December 1998 arXiv papers — page 18

S. Bose, V. Vedral, P. L. Knight

We investigate the purification of entangled states by local actions using a variant of entanglement swapping. We show that there exists a measure of entanglement which is conserved in this type of purification procedure.

Sergei V. Ketov

The supersymmetric Born-Infeld actions describing gauge-fixed D-5- and D-3-branes in ambient six-dimensional (6d) spacetime are constructed in superspace. A new 6d action is the (1,0) supersymmetric extension of the 6d Born-Infeld action. It is related via dimensional reduction to another remarkable 4d action describing the N=2 supersymmetric extension of th

Hans C. Fogedby

Presenting a general phase approach to stochastic processes we analyze in particular the Fokker-Planck equation for the noisy Burgers equation and discuss the time dependent and stationary probability distributions. In one dimension we derive the long-time skew distribution approaching the symmetric stationary Gaussian distribution. In the short time regime

Csaba Balazs, Hong-Jian He, C. -P. Yuan

We recently proposed that, due to the top-quark-mass enhanced Yukawa coupling, the s-channel production of a charged scalar or pseudo-scalar from heavy quark fusion can be an important new mechanism for discovering non-standard spin-0 particles. In this work, we present the complete O(alpha_s) QCD corrections to this s-channel production process at hadron co

H. -W. Hammer, M. J. Ramsey-Musolf

The nucleon strange vector and isoscalar electromagnetic form factors are studied using a spectral decomposition. The K\bar{K} contribution to the electric and magnetic radii as well as the magnetic moment is evaluated to all orders in the strong interaction using an analytic continuation of experimental KN scattering amplitudes and bounds from unitarity. Th

V. V. Maximov, E. Ya. Kogan, I. P. Zavershinsky, A. P. Zubarev

The classical problem of the fluid mechanics is the problem of a supersonic motion around a thin body was generalized to the case of non-equilibrium gas. The drag and lift force coefficients were founded. It is shown that the drag and lift force coefficients in the acoustically active supersonic flow are both decreased

V. Hinich

The category of unital (unbounded) dg cocommutative coalgebras over a field of characteristic zero is provided with a structure of simplicial closed model category. This generalizes the model structure defined by Quillen in 1969 for 2-reduced coalgebras. In our case, the notion of weak equivalence is structly stronger than that of quasi-isomorphism. A pair o

Ken-Ichi Aoki, Atsushi Horikoshi, Masaki Taniguchi, Haruhiko Terao

The non-perturbative renormalization group (NPRG) is applied to analysis of tunnelling in quantum mechanics. The vacuum energy and the energy gap of anharmonic oscillators are evaluated by solving the local potential approximated Wegner-Houghton equation (LPA W-H eqn.). We find that our results are very good in a strong coupling region, but not in a very wea

Gerald B. Cleaver

I discuss a method for producing a quasi-realistic inter-generational quark mass hierarchy in string models. This approach involves non-Abelian singlet states developing intermediate scale vacuum expectation values. I summarize recent investigations into string model realization of this. Talk presented at QCD98, Paris, France, 1-6 June 1998.

Massimo Di Pierro

This is a manual (built by examples) to explain the use of MDP_QCD. It consists of an ensemble of classes and functions (written in GNU C++) to help in writing programs for lattice QCD in a particularly Object Oriented fashion. Some tricks are implemented to optimize speed and reduce memory usage on PCs, workstations and parallel computers with sheared memor

Goran Wendin, Vitaly S. Shumeiko, Peter Samuelsson

We discuss how to control dc Josephson current by influencing the structure and nonequilibrium population of Andreev levels via external electrostatic gates, external current injection and electromagnetic radiation. In particular we will consider the "giant" Josephson current in "long" SIS tunnel junctions and the regular and anomalous nonequ

Abhik Basu, Jayanta K Bhattacharjee

The Dynamo effect is used to describe the generation of magnetic fields in astrophysical objects. However, no rigorous derivation of the dynamo equation is available. We justify the form of the equation using an Operator Product Expansion (OPE) of the relevant fields. We also calculate the coefficients of the OPE series using a dynamic renormalisation group

D. V. Khveshchenko

We consider electron transport through a quantum point contact between compressible Quantum Hall liquids and derive the contact's impedance function for both diffusive and ballistic regimes of the bulk electron motion. In either regime, the tunneling current deviates from a power-law behavior $I\sim V^{1/ν}$ expected on the basis of the single-mode chira

F. Combes, V. Charmandaris

It is widely accepted that shell galaxies form as a result of a merger between an elliptical and a small disk galaxy. Simulations of the stellar component have shown that the shells are created either by ``phase-wrapping'' of debris on nearly radial orbits (Quinn 1984), or by ``spatial-wrapping'' of matter in thin disks (Dupraz & Combes 1987;

Sergei A. Levshakov, David Tytler, Scott Burles

We present a new analysis of the deuterium absorption at z = 2.504 towards the quasar Q1009+2956 using the mesoturbulent model which accounts for possible correlations in the large scale velocity field. We obtain a slightly higher deuterium-to-hydrogen ratio D/H = (3.5 - 5.0)*10^{-5} as compared with the recent measurement D/H = (3.3 - 4.5)*10^{-5} (68% C.L.

D. Eichler, A. Levinson

The gamma ray burst (GRB) 980425 is distinctive in that it seems to be associated with supernova (SN) 1998bw, has no X-ray afterglow, and has a single peak light curve and a soft spectrum. The supernova is itself unusual in that its expansion velocity exceeds c/6. We suggest that many of these features can be accounted for with the hypothesis that we observe

Sandip K. Chakrabarti

Accretion flows may produce profuse winds when they have positive specific energy. Winds deplete matter from the inner region of the disk and makes the inner region thinner, optically. Since there are fewer electrons in this region, it becomes easier to Comptonize this part by the soft photons which are intercepted from the Keplerian disk farther out. We pre

Tapas K. Das, Sandip K. Chakrabarti

We compute mass outflow rates from advective accretion disks around compact objects, such as neutron stars and black holes. These computations, for the first time, are done using combinations of exact transonic inflow and outflow solutions which may or may not form standing shock waves. Assuming that the bulk of the outflow is from the effective boundary lay

W. Losert, D. G. W. Cooper, J. P. Gollub

A partial monolayer of ~ 20000 uniform spherical steel beads, vibrated vertically on a flat plate, shows remarkable ordering transitions and cooperative behavior just below 1g maximum acceleration. We study the stability of a quiescent disordered or ``amorphous'' state formed when the acceleration is switched off in the excited ``gaseous'' st

S. E. Parkhomenko

Poisson-Lie T-duality in quantum N=2 superconformal WZNW models is considered. The Poisson-Lie T-duality transformation rules of the super-Kac-Moody algebra currents are found from the conjecture that, as in the classical case, the quantum Poisson-Lie T-duality is given by an automorphism which interchanges the isotropic subalgebras of the underlying Manin t

G. W. Carter, O. Scavenius, I. N. Mishustin, P. J. Ellis

We consider an effective Lagrangian containing contributions from glueball and gluon degrees of freedom with a scale-invariant coupling between the two. The thermodynamic potential is calculated taking into account thermal fluctuations of both fields. The glueball mean field dominates at low temperature, while the high temperature phase is governed by low-ma

A. V. Rozhkov, Daniel P. Arovas

We analyze nonperturbatively the behavior of a Josephson junction in which two BCS superconductors are coupled through an Anderson impurity. We recover earlier perturbative results which found that a $δ=π$ phase difference is preferred when the impurity is singly occupied and the on-site Coulomb interaction is large. We find a novel intermediate phase in whi

Keith H. Lockitch, John L. Friedman

Almost none of the r-modes ordinarily found in rotating stars exist, if the star and its perturbations obey the same one-parameter equation of state; and rotating relativistic stars with one-parameter equations of state have no pure r-modes at all, no modes whose limit, for a star with zero angular velocity, is a perturbation with axial parity. Similarly (as

Jose L. Cereceda

Kar's recent proof showing that a maximally entangled state of two spin-1/2 particles gives the largest violation of a Bell inequality is extended to N spin-1/2 particles (with N greater than or equal to 3). In particular, it is shown that all the states yielding a direct contradiction with the assumption of local realism do generally consist of a superp

J. A. Belinchon

We consider several viscous model with metric type FRW, with k=0 and with generic equation of state. We take into account too, the conservation principle for the energy-momentum tensor. We find trivially, a set of solutions through dimensional analysis.

L. Andrew Campbell

Sergey Pinchuk discovered a class of pairs of real polynomials in two variables that have a nowhere vanishing Jacobian determinant and define maps of the real plane to itself that are not one-to-one. This paper describes the asymptotic behavior of one specific map in that class. The level of detail presented permits a good geometric visualization of the map.

Viktor L. Ginzburg, Victor L. Guillemin, Yael Karshon

We show that the theory of stable complex $G$-cobordisms, for a torus $G$, is embedded into the theory of stable complex $G$-cobordisms of not necessarily compact manifolds equipped with proper abstract moment maps. Thus the introduction of such non-compact cobordisms in the stable complex $G$-cobordism theory does not lead to new relations.

G. Domokos, S. Kovesi-Domokos

Cosmic rays of energies larger than the Greisen-Zatsepin-Kuzmin (GZK) cutoff may be neutrinos if they acquire strong interactions due to a ``precocious unification'' of forces. A scenario for this to happen is outlined. There is no contradiction with precision measurements carried out at LEP and SLAC. Observable consequences at LHC and future neutrin

W. Bernreuther, O. Nachtmann

We consider a spontaneously broken gauge theory based on the standard model (SM) group G = SU(2) x U(1) with scalar fields that carry arbitrary representations of G, and we investigate some general properties of the charged and neutral current involving these fields. In particular we derive the conditions for having real or complex couplings of the Z boson t

M. Boglione, M. R. Pennington

The scalar mesons in the 1 GeV region constitute the Higgs sector of the strong interactions. They are responsible for the masses of all light flavour hadrons. However, the composition of these scalar states is far from clear, despite decades of experimental effort. The two photon couplings of the $f_{0}$'s are a guide to their structure. Two photon resu

K. G. Baird

This paper presents measurements of the leptonic asymmetries in Z0 decays measured with the SLD detector. Using a data sample of approximately 500,000 Z0 bosons, we report preliminary values for A_e, A_mu and A_tau using both hadronic and leptonic decays.

J. W. Maluf, J. F. da Rocha-Neto

We consider Bondi's radiating metric in the context of the teleparallel equivalent of general relativity (TEGR). This metric describes the asymptotic form of a radiating solution of Einstein's equations. The total gravitational energy for this solution can be calculated by means of pseudo-tensors in the static case. In the nonstatic case, Bondi defin

Orhan Karaali, Gerald Corrigan, Noel Massey, Corey Miller

While neural networks have been employed to handle several different text-to-speech tasks, ours is the first system to use neural networks throughout, for both linguistic and acoustic processing. We divide the text-to-speech task into three subtasks, a linguistic module mapping from text to a linguistic representation, an acoustic module mapping from the lin

Jonathan Doye, Daan Frenkel

Recent work on the mechanism of polymer crystallization has led to a proposal for the mechanism of thickness selection which differs from those proposed by the surface nucleation theory of Lauritzen and Hoffman and the entropic barrier model of Sadler and Gilmer. This has motivated us to reexamine the model used by Sadler and Gilmer. We again find a fixed-po

N. B. Ivanov

Within the macroscopic Landau-de Gennes approach, we examine the Gaussian normal mode fluctuations of semi-infinite nematic liquid crystals in a regime of critical wetting. It is argued that surface free-energy potentials that strongly suppress the long-range nematic order favor the appearance of bound biaxial nematic-director fluctuation modes, located in t

Valery I. Rupasov

We study a spin-1/2 Kondo impurity coupled to an unconventional host in which the density of band states vanishes either precisely at (``gapless'' systems) or on some interval around the Fermi level (``gapped''systems). Despite an essentially nonlinear band dispersion, the system is proven to exhibit hidden integrability and is diagonalized e

S. Leon, G. Bergond, A. Vallenari

We present the tidal tail distributions of a sample of candidate binary clusters located in the bar of the Large Magellanic Cloud (LMC). One isolated cluster, SL 268, is presented in order to study the effect of the LMC tidal field. All the candidate binary clusters show tidal tails, confirming that the pairs are formed by physically linked objects. The stel

V. Castellani, S. Degl'Innocenti, M. Marconi

We present new evolutionary stellar models suitable for old Population I clusters, discussing both the consequences of the most recent improvements in the input physics and the effect of element diffusion within the stellar structures. Theoretical cluster isochrones are presented, covering the range of ages from 1 to 9 Gyr for the four selected choices on th

Hien D. Tran, M. S. Brotherton, S. A. Stanford, Wil van Breugel

We have carried out a spectropolarimetric search for hidden broad-line quasars in three ultraluminous infrared galaxies (ULIRGs) discovered in the positional correlations between sources detected in deep radio surveys and the IRAS Faint Source Catalog. Only the high-ionization Seyfert 2 galaxy TF J1736+1122 is highly polarized, displaying a broad-line spectr

Sergei Nayakshin

Recent progress in observations and understanding of spectra of Seyfert Galaxies shows that X-rays are most likely produced by magnetic flares on the surface of the disk, similar to Solar X-ray emission. However, while the model reproduces the shape of the spectrum well, the question of the overall normalization of the X-ray component relative to the bolomet

Sergei Nayakshin

Spectrum of Seyfert 1 Galaxies (S1G hereafter) is very similar to that of several Galactic Black Hole Candidates (GBHCs) in their hard state, suggestive that both classes of objects have similar physical processes. However, recent work has shown that reprocessing features make the patchy corona-disk model (PCD model: the best current explanation of S1G spect

Nader Haghighipour

A restricted planar circular three-body system, consisting of the Sun and two planets, is studied as a simple model for a planetary system. The mass of the inner planet is considered to be larger and the system is assumed to be moving in a uniform interplanetary medium with constant density. Numerical integrations of this system indicate a resonance capture

J. W. Demmel, L. Dieci, M. J. Friedman

A successive continuation method for locating connecting orbits in parametrized systems of autonomous ODEs was considered in [9]. In this paper we present an improved algorithm for locating and continuing connecting orbits, which includes a new algorithm for the continuation of invariant subspaces. The latter algorithm is of independent interest, and can be

Jan de Boer, Hirosi Ooguri, Harlan Robins, Jonathan Tannenhauser

It was shown by Brown and Henneaux that the classical theory of gravity on AdS_3 has an infinite-dimensional symmetry group forming a Virasoro algebra. More recently, Giveon, Kutasov and Seiberg (GKS) constructed the corresponding Virasoro generators in the first-quantized string theory on AdS_3. In this paper, we explore various aspects of string theory on

Dimitri Polyakov

We discuss the NSR formulation of the superstring action on AdS_5 X S^5 proposed recently by Kallosh and Tseytlin in the Green-Schwarz formalism.We show that the stress-energy tensor corresponding to the NSR action for AdS superstring contains the branelike terms, corresponding to exotic massless vertex operators (refered to as the branelike vertices). The c

Jean-Pierre De Villiers, Valeri Frolov

This paper discusses the gravitational scattering of a straight, infinitely long test cosmic string by a black hole. We present numerical results that probe the two-dimensional parameter space of impact parameter and initial velocity and compare them to approximate perturbative solutions derived previously. We analyze string scattering and loop formation in

Apostolos Pilaftsis

The scenario of baryogenesis through leptogenesis is reviewed in models involving heavy Majorana neutrinos. The various mechanisms of CP violation occurring in the out-of-equilibrium lepton-number-violating decays of heavy Majorana neutrinos are studied within a resummation approach to unstable-particle mixing. It is explicitly demonstrated how the resummati

S. Kalyana Rama, Tapobrata Sarkar

We apply the holographic principle during the inflationary stage of our universe. Where necessary, we illustrate the analysis in the case of new and extended inflation which, together, typify generic models of inflation. We find that in the models of extended inflation type, and perhaps of new inflation type also, the holographic principle leads to a lower b

J. Demsar, B. Podobnik, J. Evetts, G. Wagner

Time resolved measurements of quasiparticle (QP) relaxation dynamics on the femtosecond timescale are reported as a function of temperature and doping in YBa2Cu3O(7-x) for (0.48 < x < 0.1). In the underdoped state (x > 0.15), there is no evidence for any changes in the low-energy gap structure at Tc from either photoinduced QP absorption or QP relaxation tim

Taichi Itoh, Hiroshi Kato

In (2+1)-dimensional QED with a Chern-Simons term, we show that spontaneous magnetization occurs in the context of finite density vacua, which are the lowest Landau levels fully or half occupied by fermions. Charge condensation is shown to appear so as to complement the fermion anti-fermion condensate, which breaks the flavor U(2N) symmetry and causes fermio

S. Krishnamurthy, V. Loreto, H. J. Herrmann, S. S. Manna

We study the phenomenon of internal avalanching within the context of recently proposed ``Tetris&#39;&#39; lattice models for granular media. We define a recycling dynamics under which the system reaches a steady state which is self-structured, i.e. it shows a complex interplay between textured internal structures and critical avalanche behavior. Furthermore

V. Yu. Irkhin, Yu. P. Irkhin

The book includes all main physical properties of d- and f-transition-metal systems and corresponding theoretical concepts. Especial attention is paid to the theory of magnetism and transport phenomena. Some examples of non-traditional questions which are treated in detail in the book: the influence of density of states singularities on electron properties;

Manoranjan P. Singh, A. L. Satheesha

We propose a simple variational form of the wave function to describe the ground state and vortex states of a system of weakly interacting Bose gas in an anisotropic trap. The proposed wave function is valid for a wide range of the particle numbers in the trap. It also works well in the case of attractive interaction between the atoms. Further, it provides a

E. T. Akhmedov

D-instantons are considered as a probe of coinciding $N$ D3-branes. They can feel an external metric via the commutator terms in their effective action. We show that when the D-instantons are separated from the D3-branes, the metric which is probed at the one loop level, {\it exactly} coincides with that of the BPS R-R 3-brane. Interesting connection of this

Arthur Lue, Limin Wang, Marc Kamionkowski

Does Nature yield any manifestations of parity violation other than those observed in weak interactions? A map of the cosmic microwave background (CMB) temperature and polarization will provide a new signature of P violation. We give two examples of new P violating interactions, which may have something to do with Planck-scale physics, inflation, and/or quin

Wen-Li Yang, Yao-Zhong Zhang

We re-examine the level-one irreducible highest weight representations of the quantum affine superalgebra $U_q(\hat{sl}(2|1))$ and derive the characters and supercharacters associated with these representations. We calculate the exchange relations of the vertex operators and find that these vertex operators satisfy the graded Faddeev-Zamolodchikov algebra. W

John H. Schwarz

An introductory survey of some of the developments that have taken place in superstring theory in the past few years is presented. The main focus is on three particular dualities. The first one is the appearance of an 11th dimension in the strong coupling limit of the type IIA theory, which give rise to M theory. The second one is the duality between the typ

R. Conte

The ``truncation procedure&#39;&#39; initiated by Weiss et al. is best understood as a Darboux transformation. If it leads to the Lax pair of the PDE under study, the Bäcklund transformation follows by an elimination, thus proving the integrability. We present the state of the art of this powerful technique. The easy situations were all handled by the WTC on

R. Conte

There exist many situations where an ordinary differential equation admits a movable critical singularity which the test of Kowalevski and Gambier fails to detect. Some possible reasons are: existence of negative Fuchs indices, insufficient number of Fuchs indices, multiple family, absence of an algebraic leading order. Mainly giving examples, we present the

H. Nikolic

A clear explanation is given on how the causal, psychological, and electrodynamic time arrows emerge from the thermodynamic time arrow.

The Jefferson Lab Hall A Collaboration, L. C Alexa

The deuteron elastic structure function A(Q^2) has been extracted in the Q^2 range 0.7 to 6.0 (GeV/c)^2 from cross section measurements of elastic electron-deuteron scattering in coincidence using the Hall A Facility of Jefferson Laboratory. The data are compared to theoretical models based on the impulse approximation with inclusion of meson-exchange curren

S. Deser

The essential role played by Chern--Simons terms in a variety of physical models provides yet another illustration of the unexpected but profound interactions between the two disciplines.

Frederic Haglund, Frederic Paulin

We prove that numerous negatively curved simply connected locally compact polyhedral complexes, admitting a discrete cocompact group of automorphisms, have automorphism groups which are locally compact, uncountable, non linear and virtually simple. Examples include hyperbolic buildings, Cayley graphs of word hyperbolic Coxeter systems, and generalizations of

G. Ali, J. K. Hunter

We derive an asymptotic solution of the Einstein field equations which describes the propagation of a thin, large amplitude gravitational wave into a curved space-time. The resulting equations have the same form as the colliding plane wave equations without one of the usual constraint equations.

Robert Gilman Michael Shapiro

Accessible groups for which the language of all words defining the identity is accepted by a certain class of nested stack automata are virtually free.

William P. Thurston

The space of shapes of a polyhedron with given total angles less than 2πat each of its n vertices has a Kaehler metric, locally isometric to complex hyperbolic space CH^{n-3}. The metric is not complete: collisions between vertices take place a finite distance from a nonsingular point. The metric completion is a complex hyperbolic cone-manifold. In some inte

P. F. Borges, H. Boschi-Filho, C. Farina

We construct a partition function for fields obeying a quasiperiodic boundary condition at finite temperature, $ψ(0;\vec x)= e^{iθ} ψ(β;\vec x)$, which interpolate continously that ones corresponding to bosons and fermions and discuss the possibility of condensation for these fields.

Alberto Blasi, Nicola Maggiore, Silvio P. Sorella, Luiz C. Q. Vilar

We give a simple and elegant proof of the Equivalence Theorem, stating that two field theories related by nonlinear field transformations have the same S matrix. We are thus able to identify a subclass of nonrenormalizable field theories which are actually physically equivalent to renormalizable ones. Our strategy is to show by means of the BRS formalism tha

J. F. Morales, J. C. Plefka, C. A. Scrucca, M. Serone

Spin interactions beteween two moving Dp-branes are analyzed using the Green-Schwarz formalism of boundary states. This approach turns out to be extremely efficient to compute all the spin effects related by supersymmetry to the leading v^4/r^7-p term. All these terms are shown to be scale invariant, supporting a matrix model description of supergravity inte

S. Gogilidze, N. Ilieva, E. Lipartia, V. N. Pervushin

The paper has been withdrawn for further elaboration.

Xiaofeng Guo

We show explicitly that the leading soft gluon $p_T$ distribution, predicted by Kovner, McLerran, and Weigert after solving classical Yang-Mills equations, can be understood in terms of conventional QCD perturbation theory. We also demonstrate that the key logarithm in their result represents the logarithm in DGLAP evolution equations.

J. G. Contreras

Recently the H1 and ZEUS collaborations have presented cross sections for DIS events with a forward jet. The BFKL formalism is able to produce an excellent fit to these data. The extracted intercept of the hard pomeron suggests that when all higher order corrections are taken into account the cross section will still rise very rapidly as expected for low $x$

Y. Tsue, D. Vautherin, T. Matsui

Mean field theory for the time evolution of quantum meson fields is studied in terms of the functional Schroedinger picture with a time-dependent Gaussian variational wave functional. We first show that the equations of motion for the variational wavefunctional can be rewritten in a compact form similar to the Hartree-Bogoliubov equations in quantum many-bod

Katri Huitu, Cai-Dian Lü, Paul Singer, Da-Xin Zhang

In the Standard Model, the box-diagram mediated decay $b\to s s \bar d$ is predicted to occur with an extremely small branching ratio of below $10^{-11}$, thus providing a safe testing ground for exposing new physics. We study this process in several Two Higgs Doublet Models and explore their parameter space, indicating where this process becomes observable.

Yuri L. Dokshitzer

Following the logic of the great Chinese warrior-philosopher Master Sun Tzu, &#34;The rules of the military are five: measurement, assessment, calculation, comparison and victory&#34;, we address the problem of what we know, think we know, and think about the QCD coupling.

Graham Smye

We investigate the power-suppressed corrections to fragmentation functions in flavour-singlet deep inelastic lepton scattering, to complement the previous results for the non-singlet contribution. Our method is a dispersive approach based on an analysis of Feynman graphs containing massive gluons. As in non-singlet deep inelastic scattering we find that the

O. V. Tarasov

An algorithm for the reduction of massive Feynman integrals with any number of loops and external momenta to a minimal set of basic integrals is proposed. The method is based on the new algorithm for evaluating tensor integrals, representation of generalized recurrence relations for a given kind of integrals as a linear system of PDEs and the reduction of th

Debasish Majumdar, Amitava Raychaudhuri

Results for solar neutrino detection from the SuperKamiokande collaboration have been presented recently while those from the Sudbury Neutrino Observatory are expected in the near future. These experiments are sensitive to the 8B neutrinos from the sun, the shape of whose spectrum is well-known but the normalisation is less certain. We propose several variab

M. Dubinin, A. Semenov

In the case of minimal supersymmetric extension of the Standard Model (MSSM), when the pseudoscalar Higgs boson mass is less than the supersymmetry energy scale, the effective theory at the electroweak scale is a two-Higgs-doublet model. We diagonalize the mass matrix of the general two-Higgs-doublet model, expressing Higgs boson self-couplings in terms of t

Bing-Song Zou

Lattice QCD and other theoretical models predict that the 0(-+), 2(++) and 2(-+) glueballs have masses in the range of 2.0 to 2.4 GeV. For resonances in such an energy range, three-body decay modes are expected to be large. The strategy for looking for these glueballs and the newest results from studying Crystal Barrel data on the three-body annihilation of

W. G. Unruh, Moninder Jheeta

A large set of complex path solutions for the Hartle Hawking semi-classical wave function are found for an inflationary universe in the &#34;slow roll&#34; regime. The implication of these for the semi-classical evolution of the universe is also studied.

N. Arnaud, M. Davier, F. Cavalier, P. Hello

We study in this paper some filters for the detection of burst-like signals in the data of interferometric gravitational-wave detectors. We present first two general (non-linear) filters with no {\it a priori} assumption on the waveforms to detect. A third filter, a peak correlator, is also introduced and permits to estimate the gain, when some prior informa

Patrick R Brady, Teviet Creighton

The detection of quasi-periodic sources of gravitational waves requires the accumulation of signal-to-noise over long observation times. If not removed, Earth-motion induced Doppler modulations, and intrinsic variations of the gravitational-wave frequency make the signals impossible to detect. These effects can be corrected (removed) using a parameterized mo

Paul M. Branoff, Dieter R. Brill

We address the issue of constructing continuous instantons representing the pair creation of black holes in a cosmological context. The recent attempt at constructing such solutions using virtual domain walls is reviewed first. We then explore the existence of continuous instantons in higher curvature gravity theories where the Lagrangian is polynomial in th

Oskari Heinonen

There exist several methods of calculating a similarity curve, or a sequence of similarity values, representing the lexical cohesion of successive text constituents, e.g., paragraphs. Methods for deciding the locations of fragment boundaries are, however, scarce. We propose a fragmentation method based on dynamic programming. The method is theoretically soun

Mark D. Roberts

It is argued that colour name strategy, object name strategy, and chunking strategy in memory are all aspects of the same general phenomena, called stereotyping. It is pointed out that the Berlin-Kay universal partial ordering of colours and the frequency of traffic accidents classified by colour are surprisingly similar. Some consequences of the existence o

W. E. Bies, R. J. Radtke, H. Ehrenreich

The effective transport coefficients and figure of merit ZT for anisotropic systems are derived from a macroscopic formalism. The full tensorial structure of the transport coefficients and the effect of the sample boundaries are included. Induced transverse fields develop which can be larger than the applied fields and which reduce the effective transport co

Guang-Hong Chen, M. E. Raikh

We study theoretically the renormalization of the spin-orbit coupling constant of two-dimensional electrons by electron-electron interactions. We demonstrate that, similarly to the $g$ factor, the renormalization corresponds to the enhancement, although the magnitude of the enhancement is weaker than that for the $g$ factor. For high electron concentrations

T. Schneider, J. M. Singer

We discuss the occurrence of crossing points in the magnetization - temperature $(m,T$) plane within the framework of critical phenomena. It is shown that in a two-dimensional superconducting slab of thickness $d_{s}$ $m_{z}(δ)$ versus temperature $T$ curves measured in different fields $\mathbf{H} = H(0,\sin (δ) ,\cos (δ))$ will cross at the critical temper

T. Schneider, J. M. Singer

Considerable progress has been made over the last decade in understanding the phenomenological properties of the cuprate high-T$_{c}$ superconductors and in producing well characterized high quality materials. Nevertheless, the pairing mechanism itself remains controversial. We establish a criterion to test theories for layered superconductors relying on a s

T. Winiecki, J. F. McCann, C. S. Adams

We study the flow of a weakly-interacting Bose-Einstein condensate around an obstacle by numerical solution of the Gross-Pitaevskii equation. We observe vortex emission and the formation of bow waves leading to pressure drag. We compare the drag law with that of an ideal Bose gas, and show that interactions reduce the drag force. This reduction can be explai

R. I. Eglitis, E. A. Kotomin, A. V. Postnikov, N. E. Christensen

An ab initio LMTO approach and semi-empirical quantum chemical INDO method have been used for supercell calculations of basic point defects - F-type centers and hole polarons bound to cation vacancy - in partly covalent perovskite KNbO3. We predict the existence of both one-site and two-site (molecular) polarons with close absorption energies (~ 1 eV). The r

Raphael Cerf, Emilio N. M. Cirillo

We consider the problem of bootstrap percolation on a three dimensional lattice and we study its finite size scaling behavior. Bootstrap percolation is an example of Cellular Automata defined on the $d$-dimensional lattice $\{1,2,...,L\}^d$ in which each site can be empty or occupied by a single particle; in the starting configuration each site is occupied w

D. Y. Oberli, M. -A. Dupertuis, F. Reinhardt, E. Kapon

We have studied the effect of disorder on the radiative properties of semiconductor quantum wires by time-resolved photoluminescence spectroscopy. The dependence of the radiative lifetimes is measured over a temperature range extending from 8 to 150 K. At low temperatures we find that the measured dependence does not conform to the theoretical prediction for

S. Krishnamurthy, H. J. Herrmann, V. Loreto, M. Nicodemi

We study the phenomenon of internal avalanching within the context of recently introduced lattice models of granular media. The avalanche is produced by pulling out a grain at the base of the packing and studying how many grains have to rearrange before the packing is once more stable. We find that the avalanches are long-ranged, decaying as a power-law. We

Masato Hisakado

We consider the ultra-discrete Burgers equation. All variables of the equation are discrete. We classify the equation into five regions in the parameter space. We discuss behavior of solutions. Using this equation we construct the deterministic surface growth models respectively. Furthermore we introduce noise into the ultra-discrete Burgers equation. We pre

J. M. Luck, Th. M. Nieuwenhuizen

The diffuse intensity propagating in turbid media is sensitive to the presence of any kind of object embedded in the medium, e.g. obstacles or defects. The long-ranged effects of isolated objects can be described by a stationary diffusion equation, the effect of any single object being parametrized in terms of a multipole expansion. An absorbing object is ch

Giorgio Fontana

Recent measurements on a class of high-Tc superconductors (HTSCs) have shown that Cooper-pairs wavefunction is a d-wave, while in another class, d-wave and s-wave may coexist. Conventional low-Tc superconductors are s-wave superconductors. When d-wave Cooper-pairs are injected in a superconductor that can sustain s-wave pairing, d-wave pairs are subject to t

R. Mallik, E. V. Sampathkumaran, P. L. Paulose, V. Nagarajan

The results of magnetoresistance ($Δρ/ρ$)measurements in GdNi, in the temperature range 4.2 to 300 K are reported. The sign of $Δρ/ρ$ above the Curie temperature (Tc= 70 K) is negative and its magnitude in a magnetic field of 80kOe grows with decreasing temperature below 150 K with a peak value of about -20% at Tc. These features, qualitatively resembling th

O. Narayan, S. R. Nagel

Elastoplastic and constitutive equation theories are two approaches based on very different assumptions for creating a continuum theory for the stress distributions in a static sandpile. Both models produce the same surprising prediction that in a two dimensional granular pile constructed at its angle of repose, the outside wedge will be on the verge of fail