November 2005 arXiv papers — page 18

A. Collins, J. McEvoy, D. Robinson, C. J. Hamer

A new quantum spin model with frustration, the `Union Jack' model on the square lattice, is analyzed using spin-wave theory. For small values of the frustrating coupling $α$, the system is N{\' e}el ordered as usual, while for large $α$ the frustration is found to induce a canted phase. The possibility of an intermediate spin-liquid phase is discusse

Alba Margarita Resendiz Antonio, Hernan Larralde

We calculate the explicit probability distribution function for the flux between sites in a simple discrete time diffusive system composed of independent random walkers. We highlight some of the features of the distribution and we discuss its relation to the local instantaneous entropy production in the system. Our results are applicable both to equilibrium

H. Yamauchi, K. Sakai, T. Nagai, Y. Matsui

Misfit-layered (ML) cobalt oxides of the general formula of [MmA2Om+2]qCoO2 have been proven to be efficient thermoelectric materials as the structure is capable in accommodating the two seemingly contradictory characteristics of high electrical conductivity and large thermo-electric power. They are also potential hosts for other oxymoron-like functions. The

Mukunda P Das, Frederick Green

The understanding of mesoscopic transport has now attained an ultimate simplicity. Indeed, orthodox quantum kinetics would seem to say little about mesoscopics that has not been revealed - nearly effortlessly - by more popular means. Such is far from the case, however. The fact that kinetic theory remains very much in charge is best appreciated through the p

Jae Dong Noh

We study the condensation phenomenon in a zero range process on scale-free networks. We show that the stationary state property depends only on the degree distribution of underlying networks. The model displays a stationary state phase transition between a condensed phase and an uncondensed phase, and the phase diagram is obtained analytically. As for the dy

Kun Yang

In a very interesting recent Letter\cite{machida}, the authors suggested the possibility of realizing the spatially modulated, or Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluid state in trapped atomic fermion systems. The authors this Letter used a 1D mean field solution as guidance to estimate the parameter range for the existence of the FFLO phase, and

Ch. Kolf, J. Kroha, M. Ternes, W. -D. Schneider

In a recent Letter, Luo et al. (Phys. Rev. Lett. 92, 256602 (2004)) analyze the Fano line shapes obtained from scanning tunneling spectroscopy (STS) of transition metal impurities on a simple metal surface, in particular of the Ti/Au(111) and Ti/Ag(100) systems. As the key point of their analysis, they claim that there is not only a Fano interference effect

M. Yokoyama, H. Amitsuka, K. Tenya, K. Watanabe

We have performed elastic neutron scattering experiments under uniaxial stress sigma applied along the tetragonal [100], [110] and [001] directions for the heavy electron compound URu2Si2. We found that antiferromagnetic (AF) order with large moment is developed with sigma along the [100] and [110] directions. If the order is assumed to be homogeneous, the s

A. Panaitescu

We use the available radio, optical and X-ray measurements for the afterglows of the short bursts 050709 and 050724 to constrain the blast-wave energy, its collimation and the density of the circumburst medium. For GRB 050709 (whose duration was 0.07 s), we identify two models: i) a high-density solution, where the ejecta are collimated in a jet of half-angl

C. Froehlich, W. R. Hix, G. Martinez-Pinedo, M. Liebendoerfer

Core collapse supernovae are the leading actor in the story of the cosmic origin of the chemical elements. Existing models, which generally assume spherical symmetry and parameterize the explosion, have been able to broadly replicate the observed elemental pattern. However, inclusion of neutrino interactions produces noticeable improvement in the composition

Renato Dupke

Cold fronts are sharp surface brightness discontinuities characterized by a jump in gas temperature accompanied by a decline in X-ray surface brightness such that the gas pressure remains continuous across the front and, thus, these structures differ from bow shocks. Models suggest that cold fronts can be generated by external mechanisms involving the accret

A. van der Wel, M. Franx, P. G. van Dokkum, J. Huang

We measure the evolution of the rest-frame K-band Fundamental Plane from z=1 to the present by using IRAC imaging of a sample of early-type galaxies in the Chandra Deep Field-South at z~1 with accurately measured dynamical masses. We find that $M/L_K$ evolves as $Δ\ln{(M/L_K)}=(-1.18\pm0.10)z$, which is slower than in the B-band ($Δ\ln{(M/L_B)}=(-1.46\pm0.09

S. D. Barthelmy, G. Chincarini, D. N. Burrows, N. Gehrels

Two short (<2 s) g-ray bursts (GRBs) have recently been localized and fading afterglow counterparts detected. The combination of these two results left unclear the nature of the host galaxies of the bursts, because one was a star-forming dwarf, while the other was probably an elliptical galaxy. Here we report the X-ray localization of a short burst (GRB 0507

A. B. Garson, I. V. Jung, J. Perkins, H. Krawczynski

Using 2.0 cm x 2.0 cm x 0.5 cm Cadmium Telluride (CdTe) substrates from the company Acrorad, we have fabricated detectors with planar cathode contacts and 8x8 anode pixels. We investigate the I-V characteristics and energy resolution of the detectors for different contact materials and surface treatments. After biasing the detectors for a certain period of t

S. D. Barthelmy, J. K. Cannizzo, N. Gehrels, G. Cusumano

BAT and XRT observations of two recent well-covered GRBs observed by Swift, GRB 050315 and GRB 050319, show clearly a prompt component joining the onset of the afterglow emission. By fitting a power law form to the gamma-ray spectrum, we extrapolate the time dependent fluxes measured by the BAT, in the energy band 15-350 keV, into the spectral regime observe

I. Jung, A. B. Garson, J. S. Perkins, H. Krawczynski

We explore the possibility to improve the performance of 0.5 cm thick Cadmium Zinc Telluride (CZT) detectors with the help of steering grids on the anode side of the detectors. Steering grids can improve the energy resolution of CZT detectors by enhancing the small pixel effect; furthermore, they can increase their detection efficiency by steering electrons

Josefa Perez, Patricia Tissera, Diego Garcia Lambas, Cecilia Scannapieco

Using chemical hydrodynamical simulations consistent with a Lambda-CDM model, we study the role played by mergers and interactions in the regulation of the star formation activity, colours and the chemical properties of galaxies in pairs. A statistical analysis of the orbital parameters in galaxy pairs (r <100 kpc/h) shows that the star formation (SF) activi

K. I. Caputi, R. J. McLure, J. S. Dunlop, M. Cirasuolo

We have selected and analysed the properties of a sample of 2905 Ks<21.5 galaxies in ~ 131 sq.arcmin of the Great Observatories Origins Deep Survey (GOODS) Chandra Deep Field South (CDFS), to obtain further constraints on the evolution of Ks-selected galaxies with respect to the results already obtained in previous studies. We made use of the public deep mul

V. Mukhanov

I review the motivation for the early-time cosmic acceleration stage in expanding universe and discuss simple inflationary scenarios. Preheating and reheating are considered in great detail. This is a sample chapter from my book &#34;Physical Foundations of Cosmology&#34; published by Cambridge University Press (2005).

Jiri Horak

It was pointed out by Paczynski (1987) that the X-ray luminosity of accreting neutron stars is very sensitive to the physical properties of the accretion flow close to the innermost stable circular orbit. The X-ray radiation is dominated by that emitted in the boundary layer, where accreted matter hits a star surface. The X-ray luminosity of the boundary lay

J Crummy, AC Fabian, L Gallo, RR Ross

We present a large sample of type 1 AGN spectra taken with XMM-Newton. We fit them with the relativistically blurred photoionized disc model of Ross & Fabian (2005). This model is based on an illuminated accretion disc of fluorescing and Compton-scattering gas, and includes relativistic Doppler effects due to the rapid motion of the disc and general relativi

Sergey Mashchenko, Alison Sills, H. M. P. Couchman

By fitting a flexible stellar anisotropy model to the observed surface brightness and line-of-sight velocity dispersion profiles of Draco we derive a sequence of cosmologically plausible two-component (stars + dark matter) models for this galaxy. The models are consistent with all the available observations and can have either cuspy Navarro-Frenk-White or fl

Sverre Aarseth

(Abridged) In this celebratory contribution, we present some new data from standard star cluster modelling containing primordial binaries and triples, as well as results from a binary black hole simulation with two massive members. In the star cluster case, the process of mass loss from evolving stars, together with general mass segregation, promotes favoura

Paola D&#39;Alessio, Nuria Calvet, Lee Hartmann, Ramiro Franco-Hernandez

We present self-consistent disk models for T Tauri stars which include a parameterized treatment of dust settling and grain growth, building on techniques developed in a series of papers by D&#39;Alessio etal. The models incorporate depleted distributions of dust in upper disk layers along with larger-sized particles near the disk midplane, as expected theor

G. Rodighiero, C. Lari, F. Pozzi, C. Gruppioni

We address the question of how to deal with confusion limited surveys in the mid-infrared domain by using informations from higher frequency observations over the same sky regions. Such informations, once applied to apparently extended mid-infrared sources, which are indeed ``blends&#39;&#39; of two or more different sources, allow us to disentangle the sing

H. P. Summers, W. J. Dickson, M. G. O&#39;Mullane, N. R. Badnell

The paper presents an integrated view of the population structure and its role in establishing the ionisation state of light elements in dynamic, finite density, laboratory and astrophysical plasmas. There are four main issues, the generalised collisional-radiative picture for metastables in dynamic plasmas with Maxwellian free electrons and its particularis

Sylvain Chaty, Roberto P. Mignani, Gianluca Israel

We had reported in Chaty, Mignani, Israel (2002) on the near-infrared (NIR) identification of a possible counterpart to the black hole candidate XTE J1908+094 obtained with the ESO/NTT. Here, we present new, follow-up, CFHT adaptive optics observations of the XTE J1908+094 field, which resolved the previously proposed counterpart in two objects separated by

G. Ghirlanda, G. Ghisellini, C. Firmani, L. Nava

We present the constraints on the cosmological parameters obtained with the $E_{\rm peak}$--$E_γ$ correlation found with the most recent sample of 19 GRBs with spectroscopically measured redshift and well determined prompt emission spectral and afterglow parameters. We compare our results obtained in the two possible uniform jet scenarios, i.e. assuming a ho

J. H. Knapen, L. M. Mazzuca, T. Boeker, I. Shlosman

Context: The morphology of massive star formation in the central regions of galaxies is an important tracer of the dynamical processes that govern the evolution of disk, bulge, and nuclear activity. Aims: We present optical imaging of the central regions of a sample of 73 spiral galaxies in the H alpha line and in optical broad bands, and derive information

Martin Bojowald

Loop quantum cosmology is an application of recent developments for a non-perturbative and background independent quantization of gravity to a cosmological setting. Characteristic properties of the quantization such as discreteness of spatial geometry entail physical consequences for the structure of classical singularities as well as the evolution of the ve

Carlos G. Bornancini, Diego G. Lambas, Carlos De Breuck

We have analyzed galaxy properties in the environment of a sample of 70 Ultra Steep Spectrum (USS) radio sources selected from the Sydney University Molonglo sky Survey and the NRAO VLA Sky Survey catalogues, using near-IR data complete down to Ks=20. We have quantified galaxy excess around USS targets using an Abell-type measurement N0.5 (Hill & Lilly 1991)

V. N. Frolov, J. K. Ananjevskaja, E. G. Jilinski, D. L. Gorshanov

The results of the complex study of galactic open cluster Trumpler 2 are presented. In order to obtain the proper motions the positions of 2600 stars up to the limit magnitude B ~ 16.25 mag in the area 80x80 arcmin around the cluster were measured on 6 plates with the maximal epoch difference of 63 years. The root-mean error of the relative proper motions is

J. Silverman, P. Green, W. Barkhouse, R. Cameron

X-ray surveys of the extragalactic universe are now able to detect significant numbers of AGN out to high redshift (z~5). We highlight some results from the Chandra Multiwavelength Project (ChaMP) to measure the X-ray luminosity function out to these early epochs. At z > 3, we show that the comoving space density of luminous (log Lx > 44.5) AGN has a behavio

M. A. Hendry, R. Ignace, H. M. Bryce

This paper examines line profile evolution due to the linear expansion of circumstellar material obsverved during a microlensing event. This work extends our previous papers on emission line profile evolution from radial and azimuthal flow during point mass lens events and fold caustic crossings. Both &#39;&#39;flavours&#39;&#39; of microlensing were shown t

Xin Liu, Shuang Nan Zhang

We cross correlate the Wilkinson Microwave Anisotropy Probe (WMAP) first year data and the diffuse gamma-ray intensity maps from the Energetic Gamma Ray Experiment Telescope (EGRET) using spherical wavelet approaches. Correlations at 99.7% significance level have been detected, at scales around $15^{\circ}$ in the WMAP foreground cleaned W-band and Q-band ma

Aristotle Socrates, Shane W. Davis

The radiation spectra of many of the brightest ultraluminous X-ray sources (ULXs) are dominated by a hard power law component, likely powered by a hot, optically thin corona that Comptonizes soft seed photons emitted from a cool, optically thick black hole accretion disk. Before its dissipation and subsequent conversion into coronal photon power, the randomi

Weijun Zheng, David Jewitt, Ralf I. Kaiser

Water ice is abundant both astrophysically, for example in molecular clouds, and in planetary systems. The Kuiper belt objects, many satellites of the outer solar system, the nuclei of comets and some planetary rings are all known to be water-rich. Processing of water ice by energetic particles and ultraviolet photons plays an important role in astrochemistr

R. Weinberger, S. Temporin, B. Stecklum

The Monogem Ring is a huge bright soft X-ray enhancement with a diameter of ~ 25$\degr$. This 0.3 kpc distant structure is a peculiar Galactic supernova remnant in that it is obviously visible only in X-rays, due to its expansion into a region of extremely low ambient density: hence, practically no optical emission or a neutral HI shell was expected to be de

Laurent Piau

We investigate the history of $^6$Li and $^7$Li in population II dwarfs during the pre main sequence and main sequence. The evolution is followed using the CESAM code and taking into account the most recent physics. The effective temperature ranges from $\approx$ 4700 K to $\approx$ 6400 K and therefore concerns objects on the so-called Spite plateau and coo

Edward N Taylor

We have developed a simple, static model designed to place a very solid lower limit on the star formation rate (SFR) expected in a dwarf disk galaxy, which leads to the prediction of a previously undocumented relation between HI mass, M_HI, and SFR. Over the mass range 10^8--10^10 M_sun, a wide variety of galaxies are observed to follow such a relation -- SF

G. Polenta, D. Marinucci, A. Balbi, P. de Bernardis

We discuss the derivation of the analytic properties of the cross-power spectrum estimator from multi-detector CMB anisotropy maps. The method is computationally convenient and it provides unbiased estimates under very broad assumptions. We also propose a new procedure for testing for the presence of residual bias due to inappropriate noise subtraction in ps

Nemanja Kaloper, Lorenzo Sorbo

We review the pNGB quintessence models, and point out that the reason why the large decay constants $f_a \ga {\cal O}(1)M_{Pl}$ are really needed is to tame a tachyonic instability present for a wide range of initial $vev$s. Starting very close to potential maxima does not help because quantum fluctuations during early inflation at a scale $H_I$ perturb the

Paul Vojta

In 1982-83, E. Nochka proved a conjecture of Cartan on defects of holomorphic curves in $\Bbb P^n$ relative to a possibly degenerate set of hyperplanes. This was further explained by W. Chen in his 1987 thesis, and subseqently simplified by M. Ru and P.-M. Wong in 1991. The proof involved assigning weights to the hyperplanes. This paper provides a mild simpl

John F. Donoghue, Koushik Dutta, Andreas Ross

Even if quark and lepton masses are not uniquely predicted by the fundamental theory, as may be the case in the string theory landscape, nevertheless their pattern may reveal features of the underlying theory. We use statistical techniques to show that the observed masses appear to be representative of a scale invariant distribution, rho(m) ~ 1/m. If we exte

Robert B. Mann, Cristian Stelea

We use local counterterm prescriptions for asymptotically flat space to compute the action and conserved quantities in five-dimensional Kaluza-Klein theories. As an application of these prescriptions we compute the mass of the Kaluza-Klein magnetic monopole. We find consistent results with previous approaches that employ a background subtraction.

Jiamin Jin

This poster presents the PHENIX results on high-p_T gamma-hadron and pi0-hadron correlations and shows the modification of away side jet shape by the medium. By comparing their jet shapes and yields, we see some evidence of the direct gamma contribution to correlation functions.

Qi Wen, Jay X Tang

We seek to determine the mechanism of like-charge attraction by measuring the temperature dependence of critical divalent counterion concentration ($\rm{C_{c}}$) for the aggregation of fd viruses. We find that an increase in temperature causes $\rm{C_c}$ to decrease, primarily due to a decrease in the dielectric constant ($ε$) of the solvent. At a constant $

Caitlin J. Ramsey, Rosa M. Williams, Robert A. Gruendl, C. -H. Rosie Chen

We have studied the stellar and interstellar environments of two luminous X-ray sources and five ultraluminous X-ray sources (ULXs) in order to gain insight into their nature. Archival Hubble Space Telescope images were used to identify the optical counterparts of the ULXs Ho IX X-1 and NGC 1313 X-2, and to make photometric measurements of the local stellar

Hiroki Matui

Let G be a finite abelian group. We will consider a skew product extension of a product of two Cantor minimal Z-systems associated with a G-valued cocycle. When G is non-cyclic and the cocycle is non-degenerate, it will be shown that the skew product system has torsion in its coinvariants.

Ivan Calvo

It has been shown recently that extended supersymmetry in twisted first-order sigma models is related to twisted generalized complex geometry in the target. In the general case there are additional algebraic and differential conditions relating the twisted generalized complex structure and the geometrical data defining the model. We study in the Hamiltonian

T. Fujihara, T. Inagaki, D. Kimura

We study QED corrections to chiral symmetry breaking in the Nambu--Jona-Lasinio (NJL) model with two flavors of quarks. In this model, the isospin symmetry is broken by the differences between the current quark masses and the electromagnetic charges of the up and down quarks. To leading order in the 1/N expansion, we calculate the effective potential of the

Yun Soo Myung

We investigate the connection between the entanglement system in Minkowski spacetime and the black hole using the scaling analysis. Here we show that the entanglement system satisfies the Bekenstein entropy bound. Even though the entropies of two systems are the same form, the entanglement energy is different from the black hole energy. Introducing the Casim

Filippo Callegaro

In this paper we compute the homology of the braid groups, with coefficients in the module Z[q^+-1] given by the ring of Laurent polynomials with integer coefficients and where the action of the braid group is defined by mapping each generator of the standard presentation to multiplication by -q. The homology thus computed is isomorphic to the homology with

A. T. Azatov, J. L. Chkareuli

The spontaneous breakdown of 4-dimensional Lorentz invariance in the framework of QED with the nonlinear vector potential constraint A_μ^{2}=M^{2}(where M is a proposed scale of the Lorentz violation) is shown to manifest itself only as some noncovariant gauge choice in the otherwise gauge invariant (and Lorentz invariant) electromagnetic theory. All the con

N. N. Ajitanand

Modifications of jet properties resulting from the coupling of jets to the strongly interacting matter produced in RHIC collisions are of great current interest. In recent work, the PHENIX collaboration has applied a novel technique to the analysis of two particle azimuthal correlations which extinguishes the harmonic part of the underlying event revealing t

David M. Jackson, Iain Moffatt, Alejandro Morales

We study the effect of Feynman integration and diagrammatic differential operators on the structure of group-like elements in the algebra generated by coloured vertex-oriented uni-trivalent graphs. We provide applications of our results to the study of the LMO invariant, a quantum invariant of manifolds. We also indicate further situations in which our resul

Jorge L. Noronha, Hai-cang Ren, Ioannis Giannakis, Defu Hou

Type-I color superconductors display a first-order phase transition due to thermal gauge-field fluctuations. We numerically evaluated the critical temperature of the first-order phase transition and the corresponding discontinuity of the diquark condensate at the critical point.

Rakotonirina Christian

We have expressed the tensor commutation matrix n\otimes n as linear combination of the tensor products of the generalized Gell-Mann matrices. The tensor commutation matrices 3\otimes 2 and 2\otimes 3 have been expressed in terms of the classical Gell-Mann matrices and the Pauli matrices.

W. A. Moura-Melo, A. R. Pereira, L. A. S. Mol, A. S. T. Pires

We study magnetic vortex-like excitations lying on a conic space background. Two types of them are obtained. Their energies appear to be linearly dependent on the conical aperture parameter, besides of being logarithmically divergent with the sample size. In addition, we realize a geometrical-like pinning of the vortex, say, it is energetically favorable for

G. Sangiovanni, A. Toschi, E. Koch, K. Held

Studying the antiferromagnetic phase of the Hubbard model by dynamical mean field theory, we observe striking differences with static (Hartree-Fock) mean field: The Slater band is strongly renormalized and spectral weight is transferred to spin-polaron side bands. Already for intermediate values of the interaction $U$ the overall bandwidth is larger than in

Michael Strickland

I discuss recent advances in the understanding of non-equilibrium gauge field dynamics in plasmas which have particle distributions which are locally anisotropic in momentum space. In contrast to locally isotropic plasmas such anisotropic plasmas have a spectrum of soft unstable modes which are characterized by exponential growth of transverse (chromo)-magne

R. Percacci

A theory of gravity with a generic action functional and minimally coupled to N matter fields has a nontrivial fixed point in the leading large N approximation. At this fixed point, the cosmological constant and Newton&#39;s constant are nonzero and UV relevant; the curvature squared terms are asymptotically free with marginal behaviour; all higher order ter

D. J. Lancaster, J. J. Ruiz-Lorenzo

Numerical Simulations of the random phase sine-Gordon model suffer from strong finite size effects preventing the non-Gaussian $\log^2 r$ component of the spatial correlator from following the universal infinite volume prediction. We show that a finite size prediction based on perturbative Renormalisation Group (RG) arguments agrees well with new high precis

Romeel Davé, Kristian Finlator, Benjamin D. Oppenheimer

We present predictions drawn from cosmological hydrodynamic simulations for the physical, photometric and emission line properties of galaxies present during the latter stages of reionization from z=9-6. We find significant numbers of galaxies that have stellar masses exceeding 10^8 Mo during this epoch, with metallicities exceeding one-thirtieth solar. Far

Scott A. Hughes

This article is based on a pair of lectures given at the 2005 SLAC Summer Institute. Our goal is to motivate why most physicists and astrophysicists accept the hypothesis that the most massive, compact objects seen in many astrophysical systems are described by the black hole solutions of general relativity. We describe the nature of the most important black

Tetsufumi Hirano, Ulrich W. Heinz, Dmitri Kharzeev, Roy Lacey

We study the elliptic flow coefficient v_2(eta,b) in Au+Au collisions at sqrt(s)=200 A GeV as a function of pseudorapidity eta and impact parameter b. Using a hybrid approach which combines early ideal fluid dynamical evolution with late hadronic rescattering, we demonstrate strong dissipative effects from the hadronic rescattering stage on the elliptic flow

Agostino Patella

In a recent paper, Armoni, Shifman and Veneziano (ASV) gave a formal non-perturbative proof of planar equivalence between the bosonic sectors of SU(N) super Yang-Mills theory and of a gauge theory with a massless quark in the antisymmetric two-indexes representation. In the case of three colors, the latter theory is nothing but one-flavor QCD. Numerical simu

Krishnendu Gongopadhyay, Ravi S. Kulkarni

This paper has been withdrawn by the authors. Significantly revised versions of the results of this paper are now available in arXiv:0707.0487v2 and arXiv:0808.3169v1.

P. Markos, L. Schweitzer

The critical two-terminal conductance $g_c$ and the spatial fluctuations of critical eigenstates are investigated for a disordered two dimensional model of non-interacting electrons subject to spin-orbit scattering (Ando model). For square samples, we verify numerically the relation $σ_c=1/[2π(2-D(1))] e^2/h$ between critical conductivity $σ_c=g_c=(1.42\pm 0

Emanuela Zaccarelli, Ivan Saika-Voivod, Sergey V. Buldyrev, Angel J. Moreno

We numerically study a simple model for thermo-reversible colloidal gelation in which particles can form reversible bonds with a predefined maximum number of neighbors. We focus on three and four maximally coordinated particles, since in these two cases the low valency makes it possible to probe, in equilibrium, slow dynamics down to very low temperatures $T

E. Rufeil Fiori, H. M. Pastawski

The decay of a local spin excitation in an inhomogeneous spin chain is evaluated exactly: I) It starts quadratically up to a spreading time t_{S}. II) It follows an exponential behavior governed by a self-consistent Fermi Golden Rule. III) At longer times, the exponential is overrun by an inverse power law describing return processes governed by quantum diff

K. Jahoda, C. B. Markwardt, Y. Radeva, A. Rots

We present the calibration and background model for the Proportional Counter Array (PCA) aboard the Rossi X-ray Timing Explorer (RXTE). The energy calibration is systematics limited below 10 keV with deviations from a power-law fit to the Crab nebula plus pulsar less than 1%. Unmodelled variations in the instrument background amount to less than 2% of the ob

James E. Lidsey

It is shown that all contracting, spatially homogeneous, orthogonal Bianchi cosmologies that are sourced by an ultra-stiff fluid with an arbitrary and, in general, varying equation of state asymptote to the spatially flat and isotropic universe in the neighbourhood of the big crunch singularity. This result is employed to investigate the asymptotic dynamics

Jean-Guillaume Dumas, Anna Urbanska

We present an algorithm computing the determinant of an integer matrix A. The algorithm is introspective in the sense that it uses several distinct algorithms that run in a concurrent manner. During the course of the algorithm partial results coming from distinct methods can be combined. Then, depending on the current running time of each method, the algorit

A. B. Tumpach

In this paper, we describe an example of a hyperkaehler quotient of a Banach manifold by a Banach Lie group. Although the initial manifold is not diffeomorphic to a Hilbert manifold (not even to a manifold modelled on a reflexive Banach space), the quotient space obtained is a Hilbert manifold, which can furthermore be identified either with the cotangent sp

Kirill Krasnov, Jean-Marc Schlenker

We use minimal (or CMC) surfaces to describe 3-dimensional hyperbolic, anti-de Sitter, de Sitter or Minkowski manifolds. We consider whether these manifolds admit ``nice&#39;&#39; foliations and explicit metrics, and whether the space of these metrics has a simple description in terms of Teichmüller theory. In the hyperbolic settings both questions have posi

Tal Mor

An interesting protocol for classical teleportation of an unknown classical state was recently suggested by Cohen, and by Gour and Meyer. In that protocol, Bob can sample from a probability distribution P that is given to Alice, even if Alice has absolutely no knowledge about P. Pursuing a similar line of thought, we suggest here a limited form of nonlocalit

M. J. Hardcastle

By considering a small sample of core-dominated radio-loud quasars with X-ray jets, I show, as has been argued previously by others, that the observations require bulk jet deceleration if all of the X-ray emission is to be explained using the widely adopted beamed inverse-Compton model, and argue that jets even in these powerful objects must have velocity st

Scott Dodelson, Alessandro Melchiorri, Anze Slosar

By combining data from cosmic microwave background (CMB) experiments (including the recent WMAP third year results), large scale structure (LSS) and Lyman-alpha forest observations, we constrain the hypothesis of a fourth, sterile, massive neutrino. For the 3 massless + 1 massive neutrino case we bound the mass of the sterile neutrino to m_s<0.26eV (0.44eV)

Marco Frasca

We prove that in the limit of the coupling going to infinity a Yang-Mills theory is equivalent to a $λϕ^4$ theory with the dynamics ruled just by a homogeneous equation. This gives explicitly the Green function and the mass spectrum proving that such gauge theories are confining. The scalar glueball spectrum is then proven to be in fair agreement with lattic

Evgeny N. Bulgakov, Victor A. Gopar, Pier A. Mello, Ingrid Rotter

In the past, a maximum-entropy model was introduced and applied to the study of statistical scattering by chaotic cavities, when short paths may play an important role in the scattering process. In particular, the validity of the model was investigated in relation with the statistical properties of the conductance in open chaotic cavities. In this article we

F. Stefani, M. Xu, G. Gerbeth, F. Ravelet

The intention of the &#39;&#39;von Karman sodium&#39;&#39; (VKS) experiment is to study the hydromagnetic dynamo effect in a highly turbulent and unconstrained flow. Much effort has been devoted to the optimization of the mean flow and the lateral boundary conditions in order to minimize the critical magnetic Reynolds number and hence the necessary motor pow

Songbai Chen, Jiliang Jing

Using the technique of spectral decomposition, we investigated the late-time tails of massless and massive coupled scalar fields in the background of a black hole with a global monopole. We found that due to existence of the coupling between the scalar and gravitational fields, the massless scalar field decay faster at timelike infinity $i_+$, and so does th

Ryuichi Takahashi

When a gravitational wave (GW) from a distant source propagates through the universe, its amplitude and phase change due to gravitational lensing by the inhomogeneous mass distribution. We derive the amplitude and phase fluctuations, and calculate these variances in the limit of a weak gravitational field of density perturbation. If the scale of the perturba

B. Abdesselam, A. Chakrabarti, R. Chakrabarti, A. Yanallah

A nonlinear realisation of the nonstandard (super-Jordanian) deformed ${\cal U}_{\sf h}(sl(N|1))$ algebra is given for arbitrary $N$.

M. Sun, C. Jones, W. Forman, P. E. J. Nulsen

We present the discovery of a 70 kpc X-ray tail behind the small late-type galaxy ESO137-001 in the nearby, hot (T=6.5 keV) merging cluster A3627, from both Chandra and XMM observations. The tail has a length-to-width ratio of ~ 10. It is luminous (L_{0.5-2 keV} ~ 10^41 ergs s^-1, with a temperature of ~ 0.7 keV and an X-ray M_gas of ~ 10^9 M_solar (~ 10% of

Xiang-hua Zhai, Yi-bin Zhao

In this paper, we study a realistic model of quintessential inflation with radiation and matter. By the analysis of the dynamical system and numerical work about the evolution of the equation of state and cosmic density parameter, we show that this model is a good match for the current astronomical observation. The conclusion we obtain is in favor of the mod

A. DeBenedictis, D. Horvat, S. Ilijic, S. Kloster

We study the gravitational vacuum star (gravastar) configuration as proposed by other authors in a model where the interior de Sitter spacetime segment is continuously extended to the exterior Schwarzschild spacetime. The multilayered structure in previous papers is replaced by a continuous stress-energy tensor at the price of introducing anisotropy in the (

Simon J. Devitt, Jared H. Cole, Lloyd C. L. Hollenberg

The construction of two-qubit gates appropriate for universal quantum computation is of enormous importance to quantum information processing. Building such gates is dependent on accurate knowledge of the interaction dynamics between two qubit systems. This letter will present a systematic method for reconstructing the full two-qubit interaction Hamiltonian

Miroslaw Kozlowski, Janina Marciak-Kozlowska

In this paper the Klein-Gordon equation (K-GE) is solved for the interaction of attosecond laser pulses with medium in which Casimir force operates. It is shown that for nanoscale structures, NEMS and MEMS, the attosecond laser pulses can be used as the tool for the investigation of the role played by Casimir force on the nanoscale. Key words: Casimir force;

Sergey Bravyi

We consider topological quantum computation (TQC) with a particular class of anyons that are believed to exist in the Fractional Quantum Hall Effect state at Landau level filling fraction nu=5/2. Since the braid group representation describing statistics of these anyons is not computationally universal, one cannot directly apply the standard TQC technique. W

Gerald Gilbert, Michael Hamrick, F. Javier Thayer, Yaakov S. Weinstein

The Quantum Computer Condition (QCC) provides a rigorous and completely general framework for carrying out analyses of questions pertaining to fault-tolerance in quantum computers. In this paper we apply the QCC to the problem of fluctuations and systematic errors in the values of characteristic parameters in realistic systems. We show that fault-tolerant qu

Eli Biham, Michel Boyer, P. Oscar Boykin, Tal Mor

We prove the security of theoretical quantum key distribution against the most general attacks which can be performed on the channel, by an eavesdropper who has unlimited computation abilities, and the full power allowed by the rules of classical and quantum physics. A key created that way can then be used to transmit secure messages such that their security

K. Hammerer, E. S. Polzik, J. I. Cirac

We present a protocol for the teleportation of the quantum state of a pulse of light onto the collective spin state of an atomic ensemble. The entangled state of light and atoms employed as a resource in this protocol is created by probing the collective atomic spin, Larmor precessing in an external magnetic field, off resonantly with a coherent pulse of lig

Anders S. Mouritzen, Klaus Molmer

Most quantum tomographic methods can only be used for one-dimensional problems. We show how to infer the quantum state of a non-relativistic N-dimensional harmonic oscillator system by simple inverse Radon transforms. The procedure is equally applicable to finding the joint quantum state of several distinguishable particles in different harmonic oscillator p

C. G. Chakrabarti, Indranil Chakrabarty

We have presented a new axiomatic derivation of Shannon Entropy for a discrete probability distribution on the basis of the postulates of additivity and concavity of the entropy function.We have then modified shannon entropy to take account of observational uncertainty.The modified entropy reduces, in the limiting case, to the form of Shannon differential en

Keiji Matsumoto

Many problems in quantum information theory can be vied as interconversion between resources. In this talk, we apply this view point to state estimation theory, motivated by the following observations. First, a monotone metric takes value between SLD and RLD Fisher metric. This is quite analogous to the fact that entanglement measures are sandwiched by disti

Indranil Chakrabarty

The paper deals with the reformulation of quantum uncertainty relation involving position and momentum of a particle on the basis of the Kerridge measure of inaccuracy and the Fisher information.

Heng Fan, Vladimir Korepin, Vwani Roychowdhury

The Valence-Bond-Solid (VBS) states are in general ground states for certain gapped models. We consider the entanglement of VBS states on a two-dimensional Cayley tree. We show that the entropy of the reduced density operator does not depend on the whole size of the Cayley tree. We also show that asymptotically, the entropy is liearly proportional to the num

Miroslaw Kozlowski, Janina Marciak-kozlowska

In this paper the heat transport in microtubules (MT) is investigated. When the dimension of the structure is of the order of the de Broglie wave length the transport phenomena must be analyzed within quantum mechanics. In this paper we developed the Dirac type thermal equation for MT .The solution of the equation-the temperature fields for electrons can be