May 2003 arXiv papers — page 24

M. G. Vavilov, L. I. Glazman, A. I. Larkin

We consider the effect of the RKKY interaction between magnetic impurities on the electron relaxation rates in a normal metal. The interplay between the RKKY interaction and the Kondo effect may result in a non-monotonic temperature dependence of the electron momentum relaxation rate, which determines the Drude conductivity. The electron phase relaxation rat

Yacov Kantor, Mehran Kardar

We investigate the probability for appearance of knots in self-avoiding loops (SALs) on a cubic lattice. A set of N-step loops is generated by attempting to combine pairs of (N/2)-step self-avoiding walks constructed by a dimerization method. We demonstrate that our method produces unbiased samples of SALs, and study the knot formation probability as a funct

V. V. Bazhanov, S. L. Lukyanov, A. M. Tsvelik

Using the approach alternative to the traditional Thermodynamic Bethe Ansatz, we derive analytical expressions for the free energy of Coqblin-Schrieffer model with arbitrary magnetic and crystal fields. In Appendix we discuss two concrete examples including the field generated crossover from the SU(4) to the SU(2) symmetry in the SU(4)-symmetric model.

M. Wouters, J. Tempere, J. T. Devreese

Strongly confining an ultracold atomic gas in one direction to create a quasi-2D system alters the scattering properties of this gas. We investigate the effects of confinement on Feshbach scattering resonances and show that strong confinement results in a shift in the position of the Feshbach resonance as a function of the magnetic field. This shift, as well

Farshid Mohammad-Rafiee, Ramin Golestanian

The electrostatic contribution to twist rigidity of DNA is studied, and it is shown that the Coulomb self-energy of the double-helical sugar-phosphate backbone contributes considerably to twist rigidity of DNA--the electrostatic twist rigidity of DNA is found as $C_{\rm elec}\approx 5$ nm, which makes up about 7% of its total twist rigidity ($C_{\rm DNA}\app

D. B. Lukatsky, G. Haran, S. A. Safran

We propose an explanation for the recently measured slow fluctuations and ``blinking'' in the surface enhanced Raman scattering (SERS) spectrum of single molecules adsorbed on a silver colloidal particle. We suggest that these fluctuations may be related to the dynamic relaxation of the surface roughness on the nanometer scale and show that there are

Sumiyoshi Abe

Given an original distribution, its statistical and probabilistic attributs may be scanned by the associated escort distribution introduced by Beck and Schlogl and employed in the formulation of nonextensive statistical mechanics. Here, the geometric structure of the one-parameter family of the escort distributions is studied based on the Kullback-Leibler di

B. Hamprecht, H. Kleinert

We set up recursion relations for calculating all even moments of the end-to-end distance of a Porod-Kratky wormlike chains in $D$ dimensions. From these moments we derive a simple analytic expression for the end-to-end distribution in three dimensions valid for all peristence lengths. It is in excellent agreement with Monte Carlo data for stiff chains and g

Cathie J. Clarke, Volker Bromm

We present a model for the star formation process during the initial collapse of dark matter haloes at redshifts z=0-30. We derive a simple expression for the characteristic stellar mass scale during this initial burst of star formation. In our picture, this characteristic scale reflects both the minimum temperature to which the gas can cool (determined by t

A. V. Olinto

We give a brief overview of the highest energy messengers: very high energy photons, neutrinos, and ultra-high energy cosmic rays. The mysterious workings of the extreme universe should soon be unveil with new observatories now under construction.

P. Thomasson, D. J. Saikia, T. W. B. Muxlow

Multifrequency radio observations of the radio galaxy 3C459 using MERLIN, VLA and the EVN, and an optical HST image using the F702W filter are presented. The galaxy has a very asymmetric radio structure, a high infrared luminosity and a young stellar population. The eastern component of the double-lobed structure is brighter, much closer to the nucleus and i

T. Kato, K. Haseda

HadV98 = CoD-22 12017 = GSC 6825.253 is a variable star discovered by Katsumi Haseda. This object has been recently confirmed to be a new R CrB star (Hasselbach et al. 2002), as had been originally proposed by us at the time of the discovery alert in VSNET. We studied the light curve based on Haseda's photographic material and ASAS-3 V-band data. There w

Klaus Kroy, Xiang Guo

In a recent experimental breakthrough, Hersen et al. [1] demonstrated that by changing the agitating medium from air to water, one can obtain, on laboratory scale, dunes that are downsized copies of desert dunes, thereby overcoming a major obstacle for their systematic study. Here we argue in two steps (i),(ii) that an alternative data analysis leads to some

R. Lednicky

Recent results on particle momentum and spin correlations are discussed in view of the role played by the effects of quantum statistics, including multiboson and coherence phenomena, and final state interaction. Particularly, it is demonstrated that the latter allows for (i) correlation femtoscopy with unlike particles; (ii) study of the relative space--time

D. M. Ghilencea

Using an effective field theory approach, we address the effects on the gauge couplings of one and two additional compact dimensions in the presence of a constant background (gauge) field. Such background fields are a generic presence in models with extra dimensions and can be employed for gauge symmetry breaking mechanisms in the context of 4D N=1 supersymm

Karl Jansen, Kei-ichi Nagai

It has been suggested to project out a number of low-lying eigenvalues of the four-dimensional Wilson--Dirac operator that generates the transfer matrix of domain-wall fermions in order to improve simulations with domain-wall fermions. We investigate how this projection method reduces the residual chiral symmetry-breaking effects for a finite extent of the e

Jian-Qi Shen, Hong-Yi Zhu

By using both the Lewis-Riesenfeld invariant theory and the invariant-related unitary transformation formulation, the present paper obtains the exact solutions to the time-dependent supersymmetric two-level multiphoton Jaynes-Cummings model and the Chiao-Wu model that describes the propagation of a photon inside the optical fiber. On the basis of the fact th

Antonio O. Bouzas

We consider the renormalization of theories with many scalar fields. We discuss at the one-loop level some simple, non-gauge models with an arbitrary number of scalars and fermions both in mass-shell and MS schemes. In MS scheme we give a detailed qualitative analysis of the RG flow of dimensionless couplings in flavor space.

Norio Konno

This letter treats the quantum random walk on the line determined by a 2 times 2 unitary matrix U. A combinatorial expression for the mth moment of the quantum random walk is presented by using 4 matrices, P, Q, R and S given by U. The dependence of the mth moment on U and initial qubit state phi is clarified. A new type of limit theorems for the quantum wal

Wolfgang Sturhahn, Caroline L'abbe, Thomas S. Toellner

The time-dependent phase change of x rays after transmission through a sample has been determined experimentally. We used an x-ray interferometer with a reference sample containing sharp nuclear resonances to prepare a phase-controlled x-ray beam. A sample with similar resonances was placed in the beam but outside of the interferometer; hence our use of the

A. Boucenna, S. Madjber, A. Bouketir

We present a macroscopic model for the energy of rotation nuclei which has several refinements relative to the rotating liquid drop model. The most important features are the inclusion of the shell correction and using a new family of triaxial compact and creviced shapes to describe transition of the system from one sphere to a two separated spheres. With th

V. Greco, C. M. Ko, P. Levai

Using a covariant coalescence model, we study hadron production in relativistic heavy ion collisions from both soft partons in the quark-gluon plasma and hard partons in minijets. Including transverse flow of soft partons and independent fragmentation of minijet partons, the model is able to describe available experimental data on pion, kaon, and antiproton

B. I. Henry, M. T. Batchelor

Exact results are obtained for random walks on finite lattice tubes with a single source and absorbing lattice sites at the ends. Explicit formulae are derived for the absorption probabilities at the ends and for the expectations that a random walk will visit a particular lattice site before being absorbed. Results are obtained for lattice tubes of arbitrary

A. D. Alhaidari

Using a recently developed approach for solving the three dimensional Dirac equation with spherical symmetry, we obtain simple representations for the Green's function of the Dirac-Oscillator and Dirac-Coulomb problems. This is accomplished by setting up the relativistic problem in such a way that makes comparison with the nonrelativistic problem highly

Victor Guba, Mark Sapir

In this paper, we introduce the concept of the independence graph of a directed 2-complex. We show that the class of diagram groups is closed under graph products over independence graphs of rooted 2-trees. This allows us to show that a diagram group containing all countable diagram groups is a semi-direct product of a partially commutative group and R. Thom

Toka Diagana

The primary goal of this paper is to characterize solutions to coupled reaction-diffusion systems. Indeed, we use operators theory to show that under suitable assumptions, then the solutions to the reaction-diffusion equations exist. As applications, we consider a mathematical model arising in Biology and in Chemistry.

Dimitris Achlioptas, Assaf Naor, Yuval Peres

Maximum satisfiability is a canonical NP-hard optimization problem that appears empirically hard for random instances. Let us say that a Conjunctive normal form (CNF) formula consisting of $k$-clauses is $p$-satisfiable if there exists a truth assignment satisfying $1-2^{-k}+p 2^{-k}$ of all clauses (observe that every $k$-CNF is 0-satisfiable). Also, let $F

Hélène Esnault, Nicholas M. Katz

We show that Ax-Katz divisibility on the number of rational points of a variety defined over a finite field by equations of low degrees comes from divisibility of the eigenvalues of the Frobenius action of the $\ell$-adic cohomology with compact supports. This completes the motivc picture, as we knew already that in characteristic 0, the Hodge type was the e

Kazuhiro Hikami

Studied is a generalization of Zagier's q-series identity. We introduce a generating function of L-functions at non-positive integers, which is regarded as a half-differential of the Andrews--Gordon q-series. When q is a root of unity, the generating function coincides with the quantum invariant for the torus knot.

V. S. Guba, M. V. Sapir

We show that diagram groups can be viewed as fundamental groups of spaces of positive paths on directed 2-complexes (these spaces of paths turn out to be classifying spaces). Thus diagram groups are analogs of second homotopy groups, although diagram groups are as a rule non-Abelian. Part of the paper is a review of the previous results from this point of vi

O. I. Vasilenko

We investigate classical formation of a trap surface in $D$-dimensional Einstein gravity in the process of a head-on collision of two high-energy particles, which are treated as Aichelburg-Sexl shock waves. From the condition of the trap surface volume local maximality we deduce an explicit form of the inner trap surface. Imposing the continuity condition on

Srubabati Goswami

Neutrino Oscillation, in which a given flavour of neutrino transforms into another is a powerful tool for probing small neutrino masses. The intrinsic neutrino properties involved are neutrino mass squared difference $Δm^2$ and the mixing angle in vacuum $θ$. In this talk I will summarize the progress that we have achieved in our search for neutrino oscillat

Koske Nishihara, Takahiro Kubota

The technique of higher derivative regularization is applied to the Super-Weyl-Kahler anomaly in supergravity coupled with chiral matters and gauge multiplet. Our method makes it possible to derive directly and diagrammatically the formulae for the gaugino mass (in the Abelian case). Our procedure is applied to derivation of not only the mass formulae known

C. H. Lin

The most recent results of inclusive hadron, baryon pair and rho0 rho0 productions in two-photon collisions measured at LEP are presented.

D. Gotta

The measurement of the pion-nucleon scattering lengths constitutes a high-precision test of the methods of Chiral Pertubation Theory, which is the low-energy approach of QCD. The pion-nucleon s-wave scattering lengths are related to the strong-interaction shift and width of the s-states of the pionic hydrogen atom. Shift and width are determined from the mea

Peter Diener

I present a new general purpose event horizon finder for full 3D numerical spacetimes. It works by evolving a complete null surface backwards in time. The null surface is described as the zero level set of a scalar function, that in principle is defined everywhere. This description of the surface allows the surface, trivially, to change topology, making this

Niall O Murchadha

This letter describes a novel derivation of general relativity by considering the (non)self-consistency of theories whose Hamiltonians are constraints. The constraints, from Hamilton's equations, generate the evolution, while the evolution, in turn, must preserve the constraints. This closure requirement can be used as a selection mechanism for general r

Sung Yong Park, D. Stroud

We describe a simple model for the melting and optical properties of a DNA/gold nanoparticle aggregate. The optical properties at fixed wavelength change dramatically at the melting transition, which is found to be higher and narrower in temperature for larger particles, and much sharper than that of an isolated DNA link. All these features are in agreement

P. Shiktorov, E. Starikov, V. Gruzinskis, L. Reggiani

On the basis of the equivalence of the energy balance deacription at micro- and macro-level we propose a quantum generalization of the viscous friction law for a macroscopic Langevin equation describing thermal fluctuations without the zero point contribution. This equation recovers the classical case in the limit h -> 0. In particular it satisfies the quant

Anke Winkler, Jurgen Horbach, Walter Kob, Kurt Binder

The amorphous aluminium silicate (Al2O3)2(SiO2) [AS2] is investigated by means of large scale molecular dynamics computer simulations. We consider fully equilibrated melts in the temperature range 6100K >= T >= 2300K as well as glass configurations that were obtained from cooling runs from T=2300K to 300K with a cooling rate of about 10^12K/s. Already at tem

Michael Nauenberg

In 1916 Einstein introduced the first rules for a quantum theory of electromagnetic radiation, and he applied them to a model of matter in thermal equilibrium with radiation to derive Planck's black-body formula. Einstein's treatment is extended here to time-dependent stochastic variables, which leads to a master equation for the probability distribu

C. Nagashima, P. D. Dobbie, T. Nagayama, Y. Nakajima

We have carried out a brown dwarf search over an area of 14' x 23' near the central portion of the Pleiades open cluster in five optical and near infrared bands (i', Z, J, H, Ks) with 10 sigma detection limits of i' = 22.0, J = 20.0 and Ks = 18.5 mag. The surveyed area has large extinction in excess of Av = 3 in the Pleiades region. We detect

Mischa Schirmer, Thomas Erben, Peter Schneider, Grzesiek Pietrzynski

The Garching-Bonn Deep Survey (GaBoDS) is a virtual 12 square degree cosmic shear and cluster lensing survey, conducted with the WFI@2.2m MPG/ESO telescope at La Silla. It consists of shallow, medium and deep random fields taken in R-band in subarcsecond seeing conditions at high galactic latitude. A substantial amount of the data was taken from the ESO arch

J. Kahanpaa, K. Mattila, K. Lehtinen, C. Leinert

We present a set of 6-12 micron ISOPHOT-S spectra of the general interstellar medium of the Milky Way. This part of the spectrum is dominated by a series of strong, wide emission features commonly called the Unidentified Infrared Bands. The sampled area covers the inner Milky Way from l = -60 degr to +60 degr with a ten-degree step in galactic longitude and

K. Imanishi, H. Nakajima, M. Tsujimoto, K. Koyama

We report on the results of a systematic study of X-ray flares from low-mass young stellar objects, using Chandra observations of the main region of the Rho Oph. From 195 X-ray sources, including class I-III sources and some young brown dwarfs, we detected a total of 71 X-ray flares. Most of the flares have the typical profile of solar and stellar flares, fa

Sun Hong Rhie

It has been conjectured (astro-ph/0103463) that a gravitational lens consisting of n point masses can not produce more than 5(n-1) images as is known to be the case for n = 2 and 3. The reasoning is based on the number of finite limit points 2(n-1) which we believe to set the maximum number of positive images and the fact that the number of negative images e

B. M. Gaensler, B. J. Wallace

(Abridged) We present a detailed radio study of the young supernova remnant (SNR) G292.0+1.8 and its associated pulsar PSR J1124-5916, using the Australia Telescope Compact Array at observing wavelengths of 20, 13 and 6 cm. We find that the radio morphology of the source consists of three main components: a polarized flat-spectrum central core coincident wit

Luiz C. de Albuquerque, Jorge L. deLyra, Paulo Teotonio-Sobrinho

The spectral principle of Connes and Chamseddine is used as a starting point to define a discrete model for Euclidean quantum gravity. Instead of summing over ordinary geometries, we consider the sum over generalized geometries where topology, metric and dimension can fluctuate. The model describes the geometry of spaces with a countable number $n$ of points

Vitor Cardoso, Roman Konoplya, Jose' P. S. Lemos

We present a thorough analysis for the quasinormal (QN) behavior, associated with the decay of scalar, electromagnetic and gravitational perturbations, of Schwarzschild-anti-de Sitter black holes. As it is known the anti-de Sitter (AdS) QN spectrum crucially depends on the relative size of the black hole to the AdS radius. There are three different types of

Giuseppe D'Appollonio, Elias Kiritsis

The non-compact CFT of a class of NS-supported pp-wave backgrounds is solved exactly. The associated tree-level covariant string scattering amplitudes are calculated. The S-matrix elements are well-defined, dual but not analytic as a function of $p^+$. They have poles corresponding to physical intermediate states with $p^+\not =0$ and logarithmic branch cuts

Juan M. Romero, J. A. Santiago, J. David Vergara

In this note we show that in a two-dimensional non-commutative space the area operator is quantized, this outcome is compared with the result obtained by Loop Quantum Gravity methods.

Olaf Stenull, Hans-Karl Janssen

We study the critical behavior of various geometrical and transport properties of percolation in 6 dimensions. By employing field theory and renormalization group methods we analyze fluctuation induced logarithmic corrections to scaling up to and including the next to leading correction. Our study comprehends the percolation correlation function, i.e., the p

S. Grenier, J. P. Hill, Doon Gibbs, K. J. Thomas

We report a x-ray resonant diffraction study of the perovskite Pr0.6Ca0.4MnO3. At the Mn K-edge, this technique is sensitive to details of the electronic structure of the Mn atoms. We discuss the resonant x-ray spectra measured above and below the charge and orbital ordering phase transition temperature (TCOO = 232 K), and present a detailed analysis of the

O. Chavoya-Aceves

A rigorous application of the correspondence rules shows that the operator of the angular momentum of a quantum particle---corresponding to the classical magnitude $\mathbf{l}= m \mathbf{r} \wedge \mathbf{v}$---is given by $\mathbf{\hat{l}}=\mathbf{r}\wedge(-i\hbar\mathbf{\nabla} -\frac{e}{c}\mathbf{A})$ in the presence of an electromagnetic field. Thus, des

S. Ciechanowicz, M. Misiaszek, W. Sobkow

In this paper a scenario with the participation of the exotic scalar S, tensor T and pseudoscalar couplings of the right-handed neutrinos in addition to the standard vector V, axial A couplings of the left-handed neutrinos in the low-energy $(ν_μe^{-})$ and $(ν_{e}e^{-})$ scattering processes is considered. Neutrinos are assumed to be massive Dirac fermions

José Figueroa-O'Farrill

We classify non-dilatonic NS-NS type II supergravity backgrounds admitting a consistent absolute parallelism. They are all given by parallelised Lie groups admitting scalar flat bi-invariant lorentzian metrics. There are seven different classes, some of them containing moduli. For each class we determine the amount of supersymmetry which is preserved: there

Andre Lukas, Stephen Morris

We compute the moduli Kahler potential for M-theory on a compact manifold of G_2 holonomy in a large radius approximation. Our method relies on an explicit G_2 structure with small torsion, its periods and the calculation of the approximate volume of the manifold. As a verification of our result, some of the components of the Kahler metric are computed direc

Pavel Rodin

We present a generic nonlinear model for current filamentation in semiconductor structures with S-shaped current-voltage characteristics. The model accounts for Joule self-heating of a current density filament. It is shown that the self-heating leads to a bifurcation from static to traveling filament. Filaments start to travel when increase of the lattice te

Eva Maria Feichtner, Sergey Yuzvinsky

We study a graded algebra D=D(L,G) defined by a finite lattice L and a subset G in L, a so-called building set. This algebra is a generalization of the cohomology algebras of hyperplane arrangement compactifications found in work of De Concini and Procesi. Our main result is a representation of D, for an arbitrary atomic lattice L, as the Chow ring of a smoo

Luis Anchordoqui, Carlos Hojvat, Thomas McCauley, Thomas Paul

Using data from the SUGAR and the AGASA experiments taken during a 10 yr period with nearly uniform exposure to the entire sky, we search for large-scale anisotropy patterns in the arrival directions of cosmic rays with energies > 10^{19.6} eV. We determine the angular power spectrum from an expansion in spherical harmonics for modes out to \ell=5. Based on

Everton M. C. Abreu

It is a well known result that the scalar field is composed of two chiral particles (Floreanini-Jackiw particles) of opposite chiralities. Also, that a Siegel particle spectrum is formed by a nonmover field (a Hull's noton) and a FJ particle. In this work we show that in a scalar field spectrum, in a curved expanding universe scenario, we can find two dy

T. Hambye, S. Peris, E. de Rafael

We present new results for the matrix elements of the Q_6 and Q_4 penguin operators, evaluated in a large-Nc approach which incorporates important O(N_c^2\frac{n_f}{N_c}) unfactorized contributions. Our approach shows analytic matching between short- and long-distance scale dependences within dimensional renormalization schemes, such as MS-bar. Numerically,

L. Burderi, T. Di Salvo, F. D'Antona, N. R. Robba

The optical counterpart of the binary millisecond X-ray pulsar SAX J1808.4-3658 during quiescence was detected at V = 21.5 mag by Homer et al. (2001). This star shows a 6% semi-amplitude sinusoidal modulation of its flux at the orbital period of the system. It was proposed that the modulation arises from X-ray irradiation of the intrinsically faint companion

T. Carli, V. Chiochia, K. Klimek

The uncertainties involved in the calculation of bottom quark cross-sections in deep-inelastic scattering at HERA are studied in different phase space regions. Besides the inclusive bottom quark cross-section, definitions closer to the detector acceptance requiring at least one high energetic muon from the semi-leptonic \bquark decay or a jet with high trans

Andrei Moroianu, Liviu Ornea

We prove that on a compact $n$-dimensional spin manifold admitting a non-trivial harmonic 1-form of constant length, every eigenvalue $λ$ of the Dirac operator satisfies the inequality $λ^2 \geq \frac{n-1}{4(n-2)}\inf_M Scal$. In the limiting case the universal cover of the manifold is isometric to $R\times N$ where $N$ is a manifold admitting Killing spinor

M. S. Shell, P. G. Debenedetti, A. Z. Panagiotopoulos

We present an efficient Monte Carlo algorithm for determining the density of states which is based on the statistics of transition probabilities between states. By measuring the infinite temperature transition probabilities--that is, the probabilities associated with move proposal only--we are able to extract excellent estimates of the density of states. Whe

Jaume Guasch, Petra Häfliger, Michael Spira

We present an update of neutral Higgs boson decays into bottom quark pairs in the minimal supersymmetric extension of the Standard Model. In particular the resummation of potentially large higher-order corrections due to the soft SUSY breaking parameters A_b and mu is extended. The remaining theoretical uncertainties due to unknown higher-order SUSY-QCD corr

V. A. Benderskii, E. V. Vetoshkin, E. I. Kats

We examine one important (and overlooked in all previous investigations) aspect of well - known crossing diabatic potentials or Landau - Zener (LZ) problem. We derive the semiclassical quantization rules for the crossing diabatic potentials with localized initial and localized or delocalized final states, in the intermediate energy region, when all four adia

Roberto Bergamini, Stefano Viaggiu

We present a simple novel derivation, ab initio, of the equations appropriate for stationary axisymmetric spacetimes using the Papapetrou form of the metric (Papapetrou gauge). It is shown that using coordinates which preserve the Papapetrou gauge three separated solutions of the Ernst equations appear in the case of Kerr metric. In this context a parameter

Luis Morales-Molina, Niurka R. Quintero, Franz G. Mertens, Angel Sanchez

We study directed energy transport in homogeneous nonlinear extended systems in the presence of homogeneous ac forces and dissipation. We show that the mechanism responsible for unidirectional motion of topological excitations is the coupling of their internal and translation degrees of freedom. Our results lead to a selection rule for the existence of such

C. M. S. Gannarelli, D. Alfe, M. J. Gillan

We assess the quantitative accuracy of the particle-in-cell (PIC) approximation used in recent ab initio predictions of the thermodynamic properties of hexagonal-close-packed iron at the conditions of the Earth's inner core. The assessment is made by comparing PIC predictions for a range of thermodynamic properties with the results of more exact calculat

Q. Liu, T. Meng

It is pointed out that the concepts and methods introduced by Bachelier and by Mandelbrot to Finance and Economics can be used to examine the fluctuations observed in high-energy hadron production processes. Theoretical arguments and experimental evidences are presented which show that the relative variations of hadron-numbers between successive rapidity int

Hajime Inoue, Noriko Y. Yamasaki

A possibility to detect X-rays from star-formation burst activities in proto-elliptical galaxies is considered. The X-ray flux of an emission due to inverse Compton scattering of the cosmic microwave background (CMB) by high energy electrons accelerated in SNRs is shown to increase as z increases far beyond unity, since the local CMB flux largely increases i

A. N. Timokhin, F. A. Aharonian, A. Yu. Neronov

The origin of the nonthermal EUV and hard X-ray emission "excess" reported from some galaxy clusters has been intensively debated over last several years. The most favored models which refer this excess to relativistic electrons upscattering the 2.7 K CMBR generally requires very low magnetic field, significantly below the estimates derived from the

A. S. Mellish, G. Duffy, C. McKenzie, R. Geursen

We present a scheme for rapid loading of a Bose-Einstein condensate into a single Bloch state of a weak optical lattice at a quasi-momentum of q = hbar k. Rabi cycling of a Bose condensate between momentum states is modified by a phase shift applied to the lattice. With an appropriate choice of the magnitude and timing of the phase shift, we demonstrate near

Yong Zhou

We have investigated the present renormalization prescriptions of Cabibbo-Kobayashi-Maskawa (CKM) matrix at one-loop level. We emphasize at one prescription which is formulated with reference to the case of no mixing of quark's generations and point out that it doesn't make the physical amplitude involving quark mixing ultraviolet finite. We then pro

Jay Gambetta, H. M. Wiseman

An important and well established area of quantum optics is the theory of Markovian stochastic Schrödinger equations (or by another name quantum trajectory theory). Recently stochastic Schrödinger equations have been developed for non-Markovian systems. In this paper we extend the current known stochastic Schrödinger equations for non-Markovian systems to in

Andrei Pomeransky

The additivity of both the entanglement of formation and the classical channel capacity is known to be a consequence of the strong superadditivity conjecture. We show that, conversely, the strong superadditivity conjecture follows from the additivity of the entanglement of formation; this means that the two conjectures are equivalent and that the additivity

Jiangfeng Du, Ping Zou, Mingjun Shi, Leong Chuan Kwek

Examples of geometric phases abound in many areas of physics. They offer both fundamental insights into many physical phenomena and lead to interesting practical implementations. One of them, as indicated recently, might be an inherently fault-tolerant quantum computation. This, however, requires to deal with geometric phases in the presence of noise and int

Christof Zalka

This is a short introduction to Quantum Computing intended for physicists. The basic idea of a quantum computer is introduced. Then we concentrate on Shor's integer factoring algorithm.

S. G. Schirmer, A. D. Greentree, D. K. L. Oi

We consider a mechanism to generate controllable qudit-qudit interactions in a charge-position paradigm for a quantum computer, through the use of auxiliary states. By controlling the tunneling rates onto these auxiliaries from the qudits proper, we can controllably switch the entangling operations. We consider a practical architecture in which to realize su

A. C. Aguiar Pinto, T. M. Britto, F. Pascoal, F. S. S. da Rosa

We present explicitly another example of a temperature inversion symmetry in the Casimir effect for a nonsymmetric boundary condition. We also give an interpretation for our result.

Dominik Janzing, Pawel Wocjan, Thomas Beth

We define the problem identity check: Given a classical description of a quantum circuit, determine whether it is almost equivalent to the identity. Explicitly, the task is to decide whether the corresponding unitary is close to a complex multiple of the identity matrix with respect to the operator norm. We show that this problem is QMA-complete. A generaliz

David Fattal, Kyo Inoue, Jelena Vuckovic, Charles Santori

We report the generation of polarization-entangled photons, using a quantum dot single photon source, linear optics and photodetectors. Two photons created independently are observed to violate Bell's inequality. The density matrix describing the polarization state of the postselected photon pairs is also reconstructed, and agrees well with a simple mode

Subhash Kak

The commonly used circuit model of quantum computing leaves out the problems of imprecision in the initial state preparation, particle statistics (indistinguishability of particles belonging to the same quantum state), and error correction (current techniques cannot correct all small errors). The initial state in the circuit model computation is obtained by

A. Loinger, T. Marsico

We show that the supermassive celestial body at the centre of the Milky Way and the two supermassive celestial bodies at the centre of the distant galaxy NGC 6240 cannot be black holes.

B. G. Sidharth

We review Cantorian and Non Commutative Spacetime, work which has occupied El Naschie in the past several years. These concepts are now the subject of intense research, thanks to Quantum Gravity, Quantum Super String Theory and a few other approaches. It now appears that we are on the verge of a breakthrough in finding solutions to longstanding problems, lik

Ilya V. Shadrivov, Alexander A. Zharov, Yuri S. Kivshar

We study the beam reflection from a layered structure with a left-handed metamaterial. We predict a giant lateral (Goos-Hanchen) shift and splitting of the beam due to the resonant excitation of surface polaritons with a vortex-like energy flow between the right- and left-handed materials.

L. J. Nickisch, Jules Mollere

Newton's Second Law defines inertial mass as the ratio of the applied force on an object to the responding acceleration of the object (viz., F=ma). Objects that exhibit finite accelerations under finite forces are described as being "massive'' and this mass has usually been considered to be an innate property of the particles composing the ob

T. Hyodo, S. I. Nam, D. Jido, A. Hosaka

We calculate the magnetic moments of the N(1535) resonance using the chiral unitary model, where the resonance is dynamically generated in the scatterings of the lowest-lying mesons and baryons. We obtain the magnetic moments of the resonance as +1.1 and -0.25 for p(1535) and n(1535), respectively, in units of the nuclear magneton. We discuss the origin of t

D. Dutta

We have measured the nuclear transparency of the fundamental process $γ$ n $\to π^-$ p in $^4$He. These measurements were performed at Jefferson Lab in the photon energy range of 1.6 to 4.5 GeV and at $θ^π_{cm}= 70^\circ$ and $90^\circ$. These measurements are the first of their kind in the study of nuclear transparency in photoreactions. They also provide a

Artur Cristea, Victor Sofonea

The origin of the spurious interface velocity in finite difference lattice Boltzmann models for liquid - vapor systems is related to the first order upwind scheme used to compute the space derivatives in the evolution equations. A correction force term is introduced to eliminate the spurious velocity. The correction term helps to recover sharp interfaces and

J. G. Reid, T. A. Trainor

We compare limit-based and scale-local dimensions of complex distributions, particularly for a strange attractor of the Henon map. Scale-local dimensions as distributions on scale are seen to exhibit a wealth of detail. Limit-based dimensions are shown to be averages of scale-local dimensions, in principle over a semi-infinite scale interval. We identify som

José F. Cariñena, Arturo Ramos

Some simple examples from quantum physics and control theory are used to illustrate the application of the theory of Lie systems. We will show, in particular, that for certain physical models both of the corresponding classical and quantum problems can be treated in a similar way, may be up to the replacement of the involved Lie group by a central extension

Richard L. Hall, Qutaibeh D. Katatbeh

We study a single particle which obeys non-relativistic quantum mechanics in R^N and has Hamiltonian H = -Delta + V(r), where V(r) = sgn(q)r^q. If N \geq 2, then q > -2, and if N = 1, then q > -1. The discrete eigenvalues E_{n\ell} may be represented exactly by the semiclassical expression E_{n\ell}(q) = min_{r>0}\{P_{n\ell}(q)^2/r^2+ V(r)}. The case q = 0 c

W. Chen

Chen [1] builds the intrinsic link between the 1/f power spectra and the acoustic frequency power law dissipation and, accordingly, presents two explanations of the so-called infrared catastrophe of the 1/f power spectra. This note is an immediate follow-up. The major progress is to connect the 1/f power spectra and the power law dissipation of an acoustic s

Philippe Caldero, Ralf Schiffler

With the help of Lusztig's canonical basis, we study local intersection cohomology of the Zariski closures of orbits of representations of a quiver of type A, D or E. In particular, we characterize the rationally smooth orbits and prove that orbit closures are smooth if and only if they are rationally smooth. This provides an analogue of theorems of V. D

Leonardo Macarini, Felix Schlenk

The Hofer-Zehnder theorem states that almost every hypersurface in a thickening of a hypersurface $S$ in a symplectic manifold $(M,ω)$ carries a closed characteristic provided that $S$ bounds a compact submanifold and $(M,ω)$ has finite capacity. We show that it is enough to assume that the thickening of $S$ has finite capacity.

Roger Picken

We describe the geometrical ladder of equations for Abelian bundles and gerbes, as well as higher generalisations, in terms of the cohomology of an operator that combines de Rham and Cech cohomology.

Urs Frauenfelder, Felix Schlenk

We prove the following three results in Hamiltonian dynamics. 1. The Weinstein conjecture holds true for every displaceable hypersurface of contact type. 2. Every magnetic flow on a closed Riemannian manifold has contractible closed orbits for a dense set of small energies. 3. Every closed Lagrangian submanifold of an arbitrary symplectic manifold whose fund