August 2006 arXiv papers — page 3

A. Bik, L. Kaper, M. M. Hanson, L. B. F. M. Waters

We have obtained high resolution (R = 10,000) K-band spectra of candidate young massive stars deeply embedded in high-mass star-forming regions. These objects were selected from a near-infrared survey of 44 regions of high-mass star-formation (Kaper et al, 2006). In these clusters, 38 OB stars are identified whose K-band spectra are dominated by photospheric

Jacek Szklarski, Günther Rüdiger

The magnetorotational instability (MRI) in cylindrical Taylor-Couette flow with external helical magnetic field is simulated for infinite and finite aspect ratios. We solve the MHD equations in their small Prandtl number limit and confirm with time-dependent nonlinear simulations that the additional toroidal component of the magnetic field reduces the critic

F. Fontani, P. Caselli, A. Crapsi, R. Cesaroni

We have measured the deuterium fractionation (through the column density ratio N(N2D+)/N(N2H+)) and the CO depletion factor (ratio between expected and observed CO abundance) in a sample of 10 high-mass protostellar candidates, in order to understand whether the earliest evolutionary stages of high-mass stars have chemical characteristics similar to those of

Ioannis Contopoulos Demosthenes Kazanas Dimitris M. Christodoulou

We reinvestigate the generation and accumulation of magnetic flux in optically thin accretion flows around active gravitating objects. The source of the magnetic field is the azimuthal electric current associated with the Poynting-Robertson drag on the electrons of the accreting plasma. This current generates magnetic field loops which open up because of the

J. H. Croston, M. Arnaud, E. Pointecouteau, G. W. Pratt

We have developed a regularisation procedure for the direct deprojection and PSF-deconvolution of X-ray surface brightness profiles of clusters of galaxies. This procedure allows us to obtain accurate density profiles in a straightforward manner from X-ray observations (in particular data from XMM-Newton, where the PSF correction is important), while retaini

Todd A. Thompson, Eliot Quataert, Eli Waxman, Abraham Loeb

If cosmic ray protons interact with gas at roughly the mean density of the interstellar medium in starburst galaxies, then pion decay in starbursts is likely to contribute significantly to the diffuse extra-galactic background in both gamma-rays and high energy neutrinos. We describe the assumptions that lead to this conclusion and clarify the difference bet

Claus Leitherer

Stellar clusters are thought to be the simplest stellar systems and the closest observational counterparts to theoretical models for single stellar populations. Progress in our understanding of the atmospheres and evolution of massive stars has led to generally reliable synthesis models. The future release of new evolution models with rotation, however, will

N. Grosso, K. R. Briggs, M. Guedel, S. Guieu

The XMM-Newton Extended Survey of the TMC (XEST) is a large program designed to systematically investigate the X-ray properties of young stellar/substellar objects in the TMC. In particular, the area surveyed by 15 XMM-Newton pointings (of which three are archival observations), supplemented with one archival Chandra observation, allows us to study 17 BDs wi

J. C. B. Papaloizou, G. J. Savonije

In this paper we study the effect of the quadrupole-term in the gravitational potential of a rotationally deformed central Be star on one armed density waves in the circumstellar disc. The aim is to explain the observed long-term violet over red (V/R) intensity variations of the double peaked Balmer emission-lines, not only in cool Be star systems, but also

A. A. Nucita, F. De Paolis, G. Ingrosso, D. Elia

MACHO-96-BLG-5 is a microlensing event observed towards the bulge of the Galaxy with exceptionally long duration of $\sim 970$ days. The microlensing parallax fit parameters were used to estimate the lens mass $M=6^{+10}_{-3}$ M$_{\odot}$ and its distance $d$ which results to be in the range 0.5 kpc - 2 kpc. The upper limit on the absolute brightness for mai

C. Kobayashi, H. Umeda, K. Nomoto, N. Tominaga

We calculate the evolution of heavy element abundances from C to Zn in the solar neighborhood adopting our new nucleosynthesis yields. Our yields are calculated for wide ranges of metallicity (Z=0-Z_\odot) and the explosion energy (normal supernovae and hypernovae), based on the light curve and spectra fitting of individual supernovae. The elemental abundanc

J. V. Cunha, L. Marassi, R. C. Santos

Recent measurements are suggesting that we live in a flat Universe and that its present accelerating stage is driven by a dark energy component whose equation of state may evolve in time. Assuming two different parameterizations for the function $ω(z)$, we constrain their free parameters from a joint analysis involving measurements from X-Ray luminosity of g

Petter Holme

Symmetry -- invariance to certain operators -- is a fundamental concept in many branches of physics. We propose ways to measure symmetric properties of vertices, and their surroundings, in networks. To be stable to the randomness inherent in many complex networks, we consider measures that are continuous rather than dichotomous. The main operator we suggest

Robert Oeckl

The solution of quantum Yang-Mills theory on arbitrary compact two-manifolds is well known. We bring this solution into a TQFT-like form and extend it to include corners. Our formulation is based on an axiomatic system that we hope is flexible enough to capture actual quantum field theories also in higher dimensions. We motivate this axiomatic system from a

Congjun Wu

Optical traps and lattices provide a new opportunity to study strongly correlated high spin systems with cold atoms. In this article, we review the recent progress on the hidden symmetry properties in the simplest high spin fermionic systems with hyperfine spin $F=3/2$, which may be realized with atoms of $^{132}$Cs, $^9$Be, $^{135}$Ba, $^{137}$Ba, and $^{20

Brian D. Metzger, Todd A. Thompson, Eliot Quataert

We solve the 1D neutrino-heated non-relativistic MHD wind problem for conditions that range from slowly rotating (spin period P > 10 ms) protoneutron stars (PNSs) with surface field strengths typical of radio pulsars (B < 10^13 G), to &#34;proto-magnetars&#34; with B ~ 10^14-10^15 G in their hypothesized rapidly rotating initial states (P ~ 1 ms). We use the

Markus Lohrey, Benjamin Steinberg

We show that the membership problem in a finitely generated submonoid of a graph group (also called a right-angled Artin group or a free partially commutative group) is decidable if and only if the independence graph (commutation graph) is a transitive forest. As a consequence we obtain the first example of a finitely presented group with a decidable general

Rituparno Goswami, Pankaj S Joshi

We investigate here spherically symmetric gravitational collapse in a spacetime with an arbitrary number of dimensions and with a general {\it type I} matter field, which is a broad class that includes most of the physically reasonable matter forms. We show that given the initial data for matter in terms of the initial density and pressure profiles at an ini

T. R. Greve, J. Sommer-Larsen

[Abridged] The detection of the rotational lines of CO in proto-galaxies in the early Universe provides one of the most promising ways of probing the fundamental physical properties of a galaxy, such as its size, dynamical mass, gas density, and temperature. While such observations are currently limited to the most luminous galaxies, the advent of ALMA will

Jiangfeng Zhou, Thomas Koschny, Lei Zhang, Gary Tuttle

We introduce an improved and simplified structure made of periodic arrays of pairs of H-shaped metallic wires that offer a potentially simpler approach in building negative-index materials. Using simulations and microwave experiments, we have investigated the negative-index n properties of these structures. We have measured experimentally both the transmitta

Amir Hajian

Traditional Markov Chain Monte Carlo methods suffer from low acceptance rate, slow mixing and low efficiency in high dimensions. Hamiltonian Monte Carlo resolves this issue by avoiding the random walk. Hamiltonian Monte Carlo (HMC) is a Markov chain Monte Carlo (MCMC) technique built upon the basic principle of Hamiltonian mechanics. Hamiltonian dynamics all

B. E. Cobb, C. D. Bailyn, P. G. van Dokkum, P. Natarajan

The lack of an observed supernova associated with GRB 060614 appears to require a new paradigm for the formation of (a subset of) long-duration GRBs. This requirement is based on the presumed low redshift of the burst, which was inferred from the spatial coincidence of the afterglow with a z=0.125 galaxy. We explore the possibility that this low-redshift gal

R. Jauregui, R. Paredes, G. Toledo Sanchez

We perform a variational quantum Monte Carlo simulation of an interacting Fermi gas confined in a three dimensional harmonic potential. This gas is considered as the precursor system from which a molecular bosonic gas is formed. Based on the results of two-body calculations for trapped atoms, we propose a family of variational many-body wave functions that t

W. So, D. V. Lang, V. Y. Butko, X. Chi

We develop a broadly applicable transport-based technique, GAte Modulated activation Energy Spectroscopy (GAMEaS), for determining the density of states (DOS) in the energy gap. GAMEaS is applied to field effect transistors made from different single crystal oligomer semiconductors to extract the free-carrier mobility, u_0, from the field effect mobility, u_

A. Mani

In this expository paper we will be primarily concerned with core aspects of Grids and Grid computing using free and open-source software with some emphasis on utility computing. It is based on a technical report entitled &#39;Grid-Computing Using GNU/Linux&#39; by the present author. This article was written in 2006 and should be of historical interest.

Man-Duen Choi, John A. Holbrook, David W. Kribs, Karol Zyczkowski

We verify a conjecture on the structure of higher-rank numerical ranges for a wide class of unitary and normal matrices. Using analytic and geometric techniques, we show precisely how the higher-rank numerical ranges for a generic unitary matrix are given by complex polygons determined by the spectral structure of the matrix. We discuss applications of the r

N. A. Sinitsyn, A. H. MacDonald, T. Jungwirth, V. K. Dugaev

The anomalous Hall effect (AHE) is a consequence of spin-orbit coupling in a ferromagnetic metal and is related primarily to density-matrix response to an electric field that is off-diagonal in band index. For this reason disorder contributions to the AHE are difficult to treat systematically using a semi-classical Boltzmann equation approach, even when weak

F. Fontanot, S. Cristiani, P. Monaco, M. Nonino

Aims: In this work the luminosity function of QSOs is measured in the redshift range 3.5<z<5.2 for the absolute magnitude interval -21<M_{145}<-28. The determination of the faint end of the luminosity function at these redshifts provides important constraints on models of joint evolution of galaxies and AGNs. Methods: We have defined suitable criteria to sel

A. Christian Silva, Victor M. Yakovenko

We present an empirical study of the subordination hypothesis for a stochastic time series of a stock price. The fluctuating rate of trading is identified with the stochastic variance of the stock price, as in the continuous-time random walk (CTRW) framework. The probability distribution of the stock price changes (log-returns) for a given number of trades N

Laura G. DeMarco, Curtis T. McMullen

The basin of infinity of a polynomial map $f : {\bf C} \arrow {\bf C}$ carries a natural foliation and a flat metric with singularities, making it into a metrized Riemann surface $X(f)$. As $f$ diverges in the moduli space of polynomials, the surface $X(f)$ collapses along its foliation to yield a metrized simplicial tree $(T,η)$, with limiting dynamics $F :

Cesar N. Galindo, Sonia Natale

We show that certain twisting deformations of a family of supersolvable groups are simple as Hopf algebras. These groups are direct products of two generalized dihedral groups. Examples of this construction arise in dimensions 60 and p^2q^2, for prime numbers p, q with q dividing p-1. We also show that certain twisting deformation of the symmetric group is s

Rodolfo Gambini, Jorge Pullin

The use of real clocks and measuring rods in quantum mechanics implies a natural loss of unitarity in the description of the theory. We briefly review this point and then discuss the implications it has for the measurement problem in quantum mechanics. The intrinsic loss of coherence allows to circumvent some of the usual objections to the measurement proces

Iosif Bena, Chih-Wei Wang, Nicholas P. Warner

We use mergers of microstates to obtain the first smooth horizonless microstate solutions corresponding to a BPS three-charge black hole with a classically large horizon area. These microstates have very long throats, that become infinite in the classical limit; nevertheless, their curvature is everywhere small. Having a classically-infinite throat makes the

Detlev Buchholz, Jan Schlemmer

A physically meaningful local concept of temperature is introduced in quantum field theory on curved spacetime and applied to the example of a massless field on de Sitter space. It turns out in this model that the equilibrium (Gibbs) states which can be prepared by a geodesic observer have in general a varying temperature distribution in the neighborhood of

A. Denner, B. Jantzen, S. Pozzorini

We consider two-loop leading and next-to-leading logarithmic virtual corrections to arbitrary processes with external massless fermions in the electroweak Standard Model at energies well above the electroweak scale. Using the sector-decomposition method and alternatively the strategy of regions we calculate the mass singularities that arise as logarithms of

C. Q. Geng, Y. K. Hsiao, J. N. Ng

We study the direct CP violation in $B^\pm\to p\bar p K^{(*)\pm}$ decays in the standard model. We point out that these three-body baryonic B decays can be important tools for detecting the direct CP violation in the charged $B$ system, in which there are no conclusive signatures yet. In particular, we show that the direct CP violating asymmetry in $B^\pm\to

Thomas M. Fiore

As an example of the categorical apparatus of pseudo algebras over 2-theories, we show that pseudo algebras over the 2-theory of categories can be viewed as pseudo double categories with folding or as appropriate 2-functors into bicategories. Foldings are equivalent to connection pairs, and also to thin structures if the vertical and horizontal morphisms coi

Pierre Jammes

On any compact manifold of dimension greater than 3, we exhibit a metric whose first positive eigenvalue for the Laplacian acting on p-form is of multiplicity 2. As a corollary, we prescribe the volume and any finite part of the spectrum of the Hodge Laplacian with multiplicity 1 or 2.

G. L. Fogli, E. Lisi, A. Mirizzi, D. Montanino

The Sun is a source of high energy neutrinos (E > 10 GeV) produced by cosmic ray interactions in the solar atmosphere. We study the impact of three-flavor oscillations (in vacuum and in matter) on solar atmosphere neutrinos, and calculate their observable fluxes at Earth, as well as their event rates in a kilometer-scale detector in water or ice. We find tha

M Tegmark, D Eisenstein, M Strauss, D Weinberg

We measure the large-scale real-space power spectrum P(k) using luminous red galaxies (LRGs) in the Sloan Digital Sky Survey (SDSS) and use this measurement to sharpen constraints on cosmological parameters from the Wilkinson Microwave Anisotropy Probe (WMAP). We employ a matrix-based power spectrum estimation method using Pseudo-Karhunen-Loeve eigenmodes, p

Juri Poutanen, Andrei M. Beloborodov

Approximate analytical formulae are derived for the pulse profile produced by small hot spots on a rapidly rotating neutron star. Its Fourier amplitudes and phases are calculated. The proposed formalism takes into account gravitational bending of light, Doppler effect, anisotropy of emission, and time delays. Its accuracy is checked with exact numerical calc

Hong-Hao Tu, Guang-Ming Zhang, Lu Yu

Based on a generalized one-band Hubbard model, we study magnetic properties of Mott insulating states for ultracold spin-3/2 fermionic atoms in optical lattices. When the \textit{s}-wave scattering lengths for the total spin $S=2,0$ satisfy conditions $a_{2}>a_{0}>0$, we apply a functional integral approach to the half filled case, where the spin-quadrupole

V. Buescher, M. Carena, B. Dobrescu, S. Mrenna

This is the &#34;TeV4LHC&#34; report of the &#34;Physics Landscapes&#34; Working Group, focused on facilitating the start-up of physics explorations at the LHC by using the experience gained at the Tevatron. We present experimental and theoretical results that can be employed to probe various scenarios for physics beyond the Standard Model.

Roberto Venegeroles

The leading Pollicott-Ruelle resonance is calculated analytically for a general class of two-dimensional area-preserving maps. Its wave number dependence determines the normal transport coefficients. In particular, a general exact formula for the diffusion coefficient D is derived without any high stochasticity approximation and a new effect emerges: The ang

Daniel Bundzik

We extend the definition of the star product introduced by Lunin and Maldacena to study marginal deformations of N=4 SYM. The essential difference from the latter is that instead of considering U(1)xU(1) non-R-symmetry, with charges in a corresponding diagonal matrix, we consider two Z_3-symmetries followed by an SU(3) transformation, with resulting off-diag

W. C. Lim, A. A. Coley, S. Hervik

We study the properties of a future singularity encountered by a perfect fluid observer in tilting spatially homogeneous Bianchi cosmologies. We derive the boost formulae for the Weyl tensor to establish that, for two observers that are asymptotically null with respect to each other, their respective Weyl parameters generally both tend to zero, constant, or

J. Saramaki, M. Kivela, J. -P. Onnela, K. Kaski

The recent high level of interest in weighted complex networks gives rise to a need to develop new measures and to generalize existing ones to take the weights of links into account. Here we focus on various generalizations of the clustering coefficient, which is one of the central characteristics in the complex network theory. We present a comparative study

Roy Wagner

We prove tail estimates for variables $\sum_i f(X_i)$, where $(X_i)_i$ is the trajectory of a random walk on an undirected graph (or, equivalently, a reversible Markov chain). The estimates are in terms of the maximum of the function $f$, its variance, and the spectrum of the graph. Our proofs are more elementary than other proofs in the literature, and our

S. -J. Paardekooper, G. Mellema

Aims: We investigate the effect of including a proper energy balance on the interaction of a low-mass planet with a protoplanetary disk. Methods: We use a three-dimensional version of the RODEO method to perform hydrodynamical simulations including the energy equation. Radiation is included in the flux-limited diffusion approach. Results: The sign of the tor

Gabor Ivanyos, Attila B. Nagy, Lajos Ronyai

We present generalized and improved constructions for simulating quantum computers with a polynomial slowdown on lattices composed of qubits on which certain global versions of one- and two-qubit operations can be performed.

R. Garcia Martin, J. R. Pelaez

We present a model independent study of the chiral condensate evolution in a hadronic gas, in terms of temperature and baryon chemical potential. The meson-meson interactions are described within Chiral Perturbation Theory and the pion-nucleon interaction by means of Heavy Baryon Chiral Perturbation Theory, both at one loop, and nucleon-nucleon interactions

H. C. Krahl, C. Wetterich

The temperature dependence of d-wave superconducting order for two dimensional fermions with d-wave attraction is investigated by means of the functional renormalization group with partial bosonization. Below the critical temperature T_c we find superconductivity, a gap in the electron propagator and a temperature dependent anomalous dimension. At T_c the re

A. Baykal, S. C. Inam, M. J. Stark, C. M. Heffner

SAX J2103.5+4545 has been continuously monitored for $\sim $ 900 days by Rossi X-ray Timing Explorer (RXTE) since its outburst in July 2002. Using these observations and previous archival RXTE observations of SAX J2103.5+4545, we refined the binary orbital parameters and find the new orbital period as P= (12.66536 $\pm $ 0.00088) days and the eccentricity as

Tomoyoshi Hirata, Tadashi Takayanagi

Recently, a holographic computation of the entanglement entropy in conformal field theories has been proposed via the AdS/CFT correspondence. One of the most important properties of the entanglement entropy is known as the strong subadditivity. This requires that the entanglement entropy should be a concave function with respect to geometric parameters. It i

S. G. Ghosh

We obtain the analogue of collapsing Vaidya-like solution to include both a null fluid and a string fluid, with a linear equation of state ($p_{\bot} = k ρ$), in non-spherical (plane symmetric and cylindrically symmetric) anti-de Sitter space-timess. It turns out that the non-spherical collapse of two fluid in anti-de Sitter space-times, in accordance with c

Thierry Cachat

Ordinal automata are used to model physical systems with Zeno behavior. Using automata and games techniques we solve a control problem formulated and left open by Demri and Nowak in 2005. It involves partial observability and a new synchronization between the controller and the environment.

Etera R. Livine, Simone Speziale

We consider the proposal of gr-qc/0508124 for the extraction of the graviton propagator from the spinfoam formalism. We propose a new ansatz for the boundary state, using which we can write the propagator as an integral over SU(2). The perturbative expansion in the Planck length can be recast into the saddle point expansion of this integral. We compute the l

Will J. Percival, Robert C. Nichol, Daniel J. Eisenstein, David H. Weinberg

We measure the cosmological matter density by observing the positions of baryon acoustic oscillations in the clustering of galaxies in the Sloan Digital Sky Survey (SDSS). We jointly analyse the main galaxies and LRGs in the SDSS DR5 sample, using over half a million galaxies in total. The oscillations are detected with 99.74% confidence (3.0sigma assuming G

Will J. Percival, Robert C. Nichol, Daniel J. Eisenstein, Joshua A. Frieman

We present a Fourier analysis of the clustering of galaxies in the combined Main galaxy and Luminous Red Galaxy (LRG) Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) sample. The aim of our analysis is to consider how well we can measure the cosmological matter density using the signature of the horizon at matter-radiation equality embedded in the large-

Rabin Banerjee, Saurav Samanta

By abstracting a connection between gauge symmetry and gauge identity on a noncommutative space, we analyse star (deformed) gauge transformations with usual Leibnitz rule as well as undeformed gauge transformations with a twisted Leibnitz rule. Explicit structures of the gauge generators in either case are computed. It is shown that, in the former case, the

Javier Aramayona, Hugo Parlier, Kenneth J. Shackleton

Our main theorem asserts that every Farey graph embedded in the 1-skeleton of the pants complex of any finite type surface is totally geodesic.

Sho Matsumoto

We express the averages of products of characteristic polynomials for random matrix ensembles associated with compact symmetric spaces in terms of Jack polynomials or Heckman and Opdam's Jacobi polynomials depending on the root system of the space. We also give explicit expressions for the asymptotic behavior of these averages in the limit as the matrix size

A. A. Lopatin

Amitsur&#39;s formula, which expresses det(A+B) as a polynomial in coefficients of the characteristic polynomial of a matrix, is generalized for partial linearizations of the pfaffian of block matrices. As applications, in upcoming papers we determine generators for the SO(n)-invariants of several matrices and relations for the O(n)-invariants of several mat

A. A. Lopatin

We consider a generalization of representations of quivers that can be derived from the ordinary representations of quivers by considering a product of arbitrary classical groups instead of a product of the general linear groups and by considering the dual action of groups on &#34;vertex&#34; vector spaces together with the usual action. A generating system

Fuqiang Xu, Jin Min Yang

We examine the constraints on F-term hybrid inflation by considering the flat directions in the Minimal Supersymmetric Standard Model (MSSM). We find that some coupling terms between the flat direction fields and the field which dominates the energy density during inflation are quite dangerous and can cause the no-exit of hybrid inflation even if their coupl

M. Cencelj, J. Dydak, J. Smrekar, A. Vavpetic

The simplest condition characterizing quasi-finite CW complexes $K$ is the implication $Xτ_h K\implies β(X)τK$ for all paracompact spaces $X$. Here are the main results of the paper: Theorem: If $\{K_s\}_{s\in S}$ is a family of pointed quasi-finite complexes, then their wedge $\bigvee\limits_{s\in S}K_s$ is quasi-finite. Theorem: If $K_1$ and $K_2$ are quas

Takuma Ohashi, Sei-ichiro Suga, Norio Kawakami, Hirokazu Tsunetsugu

We investigate the characteristics of the metallic phase near the Mott transition in the Kagomé lattice Hubbard model using the cellular dynamical mean field theory. By calculating the specific heat and spin correlation functions, we demonstrate that the quasiparticles show anomalous properties in the metallic phase close to the Mott transition. We find clea

H. G. Khachatryan

We have derived the invariants of cosmological models with Gurzadyan-Xue dark energy, along with the solutions for any time dependent light speed and gravitational constant. The correspondence of the invariants with the separatrices found earlier for the GX-models in \cite{Ver06a} is shown, and hence the basis of then detected hidden symmetry is now revealed

Guoming Wang, Mingsheng Ying

We propose a scheme that can realize a class of positive-operator-valued measures (POVMs) by performing a sequence of projective measurements on the original system, in the sense that for an arbitrary input state the probability distribution of the measurement outcomes is faithfully reproduced. A necessary and sufficient condition for a POVM to be realizable

Dongsheng Du

CP asymmetries for neutral charmed meson decays to CP eigenstates are carefully studied. The formulas and numerical results are presented. The impact on experiments is briefly discussed.

Kenichi Kasamatsu, Makoto Tsubota

We present simulation results of the vortex dynamics in a trapped Bose-Einstein condensate in the presence of a rotating optical lattice. Changing the potential amplitude and the relative rotation frequency between the condensate and the optical lattice, we find a rich variety of dynamical phases of vortices. The onset of these different phases is described

X. L. Lei, S. Y. Liu

The magnetoresistance oscillations in high-mobility two-dimensional electron systems induced by two radiation fields of frequencies 31 GHz and 47 GHz, are analyzed in a wide magnetic-field range down to 100 G, using the balance-equation approach to magnetotransport for high-carrier-density systems. The frequency mixing processes are shown to be important. Th

Bernard Shiffman, Steve Zelditch

We show that the variance of the number of simultaneous zeros of $m$ i.i.d. Gaussian random polynomials of degree $N$ in an open set $U \subset C^m$ with smooth boundary is asymptotic to $N^{m-1/2} \nu_{mm} Vol(\partial U)$, where $\nu_{mm}$ is a universal constant depending only on the dimension $m$. We also give formulas for the variance of the volume of t

Y. Shi, G. H. Rieke, D. C. Hines, V. Gorjian

We describe observations of 9.7 um silicate features in 97 AGNs, exhibiting a wide range of AGN types and of X-ray extinction toward the central nuclei. We find that the strength of the silicate feature correlates with the HI column density estimated from fitting the X-ray data, such that low HI columns correspond to silicate emission while high columns corr

O. A. Grachov, M. J. Murray, A. S. Ayan, P. Debbins

The Zero Degree Calorimeter (ZDC) is integral part of the CMS experiment, especially, for heavy ion studies. The design of the ZDC includes two independent calorimeter sections: an electromagnetic section and a hadronic section. Sampling calorimeters using tungsten and quartz fibers have been chosen for the energy measurements. An overview of the ZDC is pres

Richard Massey, Catherine Heymans, Joel Berge, Gary Bernstein

The Shear TEsting Programme (STEP) is a collaborative project to improve the accuracy and reliability of weak lensing measurement, in preparation for the next generation of wide-field surveys. We review sixteen current and emerging shear measurement methods in a common language, and assess their performance by running them (blindly) on simulated images that

M. M. Parish, F. M. Marchetti, A. Lamacraft, B. D. Simons

We consider a two-component atomic Fermi gas within a mean-field, single-channel model, where both the mass and population of each component are unequal. We show that the tricritical point at zero temperature evolves smoothly from the BEC- to BCS-side of the resonance as a function of mass ratio r. We find that the interior gap state proposed by Liu and Wilc

Nahum Zobin

We propose a construction of actions of a quantum gauge field theory on a noncommutative space-time, based on a Fourier transform on the Doplicher-Fredenhagen-Roberts group. This approach leads to a functional integral representation of the action, which in turn leads to considering the space of probability measures on the classical space-time as a noncommut

J. A. Dunningham, K. Burnett, R. Roth, W. D. Phillips

We consider how macroscopic quantum superpositions may be created from arrays of Bose-Einstein condensates. We study a system of three condensates in Fock states, all with the same number of atoms and show that this has the form of a highly entangled superposition of different quasi-momenta. We then show how, by partially releasing these condensates and dete

D. L. Zhou, B. Zeng, Z. Xu, L. You

We propose a genuine multi-party correlation measure for a multi-party quantum system as the trace norm of the cumulant of the state. The legitimacy of our multi-party correlation measure is explicitly demonstrated by proving it satisfies the five basic conditions required for a correlation measure. As an application we construct an efficient algorithm for t

K. De Raedt, K. Michielsen, H. De Raedt, B. Trieu

We describe portable software to simulate universal quantum computers on massive parallel computers. We illustrate the use of the simulation software by running various quantum algorithms on different computer architectures, such as a IBM BlueGene/L, a IBM Regatta p690+, a Hitachi SR11000/J1, a Cray X1E, a SGI Altix 3700 and clusters of PCs running Windows X

Tao Zhang, Zheng-Fu Han, Xiao-Fan Mo, Guang-Can Guo

A feasible quantum key distribution (QKD) network scheme has been proposed with the wavelength routing. An apparatus called &#34;quantum router&#34;, which is made up of many wavelength division multiplexers, can route the quantum signals without destroying their quantum states. Combining with existing point-to-point QKD technology, we can setup a perfectly

Erik Sjöqvist

A sequence of completely positive maps can be decomposed into quantum trajectories. The geometric phase or holonomy of such a trajectory is delineated. For nonpure initial states, it is shown that well-defined holonomies can be assigned by using Uhlmann&#39;s concept of parallel transport along the individual trajectories. We put forward an experimental real

Sung Soon Jang, Yong Wook Cheong, Jaewan Kim, Hai-Woong Lee

We investigate the robustness of multiparty nonlocality under local decoherence, acting independently and equally on each subsystems. To be specific, we consider an N-qubit GHZ state under depolarization, dephasing, or dissipation channel, and tested the nonlocality by violation of Mermin-Klyshko inequality, which is one of Bell&#39;s inequalities for multi-

Shujing Li, Bo Wang, Xudong Yang, Yanxu Han

We investigate, both theoretically and experimentally, the phenomenon of polarization rotation of a weak, linearly-polarized optical (probe) field in an atomic system with multiple three-level electromagnetically induced transparency (EIT) sub-systems. The polarization rotation angle can be controlled by a circularly-polarized coupling beam, which breaks the

Stein Olav Skrøvseth

We investigate the entanglement properties of a finite size 1+1 dimensional Ising spin chain, and show how these properties scale and can be utilized to reconstruct the ground state wave function. Even at the critical point, few terms in a Schmidt decomposition contribute to the exact ground state, and to physical properties such as the entropy. Nevertheless

W. A. Al-Saidi, Henry Krakauer, Shiwei Zhang

A series of calculations for the first- and second-row post-d elements (Ga-Br and In-I) are presented using the phaseless auxiliary-field quantum Monte Carlo (AF QMC) method. This method is formulated in a Hilbert space defined by any chosen one-particle basis, and maps the many-body problem into a linear combination of independent-particle solutions with ex

Pablo Jensen

I study the spatial organization of retail commercial activities. These are organized in a network comprising &#34;anti-links&#34;, i.e. links of negative weight. From pure location data, network analysis leads to a community structure that closely follows the commercial classification of the US Department of Labor. The interaction network allows to build a

Stacey M. Davis, Scott V. Franklin

Students express a wide range of preferences for learning environments. We are trying to measure the manifestation of learning styles in various learning environments. In particular, we are interested in performance in an environment that disagrees with the expressed learning style preference, paying close attention to social (group vs. individual) and audit

Charles Henderson, Melissa H. Dancy

Physics Education Research (PER) practitioners have engaged in substantial curriculum development and dissemination work in recent years. Yet, it appears that this work has had minimal influence on the fundamental teaching practices of typical physics faculty. To better understand this situation interviews were conducted with 5 likely users of physics educat

Charles Henderson, Andrea Beach, Michael Famiano

Physics Education Research (PER) has made significant progress in developing knowledge about teaching and learning as well as effective instructional strategies based on this knowledge. Disseminating knowledge and strategies to other faculty, however, has proven difficult. Coteaching is a promising and cost-effective alternative to traditional professional d

Malgorzata Snarska, Jakub Krzych

Portfolio theory is a very powerful tool in the modern investment theory. It is helpful in estimating risk of an investor&#39;s portfolio, which arises from our lack of information, uncertainty and incomplete knowledge of reality, which forbids a perfect prediction of future price changes. Despite of many advantages this tool is not known and is not widely u

A. P. Willis, R. R. Kerswell

The statistics of the relaminarisation of localised turbulence in a pipe are examined by direct numerical simulation. As in recent experimental data (Peixinho & Mullin, Phys. Rev. Lett. 96, 094501, 2006), the half life for the decaying turbulence is consistent with the scaling (Re_c-Re)^{-1}, indicating a boundary crisis of the localised turbulent state fami

Niels Gregersen, Bjarne Tromborg, Sergey I. Bozhevolnyi

Using exact three-dimensional vectorial simulations of radiation coupling into uncoated dielectric fiber probes, we calculate amplitude transfer functions for conical single-mode fiber tips at the light wavelength of 633 nm. The coupling efficiency of glass fiber tips is determined in a wide range of spatial frequencies of the incident radiation for opening

Bernd Surrow

An electron-proton/ion collider facility (eRHIC) is under consideration at Brookhaven National Laboratory (BNL). An overview of the accelerator and detector design concepts will be provided.

Jason N. Hancock, Trieu T. Mai, Zack Schlesinger

We demonstrate that an effect other than anharmonicity can severely distort the spectroscopic signatures of quantum mechanical systems. This is done through an analytic calculation of the spectroscopic response of a simple system, a charged torsional pendulum. One may look for these effects in the optical data of real systems when for example a significant r

Charles B. Chiu, Rudolph C. Hwa

A model of parton multiple scattering in a dense and expanding medium is described. The simulated results reproduce the general features of the data. In particular, in the intermediate trigger momentum region there is a dip-bump structure, while at higher trigger momentum the double bumps merge into a central peak. Also, a new measure is proposed to quantify

B. Julia-Diaz

The use of relativistic quark models with simple parametric wave functions for the understanding of the electromagnetic structure of nucleons together with their electromagnetic transition to resonances is discussed. The implications of relativity in the different ways it can be implemented in a simple model are studied together with the role played by mixed

Stephane Haussler, Mohamed Abdel-Aziz, Marcus Bleicher

We use the Ultra-relativistic Quantum Molecular Dynamic model (UrQMD v2.2) to study forward-backward fluctuations and compare our results with the data published by the PHOBOS experiment. The extracted effective cluster multiplicities show a clear centrality dependence within the present hadron-string transport approach. This behavior is not reproduced with

Th. A. Rijken, Y. Yamamoto

This paper presents the Extended-Soft-Core (ESC) potentials ESC04a-d for baryon-baryon channels with total strangeness $S=-2$. For these channels no experimental scattering data exist, and alsothe information from hypernuclei is very limited.The potential models for $S=-2$ are based on SU(3) extensions of potential models for the $S=0,-1$ sectors, which are