January 2002 arXiv papers — page 6

A. J. Korn, S. C. Keller, A. Kaufer, N. Langer

We present chemical abundances for four main sequence B stars in the young cluster NGC 2004 in the Large Magellanic Cloud (LMC). Apart from H II regions, unevolved OB-type stars are currently the only accessible source of present-day CNO abundances for the MCs not altered by stellar evolution. Using UVES on the VLT, we obtained spectra of sufficient resoluti

John J. Feldmeier

We review the progress of research on intracluster planetary nebulae (IPN). In the past five years, hundreds of IPN candidates have been detected in the Virgo and Fornax galaxy clusters and searches are also underway in poorer galaxy groups. From the observations to date, and applying the known properties of extragalactic planetary nebulae, the intracluster

Ignacio Negueruela, Malcolm J. Coe

We present high resolution blue spectroscopy of an almost complete sample of optical counterparts to massive X-ray binaries in the Large Magellanic Cloud (LMC) and derive their spectral classification. We find an spectral type B0II for the optical counterpart to RX J0532.5-6551, confirming it as the first wind-fed massive X-ray binary in the LMC. We also con

A. Tarchi, C. Henkel, A. B. Peck, K. M. Menten

The detection of 22 GHz water vapor emission from IC342 is reported, raising the detection rate among northern galaxies with 100 micron IRAS point source fluxes > 50 Jy to 16%. The maser, associated with a star forming region 10-15 arcsec west of the nucleus, consists of a single 0.5 km/s wide feature and reaches an isotropic luminosity of 0.01 solar luminos

Gordon T. Richards, Michael D. Gregg, Robert H. Becker, Richard L. White

We present a Keck ESI spectrum of FIRST 074711.2+273904, a K=15.4 quasar with redshift 4.11 that is detected by both FIRST and 2MASS. The spectrum contains at least 14 independent C IV absorption systems longward of the Ly-alpha forest. These systems are found over a path length of Delta z = 0.984, constituting one of the highest densities per unit redshift

E. Parizot, R. Lehoucq

A gamma-ray line production calculation in astrophysics depends on i) the composition and energy source spectrum of the energetic particles, ii) the propagation model, and iii) the nuclear cross sections. The main difficulty for model predictions and data interpretation comes from the fact that the spectrum of the particles which actually interact in the ISM

Livia Origlia, Francesco R. Ferraro, Flavio Fusi Pecci, Robert T. Rood

Deep images in the 10 micron spectral region have been obtained for five massive Galactic globular clusters, NGC 104 (=47 Tuc), NGC 362, NGC 5139 (omega Cen), NGC 6388, NGC 7078 (=M15) and NGC 6715 (=M54) in the Sagittarius Dwarf Spheroidal using ISOCAM in 1997. A significant sample of bright giants have an ISOCAM counterpart but only < 20% of these have a s

D. Elbaz

Until 1996, there was little evidence that most galaxies were ``shy&#39;&#39;, i.e. that they would hide their stars behind a veil of dust and turn red when forming stars, radiating the bulk of their luminosity in the infrared (IR) at a given epoch of their history. Ten years before, IRAS had unveiled a population of luminous IR galaxies exhibiting such a ``

Brian Chaboyer, Lawrence M. Krauss

The theoretical uncertainties in the calibration of the relationship between the subgiant mass and age in metal-poor stars are investigated using a Monte Carlo approach. Assuming that the mass and iron abundance of a subgiant star are known exactly, uncertainties in the input physics used to construct stellar evolution models and isochrones lead to a Gaussia

Jun Ma, Xu Zhou, Jiansheng Chen, Hong Wu

In this paper we study the properties of ten halo globular clusters in the nearby spiral galaxy M33. CCD images of M33 were obtained as a part of the BATC Colour Survey of the sky in 13 intermediate-band filters from 3800 to 10000Å. By aperture photometry, we obtain the spectral energy distributions (SEDs) of these globular clusters. We estimate the ages of

E. B. Fomalont, K. I. Kellermann, R. B. Partridge, R. A. Windhorst

We present the results from two radio integrations at 8.4 GHz using the VLA. One of the fields, at 13h,+43d (SA13 field), has an rms noise level of 1.49 microJy and is the deepest radio image yet made. Thirty-four sources in a complete sample were detected above 7.5 microJy and 25 are optically identified to a limit of I=25.8, using our deep HST and ground-b

H. Katayama, I. Takahashi, Y. Ikebe, K. Matsushita

Understanding a background is crucial in particular for a study of low surface brightness objects. In order to establish the background subtraction method, we have studied properties of the EPIC background. Count rates of the background vary violently by two order of magnitude at the maximum, while during the most quiet period, these are stable within 8 % at

S. Dye, A. N. Taylor, T. R. Greve, O. E. Rognvaldsson

[ABRIDGED] We estimate the total mass distribution of the galaxy cluster CL0024+1654 from the measured source depletion due to lens magnification in the R band. Within a radius of 0.54Mpc/h, a total projected mass of (8.1+/-3.2)*10^14 M_sol/h (EdS) is measured, which corresponds to a mass- to-light ratio of M/L(B)=470+/-180. We compute the luminosity functio

Ohad Shemmer, Hagai Netzer

The well known relationship between metallicity and luminosity in AGN is addressed by introducing new metallicity measurements (based on the method of Hamann & Ferland 1993; HF93) for a sample of narrow-line Seyfert 1 (NLS1) galaxies. Our new results, based on a sample of 162 AGN, including 9 NLS1s, indicate that, while broad-line AGN trace a metallicity--lu

Roman Bezrukavnikov

In math.RT/0201073 we constructed an equivalence between the derived category of equivariant coherent sheaves on the cotangent bundle to the flag variety of a simple algebraic group and a (quotient of) the category of constructible sheaves on the affine flag variety of the Langlands dual group. Below we prove certain properties of this equivalence; provide a

Angelo Bassi, GianCarlo Ghirardi

We consider the effect of replacing in stochastic differential equations leading to the dynamical collapse of the statevector, white noise stochastic processes with non white ones. We prove that such a modification can be consistently performed without altering the most interesting features of the previous models. One of the reasons to discuss this matter de

Luc T. Wille, U. H. E. Hansmann

We introduce a novel heuristic global optimization method, energy landscape paving (ELP), which combines core ideas from energy surface deformation and tabu search. In appropriate limits, ELP reduces to existing techniques. The approach is very general and flexible and is illustrated here on two protein folding problems. For these examples, the technique giv

Marco Lenci

In a previous paper (nlin.CD/0107041) the following class of billiards was studied: For $f: [0, +\infty) \longrightarrow (0, +\infty)$ convex, sufficiently smooth, and vanishing at infinity, let the billiard table be defined by $Q$, the planar domain delimited by the positive $x$-semiaxis, the positive $y$-semiaxis, and the graph of $f$. For a large class of

Sarika Jalan, R. E. Amritkar

As a model of evolving networks, we study coupled logistic maps on scale free networks. For small coupling strengths nodes show turbulent behavior but form phase synchronized clusters as coupling increases. We identify two different ways of cluster formation. For small coupling strengths we get {\it self-organized clusters} which have mostly intra-cluster co

Michel Boileau, Lee Rudolph

An oriented link L in a 3-sphere S in complex 2-space is a C-boundary if it bounds a piece of algebraic curve in the 4-ball bounded by S. Using Kronheimer and Mrowka&#39;s proof of the Thom Conjecture, we construct many oriented knots which are not concordant to a C-boundary. We use the two-variable HOMFLY polynomial to give an obstruction to a knot&#39;s be

Alejandro Adem, Daniel C. Cohen, Frederick R. Cohen

Let G be the fundamental group of the complement of a K(G,1) hyperplane arrangement (such as Artin&#39;s pure braid group) or more generally a homologically toroidal group (as defined in the paper). The subgroup of elements in the complex K-theory of BG which arises from complex unitary representations of G is shown to be trivial. In the case of real K-theor

M. R. Setare, R. Mansouri

In this paper we calculate the Casimir energy for spherical shell with massless self-interacting scalar filed which satisfying Dirichlet boundary conditions on the shell. Using zeta function regularization and heat kernel coefficients we obtain the divergent contributions inside and outside of Casimir energy. The effect of self-interacting term is similar wi

G. Zet

A model of spherically symmetric SU(2) gauge theory is considered. The self-duality equations are written and it is shown that they are compatible with the Einstein-Yang-Mills equations. It is proven that this property is true for any gauge theory with curved base space-time and having a compact Lie group as structural group.

Leonard Gamberg, Gary R. Goldstein

Exploiting an approximate phenomenological symmetry of the $J^{PC}=1^{+-}$ light axial vector mesons and using pole dominance, we calculate the flavor contributions to the nucleon tensor charge. The result depends on the decay constants of the axial vector mesons and their couplings to the nucleons.

Gudrun Hiller, Martin Schmaltz

We point out that the hierarchy between the measured values of the CKM phase and the strong CP phase has a natural origin in supersymmetry with spontaneous CP violation and low energy supersymmetry breaking. The underlying reason is simple and elegant: in supersymmetry the strong CP phase is protected by an exact non-renormalization theorem while the CKM pha

Yoshio Koide

The Zee model is one of promising models of neutrino mass generation mechanism. However, the original Zee model is not on the framework of the ground unification scenario, and moreover, it is recently pointed out that the predicted value of $\sin^2 2θ_{solar}$ must be satisfied the relation $\sin^2 2θ_{solar} > 0.99$. We discuss whether possible GUT versions

P. Leifer

State-dependent gauge principle invoked to realize the relativity to a measuring device, has been proposed. Self-consistent global (cosmic) potential forms the state space of the fundamental field and its connection, agreed with Fubini-Study metric of $CP(N-1)$, serves as state-dependent gauge potential. In this framework the linearity of the ordinary quantu

Nelson A. Alves, U. H. E. Hansmann, Y. Peng

We compare two recently proposed methods for the characterization of phase transitions in small systems. The usefulness of these techniques is evaluated for the case of structural transition in alanine-based peptides.

G. P. Zhang, T. A. Callcott, G. T. Woods, L. Lin

Element- and site-specific resonant inelastic x-ray scattering spectroscopy (RIXS) is employed to investigate electron correlation effects in {$\rm NaV_2O_5$}. In contrast to single photon techniques, RIXS at the vanadium $L_3$ edge is able to probe $d-d^*$ transitions between V d-bands. A sharp energy loss feature is observed at -1.56 eV, which is well repr

W. Janke, D. A. Johnston, M. Stathakopoulos

The identification of phase transition points, beta_c, with the percolation thresholds of suitably defined clusters of spins has proved immensely fruitful in many areas of statistical mechanics. Some time ago Kertesz suggested that such percolation thresholds for models defined in field might also have measurable physical consequences for regions of the phas

J. B. Neaton, N. W. Ashcroft

Using density functional theory implemented within the generalized gradient approximation, a new non-magnetic insulating ground state of solid oxygen is proposed and found to be energetically favored at pressures corresponding to the $ε$-phase. The newly-predicted ground state is composed of linear herringbone-type chains of O$_2$ molecules and has {\it Cmcm

L. E. Helseth

A theoretical model for magnetooptic imaging is presented. The model gives a detailed description of the magnetooptic indicator and the optical imaging system, where the intensity at the detector plane is described by a set of diffraction integrals. To demonstrate the applicability of the model, some issues concerning imaging of single vortices in supercondu

L. E. Helseth, E. I. Il&#39;yashenko, M. Baziljevich, T. H. Johansen

We investigate detection of magnetic data using magnetooptical indicators with in-plane magnetization. A simple model for the magnetooptical detection system is presented. We find that the signal to noise ratio changes strongly with the bit size, the polarization noise and the distance between the magnetic carrier and the indicator. In particular, it is foun

V. V. Savkin, A. N. Rubtsov

The quantum discrete $ϕ^4$ model at finite temperature is studied in the mean-field approximation. The phase diagrams are obtained for a wide range of the model parameters. The domains of applicability for the classical, quantum, and order-disorder limits are determined. It is shown that a remarkable part of the phase diagram is reproduced by the first quant

Jonathan Arons

I discuss recent work on the nature of relativistic winds from Rotation Powered Pulsars, on the physics of how they transport energy from the central compact object to the surrrounding world, and how that energy gets converted into observable synchrotron emission.

M. P. Hobson, Klaus Maisinger

A maximum-likelihood method is presented for estimating the power spectrum of anisotropies in the cosmic microwave background (CMB) from interferometer observations. The method calculates flat band-power estimates in separate bins in l-space, together with confidence intervals on the power in each bin. For multifrequency data, the power spectrum of the other

Michele Cappellari

We describe a simple, efficient, robust and fully automatic algorithm for the determination of a Multi-Gaussian Expansion (MGE) fit to galaxy images, to be used as a parametrization for the galaxy stellar surface brightness. In most cases the least-squares solution found by this method essentially corresponds to the minimax, constant relative error, MGE appr

M. N. Achasov, V. M. Aulchenko, K. I. Beloborodov, A. V. Berdyugin

The cross section of the process $e^+e^-\to π^+π^-π^0$ was measured in the Spherical Neutral Detector experiment at the VEPP-2M collider in the energy region $\sqrt[]{s} = 980 ÷1380$ MeV. The measured cross section, together with the $e^+e^-\to π^+π^-π^0$ and $ωπ^+π^-$ cross sections obtained in other experiments, was analyzed in the framework of the general

Sergey N. Solodukhin

We suggest a simple model to study the problem of the black hole production in particle collisions. The cross-section for the classical and quantum production is analysed within this model. In particular, the possibility to form a black hole in collision of low energy particles (or at large impact parameter) via the quantum tunneling mechanism is pointed out

Elisabeth Kraus, Dominik Stöckinger

We present a minimal version for the renormalization of softly broken Super-Yang-Mills theories using the extended model with a local gauge coupling. It is shown that the non-renormalization theorems of the case with unbroken supersymmetry are valid without modifications and that the renormalization of soft-breaking parameters is completely governed by the r

Steven A. Balbus, John F. Hawley

The principles underlying a proposed class of black hole accretion models are examined. The flows are generally referred to as ``convection-dominated,&#39;&#39; and are characterized by inward transport of angular momentum by thermal convection and outward viscous transport, vanishing mass accretion, and vanishing local energy dissipation. We examine the via

G. M. Chechin, N. V. Novikova, A. A. Abramenko

Some exact solutions and multi-mode invariant submanifolds were found for the Fermi-Pasta-Ulam (FPU) beta-model by Poggi and Ruffo in Phys. D 103 (1997) 251. In the present paper we demonstrate how results of such a type can be obtained for an arbitrary N-particle chain with periodic boundary conditions with the aid of our group-theoretical approach [Phys. D

Lin-Hong Chen, Ren-Cheng Shang

The equilibrium geometry, harmonic frequency and dissociation energy of lanthanum monochloride have been calculated at B3LYP, MP2, QCISD(T) levels with energy-consistent relativistic effective core potentials. The possible electronic state and reasonable dissociation limit for the ground state are determined based on atomic and molecular reaction statics. Po

Shin&#39;ichi Nojiri, Sergei D. Odintsov

The number of asymptotically de Sitter (non-singular) solutions of 5d dilatonic gravity with positive cosmological constant is found. These solutions are similar to the previously known asymptotically AdS spaces where dilaton may generate the singularity. Using these solutions the consistent $c$-function is proposed in the same way as in AdS/CFT. The consist

Sos S. Agaian, Andreas Klappenecker

A quantum computer directly manipulates information stored in the state of quantum mechanical systems. The available operations have many attractive features but also underly severe restrictions, which complicate the design of quantum algorithms. We present a divide-and-conquer approach to the design of various quantum algorithms. The class of algorithm incl

Hiroshi Sato

We completely classify toric weakened Fano 3-folds, that is, smooth toric weak Fano 3-folds which are not Fano but are deformed to smooth Fano 3-folds. There exist exactly 15 toric weakened Fano 3-folds up to isomorphisms.

Hiroshi Sato

In this paper, we investigate whether the 124 nonsingular toric Fano 4-folds admit totally nondegenerate embeddings from abelian surfaces or not. As a result, we determine the possibilities for such embeddings except for the remaining 21 nonsingular toric Fano 4-folds.

A. Zinger

We give detailed descriptions of gluing pseudoholomorphic maps in symplectic geometry, especially in the presence of an obstruction bundle. The main motivation is to try to compare the symplectic and enumerative invariants of algebraic manifolds. These descriptions can also be used to enumerate rational curves with high-order degeneracies of local nature in

I. Dolgachev, S. Kondo

We construct a K3 surface over an algebraically closed field of characteristic 2 which contains two sets of 21 disjoint smooth rational curves such that each curve from one set intersects exactly 5 curves from the other set. This configuration is isomorphic to the configuration of points and lines on the projective plane over the finite field of 4 elements.

Kai Chen, Heng Fan, Bo-yu Hou, Kang-jie Shi

The relationship between Elliptic Ruijsenaars-Schneider (RS) and Calogero-Moser (CM) models with Sklyanin algebra is presented. Lax pair representations of the Elliptic RS and CM are reviewed. For n=2 case, the eigenvalue and eigenfunction for Lame equation are found by using the result of the Bethe ansatz method.

V. Drollinger, T. Muller, D. Denegri

We present a method how to detect the WH -> lnbb in the high luminosity LHC environment with the CMS detector. This study is performed with fast detector response simulation including high luminosity event pile up. The main aspects of reconstruction are pile up jet rejection, identification of b-jets and improvement of Higgs mass resolution. The detection po

V. Dzhunushaliev

It is offered to consider monopoles in Abelian Projection as quantum excitations which are solutions of the quantized Yang-Mills equations. According to the Heisenberg quantization method these equations are equivalent an infinite set of equations for Green&#39;s functions. A procedure for cutting off these infinite series of differential equations after som

Andree Blotz, Franz Huber, Heiko Loetzbeyer, Alexander Pretschner

In this paper we outline a software development process for safety-critical systems that aims at combining some of the specific strengths of model-based development with those of programming language based development using safety-critical subsets of Ada. Model-based software development and model-based test case generation techniques are combined with code

N. Theodoropoulou, A. F. Hebard, M. E. Overberg, C. R. Abernathy

Ion implantation of Mn ions into hole-doped GaP has been used to induce ferromagnetic behavior above room temperature for optimized Mn concentrations near 3 at.%. The magnetism is suppressed when the Mn dose is increased or decreased away from the 3 at.% value, or when n-type GaP substrates are used. At low temperatures the saturated moment is on the order o

S. J. Papadakis, E. P. De Poortere, H. C. Manoharan, J. B. Yau

We report low-field magnetotransport data in two-dimensional hole systems in GaAs/AlGaAs heterostructures and quantum wells, in a large density range, $2.5 \times 10^{10} \leq p \leq 4.0 \times 10^{11}$ cm$^{-2}$, with primary focus on samples grown on (311)A GaAs substrates. At high densities, $p \gtrsim 1 \times 10^{11}$ cm$^{-2}$, we observe a remarkably

M. Polini, K. Moulopoulos, B. Davoudi, M. P. Tosi

We present a variational study of both unpaired and spin-singlet paired states induced in a two-dimensional electron gas at low density by a perpendicular magnetic field. It is based on an improved circular-cell approximation which leads to a number of closed analytical results. The ground-state energy of the Wigner crystal containing a single electron per c

Sam Young Cho, Ross H. McKenzie, Kicheon Kang, Chul Koo Kim

We investigate coherent electron transport through a parallel circuit of two quantum dots, each of which has a single tunable energy level. Electrons tunneling via each dot from the left lead interfere with each other at the right lead. It is shown that due to the quantum interference of tunneling electrons the double quantum dot device is magnetically polar

N. L. Wang, T. Timusk, J. P. Franck, P. Schweiss

We have measured the effect of oxygen isotope substitution on the ab-plane reflectance of underdoped YBCO. The frequency shift of the transverse optic phonons due to the substitution of O-16 by O-18 yields an isotope effect of the expected magnitude for copper-oxygen stretching modes with alpha=0.5 +- 0.1. The reflectance shoulder at 400 - 500 cm^-1 shows a

Philippe Jacquod

We calculate the interaction kernel K for two-dimensional diffusive electrons. The screening of the Coulomb interaction together with the Fermi statistics induces a spin selection rule for electron-electron scattering so that in leading order in the inverse conductance only pairs of electrons with antiparallel spins do scatter. At low temperature, this resul

Ken Pounds, James Reeves

The EPIC detectors on XMM-Newton provide the most sensitive broad band (0.3-12 keV) X-ray spectra to date. Observations of 6 Seyfert 1 galaxies, covering a wide luminosity range, are examined with the aim of identifying the primary X-ray continuum and constraining superimposed emission and absorption features. A soft excess emission component is seen in ever

S. M. Khairul Alam, Barbara S. Ryden

We estimate the distribution of apparent axis ratios $q$ for galaxies in the Sloan Digital Sky Survey (SDSS) Early Data Release. We divide the galaxies by profile type (de Vaucouleurs versus exponential) as well as by color ($u^* - r^* \leq 2.22$ versus $u^* - r^* > 2.22$). The axis ratios found by fitting models to the surface photometry are generally small

P. Haensel, J. L. Zdunik, F. Douchin

Equilibrium configurations of cold neutron stars near the minimum mass are studied, using the recent equation of state SLy, which describes in a unified, physically consistent manner, both the solid crust and the liquid core of neutron stars. Results are compared with those obtained using an older FPS equation of state of cold catalyzed matter. The value of

Sarmistha Banik, Debades Bandyopadhyay

We investigate antikaon condensation in compact star matter using a relativistic mean field model. Antikaon condensates make the equation of state softer resulting in a smaller maximum mass star compared to the case without condensate. It is found that the equation of state including antikaon condensates gives rise to a stable sequence of compact stars calle

Yi-Ping Qin, Guang-Zhong Xie

A preview study of using observational data of proper motions and Doppler shifted velocities of twin-jets to determine the distance of sources inside and outside our galaxy is made. We investigate the feasibility of this method by studying the uncertainty of the distance caused by the uncertainties of the measured quantities. It shows that, when the motion o

D. Potter, E. L. Martín, M. C. Cushing, P. Baudoz

We report the discovery of two faint ultracool companions to the nearby (d~17.9 pc) young G2V star HD 130948 (HR 5534, HIP 72567) using the Hokupa&#39;a adaptive optics instrument mounted on the Gemini North 8-meter telescope. Both objects have the same common proper motion as the primary star as seen over a 7 month baseline and have near-IR photometric colo

A. Serquis, X. Y. Liao, Y. T. Zhu, J. Y. Coulter

This work studies the influence of microstructures and crystalline defects on the superconductivity of MgB2, with the objective to improve its flux pinning. A MgB2 sample pellet that was hot isostatic pressed (HIPed) was found to have significantly increased critical current density (Jc) at high fields than its un-HIPed counterpart. The HIPed sample had a Jc

Aristides T. Hatjimihail

In clinical chemistry, a number of studies shows that the probability of very large errors is much greater than expected from the Gaussian distribution. In addition, it has been empirically found that the behavior of nonlinear complex systems is often asymptotically exponential. Consequently, we may assume that the error of some analytical systems may be app

D. Cremades, L. E. Ibanez, F. Marchesano

We present a class of chiral non-supersymmetric D=4 field theories in which quadratic divergences appear only at two loops. They may be depicted as ``SUSY quivers&#39;&#39; in which the nodes represent a gauge group with extended e.g., N=4 SUSY whereas links represent bifundamental matter fields which transform as chiral multiplets with respect to different

Michael E. Hoffman

We begin by considering the graded vector space with a basis consisting of rooted trees, graded by the count of non-root vertices. We define two linear operators on this vector space, the growth and pruning operators, which respectively raise and lower grading; their commutator is the operator that multiplies a rooted tree by its number of vertices. We defin

Pasquale Mazzotta, Roberto Fusco-Femiano, Alexey Vikhlinin

We present results from the combination of two Chandra pointings of the central region of the cluster of galaxies A3667. From the data analysis of the first pointing Vikhlinin et al. reported the discovery of a prominent cold front which is interpreted as the boundary of a cool gas cloud moving through the hotter ambient gas. Vikhlinin et al. discussed the r

Shaouly Bar-Shalom, Gad Eilam, Ya-Dong Yang

We study the pure penguin decays $B \to ϕπ$ and $B^0 \to ϕϕ$. Using QCD factorization, we find ${\cal B}(B^\pm \toϕπ^{\pm} )=2.0^{+0.3}_{-0.1}\times 10^{-8}$. For the pure penguin annihilation process $B^0 \to ϕϕ$, analyzed here for the first time, ${\cal B}(B^0 \toϕϕ)=2.1^{+1.6}_{-0.3}\times 10^{-9}$. The smallness of these decays in the Standard Model make

N. Michel, W. Nazarewicz, M. Ploszajczak, K. Bennaceur

This work presents the first continuum shell-model study of weakly bound neutron-rich nuclei involving multiconfiguration mixing. For the single-particle basis, the complex-energy Berggren ensemble representing the bound single-particle states, narrow resonances, and the non-resonant continuum background is taken. Our shell-model Hamiltonian consists of a on

P. Facchi, S. Pascazio

The quantum Zeno effect is recast in terms of an adiabatic theorem when the measurement is described as the dynamical coupling to another quantum system that plays the role of apparatus. A few significant examples are proposed and their practical relevance discussed. We also focus on decoherence-free subspaces.

Holger Ebel, Lutz-Ingo Mielsch, Stefan Bornholdt

We study the topology of e-mail networks with e-mail addresses as nodes and e-mails as links using data from server log files. The resulting network exhibits a scale-free link distribution and pronounced small-world behavior, as observed in other social networks. These observations imply that the spreading of e-mail viruses is greatly facilitated in real e-m

Timothy L. Barklow, R. Sekhar Chivukula, Joel Goldstein, Tao Han

We discuss the possible signatures in the electroweak symmetry breaking sector by new strong dynamics at future hadron colliders such as the Tevatron upgrade, the LHC and VLHC, and $e^+e^-$ linear colliders. Examples include a heavy Higgs-like scalar resonance, a heavy Technicolor-like vector resonance and pseudo-Goldstone states, non-resonance signatures vi

A. van de Walle, M. Asta

Monte Carlo (MC) simulations of lattice models are a widely used way to compute thermodynamic properties of substitutional alloys. A limitation to their more widespread use is the difficulty of driving a MC simulation in order to obtain the desired quantities. To address this problem, we have devised a variety of high-level algorithms that serve as an interf

S. Lubeck, A. Misra

Extensive simulations are performed to study the persistence behavior of a conserved lattice gas model exhibiting an absorbing phase transition from an active phase into an inactive phase. Both the global and the local persistence exponents are determined in two and higher dimensions. The local persistence exponent obeys a scaling relation involving the orde

M. A. Cazalilla

The ground state properties and low-lying excitations of a (quasi) one-dimensional system of longitudinally confined interacting bosons are studied. This is achieved by extending Haldane&#39;s harmonic-fluid description to open boundary conditions. The boson density, one-particle density matrix, and momentum distribution are obtained accounting for finite-si

V. S. Alves, Ashok Das, Silvana Perez

In this paper, we systematically study the question of screening length in Abelian Chern-Simons theories. In the Abelian Higgs theory, where there are two massive poles in the gauge propagator at the tree level, we show that the coefficient of one of them becomes negligible at high temperature and that the screening length is dominantly determined by the par

A. L. Chernyshev, S. R. White, A. H. Castro Neto

The microscopic structure of a charge stripe in an antiferromagnetic insulator is studied within the t-Jz model using analytical and numerical approaches. We demonstrate that a stripe in an antiferromagnet should be viewed as a system of composite holon-spin-polaron excitations condensed at the self-induced antiphase domain wall (ADW) of the antiferromagneti

Ping Zhang, Qi-Kun Xue, X. C. Xie

This paper has been withdrawn by the authors, since the reference citation were not appropriately arranged.

O. Lange, B. J. Schroers

The time evolution of several interacting Ginzburg-Landau vortices according to an equation of Schroedinger type is approximated by motion on a finite-dimensional manifold. That manifold is defined as an unstable manifold of an auxiliary dynamical system, namely the gradient flow of the Ginzburg-Landau energy functional. For two vortices the relevant unstabl

Harvendra Singh

In this paper we study $T^2$ compactification of 6-dimensional massive type IIA supergravity in presence of Ramond-Ramond background fluxes. The resulting theory in four dimensions is shown to possess $SL(2,R)\times SL(2,R)\times O(4,20)$ duality symmetry. It is shown that specific elements of this symmetry relate massive type IIA compactified on $K3\times T

Ahmed Jellal, Hendrik B. Geyer

The second virial coefficient $B_{2}^{nc}(T)$ for non-interacting particles moving in a two-dimensional noncommutative space and in the presence of a uniform magnetic field $\vec B$ is presented. The noncommutativity parameter $\te$ can be chosen such that the $B_{2}^{nc}(T)$ can be interpreted as the second virial coefficient for anyons of statistics $\al$

M. Kessler, W. Dieterich, H. L. Frisch, J. F. Gouyet

Time-dependent density functional theory, proposed recently in the context of atomic diffusion and non-equilibrium processes in solids, is tested against Monte Carlo simulation. In order to assess the basic approximation of that theory, the representation of non-equilibrium states by a local equilibrium distribution function, we focus on one-dimensional latt

J. Goryo, M. Kohmoto

We consider Bloch electrons in the presence of the uniform electromagnetic field in two- and three-dimensions. It is renowned that the quantized Hall effect occurs in such systems. We suppose a weak and homogeneous electric field represented by the time-dependent vector potential which is changing adiabatically. The adiabatic process can be closed in the par

Toru Aonishi, Koji Kurata, Masato Okada

We have developed a curved isochron clock (CIC) by modifying the radial isochron clock to provide a clean example of the acceleration (deceleration) effect. By analyzing a two-body system of coupled CICs, we determined that an unbalanced mutual interaction caused by curved isochron sets is the minimum mechanism needed for generating the acceleration (deceler

Olindo Corradini, Alberto Iglesias, Zurab Kakushadze, Peter Langfelder

We discuss some issues arising in studying (linearized) gravity on non-BPS higher codimension branes in an infinite-volume bulk. In particular, such backgrounds are badly singular for codimension-3 and higher delta-function-like branes with non-zero tension. As we discuss in this note, non-trivial issues arise in smoothing out such singularities. Thus, addin

Yu. Eltsev, S. Lee, K. Nakao, N. Chikumoto

We report on study of the electronic anisotropy of the newly discovered MgB2 superconductor using the in-plane resistivity measurements in magnetic field applied perpendicular and parallel to Mg and B planes of MgB2 single crystals. The results show temperature dependent anisotropy of the upper critical field with anisotropy ratio increasing from 2.2 close t

D. W. Leung

Quantum process tomography is a procedure by which an unknown quantum operation can be fully experimentally characterized. We reinterpret Choi&#39;s proof of the fact that any completely positive linear map has a Kraus representation [Lin. Alg. and App., 10, 1975] as a method for quantum process tomography. Furthermore, the analysis for obtaining the Kraus o

Wojciech Hubert Zurek

Heisenberg&#39;s principle$^1$ states that the product of uncertainties of position and momentum should be no less than Planck&#39;s constant $\hbar$. This is usually taken to imply that phase space structures associated with sub-Planck ($\ll \hbar$) scales do not exist, or, at the very least, that they do not matter. I show that this deeply ingrained prejud

H. Buhrman, L. Fortnow, I. Newman, H. Roehrig

A language L has a property tester if there exists a probabilistic algorithm that given an input x only asks a small number of bits of x and distinguishes the cases as to whether x is in L and x has large Hamming distance from all y in L. We define a similar notion of quantum property testing and show that there exist languages with quantum property testers

P. Mataloni, G. Giorgi, F. De Martini

A novel single-photon Mach-Zehnder interferometer terminated at two different frequencies realizes the nonlinear frequency conversion of optical quantum superposition states. The information-preserving character of the relevant unitary transformation has been experimentally demonstrated for input qubits and ebits. Besides its own intrinsic fundamental intere

Radim Filip, L. Mista

Transfer of nonlocal two-mode squeezed vacuum state through symmetrical and asymmetrical lossy channel is analysed and we demonstrate that the nonlocality is more robust against losses, than it has been previously suggested. It can be important for security of continuous-variable quantum cryptography employing entangled states.

S. N. Molotkov

The time-energy uncertainty relation is discussed for a relativistic massless particle. The Lorentz-invariant uncertainty relation is obtained between the root-mean-square energy deviation and the scatter of registration time. The interconnection between this uncertainty relation and its classical analogue is established.

Stephen Blaha

We show that human consciousness can be modeled as a classical (not quantum) probabilistic computer. A quantum computer representation does not appear to be indicated because no known feature of consciousness depends on Planck&#39;s constant h, the telltale sign of quantum phenomena. It is argued that the facets of consciousness are describable by an object-

Savely G. Karshenboim

A brief overview is given on precision determinations of values of the fundamental physical constants and the search for their variation with time by means of precision spectroscopy in the optical domain.

S. V. Naydenov, V. D. Ryzhikov

The development prospects of a scintillator-photodiode type detector with an improved energy resolution attaining few per cent, R from 1 to 2%, are considered. The main resolution components have been analyzed theoretically, their theoretical and physical limits have been established. Empirical data on the properties of novel scintillators have been presente

Giorgio Fontana

This document contains two presentations which describe the working principles of a class of electrostatic multidimensional sensors and force actuators. The subject of the study is the search of the most effective methods for measuring the position of a cubical conducting proof mass which floats in a weightless environment. The same proof mass must be contro

D F Roscoe

This paper is essentially a speculation on the realization of Mach&#39;s Principle, and we came to the details of the present analysis via the formulation of two questions: (A) Can a globally inertial space & time be associated with a non-trivial global matter distribution? (B) If so, what are the general properties of such a global distribution? These quest