications of this formalism have been discussed. It has been shown that the N=1 and 2 conformal SUSY QM is generalized for any N.

Nobuo Furukawa

In order to study the magnetic excitation behaviors in colossal magnetoresistance manganites, a magnon-phonon interacting system is investigated. Sudden broadening of magnon linewidth is obtained when a magnon branch crosses over an optical phonon branch. Onset of the broadening is approximately determined by the magnon density of states. Anomalous magnon da

Fabrizio Palumbo

We derive the pion-nucleon interaction in the framework of a new perturbative approach to QCD, based on the use of quark composites as fundamental variables. The composites with the quantum numbers of the nucleons are assumed as new integration variables in the Berezin integral which defines the partition function, while the composites with the quantum numbe

Alfredo Iorio

The central charge for the Seiberg-Witten low-energy effective Action is computed using Noether supercharges. A reliable method to construct supersymmetric Noether currents is presented.

H. Saida, M. Sakagami

We consider one model of a black hole radiation, in which the equation of motion of a matter field is modified to cut off high frequency modes. The spectrum in the model has already been analytically derived in low frequency range, which has resulted in the Planckian distributin of the Hawking temperature. On the other hand, it has been numerically shown tha

W. N. Cottingham, H. Mehrban, I. B. Whittingham

Two aspects of hadronic B decays are investigated. Firstly, the supersymmetric enhancement of hadronic b decays by gluino penguin processes is studied through their effect on the Wilson coefficients of the effective Hamiltonian. Secondly, hadronization of the final state quarks is studied through a simple phase space spectator model.

Sibasish Ghosh, Somshubhro Bandyopadhyay, Anirban Roy, Debasis Sarkar

We derive the optimal curve satisfied by the reduction factors, in the case of universal disentangling machine which uses only local operations. Impossibility of constructing a better disentangling machine, by using non-local operations, is discussed.

B. Geyer, M. Lazar, D. Robaschik

A systematic procedure is introduced to uniquely decompose nonlocal LC-operators into harmonic operators of well defined geometric twist. The method will be demonstrated for (pseudo)scalar, (axial) vector and skew tensor bilocal quark light-ray operators

Daisuke Ida, Sean A. Hayward

It is known that traversible wormholes require negative energy density. We here argue how much negative energy is needed for wormholes, using a local analysis which does not assume any symmetry. and in particular allows dynamic (non-stationary) but non-degenerate wormholes. We find that wormholes require two constraints on the energy density, given by two in

A. V. Kisselev

It is shown that the problem of double counting in open charm production in DIS can be solved by using the expression for DIS coefficient functions in terms of 2PI diagrams

Victor I. Belinicher, Joao da Providencia

The consistent theory of the Heisenberg quantum antiferromagnet in the disordered phase with short range antiferromagnetic order was developed on the basis of the path integral for the spin coherent states. We have presented the Lagrangian of the theory in a form which is explicitly invariant under rotations and have found natural variables in the term of wh

K. Scholberg

In 1998, the Super-Kamiokande announced evidence for the observation of neutrino oscillations based on measurements of the atmospheric neutrino flux. This paper presents the updated results for fully and partially-contained events with 736 days of data, as well as upward-going muon results and a global analysis. Preliminary interpretations of the results in

Xiao-Gang He, Chien-Lan Hsueh, Jian-Qing Shi

Recent results from CLEO on $B\to Kπ$ indicate that the phase $γ$ may be substantially different from that obtained from other fit to the KM matrix elements in the Standard Model. We show that $γ$ extracted using $B\to Kπ, ππ$ is sensitive to new physics occurring at loop level. It provides a powerful method to probe new physics in electroweak penguin intera

Xiao-Gang He

We show that new physics effects due to extra dimensions can dramatically affect Higgs pair production at photon colliders. We find that the cross section due to extra dimensions with the scale $M_S$ of new physics around 1.5 TeV, the cross section can be as large as 0.11 pb (1.5pb) for monochromatic photon collision, $γγ\to HH$, with the collider energy $\s

P. Kanti, C. E. Vayonakis

We consider a string-inspired, gravitational theory of scalar and electromagnetic fields and we investigate the existence of axially-symmetric, Gödel-type cosmological solutions. The neutral case is studied first and an &#34;extreme&#34; Gödel-type rotating solution, that respects the causality, is determined. The charged case is considered next and two new

H. Saleur

I discuss in this paper the continuum limit of integrable spin chains based on the superalgebras sl(N/K). The general conclusion is that, with the full ``supersymmetry&#39;&#39;, none of these models is relativistic. When the supersymmetry is broken by the generator of the sub u(1), Gross Neveu models of various types are obtained. For instance, in the case

C. Brif, A. Mann

A quantum system composed of a cavity radiation field interacting with a movable mirror is considered and quantum statistical properties of the field are studied. Such a system can serve in principle as an idealized meter for detection of a weak classical force coupled to the mirror which is modelled by a quantum harmonic oscillator. It is shown that the sta

Abel Camacho Quintana

Gravity-induced quantum interference is a remarkable effect that has already been confirmed experimentally, and it is a phenomenon in which quantum mechanics and gravity play simultaneously an important role. Additionally, a generalized version of this interference experiment could offer the possibility to confront against measurement outputs one of the form

Jan Myrheim

The complex Hilbert space of standard quantum mechanics may be treated as a real Hilbert space. The pure states of the complex theory become mixed states in the real formulation. It is then possible to generalize standard quantum mechanics, keeping the same set of physical states, but admitting more general observables. The standard time reversal operator in

C. Ordenovic, G. Berginc, C. Bourrely

We analytically compute a localization criterion in double scattering approximation for a set of dielectric spheres or perfectly conducting disks uniformly distributed in a spatial volume which can be either spherical or layered. For every disordered medium, we numerically investigate a localization criterion, and examine the influence of the system paramete