December 2001 arXiv papers — page 27

X. F. Wang, M. S. Kushwaha, P. Vasilopoulos

A theoretical investigation is made of acoustic wave propagation in a periodically stubbed waveguide. In general the waveguide segments and stubs are made of different materials. The acoustic wave in such a system has two independent polarizations: out-of-plane and in-plane modes. The band structure and transmission spectrum is studied for diverse geometries

Uwe Brodatzki, Klaus Mecke

The phase behavior of colloidal particles embedded in a binary fluid is influenced by wetting layers surrounding each particle. The free energy of the fluid film depends on its morphology, i.e., on size, shape and connectivity. Under rather natural assumptions a general expression for the Hamiltonian can be given extending the model of hard spheres to partia

A. M. Tsvelik

I elaborate on the earlier suggestion that the model describing the plateaux transition in Integer Quantum Hall effect scales to a particular point on the line of critical points of a theory with a higher symmetry

G. V. Bicknell, J. K. Li

The nonthermal filaments in the Galactic Center constitute one of the great mysteries of this region of the Galaxy. We summarise the observational data on these filaments and critically review the various theories which currently outnumber the observed filaments. We summarise out theory for the longest of these filaments, the Snake, and discuss the relevance

M. S. E. Roberts, C. Tam, V. M. Kaspi, M. Lyutikov

We present high-resolution radio and X-ray studies of the composite supernova remnant G11.2-0.3. Using archival VLA data, we perform radio spectral tomography to measure for the first time the spectrum of the shell and plerion separately. We compare the radio morphology of each component to that observed in the hard and soft Chandra X-ray images. We measure

A. D. Miller

Since the discovery of the Cosmic Microwave Background (CMB) in 1965, characterization of the CMB anisotropy angular power spectrum has become somewhat of a holy grail for experimental cosmology. Because CMB anisotropy measurements are difficult, the full potential of the CMB is only now being realized. Improvements in experimental techniques and detector te

Larry Wasserman, Christopher J. Miller, Robert C. Nichol, Chris Genovese

We discuss non-parametric density estimation and regression for astrophysics problems. In particular, we show how to compute non-parametric confidence intervals for the location and size of peaks of a function. We illustrate these ideas with recent data on the Cosmic Microwave Background. We also briefly discuss non-parametric Bayesian inference.

Christopher J. Miller, Robert C. Nichol, Christopher Genovese, Larry Wasserman

We examine Cosmic Microwave Background (CMB) temperature power spectra from the BOOMERANG, MAXIMA, and DASI experiments. We non-parametrically estimate the true power spectrum with no model assumptions. This is a significant departure from previous research which used either cosmological models or some other parameterized form (e.g. parabolic fits). Our non-

Koji Mukai

In cataclysmic variables (CVs), accretion onto white dwarfs produces high temperature, high density plasmas. They cool down from kT~10 keV via bremsstrahlung continuum and K and L shell line emissions. The small volume around white dwarfs means that the plasma densities are much higher than in, e.g., stellar coronae, probably beyond the range well-described

Frederick D. Seward

A neutron star with mass close to the lower limit might be a reasonable model for some anomalous pulsars. Emission is thermal. X-ray luminosity is high. Spatial velocity can be high. Since the radius is predicted to be large, the magnetic field calculated for spin-down is lower than that required by the magnetar model.

M. A. Malkov, P. H. Diamond, T. W. Jones

The theory of shock acceleration predicts the maximum particle energy to be limited only by the acceleration time and the size (geometry) of the shock. This led to optimistic estimates for the galactic cosmic ray energy achievable in the SNR shocks. The estimates imply that the accelerated particles, while making no strong impact on the shock structure (test

M. B. Bell

It was previously shown from the redshifts and positions of the compact, high-redshift objects near the Seyfert galaxy NGC 1068 that they appear to have been ejected from the center of the galaxy in at least four similarly structured triplets. Here some of the consequences of assuming such a local model for QSOs are examined. From the ages of the ejection ev

M. Klein-Wolt, R. P. Fender, G. G. Pooley, T. Belloni

We have compared simultaneous Ryle Telescope radio and Rossi X-Ray Timing Explorer X-ray observations of the galactic microquasar GRS 1915+105, using the classification of the X-ray behaviour in terms of three states as previously established. We find a strong (one-to-one) relation between radio oscillation events and series of spectrally hard states in the

M. E. Kasper, M. Feldt, T. M. Herbst, S. Hippler

The small separation of the individual stellar components in the TTau system has prevented spectroscopy of the individual components in the near-infrared (NIR) in the past. We present NIR data (H- and K-band) on this object taken using the ALFA adaptive optics (AO) system in combination with the 3D integral field spectrograph. Except for the Brackett series

Shanil N. Virani, Paul P. Plucinsky, Catherine E. Grant, Beverly LaMarr

The MIT and CXC ACIS teams have explored a number of measures to ameliorate the effects of radiation damage suffered by the ACIS FI CCDs. One of these measures is a novel CCD read-out method called ``squeegee mode''. A variety of different implementations of the squeegee mode have now been tested on the I0 CCD. Our results for the fitted FWHM at Al-K

N. Ivanova, Ph. Podsiadlowski

We study the nucleosynthesis and the induced mixing during the merging of massive stars inside a common envelope. The systems of interest are close binaries, initially consisting of a massive red supergiant and a main-sequence companion of a few solar masses. We apply parameterized results based on hydrodynamical simulations to model the stream-core interact

B. F. Collins, E. V. Gotthelf, D. J. Helfand

We have observed the young Galactic supernova remnant Kes 75 with the Chandra X-ray Observatory. This object is one of an increasing number of examples of a shell-type remnant with a central extended radio core harboring a pulsar. Here we present a preliminary spatially resolved spectroscopic analysis of the Kes~75 system. We find that the spectrum of the pu

Melissa A. McGrath, Edmund Nelan, David C. Black, George Gatewood

Doppler spectroscopy of rho1 Cnc has detected evidence of a companion with an orbital period of 14.65 days and a minimum mass of 0.88 Jupiter masses. Astrometric observations performed with the Hubble Space Telescope Fine Guidance Sensor 1r using a novel new observing technique have placed an upper limit on the astrometric reflex motion of rho1 Cnc in a time

J. V. Arnau, A. M. Aliaga, D. Saez

This paper is concerned with small angular scale experiments for the observation of cosmic microwave background anisotropies. In the absence of beam, the effects of partial coverage and pixelisation are disentangled and analyzed (using simulations). Then, appropriate maps involving the CMB signal plus the synchrotron and dust emissions from the Milky Way are

H. J. G. L. M. Lamers, N. Panagia, S. Scuderi, M. Romaniello

We studied the HST-WFPC2 observations of the inner kpc of the interacting galaxy M51 in six bands from 2550 to 8140 Angstrom. The images show an oval shaped area ("bulge") of 11x16 arcsec or 450x650 pc around the nucleus, dominated by a smooth population of old stars with overimposed dust lanes. We found 30 bright point-like sources in the bulge of M

Sangwook Park, Peter W. A. Roming, John P. Hughes, Patrick O. Slane

We present results from the observation of the young Galactic supernova remnant (SNR) G292.0+1.8 with the Advanced CCD Imaging Spectrometer (ACIS) on board the {\it Chandra X-ray Observatory}. In the 0.3 $-$ 8 keV band, the high resolution ACIS images reveal a complex morphology consisting of knots and filaments, as well as the blast wave around the peripher

O. Zanotti, L. Rezzolla

We have solved numerically the general relativistic induction equations in the interior background spacetime of a slowly rotating magnetized neutron star. The analytic form of these equations was discussed in a recent paper (Rezzolla et al 2001a), where corrections due both to the spacetime curvature and to the dragging of reference frames were shown to be p

M. Persic, Y. Rephaeli

X-ray emission processes in starburst galaxies (SBGs) are assessed, with the aim of identifying and characterizing the main spectral components. Our survey of spectral properties, complemented with a model for the evolution of galactic stellar populations, leads to the prediction of a complex spectrum. Comparing the predicted spectral properties with current

R. F. Coker, J. M. Pittard, J. H. Kastner

IRS 13E is an infrared, mm and X-ray source in the Galactic Centre. We present the first Chandra X-ray spectrum for IRS 13E and show that it is consistent with a luminous and highly absorbed X-ray binary system. Since the X-ray luminosity is too large for a solitary star, our interpretation is that of an early-type long-period binary with strong colliding wi

L. S. Pilyugin, Mercedes Molla, Federico Ferrini, Jose M. Vilchez

The oxygen and nitrogen abundances in the HII regions of the nine Virgo spirals of the sample from Skillman et al (1996) and in nine field spiral galaxies are re-determined with the recently suggested P - method. We confirm that there is an abundance segregation in the sample of Virgo spirals in the sense that the HI deficient Virgo spirals near the core of

H. Netzer, D. Chelouche, I. M. George, T. J. Turner

A new Chandra observation and archival observations by ASCA are used to investigate spectral variations in the Sy1 galaxy NGC 3516 over a period of 7 years. A large change in flux (factor ~50 at 1keV) is observed between an ASCA observation in '94 and the Chandra observation in 2000, with the source close to the all-time maximum and minimum X-ray flux st

Kevin A. Pimbblet

I discuss the remit of Starlink's software strategy groups and a particular item on the agenda of a meeting of the image processing software strategy group held on 26th January 2001: `Why don't people use Starlink software?'. The answer to this question was speculated to be primarily a sociological effect: those people supervising UK astronomy Ph

V. F. Cardone, S. Capozziello, V. Re, E. Piedipalumbo

We present a new method to estimate the Hubble constant H_0 from the measured time delays in quadruply imaged gravitational lens systems. We show how it is possible to get an estimate of H_0 without the need to completely reconstruct the lensing potential thus avoiding any a priori hypotheses on the expression of the galaxy lens model. Our method only needs

N. Bucciantini

We present hydrodynamical simulations, using a 2-D two fluid model, of bow shocks in a representative regime for pulsar wind driven bow-shock nebulae. We also investigate the behaviour of a passive toroidal magnetic field wounded around the pulsar velocity direction. Moreover we estimate the opacity of the bow-shock to penetration of ISM neutral hydrogen. Fi

Joop Schaye

It is shown that many properties of Ly-alpha forest absorbers can be derived using simple physical arguments. Analytical expressions are derived for the density and the size of an absorber as a function of its neutral hydrogen column density, which agree well with both observations and hydrodynamical simulations. An expression is presented to compute Omega_I

Leonid A. Levin, Ramarathnam Venkatesan

NP-complete problems should be hard on some instances but those may be extremely rare. On generic instances many such problems, especially related to random graphs, have been proven easy. We show the intractability of random instances of a graph coloring problem: this graph problem is hard on average unless all NP problem under all samplable (i.e., generatab

Changhyun Ahn, Taichi Itoh

It was found that deformation of S^7 gives rise to renormalization group(RG) flow from N=8, SO(8)-invariant UV fixed point to N=1, G_2-invariant IR fixed point in four-dimensional gauged N=8 supergravity. Also BPS supersymmetric domain wall configuration interpolated between these two critical points. In this paper, we use the G_2-invariant RG flow equations

M. M. Tsypin

For systems in the universality class of the three-dimensional Ising model we compute the critical exponents in the local potential approximation (LPA), that is, in the framework of the Wegner-Houghton equation. We are mostly interested in antisymmetric corrections to scaling, which are relatively poorly studied. We find the exponent for the leading antisymm

Daniele Fargion, P. G. De Sanctis Lucentini, M. Grossi, M. De Santis

The Ultra High Energy Cosmic Ray (UHECR), by UHE neutrino-relic neutrino--Z showering in Hot Dark Halos (HDM), shows an energy spectra, an anisotropy following the relic neutrino masses and clustering in dark halo. The lighter are the relic neutrinos masses, the higher their corresponding Z resonance energy peaks. A twin light neutrino mass splitting may ref

A. D. Alhaidari

Dirac equation for a charged spinor in electromagnetic field is written for special cases of spherically symmetric potentials. This facilitates the introduction of relativistic extensions of shape invariant potential classes. We obtain the relativistic spectra and spinor wavefunctions for all potentials in one of these classes. The nonrelativistic limit repr

John R. Klauder

Phase space is the state space of classical mechanics, and this manifold is normally endowed only with a symplectic form. The geometry of quantum mechanics is necessarily more complicated. Arguments will be given to show that augmenting the symplectic manifold of classical phase space with a Riemannian metric is sufficient for describing quantum mechanics. I

Valia Allori, Nino Zangh\`ı

Contrary to the widespread belief, the problem of the emergence of classical mechanics from quantum mechanics is still open. In spite of many results on the $\h \to 0$ asymptotics, it is not yet clear how to explain within standard quantum mechanics the classical motion of macroscopic bodies. In this paper we shall analyze special cases of classical behavior

Valia Allori, Nino Zangh\`ı

Bohmian mechanics is a quantum theory with a clear ontology. To make clear what we mean by this, we shall proceed by recalling first what are the problems of quantum mechanics. We shall then briefly sketch the basics of Bohmian mechanics and indicate how Bohmian mechanics solves these problems and clarifies the status and the role of of the quantum formalism

Alec Maassen van den Brink

Recently, the paper B. Georgeot and D.L. Shepelyansky, Phys. Rev. Lett._86_, 5393 (2001) has been criticized [C. Zalka, quant-ph/0110019; L. Di'osi, quant-ph/0110026]. The Letter claims an exponential speedup and reduction in error sensitivity, when phase-space density evolution under the Arnold cat map is performed on a quantum computer. On the one hand

Valia Allori, Detlef Dürr, Shelly Goldstein, Nino Zanghí

Classical physics is about real objects, like apples falling from trees, whose motion is governed by Newtonian laws. In standard Quantum Mechanics only the wave function or the results of measurements exist, and to answer the question of how the classical world can be part of the quantum world is a rather formidable task. However, this is not the case for Bo

V O Hnatovsky, C V Usenko

Electron wave function entanglement and spin reconfiguration as source of electron correlation are investigated. Properties of correlation function are shown to have the best concordance with experimental data under supposition that probability of change of electron state to triplet state is about 0.5 or more.

I. Yu. Fedorov

Divisorial contractions to singularities, defined by equations $xy+z^n+u^n=0$ $n\ge3$ and $xy+z^3+u^4=0$ are classified.

Thomas Schlumprecht, Vladimir G. Troitsky

We show that C.J.Read's example of an operator T on l_1 which does not have any non-trivial invariant subspaces is not the adjoint of an operator on a predual of l_1. Furthermore, we present a bounded diagonal operator D such that even though its inverse is unbounded, but D^{-1}TD is a bounded operator with invariant subspaces, and is adjoint to an opera

Marek Czachor, Monika Syty

A harmonic oscillator is an indefinite-frequency one if the parameter $ω$ is replaced by an operator. An ensemble of $N$ such oscillators may be regarded as a toy model of a bosonic quantum field. All the possible frequencies associated with a given problem are present already in a single oscillator and $N$ can be finite. Due to the operator character of $ω$

Pedro Bicudo, Stephen Cotanch, Felipe Llanes-Estrada, Pieter Maris

Weinberg's theorem for π-πscattering, including the Adler zero at threshold in the chiral limit, is analytically proved for microscopic quark models that preserve chiral symmetry. Implementing Ward-Takahashi identities, the isospin 0 and 2 scattering lengths are derived in exact agreement with Weinberg's low energy results. Our proof applies to alter

M. Battaglia, A. De Roeck, J. Ellis, F. Gianotti

We introduce a set of CMSSM benchmark scenarios that take into account the constraints from LEP, Tevatron, $b \to s γ$, $g_μ- 2$ and cosmology. The benchmark points are chosen to span the range of different generic possibilities, including focus-point models, points where coannihilation effects on the relic density are important, and points with rapid relic

Satoru Watanabe, Hiromoto Shibahashi

We reexamine the theoretical limit on the axion coupling to two photons, $g_{aγγ}$, in the light of a new solar model (seismic solar model) and the latest solar neutrino observations, the Super-Kamiokande and the Sudbury Neutrino Observatory (SNO). From the comparison of the theoretically expected and the measured neutrino fluxes, we set a limit $g_{aγγ} < 4

G. Eilam, M. Ladisa, Y. D. Yang

We evaluate the form factors describing the semileptonic decays $\bar{B^0}\to J/ψ(η_c) D^+ \ell^- \bar ν_\ell$, within the framework of a QCD relativistic potential model. This decay is complementary to $\bar{B^0}\to J/ψ(η_c) D^+ π^-$ in a phase space region where a pion factors out.We estimate the branching ratio for these semileptonic and nonleptonic chann

Alexander Kusenko

Electroweak baryogenesis could be very efficient at the end of an electroweak-scale inflation. Reheating that followed inflation could create a highly non-equilibrium plasma, in which the baryon number violating transitions were rapid. In addition, the time-dependent motions of the scalar degrees of freedom could provide the requisite CP violation. If the fi

Daniele Fargion

Upward and Horizontal Tau Air-showers (UPTAUS and HORTAUS) emerging from the Earth crust, mountain chains or deep plate boundaries are the most powerful signals of Ultra High Energy UHE anti neutrinos electron at PeV and neutrino and anti-neutrino tau at energies near and above 10^15-10^19 eV. The large tau Air-showers multiplicity N in secondaries N_opt =10

Jonathan P. K. Doye, Florent Calvo

We examine in detail the causes of the structural transitions that occur for those small Lennard-Jones clusters that have a non-icosahedral global minima. Based on the principles learned from these examples we develop a method to construct structural phase diagrams that show in a coarse-grained manner how the equilibrium structure of large clusters depends o

Yi Xiao, David A. Huse, Paul M. Chaikin, Mark J. Higgins

We measure resistively the mean-field superconducting-normal phase boundaries of both kagome and honeycomb wire networks immersed in a transverse magnetic field. In addition to their agreement with theory about the overall shapes of phase diagrams, they show striking one-to-one correspondence between the cusps in the honeycomb and kagome phase boundaries. Th

P. Pfalzer, J. Will, A. Nateprov, M. Klemm

The local structure of (Al_0.06V_0.94)_2O_3 in the paramagnetic insulating (PI) and antiferromagnetically ordered insulating (AFI) phase has been investigated using hard and soft x-ray absorption techniques. It is shown that: 1) on a local scale, the symmetry of the vanadium sites in both the PI and the AFI phase is the same; and 2) the vanadium 3d - oxygen

A. Langari

We have studied the collective phenomena of multicomponent glasses at ultra low temperatures [Strehlow, et. al, Phys. Rev. Lett 80, 5361 (1998)] by taking into account the proper interaction between tunneling centers. We have considered both double and triple well potentials with different types of interactions. We show that a phase with coherent motion appe

Kwon Park, Subir Sachdev

We describe the zero temperature phases and phase boundaries of an effective lattice model for frustrated, easy-plane, spin S=1/2 quantum antiferromagnets. The model contains states with Neel and bond-centered charge order and fractionalization in different limiting regimes, and we describe how these orders compete at intermediate coupling. The complex Berry

E. V. Gotthelf, W. Zhang, F. E. Marshall, J. Middleditch

We are undertaking an extensive X-ray monitoring campaign of the two Crab-like pulsars in the Large Magellanic Clouds, PSR B0540-69 and PSR J0537-6910. We present our current phase-connected timing analysis derived from a set of 50 pointed X-ray observations spanning several years. From our initial 1.2 yr monitoring program of the young 50 ms pulsar PSR B054

J. Craig Wheeler, David L. Meier, James R. Wilson

Strong toroidal magnetic fields generated in stellar collapse can generate magneto-centrifugal jets in analogy to those found in simulations of black hole accretion and explain why all core collapse supernovae are found to be substantially asymmetric and predominantly bi-polar. We describe two phases: the initial LeBlanc-Wilson jet and a subsequent protopuls

E. V. Gotthelf, F. P. Gavriil, V. M. Kaspi, G. Vasisht

We report on a long-term monitoring campaign of 1E 1841-045, the 12-s anomalous X-ray pulsar and magnetar candidate at the center of the supernova remnant Kes 73. We have obtained approximately monthly observations of the pulsar with the Rossi X-ray Timing Explorer spanning over two years, during which time 1E 1841-045 is found to be rotating with sufficient

A. Olech, M. Wisniewski, M. Gajos

The summary of 1996-1998 visual observations collected by the Polish Comets and Meteors Workshop is presented. In total, during 2328.12 effective observing hours 14085 meteors were seen and plotted onto gnomonic starmaps by 41 observers. The date, time, magnitude, angular velocity and equatorial coordinates for each observed event are given. The full 1996--1

F. R. Ferraro, E. Pancino, M. Bellazzini

In this contribution we schematically summarize a number of ongoing, coordinated spectro-photometric projects devoted to the study of the stellar population properties in Omega Cen. All of these investigations are part of a global comprehensive project led by our team to address the complex formation history of stars in this cluster.

Elena Pancino

In this contribution I am going to present some preliminary results of a high-resolution spectroscopic campaign focussed on the most metal rich red giant stars in Omega Cen. This study is part of a long term project we started a few years ago, which is aimed at studying the properties of the different stellar populations in Omega Cen. The final goal of the w

J. Y. Wei, X. J. Jiang, D. W. Xu, A. Y. Zhou

1RXS J232953.9+062814 was identified as a cataclysmic variable by Wei et al. (1999). Four low-resolution spectra of 1RXS J232953.9+062814 were obtained by using the 2.16-m telescope of the National Astronomical Observatories, in which two of them were at outburst, and the other two were at quiescence. The system is about 16.8 B and 16.5 V at quiescence, and

N. Murray, M. Holman

Our understanding of the Solar System has been revolutionized over the past decade by the finding that the orbits of the planets are inherently chaotic. In extreme cases, chaotic motions can change the relative positions of the planets around stars, and even eject a planet from a system. Moreover, the spin axis of a planet-Earth&#39;s spin axis regulates our

Man Hoi Lee, S. J. Peale

(Abridged) A dynamical fit has placed the two planets about the star GJ 876 in coplanar orbits deep in 3 resonances at the 2:1 mean-motion commensurability with small libration amplitudes. The libration of both lowest order mean-motion resonance variables, theta_1 and theta_2, and the secular resonance variable, theta_3, about 0 deg. differs from the familia

Y. B. Lyanda-Geller, I. L. Aleiner, B. L. Altshuler

We study the mechanism of nuclear spin relaxation in quantum dots due to the electron exchange with 2D gas. We show that the nuclear spin relaxation rate is dramatically affected by the Coulomb blockade and can be controlled by gate voltage. In the case of strong spin-orbit coupling the relaxation rate is maximal in the Coulomb blockade valleys whereas for t

Matthias Burkardt, Simon Dalley

The formalism for describing hadrons using a light-cone Hamiltonian of SU(N) gauge theory on a coarse transverse lattice is reviewed. Physical gauge degrees of freedom are represented by disordered flux fields on the links of the lattice. A renormalised light-cone Hamiltonian is obtained by making a colour-dielectric expansion for the link-field interactions

I. I. Kogan, A. Nichols

We discuss the partners of the stress energy tensor and their structure in Logarithmic conformal field theories. In particular we draw attention to the fundamental differences between theories with zero and non-zero central charge. However they are both characterised by at least two independent parameters. We show how, by using a generalised Sugawara constru

Katrin Wendland

We discuss geometric aspects of orbifold conformal field theories in the moduli space of N=(4,4) superconformal field theories with central charge c=6. Part of this note consists of a summary of our earlier results on the location of these theories within the moduli space [NW01,Wen] and the action of a specific version of mirror symmetry on them [NW]. We arg

J. D. M. Champion, M. J. Harris, P. C. W. Holdsworth, A. S. Wills

Er_2Ti_2O_7 has been suggested to be a realization of the frustrated < 111 > XY pyrochlore lattice antiferromagnet, for which theory predicts fluctuation-induced symmetry breaking in a highly degenerate ground state manifold. We present a theoretical analysis of the classical model compared to neutron scattering experiments on the real material, both below a

Satoshi Yamaguchi

We apply the coset character identities (generalization of Jacobi&#39;s abstruse identity) to compact and noncompact Gepner models. In the both cases, we prove that the partition function actually vanishes due to the spacetime supersymmetry. In the case of the compact models and discrete parts of the noncompact models, the partition function includes the exp

A. D. Alhaidari

Dirac equation for a charged particle in static electromagnetic field is written for special cases of spherically symmetric potentials. Besides the well known Dirac-Coulomb and Dirac-Oscillator potentials, we obtain a relativistic version of the S-wave Morse potential. This is accomplished by adding a simple exponential potential term to the Dirac operator,

N. van Remortel, B. Buschbeck, F. Mandl

A preliminary investigation of Bose-Einstein correlations in 3 jet events has been made by analysing the collected data at the $Z^0$ peak from &#39;94 and &#39;95 and the calibration runs during the LEP2 period from &#39;97 to 2000. Three methods were used to extract two-particle correlation functions. No significant difference was found between quark and gl

M. H. Dehghani

We consider the Kerr-de Sitter (Kerr-dS) black hole in various dimensions. Introducing a counterterm, we show that the total action of these spacetimes are finite. We compute the masses and the angular momenta of Kerr-dS spaces with one rotational parameter in four, five and seven dimensions. These conserved charges are also computed for the case of Kerr-dS

Pieter Kok, Hwang Lee, Jonathan P. Dowling

Large photon-number path entanglement is an important resource for enhanced precision measurements and quantum imaging. We present a general constructive protocol to create any large photon number path-entangled state based on the conditional detection of single photons. The influence of imperfect detectors is considered and an asymptotic scaling law is deri

N. Paunkovic, Y. Omar, S. Bose, V. Vedral

We propose an entanglement concentration scheme which uses only the effects of quantum statistics of indistinguishable particles. This establishes the fact that useful quantum information processing can be accomplished by quantum statistics alone. Due to the basis independence of statistical effects, our protocol requires less knowledge of the initial state

F. Benamira, L. Guechi

The propagator for a certain class of two time-dependent coupled and driven harmonic oscillators with time-varying angular frequencies and masses is evaluated by path integration. This is simply done through suitably chosen generalized canonical transformations and without presupposing the knownledge of any auxiliary equation. The time-dependent oscillators

Akhlesh Lakhtakia

The canonical problem of a perfect lens with linear bianisotropic materials is formulated. Its solution is shown to be directly connected with the concept of nihility, the electromagnetic nilpotent. Perfect lenses as well as nihility remain unrealizable.

J. M. A. Figueiredo

A study of the non-dissipative Brownian motion in vacuum is presented. The noise source associated to the stochastic process assumed in this work is vacuum fluctuations of some quantum field capable of interact with a massive particle. For the associated Fokker-Planck equation we do a perturbation theory which has terms presenting dynamics similar to that sa

P. N. Bibikov

A new method for solving the Yang-Baxter equation is presented. It is based on the Taylor expansion of R-matrix which is developed up to the power lambda^6. Using this method the R-matrix for integrable spin ladder is calculated.

Vitaly Tarasov

We discuss relations between different integral formulae for solutions of the quantized Knizhnik-Zamolodchikov (qKZ) equation at level zero in the $U_q(sl_2)$ case for $|q|<1$. Smirnov type formulae of M.Jimbo et al. are derived from the general approach of A.Varchenko and the author. The consideration is parallel to the qKZ equation in the rational $sl_2$ c

Jan Maly, David Swanson, William P. Ziemer

We extend Federer&#39;s coarea formula to mappings $f$ belonging to the Sobolev class $W^{1,p}(R^n;R^m)$, $1 \le m < n$, $p>m$, and more generally, to mappings with gradient in the Lorentz space $L^{m,1}(R^n)$. This is accomplished by showing that the graph of $f$ in $R^{n+m}$ is a Hausdorff $n$-rectifiable set.

Cinzia Casagrande

In this paper we study smooth toric Fano varieties using primitive relations and toric Mori theory. We show that for any irreducible invariant divisor D in a toric Fano variety X, we have $0\leqρ_X-ρ_D\leq 3$, for the difference of the Picard numbers of X and D. Moreover, if $ρ_X-ρ_D>0$ (with some additional hypotheses if $ρ_X-ρ_D=1$), we give an explicit bi

Andre Henriques

``An orbifold is a space which is locally modeled on the quotient of a vector space by a finite group.&#39;&#39; This sentence is so easily said or written that more than one person has missed some of the subtleties hidden by orbifolds. Orbifolds were first introduced by Satake under the name ``V-manifold&#39;&#39; and rediscovered by Thurston who called the

Dan Abramovich, Tom Graber, Angelo Vistoli

The purpose of this note is to give an overview of our work on defining algebraic counterparts for W. Chen and Y. Ruan&#39;s Gromov-Witten Theory of orbifolds. This work will be described in detail in a subsequent paper. The presentation here is generally based on lectures given by two of us at the Orbifold Workshop in Madison, Wisconsin. Following the spiri

M. V. Karasev

The notion of quantum embedding is considered for two classes of examples: quantum coadjoint orbits in Lie coalgebras and quantum symplectic leaves in spaces with non-Lie permutation relations. A method for constructing irreducible representations of associative algebras and the corresponding trace formulas over leaves with complex polarization are obtained.

Adil Belhaj

We study Landau Ginzburg (LG) theories mirror to 2D N=2 gauged linear sigma models on toric Calabi-Yau manifolds. We derive and solve new constraint equations for Landau Ginzburg elliptic Calabi-Yau superpotentials, depending on the physical data of dual linear sigma models. In Calabi-Yau threefolds case, we consider two examples. First, we give the mirror s

Sheldon Stone

Many topics are discussed in b physics including lifetimes, decay mechanisms, determinations of the CKM matrix elements |V_{cb}| and |V_{ub}|, facilities for b quark studies, neutral $B$ meson mixing, rare b decays, hadronic decays and CP violation. I review techniques for finding physics beyond the Standard Model and describe the complimentarity of b decay

T. Csorgo, A. Ster

Modelling correlations in heavy ion collisions is reviewed from model independent characterization of the two-particle correlations to Buda-Lund hydro model fits to correlations and spectra in Au + Au collisions at sqrt{s}=130 AGeV at RHIC.

G. Passarino, S. Uccirati

A recently proposed scheme for numerical evaluation of Feynman diagrams is extended to cover all two-loop two-point functions with arbitrary internal and external masses. The adopted algorithm is a modification of the one proposed by F. V. Tkachov and it is based on the so-called generalized Bernstein functional relation. On-shell derivatives of self-energie

J. L. Hewett, F. J. Petriello, T. G. Rizzo

We examine the unitarity properties of spontaneously broken non-commutative gauge theories. We find that the symmetry breaking mechanism in the non-commutative Standard Model of Chaichian et al. leads to an unavoidable violation of tree-level unitarity in gauge boson scattering at high energies. We then study a variety of simplified spontaneously broken non-

J. Bernabeu, S. Palomares-Ruiz

We discuss the possibility to observe matter effects in atmospheric neutrino oscillations. The main conclusion is that an impact on the nu_mu survival probability requires the action of the MSW resonance, which becomes visible for baselines above ~7000 km. The associated muon charge asymmetry carries information on theta_{13} and the sign of Dm^2_{31}.

M. Chertok, G. D. Kribs, Y. Nomura, W. Orejudos

We describe a highly predictive model for supersymmetry breaking in 5 dimensions. We develop its phenomenology and the capabilities for discovery and measurement at various colliders.

Oleg Derzhko

We consider the spin-1/2 XY chain in a transverse field with regularly varying exchange interactions and on-site fields. In two limiting cases of the isotropic XX and extremely anisotropic (Ising) exchange interaction the thermodynamic quantities are calculated rigorously with the help of continued fractions. We discuss peculiarities of the low-temperature m

A. A. Aligia, C. R. Proetto

We study the current through a quantum wire side coupled to a quantum dot, and compare it with the case of an embedded dot. The system is modeled by the Anderson Hamiltonian for a linear chain, with one atom either coupled to (side-dot) or substituted by (embedded dot) a magnetic impurity. For realistic (small) hopping of the dot to the rest of the system, a

Xuedong Hu, Franco Nori

This article discusses quantum fluctuation properties of a crystal lattice, and in particular, phonon squeezed states. Squeezed states of phonons allow a reduction in the quantum fluctuations of the atomic displacements to below the zero-point quantum noise level of coherent phonon states. Here we discuss our studies of both continuous-wave and impulsive sec

Gianfranco D&#39;Anna, Franco Nori

We investigate the Portevin-Le Chatelier effect (PLC), by compressing Al-Mg alloys in a very large deformation range, and interpret the results from the viewpoint of phase transitions and critical phenomena. The system undergoes two dynamical phase transitions between intermittent (or &#34;jerky&#34;) and &#34;laminar&#34; plastic dynamic phases. Near these

A. A. Shashkin, S. V. Kravchenko, V. T. Dolgopolov, T. M. Klapwijk

We find that at intermediate temperatures, the metallic temperature dependence of the conductivity σ(T) of 2D electrons in silicon is described well by a recent interaction-based theory of Zala et al. (Phys. Rev. B 64, 214204 (2001)). The tendency of the slope dσ/dT to diverge near the critical electron density is in agreement with the previously suggested f

F. -X. Desert, A. Benoit, Ph. Camus, M. Giard

The millimetric atmospheric windows at 1 and 2 mm are interesting targets for cosmological studies. Two broad areas appear leading this field: 1) the search for high redshift star-forming galaxies and 2) the measurement of Sunyaev-Zel&#39;dovich (SZ) effect in clusters of galaxies at all redshifts. The Diabolo photometer is a dual-channel photometer working

A. Benoit, the Archeops Collaboration

The Cosmic Microwave Background Radiation is the oldest photon radiation that can be observed, having been emitted when the Universe was about 300,000 year old. It is a blackbody at 2.73 K, and is almost perfectly isotropic, the anisotropies being about one part to 100,000. However, these anisotropies, detected by the COBE satellite in 1992, constrain the co

J. H. Knapen, J. E. Beckman, I. Shlosman, T. J. Mahoney

We describe selected highlights of the international conference ``The Central Kiloparsec of Starbursts and AGN: The La Palma Connection&#39;&#39;, held in May 2001 in Los Cancajos on the Spanish island of La Palma.