January 2008 arXiv papers — page 5

J. Vidal, S. Dusuel, K. P. Schmidt

We point out some major technical and conceptual mistakes which invalidate the conclusion drawn in "Anyonic braiding in optical lattices" by C. Zhang, V. W. Scarola, S. Tewari, and S. Das Sarma published in PNAS 104, 18415 (2007).

Xavier Bressaud, Fabien Durand, Alejandro Maass

We give necessary and sufficient conditions to have measurable and continuous eigenfunctions for linearly recurrent Cantor dynamical systems. We also construct explicitly an example of linearly recurrent system with nontrivial Kronecker factor and a trivial maximal equicontinuous factor.

Matt J. Jarvis

In these proceedings I discuss various extragalactic surveys which will be undertaken over the next few years and which will be complementary to any HI and/or continuum surveys with the SKA-pathfinder telescopes. I concentrate on the near-infrared public surveys which will be undertaken with the Visible and Infrared Survey Telscope for Astronomy (VISTA), and

Maria Isabel Cortez, Fabien Durand, Bernard Host, Alejandro Maass

The class of linearly recurrent Cantor systems contains the substitution subshifts and some odometers. For substitution subshifts and odometers measure--theoretical and continuous eigenvalues are the same. It is natural to ask whether this rigidity property remains true for the class of linearly recurrent Cantor systems. We give partial answers to this quest

Norita Kawanaka, Yoshiaki Kato, Shin Mineshige

We calculate the radiation spectrum and its time variability of the black hole accretion disk-corona system based on the three-dimensional magnetohydrodynamic simulation. In explaining the spectral properties of active galactic nuclei (AGNs), it is often assumed that they consist of a geometrically thin, optically thick disk and hot, optically thin corona su

N. Siodmiak, M. Meixner, T. Ueta, B. E. K. Sugerman

The results from a Hubble Space Telescope (HST) snapshot survey of post-AGB objects are shown. The aim of the survey is to complement existing HST images of PPN and to connect various types of nebulosities with physical and chemical properties of their central stars. Nebulosities are detected in 15 of 33 sources. Images and photometric and geometric measurem

Kjetil Borkje, Asle Sudbo

We derive an effective dissipative quantum field theory for fluctuating orbital currents in clean $CuO_2$ sheets of high-$T_c$ cuprates, based on a three-band model. The Coulomb repulsion term between $Cu$- and $O$-sites is decoupled in terms of current operators representing horizontal and vertical parts of circulating currents within each $CuO_2$ unit cell

Michel Gros

We study a splitting of the Frobenius map on the whole algebra of distributions of SL_2 (over a finite field) and its relation with the explicit Frobenius descent on arithmetic D-modules over the projective line

G. S. Asanov

By performing required evaluations, we show that in the Finsleroid-regular space the Landsberg-space condition just degenerates to the Berwald-space condition (at any dimension number $N\ge2$). Simple and clear expository representations are obtained. Due comparisons with the Finsleroid-Finsler space are indicated. Keywords: Finsler metrics, spray coefficien

Seokcheon Lee

We investigate the modified gravity theories in terms of the effective dark energy models. We compare the cosmic expansion history and the linear growth in different models. We also study the evolution of linear cosmological perturbations in modified theories of gravity assuming the Palatini formalism. We find the stability of the superhorizon metric evoluti

X. -B. Wang, T. Hiroshima, A. Tomita, M. Hayashi

Quantum optical Gaussian states are a type of important robust quantum states which are manipulatable by the existing technologies. So far, most of the important quantum information experiments are done with such states, including bright Gaussian light and weak Gaussian light. Extending the existing results of quantum information with discrete quantum states

Simon Trebst, Eddy Ardonne, Adrian Feiguin, David A. Huse

We show that chains of interacting Fibonacci anyons can support a wide variety of collective ground states ranging from extended critical, gapless phases to gapped phases with ground-state degeneracy and quasiparticle excitations. In particular, we generalize the Majumdar-Ghosh Hamiltonian to anyonic degrees of freedom by extending recently studied pairwise

R. Vázquez, L. F. Miranda, L. Olguín, S. Ayala

We analyse the point-symmetric planetary nebula NGC 6309 in terms of its three-dimensional structure and of internal variations of the physical conditions to deduce the physical processes involved in its formation. We used VLA-D 3.6-cm continuum, ground-based, and HST-archive imaging as well as long slit high- and low-dispersion spectroscopy. The low-dispers

R. T. Braun, W. Tornow, C. R. Howell, D. E. Gonzalez Trotter

We present the most accurate and complete data set for the analyzing power Ay(theta) in neutron-proton scattering. The experimental data were corrected for the effects of multiple scattering, both in the center detector and in the neutron detectors. The final data at En = 12.0 MeV deviate considerably from the predictions of nucleon-nucleon phase-shift analy

M. A. Noginov, G. Zhu, M. F. Mayy, B. A. Ritzo

We have observed laser-like emission of surface plasmon polaritons (SPPs) decoupled to the glass prism in an attenuated total reflection setup. SPPs were excited by optically pumped molecules in a polymeric film deposited on the top of the silver film. Stimulated emission was characterized by a distinct threshold in the input-output dependence and narrowing

Yingying Wang, Zhenhua Ni, Zexiang Shen, Haomin Wang

Raman spectroscopic studies of graphene have attracted much interest. The G-band Raman intensity of a single layer graphene on Si substrate with 300 nm SiO2 capping layer is surprisingly strong and is comparable to that of bulk graphite. To explain this Raman intensity anomaly, we show that in addition to the interference due to multiple reflection of the in

Philip C. Argyres, Mohammad Edalati, Justin F. Vazquez-Poritz

We investigate the lightlike limit of stationary spacelike string configurations on a large class of five-dimensional asymptotically AdS backgrounds. Specific examples include gravity duals which incorporate finite 't Hooft coupling, curvature-squared corrections, and chemical potentials. A universal feature of these AdS/CFT models is that the string sol

Paul Norbury

We show how to define and count lattice points in the moduli space $\modm_{g,n}$ of genus g curves with n labeled points. This produces a polynomial with coefficients that include the Euler characteristic of the moduli space, and tautological intersection numbers on the compactified moduli space.

Zhigang Wang, Ping Zhang

The chiral edge states and the quantized Hall conductance (QHC) in the two-dimensional kagomé lattice with spin anisotropies included in a general Hund's coupling region are studied. This kagomé lattice system is periodic in the $x$ direction but has two edges in the $y$ direction. Numerical results show that the strength of the Hund's coupling, as w

Patrick B. Hall, Aaron J. Maxwell

White dwarfs (WDs) with carbon absorption features in their optical spectra are known as DQ WDs. The subclass of peculiar DQ WDs are cool objects (T_eff<6000 K) which show molecular absorption bands that have centroid wavelengths ~100-300 Angstroms shortward of the bandheads of the C_2 Swan bands. These &#34;peculiar DQ bands&#34; have been attributed to a h

Piotr Faliszewski, Lane A. Hemaspaandra

We study the complexity of the following problem: Given two weighted voting games G&#39; and G&#39;&#39; that each contain a player p, in which of these games is p&#39;s power index value higher? We study this problem with respect to both the Shapley-Shubik power index [SS54] and the Banzhaf power index [Ban65,DS79]. Our main result is that for both of these

Tadafumi Ohsaku

A possible supplementary mechanism of CP-violation to the Kobayashi-Maskawa theory is considered in the context of dynamical symmetry breaking.

Kate Brand, Dan W. Weedman, Vandana Desai, Emeric Le Floc&#39;h

We present mid-infrared spectroscopy of a sample of 16 optically faint infrared luminous galaxies obtained with the Infrared Spectrograph (IRS) on the Spitzer Space Telescope. These sources were jointly selected from Spitzer and Chandra imaging surveys in the NDWFS Bootes field and were selected from their bright X-ray fluxes to host luminous AGN. None of th

T. Wiegelmann, B. Inhester, A. Lagg, S. K. Solanki

The structure of the solar corona is dominated by the magnetic field because the magnetic pressure is about four orders of magnitude higher than the plasma pressure. Due to the high conductivity the emitting coronal plasma (visible e.g. in SOHO/EIT) outlines the magnetic field lines. The gradient of the emitting plasma structures is significantly lower paral

Ruifeng Qiu, Martin Scharlemann

A combinatorial proof of the Gordon Conjecture: The sum of two Heegaard splittings is stabilized if and only if one of the two summands is stabilized.

Edward Taylor

The Josephson relation for the superfluid density is derived for a Fermi superfluid in the BCS-BEC crossover. This identity extends the original Josephson relation for Bose superfluids. It gives a simple exact relation between the superfluid density $ρ_s$ and the broken-symmetry Cooper pair order parameter $Δ_0$ in terms of the infrared limit of the pair flu

Mikhail Gorchtein, Charles J. Horowitz

We consider the analyzing power on a spin-0 nuclear target. This observable is related to the imaginary part of the two-photon-exchange (box) diagram. We consider the contributions of elastic and inelastic intermediate states. The former requires knowledge of the elastic nuclear form factor, while the latter uses the optical theorem as input. The elastic con

Lucas A. Cieza

Circumstellar disks are an integral part of the star formation process and the sites where planets are formed. Understanding the physical processes that drive their evolution, as disks evolve from optically thick to optically thin, is crucial for our understanding of planet formation. Disks evolve through various processes including accretion onto the star,

Micheal S. Berger, Roman V. Buniy

The entanglement entropy in a quantum field theory between two regions of space has been shown in simple cases to be proportional to the volume of the hypersurface separating the regions. We prove that this is true for a free scalar field in an arbitrary geometry with purely spatial curvature and obtain a complete asymptotic expansion for the entropy.

R. Decarli, M. Dotti, M. Fontana, F. Haardt

Narrow Line Seyfert 1 galaxies (NLS1s) are generally considered peculiar objects among the broad class of Type 1 active galactic nuclei, due to the relatively small width of the broad lines, strong X-ray variability, soft X-ray continua, weak [OIII], and strong FeII line intensities. The mass M_BH of the central massive black hole (MBH) is claimed to be ligh

Seyed Ahmad Sabok-Sayr

This paper concerns exact differential equations. First, I define two types of functions which I have named Basic Function of Type One and Basic Function of Type Two. I then derive the property and theorems of these functions. Finally, by applying the property and theorems of Basic Functions, I establish the method of solving exact differential equation with

Spencer Chang, Radovan Dermisek, John F. Gunion, Neal Weiner

This review summarizes the motivations for and phenomenological consequences of nonstandard Higgs boson decays, with emphasis on final states containing a pair of non-Standard-Model particles that subsequently decay to Standard Model particles. Typically these non-Standard-Model particles are part of a ``hidden&#39;&#39; sector, for example a pair of neutral

Zohar Nussinov, Gerardo Ortiz

Charge, spin, and orbital degrees of freedom underlie the physics of transition metal compounds. Much work has revealed quantum critical points associated with spin and charge degrees of freedom in many of these systems. Here we illustrate that the simplest models that embody the orbital degrees of freedom - the two- and three-dimensional quantum orbital com

Ertan Göklü, Claus Lämmerzahl

We describe space--time fluctuations by means of small fluctuations of the metric on a given background metric. From a minimally coupled Klein--Gordon equation we obtain within a weak-field approximation up to second order and an averaging procedure over a finite space--time scale given by the quantum particle in the non--relativistic limit a modified Schröd

A. S. Denikin, V. I. Zagrebaev, P. Descouvemont

A generalized optical potential for elastic scattering induced by light nuclei is calculated within the Feshbach projection operator method. The model explicitly takes into account the contribution of the projectile break-up continuum treated within a microscopic few-cluster model. In this work we formulate the model, deriving an explicit expression for the

V. Bosch-Ramon, D. Khangulyan, F. A. Aharonian

Massive hot stars produce dense ultraviolet (UV) photon fields in their surroundings. If a very high-energy (VHE) gamma-ray emitter is located close to the star, then gamma-rays are absorbed in the stellar photon field, creating secondary (electron-positron) pairs. We study the broadband emission of these secondary pairs in the stellar photon and magnetic fi

Michael Barot, Dirk Kussin, Helmut Lenzing

We study the cluster category of a canonical algebra A in terms of the hereditary category of coherent sheaves over the corresponding weighted projective line X. As an application we determine the automorphism group of the cluster category and show that the cluster-tilting objects form a cluster structure in the sense of Buan-Iyama-Reiten-Scott. The tilting

G. S. Paraoanu

We investigate the quantum dynamics of a system of two coupled superconducting qubits under microwave irradiation. We find that, with the qubits operated at the charge co-degeneracy point, the quantum evolution of the system can be described by a new effective Hamiltonian which has the form of two coupled qubits with tunable coupling between them. This Hamil

Valeria Kagramanova, Jutta Kunz, Claus Lämmerzahl

The Plebański--Demiański solution is a very general axially symmetric analytical solution of the Einstein field equations generalizing the Kerr solution. This solution depends on seven parameters which under certain circumstances are related to mass, rotation, cosmological constant, NUT parameter, electric and magnetic charges, and acceleration. In this pape

Tommaso Giannantonio, Ryan Scranton, Robert G. Crittenden, Robert C. Nichol

We present a global measurement of the integrated Sachs-Wolfe (ISW) effect obtained by cross-correlating all relevant large scale galaxy data sets with the cosmic microwave background radiation map provided by the Wilkinson Microwave Anisotropy Probe. With these measurements, the overall ISW signal is detected at the ~ 4.5 sigma level. We also examine the co

Stefano Bianchini, Laura V. Spinolo

We deal with the viscous profiles for a class of mixed hyperbolic-parabolic systems. We focus, in particular, on the case of the compressible Navier Stokes equation in one space variable written in Eulerian coordinates. We describe the link between these profiles and a singular ordinary differential equation in the form $$ dV / dt = F(V) / z (V) . $$ Here $V

Julian Le Witt, Simon F. Ross

We propose a definition of asymptotically plane wave spacetimes in vacuum gravity in terms of the asymptotic falloff of the metric, and discuss the relation to previously constructed exact solutions. We construct a well-behaved action principle for such spacetimes, using the formalism developed by Mann and Marolf. We show that this action is finite on-shell

A. A. Usmani, P. P. Ghosh, Utpal Mukhopadhyay, P. C. Ray

We perform a study of cosmic evolution with an equation of state parameter $ω(t)=ω_0+ω_1(t\dot H/H)$ by selecting a phenomenological $Λ$ model of the form, $\dotΛ\sim H^3$. This simple proposition explains both linearly expanding and inflationary Universes with a single set of equations. We notice that the inflation leads to a scaling in the equation of stat

Fabrice Gamboa, Alain Rouault

We study some connections between the random moment problem and the random matrix theory. A uniform draw in a space of moments can be lifted into the spectral probability measure of the pair (A,e) where A is a random matrix from a classical ensemble and e is a fixed unit vector. This random measure is a weighted sampling among the eigenvalues of A. We also s

Puneet Batra, Kurt Hinterbichler, Lam Hui, Daniel Kabat

We discuss models that can account for today&#39;s dark energy. The underlying cosmological constant may be Planck scale but starts as a redundant coupling which can be eliminated by a field redefinition. The observed vacuum energy arises when the redundancy is explicitly broken, say by a non-minimal coupling to curvature. We give a recipe for constructing m

Tamar Kashti, Eli Waxman

We study the anisotropy signature which is expected if the sources of ultra high energy, >10^{19} eV, cosmic-rays (UHECRs) are extragalactic and trace the large scale distribution of luminous matter. Using the PSCz galaxy catalog as a tracer of the large scale structure (LSS), we derive the expected all sky angular distribution of the UHECR intensity. We def

Goncalo Tabuada

We construct a Quillen model structure on the category of spectral categories, where the weak equivalences are the symmetric spectra analogue of the notion of equivalence of categories.

German Olivares, Fernando Atrio-Brandela, Diego Pavon

Models with dark energy decaying into dark matter have been proposed in Cosmology to solve the coincidence problem. We study the effect of such coupling on the cosmic microwave background temperature anisotropies. The interaction changes the rate of evolution of the metric potentials, the growth rate of matter density perturbations and modifies the Integrate

Diego de Falco, Dario Tamascelli

For a continuous-time quantum walk on a line the variance of the position observable grows quadratically in time, whereas, for its classical counterpart on the same graph, it exhibits a linear, diffusive, behaviour. A quantum walk, thus, propagates at a rate which is linear in time, as compared to the square root rate for a classical random walk. Indeed, it

E. I. Jafarov, S. Lievens, J. Van der Jeugt

In the beginning of the 1950&#39;s, Wigner introduced a fundamental deformation from the canonical quantum mechanical harmonic oscillator, which is nowadays sometimes called a Wigner quantum oscillator or a parabose oscillator. Also, in quantum mechanics the so-called Wigner distribution is considered to be the closest quantum analogue of the classical proba

Walter Gubler

We prove equidistribution of a generic net of small points in a projective variety X over a function field K. For an algebraic dynamical system over K, we generalize this equidistribution theorem to a small generic net of subvarieties. For number fields, these results were proved by Yuan and we transfer here his methods to function fields. If X is a closed s

Walter Gubler

For a closed d-dimensional subvariety X of an abelian variety A and a canonically metrized line bundle L on A, Chambert-Loir has introduced measures $c_1(L|_X)^{\wedge d}$ on the Berkovich analytic space associated to A with respect to the discrete valuation of the ground field. In this paper, we give an explicit description of these canonical measures in te

F. -X. Desert, J. F. Macias-Perez, F. Mayet, G. Giardino

Archeops is a balloon-borne experiment, mainly designed to measure the Cosmic Microwave Background (CMB) temperature anisotropies at high angular resolution (~ 12 arcminutes). By-products of the mission are shallow sensitivity maps over a large fraction of the sky (about 30 %) in the millimetre and submillimetre range at 143, 217, 353 and 545 GHz. From these

T. A. Maier, D. Poilblanc, D. J. Scalapino

The question of whether one should speak of a &#34;pairing glue&#34; in the Hubbard and t-J models is basically a question about the dynamics of the pairing interaction. If the dynamics of the pairing interaction arises from virtual states, whose energies correspond to the Mott gap, and give rise to the exchange coupling J, the interaction is instantaneous o

Mark J. Reid, Avery E. Broderick, Abraham Loeb, Mareki Honma

We present measurements with the VLBA of the variability in the centroid position of Sgr A* relative to a background quasar at 7-mm wavelength. We find an average centroid wander of 71 +/- 45 micro-arcsec for time scales between 50 and 100 min and 113 +/- 50 micro-arcsec for timescales between 100 and 200 min, with no secular trend. These are sufficient to b

V. K. Magas, E. Oset, A. Ramos

We make a thorough study of the process of three body kaon absorption in nuclei, in connection with a recent FINUDA experiment which claims the existence of a deeply bound kaonic state from the observation of a peak in the Lambda d invariant mass distribution following K- absorption on Li6. We show that the peak is naturally explained in terms of K- absorpti

C. R. Das, S. Digal, T. R. Govindarajan

We study and analyse the questions regarding breakdown of global symmetry on noncommutative sphere. We demonstrate this by considering a complex scalar field on a fuzzy sphere and isolating Goldstone modes. We discuss the role of nonlocal interactions present in these through geometrical considerations.

Charles Bordenave

We give new formulas on the total number of born particles in the stable birth-and-assassination process, and prove that it has an heavy-tailed distribution. We also establish that this process is a scaling limit of a process of rumor scotching in a network, and is related to a predator-prey dynamics.

L. S. Geng, J. Martin Camalich, L. Alvarez-Ruso, M. J. Vicente Vacas

We report a theoretical study of the axial Nucleon to Delta(1232) ($N\toΔ$) transition form factors up to one-loop order in relativistic baryon chiral perturbation theory. We adopt a formalism in which the $Δ$ couplings obey the spin-3/2 gauge symmetry and, therefore, decouple the unphysical spin-1/2 fields. We compare the results with phenomenological form

Raymond Fresard, Henni Ouerdane, Thilo Kopp

The Barnes slave boson approach to the $U=\infty$ single impurity Anderson model extended by a non-local Coulomb interaction is revisited. We demonstrate first that the radial gauge representation facilitates the treatment of such a non-local interaction by performing the \emph{exact} evaluation of the path integrals representing the partition function, the

A. Akylas, I. Georgantopoulos

Chandra and XMM surveys show that the fraction of obscured AGN decreases rapidly with increasing luminosity. Although this is usually explained by assuming that the covering factor of the central engine is much smaller at luminous QSOs, the exact origin of this effect remains unknown. We perform toy simulations to test whether photo-ionisation of the obscuri

Nikolai Nikolov, Peter Pflug, Pascal J. Thomas

Necessary and sufficient conditions for Lipschitzness of the Lempert and Green functions are found in terms of their boundary behaviors.

Francisco S. N. Lobo

In this work, a general class of wormhole geometries in conformal Weyl gravity is analyzed. A wide variety of exact solutions of asymptotically flat spacetimes is found, in which the stress energy tensor profile differs radically from its general relativistic counterpart. In particular, a class of geometries is constructed that satisfies the energy condition

V. N. Zirakashvili, V. S. Ptuskin, H. J. Voelk

We have studied the non-resonant streaming instability of charged energetic particles moving through a background plasma, discovered by Bell (2004). We confirm his numerical results regarding a significant magnetic field amplification in the system. A detailed physical picture of the instability development and of the magnetic field evolution is given.

M. R. Setare, Elias C. Vagenas

Motivated by the recent work of Wang, Lin, Pavon, and Abdalla [1], we generalize their work to the non-flat case. In particular, we provide a thermodynamical interpretation for the holographic dark energy model in a non-flat universe. For this case, the characteristic length is no more the radius of the event horizon (R_E) but the event horizon radius as mea

Hossein Farajollahi

A cosmological time variable is emerged from the hamiltonian formulation of unimodular theory of gravity to measure the evolution of dynamical observables in the theory. A set of constants of motion has been identified for the theory on the null hypersurfaces that its evolution is with respect to the volume clock introduced by the cosmological time variable.

Alexander Branschädel, Thomas Gasenzer

The far-from-equilibrium dynamics of an ultracold, one-dimensional Bose gas is studied. The focus is set on the comparison between the solutions of fully dynamical evolution equations derived from the 2PI effective action and their corresponding kinetic approximation in the form of Boltzmann-type transport equations. It is shown that during the time evolutio

H. Nikolic

The unparticle field operator can be expanded in terms of creation and destruction operators corresponding to particles with a continuous mass spectrum. Hence, when the 4-momentum of an unparticle is measured, then the unparticle manifests as an ordinary particle with a definite (but arbitrary) mass.

R. Fareghbal, C. N. Gowdigere, A. E. Mosaffa, M. M. Sheikh-Jabbari

We study near-horizon limits of near-extremal charged black hole solutions to five-dimensional $U(1)^3$ gauged supergravity carrying two charges, extending the recent work of Balasubramanian et.al. We show that there are two near-horizon decoupling limits for the near-extremal black holes, one corresponding to the near-BPS case and the other for the far from

F. Heidrich-Meisner, M. Rigol, A. Muramatsu, A. E. Feiguin

We study the sudden expansion of strongly correlated fermions in a one-dimensional lattice, utilizing the time-dependent density-matrix renormalization group method. Our focus is on the behavior of experimental observables such as the density, the momentum distribution function, and the density and spin structure factors. As our main result, we show that cor

Michal P. Heller, Romuald A. Janik, Tomasz Lukowski

In this paper we give a new derivation of the generalized Luscher F-term formula from a summation over quadratic fluctuations around a given soliton. The result is very general providing that S-matrix is diagonal and is valid for arbitrary dispersion relation. We then apply this formalism to compute the leading finite size corrections to the giant magnon dis

C. C. Alan Fung, K. Y. Michael Wong, Si Wu

We investigate the dynamics of continuous attractor neural networks (CANNs). Due to the translational invariance of their neuronal interactions, CANNs can hold a continuous family of stationary states. We systematically explore how their neutral stability facilitates the tracking performance of a CANN, which is believed to have wide applications in brain fun

Y. Bugeaud, M. Mignotte, S. Siksek, M. Stoll

We give a completely explicit upper bound for integral points on (standard) affine models of hyperelliptic curves, provided we know at least one rational point and a Mordell-Weil basis of the Jacobian. We also explain a powerful refinement of the Mordell--Weil sieve which, combined with the upper bound, is capable of determining all the integral points. Our

H. Schunker, D. C. Braun, C. Lindsey, P. S. Cally

At the surface of the Sun, acoustic waves appear to be affected by the presence of strong magnetic fields in active regions. We explore the possibility that the inclined magnetic field in sunspot penumbrae may convert primarily vertically propagating acoustic waves into elliptical motion. We use helioseismic holography to measure the modulus and phase of the

Usman Ali

In this article we describe the summit sets in B_3, the smallest element in a summit set and we compute the Hilbert series corresponding to conjugacy classes.The results will be related to Birman-Menesco classification of knots with braid index three or less than three.

Mate Csanad, Boris Tomasik, Tamas Csorgo

We present a calculation of the elliptic flow and azimuthal dependence of the correlation radii in the ellipsoidally symmetric generalization of the Buda-Lund model. The elliptic flow is shown to depend only on the flow anisotropy while in case of correlation radii both flow and space anisotropy play an important role in determining their azimuthal oscillati

Hing-Tong Cho, Choon-Lin Ho

We study the self-adjoint extensions of the Hamiltonian operator with symmetric potentials which go to $-\infty$ faster than $-|x|^{2p}$ with $p>1$ as $x\to\pm\infty$. In this extension procedure, one requires the Wronskian between any states in the spectrum to approach to the same limit as $x\to\pm\infty$. Then the boundary terms cancel and the Hamiltonian

Steven V Sam

We give a new proof for a theorem of Ehrhart regarding the quasi-polynomiality of the function that counts the number of integer points in the integral dilates of a rational polytope. The proof involves a geometric bijection, inclusion-exclusion, and recurrence relations, and we also prove Ehrhart reciprocity using these methods.

Xinping Xu, Feng Liu

In this paper, we consider the quantum-mechanical phase space patterns on ordered and disordered networks. For ordered networks in which each node is connected to its 2m nearest neighbors (m on either side), the phase space quasi-probability of Wigner function shows various patterns. In the long time limit, on even-numbered networks, we find an asymmetric qu

D. A. Orlov, V. L. Alperovich, A. S. Terekhov

A spin-dependent emission of optically oriented electrons from p-GaAs(Cs,O) into vacuum was experimentally observed in a magnetic field normal to the surface. This phenomenon is explained within the model which takes into account the jump in the electron g factor at the semiconductor-vacuum interface. Due to this jump, the effective electron affinity on the

M. Wakamatsu, Y. Nakakoji

We point out that there exist two natural definitions of the nucleon magnetization densities : the density $ρ_M^K (r)$ introduced in Kelly&#39;s phenomenological analysis and theoretically more standard one $ρ_M (r)$. We can derive an explicit analytical relation between them, although Kelly&#39;s density is more useful to disentangle the physical origin of

Stefano Bianchini, Laura V. Spinolo

We study the singular ordinary differential equation $$ \frac{d U}{d t} = f (U) / z (U) + g (U), $$ where $U \in R^N$, the functions $f \in R^N $ and $g \in R^N $ are of class $C^2$ and $z $ is a real valued $C^2$ function. The equation is singular in the sense that $z (U)$ can attain the value 0. We focus on the solutions of the singular ODE that belong to

H. Bouy, E. L. Martin, W. Brandner, T. Forveille

Astrometric observations of resolved binaries provide estimates of orbital periods and will eventually lead to measurement of dynamical masses. Only a few very low mass star and brown dwarf masses have been measured to date, and the mass-luminosity relation still needs to be calibrated. We have monitored 14 very low mass multiple systems for several years to

Yonathan Schwarzkopf, M. R. Evans, David Mukamel

The steady-state distributions and dynamical behaviour of Zero Range Processes with hopping rates which are non-monotonic functions of the site occupation are studied. We consider two classes of non-monotonic hopping rates. The first results in a condensed phase containing a large (but subextensive) number of mesocondensates each containing a subextensive nu

Alex Buchel

We discuss string theory alpha&#39; corrections in the dual description of the expanding boost invariant N=4 supersymmetric Yang-Mills plasma at strong coupling. We compute finite &#39;t Hooft coupling corrections to the shear viscosity and find that it disagrees with the equilibrium correlation function computations. We comment on the possible source of the

Lauris Baum, Paul H. Frampton, Shinya Matsuzaki

In cyclic cosmology based on phantom dark energy the requirement that our universe satisfy a CBE-condition ({\it Comes Back Empty}) imposes a lower bound on the number $N_{\rm cp}$ of causal patches which separate just prior to turnaround. This bound depends on the dark energy equation of state $w = p/ρ= -1 - ϕ$ with $ϕ> 0$. More accurate measurement of $ϕ$

Colin S. Wallace, Andrew J. S. Hamilton, Gavin Polhemus

We show that the entropy created by Ohmic dissipation inside an accreting charged black hole may exceed the Bekenstein-Hawking entropy by a large factor. If the black hole subsequently evaporates, radiating only the Bekenstein-Hawking entropy, then the black hole appears to destroy entropy, violating the second law of thermodynamics. A companion paper discus

Jared Weinstein

Let $K$ be a totally real field. In this article we present an asymptotic formula for the number of Hilbert modular cusp forms $f$ with given ramification at every place $v$ of $K$. When $v$ is an infinite place, this means specifying the weight of $f$ at $k$, and when $v$ is finite, this means specifying the restriction to inertia of the local Weil-Deligne

Avinash Kolli, Simon C. Benjamin, Jose Garcia Coello, Sougato Bose

We show that a large entangled current can be produced from a very simple passive device: a cluster of three resonant quantum dots, tunnel coupled to one input lead and two output leads. The device can function in a `clean&#39; mode, when almost all emitted electrons are paired in Bell states, or a `dirty&#39; mode with a far higher emission rate but a signi

Yuzo Maruyama, Edward I. George

For the normal linear model variable selection problem, we propose selection criteria based on a fully Bayes formulation with a generalization of Zellner&#39;s $g$-prior which allows for $p>n$. A special case of the prior formulation is seen to yield tractable closed forms for marginal densities and Bayes factors which reveal new model evaluation characteris

Brendon J. Brewer

A Bayesian Survival Analysis method is motivated and developed for analysing sequences of scores made by a batsman in test or first class cricket. In particular, we expect the presence of an effect whereby the distribution of scores has more probability near zero than a geometric distribution, due to the fact that batting is more difficult when the batsman i

Lucas Cieza, William D. Cochran, Jean-Charles Augereau

We use the Spitzer Space Telescope to search for infrared excess at 24, 70, and 160 micron due to debris disks around a sample of 45 FGK-type members of the Hyades cluster. We supplement our observations with archival 24 and 70 micron Spitzer data of an additional 22 FGK-type and 11 A-type Hyades members in order to provide robust statistics on the incidence

Maurice Pouzet, Nicolas M. Thiéry

The profile of a relational structure $R$ is the function $φ_R$ which counts for every integer $n$ the number, possibly infinite, $φ_R(n)$ of substructures of $R$ induced on the $n$-element subsets, isomorphic substructures being identified. If $φ_R$ takes only finite values, this is the Hilbert function of a graded algebra associated with $R$, the age algeb

Alfredo Macias, Abel Camacho, Jutta Kunz, Claus Laemmerzahl

We investigate the canonical quantization in the framework of N=1 simple supergravity for the case of a very simple gravitational midisuperspace described by Gowdy $T^3$ cosmological models. We consider supersymmetric quantum cosmology in the mentioned midisuperspace, where a matrix representation for the gravitino covector--spinor is used. The full Lorentz

Philip Chang, Anatoly Spitkovsky, Jonathan Arons

We study the long term evolution of magnetic fields generated by an initially unmagnetized collisionless relativistic $e^+e^-$ shock. Our 2D particle-in-cell numerical simulations show that downstream of such a Weibel-mediated shock, particle distributions are approximately isotropic, relativistic Maxwellians, and the magnetic turbulence is highly intermitte

Hashini E. Mohottala, B. O. Wells, J. I. Budnick, W. A. Hines

We have studied the magnetic characteristics of a series of super-oxygenated La2-xSrxCuO4+y samples. As shown in previous work, these samples spontaneously phase separate into an oxygen rich superconducting phase with a TC near 40 K and an oxygen poor magnetic phase that also orders near 40 K. All samples studied are highly magnetically reversible even to lo

Duncan Kilburn, Paul E. Sokol

We report measurements of the x-ray scattering intensity as mesoporous glasses are filled with Neon. We outline a simple model to account for the non-linear increase in the intensity of the first peak in a liquid-like diffraction pattern as a monolayer is formed. This allows us to demonstrate an approach for surface area determination which does not rely on

Yu-Ming Lin, Phaedon Avouris

Low-frequency 1/f noise is ubiquitous, and dominates the signal-to-noise performance in nanodevices. Here we investigate the noise characteristics of single-layer and bilayer graphene nano-devices, and uncover an unexpected 1/f noise behavior for bilayer devices. Graphene is a single layer of graphite, where carbon atoms form a 2D honeycomb lattice. Despite

Ronghui Tu, Yongyi Mao, Jiying Zhao

The Survey Propagation (SP) algorithm for solving $k$-SAT problems has been shown recently as an instance of the Belief Propagation (BP) algorithm. In this paper, we show that for general constraint-satisfaction problems, SP may not be reducible from BP. We also establish the conditions under which such a reduction is possible. Along our development, we pres

Martin E. Pessah, Chi-kwan Chan

We carry out a comprehensive analysis of the behavior of the magnetorotational instability (MRI) in viscous, resistive plasmas. We find exact, non-linear solutions of the non-ideal magnetohydrodynamic (MHD) equations describing the local dynamics of an incompressible, differentially rotating background threaded by a vertical magnetic field when disturbances