August 2002 arXiv papers — page 26

Hwa-Kyun Park, Sang Wook Kim

We show that classical-quantum correspondence of center of mass motion in two coupled delta-kicked rotors can be obtained from intrinsic decoherence of the system itself which occurs due to the entanglement of the center of mass motion to the internal degree of freedom without coupling to external environment.

M. Blasone, E. Celeghini, P. Jizba, G. Vitiello

We study algebraic structures underlying 't Hooft's construction relating classical systems with the quantum harmonic oscillator. The role of group contraction is discussed. We propose the use of SU(1,1) for two reasons: because of the isomorphism between its representation Hilbert space and that of the harmonic oscillator and because zero point ener

Shun-ichiro Koh

The black-body radiation is reinterpreted in terms of the photon's many-body wave functions in analogy with the condensed matter physics. This interpretation has implications on the wave-particle duality, and on the difference between the photon and the matter wave.

Jie Liu, Biao Wu, Qian Niu

We present a general theory for adiabatic evolution of quantum states as governed by the nonlinear Schrodinger equation, and provide examples of applications with a nonlinear tunneling model for Bose-Einstein condensates. Our theory not only spells out conditions for adiabatic evolution of eigenstates, but also characterizes the motion of non-eigenstates whi

Victor Kourassov

Different approximations to describe nucleation kinetics have been analyzed. Some new approximations for solution of diffusion problem are proposed. Error of the approximation with constant radius of an embryo is clarified. The theory is illustrated by numerical calculations.

D. P. Makhnovskiy, L. V. Panina, D. J. Mapps

This paper concerns the theoretical and experimental investigation of the magneto-impedance (MI) effect in amorphous wires in terms of the surface impedance tensor. Physical concepts of MI and problems of significant practical importance are discussed using the results obtained. The theoretical analysis is based on employing the asymptotic-series expansion m

Jaline Gerardin, Akhlesh Lakhtakia

Whereas Cantor multilayers made of an isotropic dielectric-magnetic material with positive refractive index will show power-law characteristics, low-order Cantor multilayers made of materials with negative refractive index will not exhibit the power-law nature. A reason for this anomalous behavior is presented.

G. Kontrym-Sznajd

Interdependencies between experimental spectra, representing line or plane projections of electronic densities, are derived from their consistency and symmetry conditions. Some additional relations for plane projections are obtained by treating them as line projections of line projections. The knowledge of these dependencies can be utilised both for an impro

B. K. Lubsandorzhiev

New developments of photodetectors for the lake Baikal neutrino experiment are described. Some test results of photodetectors at the lake Baikal are presented.

Xavier Artru, David Fayolle

For a monopole, the analogue of the Lorentz equation in matter is shown to be f = g (H - v cross D). Dual-symmetric Maxwell equations, for matter containing hidden magnetic charges in addition to electric ones, are given. They apply as well to ordinary matter if the particles possess T-violating electric dipole moments. Two schemes of experiments for the det

Subhash Kak

The cyclic model of the universe has an old history in India. It has held the preeminent position regarding the origins of the universe, and it is described in astronomical texts, Puranic encyclopaedias, and philosophical literature. Within the current cycle, which is supposed to have begun several billion years ago, are smaller cycles of pole changes and ex

P. Moskal, H. -H. Adam, A. Budzanowski, R. Czyzykiewicz

By means of the COSY-11 detection system, using a stochastically cooled proton beam of the cooler synchrotron COSY and a hydrogen cluster target, we have performed a high statistics measurement of the pp --> pp eta reaction at an excess energy of Q = 15.5 MeV. The experiment was based on the four-momentum determination of both outgoing protons. This permits

Zhangbu Xu, the STAR Collaboration

We presented the multiplicity and the spectra of many particles in Au+Au at sqrt(s_{_{NN}})=130 GeV measured by STAR detector. Their connections to initial condition, baryon creation, freeze-out condition and strangeness enhancement were discussed.

Roman O. Popovych

The definition of Q-conditional symmetry for one PDE is correctly generalized to a special case of systems of PDEs and involutive families of operators. The notion of equivalence of Q-conditional symmetries under a group of local transformation is introduced. Using this notion, all possible single Q-conditional symmetry operators are classified for the n-dim

Palle E. T. Jorgensen, Steen Pedersen

In the first section we review recent results on the harmonic analysis of fractals generated by iterated function systems with emphasis on spectral duality. Classical harmonic analysis is typically based on groups whereas the fractals are most often not groups. We show that nonetheless those fractals that come from iteration of affine mappings in R^d have a

N. J. A. Sloane

How should you choose a good set of (say) 48 planes in four dimensions? More generally, how do you find packings in Grassmannian spaces? In this article I give a brief introduction to the work that I have been doing on this problem in collaboration with A. R. Calderbank, J. H. Conway, R. H. Hardin, E. M. Rains and P. W. Shor. We have found many nice examples

Armen Edigarian, Jan Wiegerinck

We study the pluripolar hull of the graph of a holomorphic function f, defined on a domain D in the complex plane outside a polar set A of D. This leads to a theorem that describes under what conditions f is nowhere extendable over A, while the graph of f over D \ A is NOT complete pluripolar.

Rachel Taillefer

In this paper, we compute the Hochschild and cyclic homologies of the Auslander algebras of the Taft algebras. We also describe the first Chern character for the Taft algebras and for their Auslander algebras.

Michel Nguiffo Boyom

Inspired by recent works of Zang Liu, Alan Weinstein and Ping Xu, we introduce the notions of CC algebroids and non asymmetric Courant algebroids and study these structures. It is shown that CC algebroids of rank greater than 3 are the same as Courant algebroids up to a constant factor, though the definition of CC algebroids is much simpler than that of Cour

William Dwyer, Thomas Schick, Stephan Stolz

Gromov and Lawson conjectured that a closed spin manifold M of dimension n with fundamental group pi admits a metric with positive scalar curvature if and only if an associated element in KO_n(B pi) vanishes. In this note we present counter examples to the `if' part of this conjecture for groups pi which are torsion free and whose classifying space is a

Rachel Taillefer

We prove that the category of Hopf bimodules over any Hopf algebra has enough injectives, which enables us to extend some results on the unification of Hopf bimodule cohomologies of [T1,T2] to the infinite dimensional case. We also prove that the cup-product defined on these cohomologies is graded-commutative.

Augustin-Liviu Mare

We show how the quantum Chevalley formula for G/B, as stated by Peterson and proved rigorously by Fulton and Woodward, combined with ideas of Fomin, S. Gelfand and Postnikov, leads to a formula which describes polynomial representatives of the Schubert cohomology classes in the canonical presentation of QH^*(G/B) in terms of generators and relations.

D. Toublan, J. J. M. Verbaarschot

We show that QCD Dirac spectra well below Lambda_{QCD}, both at zero and at nonzero chemical potential, can be obtained from a chiral Lagrangian. At nonzero chemical potential Goldstone bosons with nonzero baryon number condense beyond a critical value. Such superfluid phase transition is likely to occur in any system with a chemical potential with the quant

Augusto Sagnotti

Much of the recent progress in String Theory can be traced to a precise strategy: a careful study of the few models known since the beginnings of the subject, and the abstraction from them of basic properties that one would like to demand from other models. This could be termed a set of "model-building rules". The approach corresponds to the fact, of

R. G. Jafarov

A method of calculation of the scattering amplitude for fermions and scalar bosons with exchanging of a scalar particle in ladder approximation is suggested. The Bethe-Salpeter ladder integral equations system for the imaginary part of the amplitude is costructed and solution in the Regge asymptotical form is found. The corrections to the amplitude due to th

Thomas G. Rizzo

Many types of new physics can lead to contact interaction-like modifications in e^+ e^- processes below direct production threshold. We examine the possibility of uniquely identifying the effects of graviton exchange, which are anticipated in many extra dimensional theories, from amongst this large set of models by using the moments of the angular distributi

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

We present an updated analysis of the current solar neutrino data in terms of three-flavor oscillations, including the additional constraints coming from terrestrial neutrino oscillation searches at the CHOOZ (reactor), Super-Kamiokande (atmospheric), and KEK-to-Kamioka (accelerator) experiments. The best fit is reached for the subcase of two-family mixing,

Michail P. Rekalo, Egle Tomasi-Gustafsson

We suggest to measure the triple polarization correlations in the exclusive associative charm particle photoproduction, vector gamma + vector p --> vector Lambda_c^{++} bar{D^0} with linearly polarized photons, as a method to determine the P-parity of the charmed D-meson. The dependence of these correlations on the parity P(N Lambda_c D) can be predicted in

O. V. Kancheli

We propose a parton model of inelastic collisions at transplanckian energies E >> G^{-1/2}, using the gravitons, whose transverse momenta are cut at the Planck scale, as partons. For this purpose we represent the gravitational shock-wave accompanying the fast particle in terms of such partons and take into account the higher order multiperipheral-like contri

G. P. Vacca

The next-to-leading corrections to the jet vertex which is relevant for the Mueller-Navelet jets production in hadronic collisions and for the forward jet cross section in lepton-hadron collisions are presented in the context of a k_t factorizazion formula which resums the leading and next-to-leading logarithms of the energy. Both the quark- and gluon-initia

Marcus S. Cohen

Quantum gravity has been so elusive because we have tried to approach it by two paths which can never meet: quantum mechanics and general relativity. These contradict each other not only in superdense regimes, but also in the vacuum. We explore a straight road to quantum gravity here--the one mandated by Clifford-algebra covariance. This bridges the gap from

S. Klimenko, G. Mitselmakher, A. Sazonov

Stochastic gravitational waves (SGW) can be detected by measuring a cross-correlation of two or more gravitational wave (GW) detectors. In this paper we describe an optimal SGW search technique in the wavelet domain. It uses a sign correlation test, which allows calculation of the cross- correlation significance for non-Gaussian data. We also address the pro

A. Lavrenov

The pit recording of file, the coefficient of compression are introduced. The theoretical limit of the information compression as minimal coefficient of compression for the given length of alphabet are found.

Daniel Lehmann

Cumulative logics are studied in an abstract setting, i.e., without connectives, very much in the spirit of Makinson's early work. A powerful representation theorem characterizes those logics by choice functions that satisfy a weakening of Sen's property alpha, in the spirit of the author's "Nonmonotonic Logics and Semantics" (JLC). The r

W. Vincent Liu, Frank Wilczek

We propose a new state of matter in which the pairing interactions carve out a gap within the interior of a large Fermi ball, while the exterior surface remains gapless. This defines a system which contains both a superfluid and a normal Fermi liquid simultaneously, with both gapped and gapless quasiparticle excitations. This state can be realized at weak co

J. L. Cohn, J. J. Neumeier

Measurements of thermal conductivity (kappa) vs temperature are reported for a series of Ca_{1-x} La_x MnO_3(0 <= x <= 0.2) specimens. For the undoped (x=0), G-type antiferromagnetic compound a large enhancement of kappa below the Neel temperature (T_N ~ 125 K) indicates a strong coupling of heat-carrying phonons to the spin system. This enhancement exhibits

T. P. Devereaux, G. E. D. McCormack, J. K. Freericks

We calculate the inelastic light scattering from X-rays, which allows the photon to transfer both energy and momentum to the strongly correlated charge excitations. We find that the charge transfer peak and the low energy peak both broaden and disperse through the Brillouin zone similar to what is seen in experiments in materials like Ca_2 Cu O_2 Cl_2.

Vasili Perebeinos, Siu-Wai Chan, Feng Zhang

The competition between the long range Coulomb attractive and the short range repulsive interaction in ionic nanocrystals creates an effective negative pressure, which causes the lattice parameter a to increase with decreasing nanoparticle size d. A simple ``Madelung model&#39;&#39; is used to predict the dependence of the lattice parameter for CeO2 and BaTi

M. Guilleumas, L. P. Pitaevskii

We study the interaction between low-lying transverse collective oscillations and thermal excitations of an elongated Bose-Einstein condensate by means of perturbation theory. We consider a cylindrically trapped condensate and calculate the transverse elementary excitations at zero temperature by solving the linearized Gross-Pitaevskii equations in two dimen

Ain-ul Huda, Omjyoti Dutta, Abhijit Mookerjee

In this communication we introduce a pair of coupled continuum equations to model overlayer growth with evaporation-accretion due to thermal or mechanical agitations of the substrate. We gain insight into the dynamics of growth via one-loop perturbative techniques. This allows us to analyze our numerical data. We conclude that there is a crossover behaviour

Bertrand Duplantier, Ilia A. Binder

The exact joint multifractal distribution for the scaling and winding of the electrostatic potential lines near any conformally invariant scaling curve is derived in two dimensions. Its spectrum f(alpha,lambda) gives the Hausdorff dimension of the points where the potential scales with distance $r$ as $H \sim r^α$ while the curve logarithmically spirals with

G. Giunchi, S. Ceresara, L. Martini, V. Ottoboni

Highly dense MgB2 policrystalline bulk materials, obtained by reactive liquid infiltration, have been characterized in their superconducting transport and magnetic properties in magnetic field and in a temperature range of interest for the MgB2 compound. The products have a granular morphology of composite nature and their overall density affects their prope

I. Gonzalez, J. Castro, D. Baldomir

Using an extension of the Nagaev model of phase separation (E.L. Nagaev, and A.I. Podel&#39;shchikov, Sov. Phys. JETP, 71 (1990) 1108), we calculate the phase diagram for degenerate antiferromagnetic semiconductors in the T-H plane for different current carrier densities. Both, wide-band semiconductors and &#39;double-exchange&#39; materials, are investigate

Giovanni Giunchi

A new route to the sintering of MgB2 has been identified, based on a reactive infiltration of liquid Mg on a powdered B preform. The technique allows to obtain large bulk manufacts in an inexpensive way, without the need of high pressure apparatus. The best of the obtained samples shows a transport current density of 3 kA/cm2 at 4.2K and 9 T. The critical as

Indrani Bose

Integrable models are often constructed with real systems in mind. The exact solvability of the models leads to results which are unambiguous and provide the correct physical picture. In this review, we discuss the physical basis of some integrable spin models and their relevance in the study of real systems. The emphasis in the review is on physical underst

Douglas R Niven, Robert A Smith

We evaluate the superconducting fluctuation corrections to thermal conductivity in the normal state which diverge as T approaches T_c. We find zero total contribution for one, two and three-dimensional superconductors for arbitrary impurity concentration. The method used is diagrammatic many-body theory, and all contributions -- Aslamazov-Larkin (AL), Maki-T

P. Di Francesco

We present applications of rectangular matrix models to various combinatorial problems, among which the enumeration of face-bicolored graphs with prescribed vertex degrees, and vertex-tricolored triangulations. We also mention possible applications to Interaction-Round-a-Face and hard-particle statistical models defined on random lattices.

Kanako T. Sato

In this paper, we show theoretically that there exists quasi-liquid on the edges and vertices of snow crystals between -4C and -22C, while the basal and prism faces have no quasi-liquid layers. Investigating the macroscopic theory of quasi-liquid and applying to the edges and vertices of the crystal, we find that the quasi-liquid becomes unstable above the c

D. P. Makhnovskiy, L. V. Panina, D. J. Mapps, A. K. Sarychev

The approach to calculating the effective dielectric and magnetic response in bounded composite materials is developed. The method is essentially based on the renormalisation of the dielectric matrix parameters to account for the surface polarisation and the displacement currents at the interfaces. This makes it possible the use of the effective medium theor

G. M. Shim, B. Y. Park, Hoyun Lee

We present an analytic study of the urn model for separation of sand recently introduced by Lipowski and Droz (Phys. Rev. E 65, 031307 (2002)). We solve analytically the master equation and the first-passage problem. The analytic results confirm the numerical results obtained by Lipowski and Droz. We find that the stationary probability distribution and the

M. M. Savosta, V. I. Kamenev, V. A. Borodin, P. Novak

55Mn NMR was used to study the ferromagnetic insulating state in four different manganites. In all cases the coexistence of two types of regions possessing different NMR spectra and nuclear spin dynamics was found. In the ferromagnetic insulating clusters the hopping frequency fhop of the electron holes is slower comparing to the NMR frequency fres and two l

T. Mizushima, K. Machida, T. Kita

The structure and stability of various vortices in F=1 spinor Bose-Einstein condensates are investigated by solving the extended Gross-Pitaevskii equation under rotation. We perform an extensive search for stable vortices, considering both axisymmetric and non-axisymmetric vortices and covering a wide range of ferromagnetic and antiferromagnetic interactions

T. Kuroda, S. Sanguinetti, M. Gurioli, K. Watanabe

Photoemission from a single self-organized GaAs/AlGaAs quantum dot (QD) is temporally resolved with picosecond time resolution. The emission spectra consisting of the multiexciton structures are observed to depend on the delay time and the excitation intensity. Quantitative agreement is found between the experimental data and the calculation based on a model

A. A. Golubov, M. Yu. Kupriyanov, Ya. V. Fominov

Various types of the current-phase relation I(phi) in superconductor-ferromagnet-superconductor (SFS) point contacts and planar double-barrier junctions are studied within the quasiclassical theory in the limit of thin diffusive ferromagnetic interlayers. The physical mechanisms leading to highly nontrivial I(phi) dependence are identified by studying the sp

David M. Rothstein, Stephen S. Eikenberry

We report the discovery of fast (~ 100 sec) 2.2 micron flares from the microquasar GRS 1915+105, which are superimposed on longer (~ 30 min), brighter flares corresponding to episodes of jet formation. The number and strength of the sub-flares in each bright flare varies, and does not seem to correlate in any obvious way with the underlying light curve or wi

D. Watson, J. N. Reeves, J. Osborne, P. T. O&#39;Brien

The X-ray afterglows of GRB 001025A and GRB 010220 were detected by XMM-Newton with an average 0.2--10.0 keV flux of 4.4 and 3.3x10^{-14} erg cm^{-2} s^{-1} respectively; the afterglow of GRB 001025A is observed to decay. Afterglows at other wavelengths were not detected for either burst. A set of broadened soft X-ray emission lines are detected in the after

Bradley M. Peterson

The black-hole/accretion-disk paradigm for active galactic nuclei (AGNs) is now reasonably secure, but there are still important unresolved issues, some of which will require the capabilities of an 8 to 10-m class UV/optical space-based telescope. Imaging spectroscopy with a diffraction-limited large telescope will be required to measure AGN black-hole masse

Daniel C. Homan, John F. C. Wardle, Chi C. Cheung, David H. Roberts

The gamma-ray blazar PKS 1510-089 has a highly superluminal milli-arcsecond jet at a position angle (PA) of -28 degrees and an arcsecond jet with an initial PA of 155 degrees. With a PA difference of 177 degrees between the arcsecond and milli-arcsecond jets, PKS 1510-089 is perhaps the most highly misaligned radio jet ever observed and serves as a graphic e

B. M. Peterson, the International AGN Watch

We present the final installment of an intensive 13-year study of variations of the optical continuum and broad H-beta emission line in the Seyfert 1 galaxy NGC 5548. The data base consists of 1530 optical continuum measurements and 1248 H-beta measurements. The H-beta variations follow the continuum variations closely, with a typical time delay of about 20

D. Wittman

Weak lensing review at the first-year graduate student level.

Alberto Rodriguez-Ardila, Sueli M. Viegas, Miriani G. Pastoriza, Lisa Prato

We report spectroscopic observations in the wavelength region 0.8-2.4 microns aimed at detecting near-infrared coronal lines in a sample of 5 narrow-line and 1 broad-line Seyfert 1 galaxies. Our measurements show that [SiVI] 1.963mu, [SIX] 1.252mu and [SVIII] 0.991mu are present in most of the objects and are useful tracers of nuclear activity. Line ratios b

Riccardo Scarpa, Gianni Marconi, Roberto Gilmozzi

A pilot experiment suitable to test Newton&#39;s law of gravity down to the regime of acceleration typical of galaxies has been carried out in Omega Centauri. Stars in the extreme periphery of this globular cluster are used as test particles immersed in such weak gravitational field. The stellar velocity dispersion is found to remain constant at large radii,

A. Del Popolo

In this paper, I use the extension of the excursion set model of Sheth & Tormen (2002) and the barrier shape obtained in Del Popolo & Gambera (1998) to calculate the unconditional halo mass function, and the conditional mass function in several cosmological models. I show that the barrier obtained in Del Popolo & Gambera (1998), which takes account of tidal

D. Farrah, W. P. S Meikle, D. Clements, M. Rowan-Robinson

We examine the host galaxies of high redshift type Ia supernovae (SNe Ia) using archival I and R band data from the Hubble Space Telescope. The SNe Ia host galaxies show a wide variety of morphologies, including undisturbed ellipticals, spirals and disturbed systems. SNe Ia are also found over a wide range of projected distances from the host galaxy centres,

A. W. A. Pauldrach, T. L. Hoffmann, R. H. Méndez

Recent advances in the modelling of stellar winds driven by radiation pressure make it possible to fit many wind-sensitive features in the UV spectra of hot stars, opening the way for a hydrodynamically consistent determination of stellar radii, masses, and luminosities from the UV spectrum alone. It is thus no longer necessary to assume a theoretical mass-l

Maurizio Salaris, Leo Girardi

We present a detailed analysis of the behaviour of the Red Clump K-band absolute magnitude (M(K,RC)) in simple and composite stellar populations, in light of its use as standard candle for distance determinations. The advantage of using M(K,RC), following recent empirical calibrations of its value for the solar neighbourhood, arises from its very low sensiti

S. M. Andrievsky, V. V. Kovtyukh, R. E. Luck, J. R. D. Lepine

As a continuation of our previous work, which concerned the radial abundance distribution in the galactic disc over the distances 4-10 kpc this paper presents the first results on the metallicicty in the outer disc (RG > 10 kpc). Based on high-resolution spectra obtained for 19 distant Cepheids we sampled galactocentric distances from 10 to 12 kpc. Combined

Carlos De Breuck, Yuan Tang, A. G. de Bruyn, Huub Rottgering

The 352 MHz Westerbork In the Southern Hemisphere (WISH) survey is the southern extension of the WENSS, covering 1.60 sr between -9 < DEC < -26 to a limiting flux density of ~18 mJy (5sigma). Due to the very low elevation of the observations, the survey has a much lower resolution in declination than in right ascension (54&#34; x 54&#34;cosec(DEC)). A correl

H. Mouri, Y. Taniguchi

Mass segregation in a star cluster is studied in an analytical manner. We consider a two-component cluster, which consists of two types of stars with different masses. Plummer&#39;s model is used for the initial condition. We trace the overall behaviors of the probability distribution functions of the two components and obtain the timescale of mass segregati

W. H. T. Vlemmings, P. J. Diamond, H. J. van Langevelde

We present the first circular polarization measurements of circumstellar water masers around a sample of late-type stars. These observations are used to obtain the magnetic field strength in the water maser region with both an LTE and non-LTE analysis. We find fields from a few hundred milliGauss up to a few Gauss, indicating a solar-type r^(-2) dependence o

W. H. T. Vlemmings

We present the first results of our 3D Monte Carlo maser radiative transfer code, used to model the 1612 MHz OH maser shell and the amplification of emission from the stellar radio-photosphere.

Hyun-chul Lee, Young-Wook Lee, Brad K. Gibson

Theoretical integrated broad-band colors ranging from far-UV to near-IR have been computed for old stellar systems from our evolutionary population synthesis code. These models take into account, for the first time, the detailed systematic variation of horizontal-branch (HB) morphology with age and metallicity. Our models show that some temperature-sensitive

Yoram Lithwick, Peter Goldreich

MHD turbulence consists of waves that propagate along magnetic fieldlines, in both directions. When two oppositely directed waves collide, they distort each other, without changing their respective energies. In weak MHD turbulence, a given wave suffers many collisions before cascading. &#34;Imbalance&#34; means that more energy is going in one direction than

Sungeun Kim, Christopher L. Martin, Antony A. Stark, Adair P. Lane

We present position-velocity strip maps of the Galactic Center region in the CO J=7-6 and J=4-3 transitions observed with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) located at Amundsen-Scott South Pole Station. Emission from the two rotational transitions of 12^CO was mapped at b=0 deg for 3.5 deg > l > -1.5 deg, on a 1&#39; grid w

Lisa Dyson, Matthew Kleban, Leonard Susskind

In this paper we consider the implications of a cosmological constant for the evolution of the universe, under a set of assumptions motivated by the holographic and horizon complementarity principles. We discuss the ``causal patch&#34; description of spacetime required by this framework, and present some simple examples of cosmologies described this way. We

Revaz Ramazashvili

This article revisits Ward identities for disordered interacting normal metals and superconductors. It offers a simple derivation based on gauge invariance and recasts the identities in a new form that allows easy analysis of the quasiparticle charge conservation (as e.g. in a normal metal) or non-conservation (as e.g. in a d-wave superconductor).

Takafumi Kita

This paper studies vortex-lattice phases of rapidly rotating superfluid ^3He based on the Ginzburg-Landau free-energy functional. To identify stable phases in the p-Omega plane (p: pressure; Omega: angular velocity), the functional is minimized with the Landau-level expansion method using up to 3000 Landau levels. This system can sustain various exotic vorti

O. Cakir, E. Ateser, H. Koru

We study scalar leptoquark production at TESLA and CLIC based e-gamma colliders. Both direct and resolved contributions to the cross section are examined. We find that the masses of scalar leptoquarks can be probed up to about 0.9 TeV at TESLA and 2.6 TeV at CLIC.

Itzhak Bars

It is shown that AdS(5)xS(5) supergravity has hitherto unnoticed supersymmetric properties that are related to a hidden 12-dimensional structure. The totality of the AdS(5)xS(5) supergravity Kaluza-Klein towers is given by a single superfield that describes the quantum states of a 12-dimensional supersymmetric particle. The particle has super phase space (X,

E. Gubankova

Using flow equations, we derive an effective quark-quark interaction and obtain the coupled set of gap equations for the condensates of the CFL phase of massless N_f=3 dense QCD. We find two different sources of the infrared cutoff in magnetic interaction. When the penetration depth of the magnetic field inside the superconductor is less than the coherence l

M. Bertola, B. Eynard, J. Harnad

We consider biorthogonal polynomials that arise in the study of a generalization of two--matrix Hermitian models with two polynomial potentials V_1(x), V_2(y) of any degree, with arbitrary complex coefficients. Finite consecutive subsequences of biorthogonal polynomials (`windows&#39;), of lengths equal to the degrees of the potentials, satisfy systems of OD

Andrei Parnachev, Anton V. Ryzhov

We study the AdS/CFT correspondence for string states which flow into plane wave states in the Penrose limit. Leading finite radius corrections to the string spectrum are compared with scaling dimensions of finite R-charge BMN-like operators. We find agreement between string and gauge theory results.

A. Fabbri, D. J. Navarro, J. Navarro-Salas, G. J. Olmo

We analyse the quantum corrected geometry and radiation in the scattering of extremal black holes by low-energy neutral matter. We point out the fact that the correlators of local observables inside the horizon are the same as those of the vacuum. Outside the horizon the correlators at late times are much bigger than those of the (thermal) case obtained negl

D. P. Makhnovskiy, L. V. Panina

The effective permittivity of composites containing ferromagnetic microwires has been analysed within a one-particle approximation, by considering a wire piece as an independent scatterer and solving the scattering problem with the impedance boundary condition. A new integro-differential equation for the current distribution in a wire is obtained, which is v

Justin R. David

We study exact string backgrounds representing a constant magnetic field background in heterotic string theory. These backgrounds are obtained by Kaluza-Klein reduction of a special class of plane wave solutions. For small values of the magnetic field they possess localized closed string tachyons analogous to the Nielsen-Olesen instability of a constant magn

Antonio Dobado, Maria J. Herrero, Wolfgang Hollik, Siannah Penaranda

We investigate the decoupling properties of the Higgs-sector-induced one-loop corrections in the lightest Higgs-boson self-couplings, in the framework of the Minimal Supersymmetric Standard Model (MSSM). The renormalized n-point vertex functions with external Higgs particles in the MSSM and in the SM are derived to the one-loop level and compared in the MA >

Samuli Hemming, Esko Keski-Vakkuri, Per Kraus

We study string theory on the extended spacetime of the BTZ black hole, as described by an orbifold of the SL(2,R) WZW model. The full spacetime has an infinite number of disconnected boundary components, each corresponding to a dual CFT. We discuss the computation of bulk and boundary correlation functions for operators inserted on different components. Str

Kazuki Ohmori

After discussing the general form of the kinetic operator around the tachyon vacuum, we determine the specific form of the pure-ghost kinetic operator Q^ by requiring the twist invariance of the action. We obtain a novel result that the Grassmann-even piece Q_even of Q^ must act differently on GSO(+) sector and on GSO(-) sector to preserve the twist invarian

David V. Bowen, Max Pettini, J. Chris Blades

We have used STIS aboard HST to search for Lyman-alpha (Lya) absorption lines in the outer regions of eight nearby galaxies using background QSOs and AGN as probes. Lya lines are detected within a few hundred km/s of the systemic velocity of the galaxy in all cases. We conclude that a background line-of-sight which passes within 26-200 h-1 kpc of a foregroun

Mark Friesen, Paul Rugheimer, Donald E. Savage, Max G. Lagally

Spins based in silicon provide one of the most promising architectures for quantum computing. A scalable design for silicon-germanium quantum dot qubits is presented. The design incorporates vertical and lateral tunneling. Simulations of a four-qubit array suggest that the design will enable single electron occupation of each dot of a many-dot array. Perform

Yu. G. Naidyuk, O. E. Kvitnitskaya, I. K. Yanson, S. -L. Drechsler

The electron-phonon interaction (EPI) in transition metal diborides TB_2 (T=Zr, Nb, Ta) is investigated by point-contact (PC) spectroscopy. The PC EPI functions were recovered and the EPI parameters lambda<0.1 were estimated for all three compounds. Common and distinctive features between the EPI functions for those diborides are discussed also in connection

Amina Helmi, Simon D. M. White, Volker Springel

We study the formation of the Milky Way&#39;s halo in a $Λ$CDM cosmology by scaling down a high resolution simulation of the formation of a cluster of galaxies. We determine how much phase-space substructure is left over from the objects that merge to build up the present galaxy. We study the debris streams originating from such objects and find that their e

M. Neef, S. Tornow, V. Zevin, G. Zwicknagl

We study the low-temperature behavior of a magnetic impurity which is weakly coupled to correlated conduction electrons. To account for conduction electron interactions a diagrammatic approach in the frame of the 1/N expansion is developed. The method allows us to study various consequences of the conduction electron correlations for the ground state and the

Mathias Th. Keil, Georg G. Raffelt, Hans-Thomas Janka

The neutrino flux and spectra formation in a supernova core is studied by using a Monte Carlo code. The dominant opacity contribution for nu_mu and nu_tau is elastic scattering on nucleons. In addition we switch on or off a variety of processes which allow for the exchange of energy or the creation and destruction of neutrino pairs, notably nucleon bremsstra

L. Amendola, M. Gasperini, D. Tocchini-Valentini, C. Ungarelli

We estimate the growth of matter perturbations in a class of recently proposed dark-energy models based on the (loop-corrected) gravi-dilaton string effective action, and characterized by a global attractor epoch in which dark-matter and dark-energy density scale with the same effective equation of state. Unlike most dark-energy models, we find that the acce

V. V. Gvaramadze, A. A. Vikhlinin

We report the results of a search for a point X-ray source (stellar remnant) in the southwest protrusion of the supernova remnant G 315.4-2.30 (MSH 14-63, RCW 86) using the archival data of the Chandra X-ray Observatory. The search was motivated by a hypothesis that G 315.4-2.30 is the result of an off-centered cavity supernova explosion of a moving massive

Metin Arik, Ozgur Delice

We present cylindrically symmetric, static solutions of the Einstein field equations around a line singularity such that the energy momentum tensor corresponds to infinitely thin photonic shells. Positivity of the energy density of the thin shell and the line singularity is discussed. It is also shown that thick shells containing mostly radiation are possibl

Ph. Boucaud, F. De Soto, A. Le Yaouanc, J. P. Leroy

We give a more transparent understanding of the vacuum expectation value of the renormalised local operator A^2 by relating it to the gluon propagator integrated over the momentum. The quadratically divergent perturbative contribution is subtracted and the remainder, dominantly due to the O(1/p^2) correction to the perturbative propagator at large p^2 is log

T. Sasagawa, P. K. Mang, O. P. Vajk, A. Kapitulnik

Although La(2)Cu(1-x)Li(x)O(4) [Li-LCO] differs from La(2-x)Sr(x)CuO(4) [Sr-LCO] in many ways (e.g., the absence of metallic transport, high-Tc superconductivity, and incommensurate antiferromagnetic correlations), it has been known that certain magnetic properties are remarkably similar. The present work establishes the detailed bulk magnetic phase diagram

P. Baseilhac, K. Koizumi

The sine-Gordon model on the half-line with a dynamical boundary introduced by Delius and one of the authors is considered at quantum level. Classical boundary conditions associated with classical integrability are shown to be preserved at quantum level too. Non-local conserved charges are constructed explicitly in terms of the field and boundary operators.