September 2006 arXiv papers — page 16

F. Heidrich-Meisner, I. A. Sergienko, A. E. Feiguin, E. R. Dagotto

We present a numerical study of the magnetization process of frustrated quantum spin-S chains with S=1, 3/2, 2 as well as the classical limit. Using the exact diagonalization and density-matrix renormalization techniques, we provide evidence that a plateau at one third of the saturation magnetization exists in the magnetization curve of frustrated spin-S cha

Stefan Duhr, Dieter Braun

Thermophoresis (thermodiffusion, Soret effect) moves molecules along thermal gradients. We measure its phenomenological linear drift relation by single particle tracking in convection-free settings. For moderate thermal gradients, drift velocity depends linearly on the gradient. However, for strong thermal gradients, we find a nonlinear dependence of the dri

G. S. Lozano, O. Piguet, F. A. Schaposnik, L. Sourrouille

We discuss a 1+1 dimensional Galilean invariant model recently introduced in connection with ultracold quantum gases. After showing its relation to a nonrelativistic 2+1 Chern-Simons matter system, we identify the generators of the supersymmetry and its relation with the existence of self-dual equations

Jeferson J. Arenzon

Kinetically constrained models (KCM) are systems with trivial thermodynamics but often complex dynamical behavior due to constraints on the accessible paths followed by the system. Exploring these properties, the Kob-Andersen (KA) model was introduced to study the slow dynamics of glass forming liquids and later extended to granular materials. In this last c

Marcia M. Szortyka, Marcia C. Barbosa

We investigate the relation between thermodynamic and dynamic properties of an associating lattice gas (ALG) model. The ALG combines a two dimensional lattice gas with particles interacting through a soft core potential and orientational degrees of freedom. From the competition between the directional attractive forces and the soft core potential results two

Florian R. Ong, Olivier Bourgeois, Sergey E. Skipetrov, Jacques Chaussy

We present the first measurements of thermal signatures of the Little-Parks effect using a highly sensitive nanocalorimeter. Small variations of the heat capacity $C\_p$ of 2.5 millions of non interacting micrometer-sized superconducting rings threaded by a magnetic flux $Φ$ have been measured by attojoule calorimetry. This non-invasive method allows the mea

B. Gorshunov, A. S. Prokhorov, S. Kaiser, D. Faltermeier

Measurements of electrodynamic response of of spin glass AuFe films in comparison with pure gold films are performed at frequencies from 0.3 THz (10 cm-1) up to 1000 THz (33000 cm-1) using different spectroscopic methods. At room temperatures the spectra of pure gold and of AuFe are typically metallic with the scattering rate of carriers in AuFe being signif

Volker Becker Andreas Engel

Orientational fluctuations of colloidal particles with magnetic moments may be rectified with the help of external magnetic fields with suitably chosen time dependence. As a result a noise-driven rotation of particles occurs giving rise to a macroscopic torque per volume of the carrier liquid. We investigate the influence of mutual interactions between the p

Paolo Politi, Ruggero Vaia

Recent work on the dynamics of a crystal surface [T.Frisch and A.Verga, Phys. Rev. Lett. 96, 166104 (2006)] has focused the attention on the conserved Kuramoto-Sivashinsky (CKS) equation: \partial_t u = -\partial_{xx}(u+u_{xx}+u_x^2), which displays coarsening. For a quantitative and qualitative understanding of the dynamics, the analysis of steady states is

Heidi Forster, Peter Samuelsson, Sebastian Pilgram, Markus Buttiker

Voltage and dephasing probes introduce incoherent inelastic and incoherent quasi-elastic scattering into a coherent mesoscopic conductor. We discuss in detail the concepts of voltage and dephasing probes and develop a full counting statistics approach to investigate their effect on the transport statistics. The formalism is applied to several experimentally

Karlo Penc, Nic Shannon, Yukitoshi Motome, Hiroyuki Shiba

We present a detailed symmetry analysis of the degeneracy lifting due to higher order spin exchanges in the pyrochlore lattice in applied magnetic field. Under the assumption of the 4 sublattice ordering, the criteria for a stable half-magnetization plateau are deduced. The higher order exchange terms may originate from spin-lattice coupling, or can describe

Aline Balladares, Vera B. Henriques, Marcia C. Barbosa

We have investigated the effects of either distorting hydrogen bonds or removing proton degeneracy on the thermodynamic properties of a minimal model for associating liquids. The presence of two liquid phases and a density anomaly is unaffected in both cases. Increasing the degeneracy of bonded structures leads to lower temperature critical points and a stee

K. M. Indlekofer, R. Németh

In this article, we describe a recursive method to construct a subset of relevant Slater-determinants for the use in many-body diagonalization schemes that will be employed in our forthcoming papers on the simulation of excited many-body states in discrete electronic nanosystems. The algorithm is intended for the realistic simulation of nanodevices which typ

Marcello B. Silva Neto

We revisit the ground state of the spin-Fermion model within a semiclassical approximation. We demonstrate that antiphase spin spirals, or pi-spirals, whose chirality alternates between consecutive rows (or columns) of local moments, have, for sufficiently high carrier concentration, lower energy than the traditional Shraiman and Siggia spirals. Furthermore,

M. Orendac, J. Hanko, E. Cizmar, A. Orendacova

The magnetocaloric effect of polycrystalline samples of pure and Y-doped dipolar spin ice Dy2Ti2O7 was investigated at temperatures from nominally 0.3 K to 6 K and in magnetic fields of up to 2 T. As well as being of intrinsic interest, it is proposed that the magnetocaloric effect may be used as an appropriate tool for the qualitative study of slow relaxati

G. Gangadhar Reddy, A. Ramakanth, S. K. Ghatak, S. N. Behera

A model calculation is presented with the aim to study the interplay between magnetic and structural transitions. The model consists of an orbitally doubly degenerate conduction band and a periodic array of local moments. The band electrons interact with the local spins via the s-f interaction. The interaction of the band electrons with phonons is introduced

Dario Poletti, Giuliano Benenti, Giulio Casati, Baowen Li

We study the dynamics of a dilute Bose-Einstein condensate confined in a toroidal trap and exposed to a pair of periodically flashed optical lattices. We first prove that in the noninteracting case this system can present a quantum symmetry which forbids the ratchet effect classically expected. We then show how many-body atom-atom interactions, treated withi

E. B. Olshanetsky, Vincent Thomas Francois Renard, Z. D. Kvon, J. -C. Portal

In the present work we have investigated the transport properties in a number of Si/SiGe samples with square antidot lattices of different periods. In samples with lattice periods equal to 700 nm and 850 nm we have observed the conventional low-field commensurability magnetoresistance peaks consistent with the previous observations in GaAs/AlGaAs and Si/SiGe

Xiangjun Xing, Paul M. Goldbart, Leo Radzihovsky

The effects of thermal elastic fluctuations in rubber materials are examined. It is shown that, due to an interplay with the incompressibility constraint, these fluctuations qualitatively modify the large-deformation stress-strain relation, compared to that of classical rubber elasticity. To leading order, this mechanism provides a simple and generic explana

W. Yang, Kai Chang, X. G. Wu, H. Z. Zheng

We investigate the spin-polarized transport properties of a two-dimensional electron gas in a n-type diluted magnetic narrow gap semiconductor quantum well subjected to a perpendicular magnetic and electric field. Interesting beating patterns in the magneto resistance are found which can be tuned significantly by varying the electric field. A resonant enhanc

T. Hu, H. Xiao, T. A. Sayles, M. B. Maple

In-plane angular dependent resistivity ADR was measured in the non-Fermi liquid regime of CeCoIn$_5$ single crystals at temperatures $T \le 20$ K and in magnetic fields $H$ up to 14 T. Two scaling behaviors were identified in low field region where resistivity shows T-linear dependence, separated by a critical angle $θ_{c}$ which is determined by the anisotr

Björn Kubala, Göran Johansson, Jürgen König

We study electronic transport through metallic multi-island Coulomb-blockade systems. Based on a diagrammatic real-time approach, we develop a computer algorithm that generates and calculates all transport contributions up to second order in the tunnel-coupling strengths for arbitrary multi-island systems. This comprises sequential and cotunneling, as well a

M. Gronsleth, J. Linder, J. -M-Borven, A. Sudbo

We study tunneling currents in a model consisting of two non-unitary ferromagnetic spin-triplet superconductors separated by a thin insulating layer. We find a novel interplay between ferromagnetism and superconductivity, manifested in the Josephson effect. This offers the possibility of tuning dissipationless currents of charge and spin in a well-defined ma

I. B. Vavilova, V. E. Karachentseva, D. I. Makarov, O. V. Melnyk

We considered kinematic and virial parameters of a sample of galaxy triplets from the Local Supercluster (LS). The galaxies were selected from the LEDA database, and their radial velocities are no more than 3100 km/s. The sample contains 176 systems selected according to the Karachentsev criterion. We calculated the following median parameters of the LS trip

Eduardo Rozo, Daisuke Nagai, Charles Keeton, Andrey Kravtsov

Using ray tracing for simple analytic profiles, we demonstrate that the lensing cross section for producing giant arcs has distinct contributions due to arcs formed through image distortion only, and arcs form from the merging of two or three images. We investigate the dependence of each of these contributions on halo ellipticity and on the slope of the dens

Nitya Kallivayalil, Brian M. Patten, Massimo Marengo, Charles Alcock

We report on the identification of the lens responsible for microlensing event MACHO-LMC-20. As part of a \textit{Spitzer}/IRAC program conducting mid-infrared follow-up of the MACHO Large Magellanic Cloud microlensing fields, we discovered a significant flux excess at the position of the source star for this event. These data, in combination with high resol

D. Andrew Howell, Mark Sullivan, Peter E. Nugent, Richard S. Ellis

The acceleration of the expansion of the universe, and the need for Dark Energy, were inferred from the observations of Type Ia supernovae (SNe Ia). There is consensus that SNe Ia are thermonuclear explosions that destroy carbon-oxygen white dwarf stars that accrete matter from a companion star, although the nature of this companion remains uncertain. SNe Ia

Emille E. O. Ishida

The quality of supernova data will dramatically increase in the next few years by new experiments that will add high-redshift supernova to the currently known ones. In order to use this new data to discriminate between different dark energy models, the statefinder diagnostic was suggested and investigated by Alam et al. in the light of the proposed SuperNova

Tracy Webb, Kim-Vy Tran, Simon Lilly, Paul van der Werf

We present deep submillimeter imaging of two spectroscopically confirmed z~6.5 Lyman-alpha emitters (LAEs) in the Subaru Deep Field. Although we reach the nominal confusion limit at 850 micron, neither LAE is detected at 850 micron nor 450 micron, thus we conclude that the LAEs do not contain large dust masses (<2.3e8 Msun and <5.7e8 Msun). The limit on thei

David M. Meyer, J. T. Lauroesch, Carl Heiles, J. E. G. Peek

The high-latitude Galactic H I cloud toward the extragalactic radio source 3C 225 is characterized by very narrow 21 cm emission and absorption indicative of a very low H I spin temperature of about 20 K. Through high-resolution optical spectroscopy, we report the detection of strong, very narrow Na I absorption corresponding to this cloud toward a number of

Letizia Stanghellini

The asymptotic giant branch (AGB) phase of stellar evolution is common to most stars of low and intermediate mass. Most of the carbon and nitrogen in the Universe is produced by AGB stars. The final fate of the AGB envelopes are represented by planetary nebulae (PN). By studying PN abundances and compare them with the yields of stellar evolution is possible

C. Foellmi

We present a new and exploratory method to estimate the distance of microquasars by suggesting an empirical correlation between the bluemost point of the bisector of the cross-correlation function and the absolute magnitude.

T. R. Bradley, J. H. Knapen, J. E. Beckman, S. L. Folkes

Context. Statistical properties of HII region populations in disk galaxies yield important clues to the physics of massive star formation. Aims. We present a set of HII region catalogues and luminosity functions for a sample of 56 spiral galaxies in order to derive the most general form of their luminosity function. Methods. HII region luminosity functions a

S. Carpano, J. Wilms, M. Schirmer, E. Kendziorra

Context. We report the discovery of a new luminous supersoft source, XMMU J005455.0-374117, in the nearby spiral galaxy NGC 300, in XMM-Newton observations performed on 2005 May 22 and on 2005 November 25. The source is not present in ROSAT data nor in the previous XMM-Newton observations of 2000 December/2001 January. The unique luminous supersoft source, X

M. Mayer

Context: Observations of X-Ray sources harbouring a black hole and an accretion disc show the presence of at least two spectral components. One component is black-body radiation from an optically thick standard accretion disc. The other is produced in a optically thin corona and usually shows a powerlaw behaviour. Electron-proton (ep) bremsstrahlung is one o

Ya. Pavlenko, B. Kaminsky, Yu. Lyubchik, La. Yakovina

We model the spectra and spectral energy distribution of V838 Mon which were observed in February, March, and November, 2002. Theoretical spectra are calculated using the classical model atmospheres taking into account absorption of atomic and molecular lines. By fitting the observed spectra we determine the physical parameters of the atmosphere of V838 Mon.

Giovanna De Francesco, Alessandro Capetti, Alessandro Marconi

We present results from a kinematical study of the gas in the nucleus of the active S0 galaxy NGC 3998 obtained from archival HST/STIS long-slit spectra. We analyzed the emission lines profiles and derived the map of the gas velocity field. The observed velocity curves are consistent with gas in regular rotation around the galaxy&#39;s center. By modeling th

Erika D. Grundstrom, Douglas R. Gies

We present numerical models of the circumstellar disks of Be stars, and we describe the resulting synthetic H-alpha emission lines and maps of the wavelength-integrated emission flux projected onto the sky. We demonstrate that there are monotonic relationships between the emission line equivalent width and the ratio of the angular half-width at half maximum

Xin-Fa Deng, Ji-Zhou He, Qun Zhang, Cong-Gen He

Using a volume-limited sample of Main Galaxies from the SDSS Data Release 5, we investigate the dependence of galaxy properties on local environment. For each galaxy, the local three-dimensional density is calculated. We find that galaxy morphologies strongly depend on local environment: galaxies in dense environments have predominantly early type morphologi

P. Magain, F. Courbin, M. Gillon, S. Sohy

A new method is presented for determining the Point Spread Function (PSF) of images that lack bright and isolated stars. It is based on the same principles as the MCS (Magain, Courbin, Sohy, 1998) image deconvolution algorithm. It uses the information contained in all stellar images to achieve the double task of reconstructing the PSFs for single or multiple

G. W. Christie

Gravitational microlensing is a new technique that allows low-mass exoplanets to be detected at large distances of ~7kpc. This paper briefly outlines the principles of the method and describes the observational techniques. It shows that small (e.g. 0.35m) telescopes with a CCD camera can make unexpectedly useful observations of these events.

A R King, J E Pringle

We consider the problem of growing the largest supermassive black holes from stellar--mass seeds at high redshift. Rapid growth without violating the Eddington limit requires that most mass is gained while the hole has a low spin and thus a low radiative accretion efficiency. If, as was formerly thought, the black--hole spin aligns very rapidly with the accr

Richard V. E. Lovelace, Akshay K. Kulkarni, Marina M. Romanova

Thermonuclear burning on the surface of a neutron star causes the expansion of a thin outer layer of the star, $ΔR(t)$. The layer rotates slower than the star due to angular momentum conservation. The shear between the star and the layer acts to twist the star&#39;s dipole magnetic field giving at first a trailing spiral field. The twist of the field acts in

G. B. Taylor, J. Granot

The multi-wavelength observations of the 2004 December~27 Giant Flare (GF) from SGR 1806-20 and its long-lived radio afterglow are briefly reviewed. The GF appears to have been produced by a dramatic reconfiguration of the magnetic field near the surface of the neutron star, possibly accompanied by fractures in the crust. The explosive release of over 10^46

Martin Pospischil, Zuzanna Piwkowska, Michelle Rudolph, Thierry Bal

The optimal patterns of synaptic conductances for spike generation in central neurons is a subject of considerable interest. Ideally, such conductance time courses should be extracted from membrane potential (Vm) activity, but this is difficult because the nonlinear contribution of conductances to the Vm renders their estimation from the membrane equation ex

Edward L. Wright

A cosmology calculator that computes times and distances as a function of redshift for user-defined cosmological parameters is available on the World Wide Web. This note gives the formulae used by the cosmology calculator and discusses some of its implementation. A version of the calculator that allows one to specify the equation of state parameter w and w&#

Ulrich Bunke, Markus Spitzweck, Thomas Schick

We show that the inertia stack of a topological stack is again a topological stack. We further observe that the inertia stack of an orbispace is again an orbispace. We show how a U(1)-banded gerbe over an orbispace gives rise to a flat line bundle over its inertia stack. Via sheaf theory over topological stacks it gives rise to the twisted delocalized cohomo

P. Bressler, A. Gorokhovsky, R. Nest, B. Tsygan

In this paper we compute the deformation theory of a special class of algebras, namely of Azumaya algebras on a manifold ($C^{\infty}$ or complex analytic).

Pieter G. van Dokkum, Roeland P. van der Marel

We present new Keck spectroscopy of early-type galaxies in three galaxy clusters at z~0.5. We focus on the fundamental plane (FP) relation, and combine the kinematics with structural parameters determined from HST images. The galaxies obey clear FP relations, which are offset from the FP of the nearby Coma cluster due to passive evolution of the stellar popu

Robert E. Smith, Roman Scoccimarro, Ravi K. Sheth

We examine the scale dependence of dark matter, halo and galaxy clustering on very large scales (0.01<k[h/Mpc]<0.15), due to non-linear effects from dynamics and halo bias. We pursue a two line offensive: high resolution numerical simulations are used to establish several new results, and an analytic model is developed to understand their origins. Our simula

Bhalchandra D. Thatte

We consider 3 (weighted) posets associated with a graph G - the poset P(G) of distinct induced unlabelled subgraphs, the lattice Omega(G) of distinct unlabelled graphs induced by connected partitions, and the poset Q(G) of distinct unlabelled edge-subgraphs. We study these posets given up to isomorphism, and their relation to the reconstruction conjectures.

Danny Calegari

Let T denote Thompson&#39;s group of piecewise 2-adic linear homeomorphisms of the circle. Ghys and Sergiescu showed that the rotation number of every element of T is rational, but their proof is very indirect. We give here a short, direct proof using train tracks, which generalizes to PL homeomorphism of the circle with rational break points and derivatives

Bela Bollobas, Vladimir Nikiforov

We prove conditions for equality between the extreme eigenvalues of a matrix and its quotient. In particular, we give a lower bound on the largest singular value of a matrix and generalize a result of Finck and Grohmann about the largest eigenvalue of a graph.

D. Peressounko

Direct photon yield measured in p+p and d+Au collisions at \sqrt{s} = 200 GeV with the PHENIX experiment is presented and compared to pQCD predictions. In the case of p+p collisions both the inclusive and isolated direct photon production cross-sections are measured. Relative contribution of isolated direct photons is somewhat below but still agree within er

Sergiu I. Vacaru, Mihai Visinescu

The common assertion that the Ricci flows of Einstein spaces with cosmological constant can be modelled by certain classes of nonholonomic frame, metric and linear connection deformations resulting in nonhomogeneous Einstein spaces is examined in the light of the role played by topological three dimensional (3D) Taub-NUT-AdS/dS spacetimes.

Sergiu I. Vacaru, Mihai Visinescu

In this work we construct and analyze exact solutions describing Ricci flows and nonholonomic deformations of four dimensional (4D) Taub-NUT spacetimes. It is outlined a new geometric techniques of constructing Ricci flow solutions. Some conceptual issues on spacetimes provided with generic off-diagonal metrics and associated nonlinear connection structures

Michael J. I. Brown, Arjun Dey, Buell T. Jannuzi, Kate Brand

We trace the assembly history of red galaxies since z=1, by measuring their evolving space density with the B-band luminosity function. Our sample of 39599 red galaxies, selected from 6.96 square degrees of imaging from the NOAO Deep Wide-Field and Spitzer IRAC Shallow surveys, is an order of magnitude larger, in size and volume, than comparable samples in t

D. Gross, J. Eisert

We establish a framework which allows one to construct novel schemes for measurement-based quantum computation. The technique further develops tools from many-body physics - based on finitely correlated or projected entangled pair states - to go beyond the cluster-state based one-way computer. We identify resource states that are radically different from the

Yi-Zhi Huang, Liang Kong

Let V^L and V^R be simple vertex operator algebras satisfying certain natural uniqueness-of-vacuum, complete reducibility and cofiniteness conditions and let F be a conformal full field algebra over the tensor product of V^L and V^R. We prove that the q_τ-\bar{q_τ}-traces (natural traces involving q_τ=e^{2πiτ} and \bar{q_τ}=\bar{e^{2πiτ}}) of geometrically m

Robert Burton, Yevgeniy Kovchegov

We provide a coupling proof that the transposition shuffle on a deck of n cards is mixing of rate Cn(log{n}) with a moderate constant, C. This rate was determined by Diaconis and Shahshahani, but the question of a natural probabilistic coupling proof has been missing, and questions of its existence have been raised. The proof, and indeed any proof, requires

Javier Grande, Joan Sola, Hrvoje Stefancic

In the recent literature on dark energy (DE) model building we have learnt that cosmologies with variable cosmological parameters can mimic more traditional DE pictures exclusively based on scalar fields (e.g. quintessence and phantom). In a previous work we have illustrated this situation within the context of a renormalization group running cosmological te

Rafael Ferraro, Maria Evangelina Lipchak

Two-dimensional Born-Infeld electrostatic fields behaving as the superposition of two point-like charges in the linearized (Maxwellian) limit are worked out by means of a non-holomorphic mapping of the complex plane. The changes underwent by the Coulombian interaction between two charges in Born-Infeld theory are computed. Remarkably, the force between equal

A. M. Mathai, H. J. Haubold

The pathway model of Mathai (2005) mainly deals with the rectangular matrix-variate case. In this paper the scalar version is shown to be associated with a large number of probability models used in physics. Different families of densities are listed here, which are all connected through the pathway parameter &#39;alpha&#39;, generating a distributional path

S. Spataro

The HADES spectrometer installed at GSI Darmstadt is devoted to study the production of di-electron pairs from proton, pion and nucleus induced reactions at 1-2 AGeV. In pp collisions at 2.2 GeV we have focused mainly on exclusive reconstruction of the $\eta$ meson decays in the hadronic ($\eta\to\pi^{+}\pi^{-}\pi^{0}$) and the electromagnetic channels ($\et

Andrei A. Agrachev, Ugo Boscain, Mario Sigalotti

We consider a generalization of Riemannian geometry that naturally arises in the framework of control theory. Let $X$ and $Y$ be two smooth vector fields on a two-dimensional manifold $M$. If $X$ and $Y$ are everywhere linearly independent, then they define a classical Riemannian metric on $M$ (the metric for which they are orthonormal) and they give to $M$

D. R. T. Jones, G. G. Ross

We show how a sparticle spectrum characteristic of anomaly mediation can arise from a theory whose Lagrangian contains no explicit mass scale. The scale of supersymmetry breaking is governed by the gravitino mass, which is the vacuum expectation value of the F-term of the conformal compensator field, and the tachyonic slepton problem is resolved by the break

Heng-Yu Chen, Minoru Eto, Koji Hashimoto

We explore the correspondence between Yang-Mills instantons and algebraic curves. The curve is defined by Higgs zero locus of dyonic instantons in 1+4 dimensional Yang-Mills-Higgs theory, and it is identified in string theory with the cross-section of supertubes connecting parallel D4-branes. To present evidence for the identification, we show that with tota

A. Ciach, W. T. Gozdz, G. Stell

The primitive model of ionic systems is investigated within a field-theoretic description for the whole range of size-, λ, and charge, Z, ratios of the two ionic species. Two order parameters (OP) are identified, and their relations to physically relevant quantities are described for various values of λand Z. Instabilities of the disordered phase associated

Elena Guardo, Adam Van Tuyl

Let Z be a finite set of double points in P^1 x P^1 and suppose further that X, the support of Z, is arithmetically Cohen-Macaulay (ACM). We present an algorithm, which depends only upon a combinatorial description of X, for the bigraded Betti numbers of I_Z, the defining ideal of Z. We then relate the total Betti numbers of I_Z to the shifts in the graded r

R. Gersch, J. Reiss, C. Honerkamp

First-order phase transitions in many-fermion systems are not detected in the susceptibility analysis of common renormalization-group (RG) approaches. Here we introduce a counterterm technique within the functional renormalization-group (fRG) formalism which allows access to all stable and metastable configurations. It becomes possible to study symmetry-brok

S. Dye, S. A. Eales, M. L. N. Ashby, J. -S. Huang

We have measured the contribution of submillimeter and mid-infrared sources to the extragalactic background radiation at 70 and 160um. Specifically, we have stacked flux in 70 and 160um Spitzer Space Telescope (Spitzer) observations of the Canada-UK Deep Sub-millimeter Survey 14h field at the positions of 850um sources detected by SCUBA and also 8 and 24um s

Pablo Serra, Juergen F. Stilck

We solve a model of self-avoiding walks with up to two monomers per site on the Bethe lattice. This model, inspired on the Domb-Joyce model, was recently proposed to describe the collapse transition observed in interacting polymers [J. Krawczyk et al, Phys. Rev. Lett. 96, 240603 (2006)]. When immediate self-reversals are allowed (RA model), the solution disp

David Joyner

A long standing problem has been to develop &#34;good&#34; binary linear codes to be used for error-correction. This paper investigates in some detail an attack on this problem using a connection between quadratic residue codes and hyperelliptic curves. One question which coding theory is used to attack is: Does there exist a c<2 such that, for all sufficien

L. Costa, R. M. Miró-Roig

The paper begins by overviewing the basic facts on geometric exceptional collections. Then, we derive, for any coherent sheaf $\cF$ on a smooth projective variety with a geometric collection, two spectral sequences: the first one abuts to $\cF$ and the second one to its cohomology. The main goal of the paper is to generalize Castelnuovo-Mumford regularity fo

Olivier Biquard, Yann Rollin

We give a new construction of Einstein and Kaehler-Einstein manifolds which are asymptotically complex hyperbolic, inspired by the work of Mazzeo-Pacard in the real hyperbolic case. The idea is to develop a gluing theorem for 1-handle surgery at infinity, which generalizes the Klein construction for the complex hyperbolic metric.

Zhiqiang Bao, Zhi Lü

In this article we describe a canonical way to expand a certain kind of $(\mathbb Z_2)^{n+1}$-colored regular graphs into closed $n$-manifolds by adding cells determined by the edge-colorings inductively. We show that every closed combinatorial $n$-manifold can be obtained in this way. When $n\leq 3$, we give simple equivalent conditions for a colored graph

Matthieu Latapy, Clemence Magnien

Complex networks, modeled as large graphs, received much attention during these last years. However, data on such networks is only available through intricate measurement procedures. Until recently, most studies assumed that these procedures eventually lead to samples large enough to be representative of the whole, at least concerning some key properties. Th

Jean-Louis Tu

Using methods of KK-theory, we generalize Poincare duality to the framework of twisted K-theory.

Yao-Bei Liu, Lin-Lin Du, Xue-Lei Wang

The physics prospect at future linear $e^{+}e^{-}$ colliders for the study of the Higgs triple self-coupling via the process of $e^{+}e^{-}\to ZHH$ is investigated. In this paper, we calculate the contribution of the new particles predicted by the littlest Higgs model to the cross sections of this process in the future high energy $e^{+}e^{-}$ collider($ILC$

Klaus Ehrenberger, Karl Svozil

We propose a new mechanism for high-pitch perception by a system of multiple neurons capable of resolving frequencies higher than the frequency associated with the mean refractory period up to a multiple thereof.

Phuoc Ha

We estimate the isospin breaking contributions to the baryon masses which we analyzed recently using a loop expansion in the heavy baryon approximation to chiral effective field theory. To one loop, the isospin breaking corrections come from the effects of the $d, u$ quark mass difference, the Coulomb and magnetic moment interactions, and effective point int

Bo Zhao, Zeng-Bing Chen, Yu-Ao Chen, Joerg Schmiedmayer

In this Letter we propose a robust quantum repeater architecture building on the original DLCZ protocol [L.M. Duan \textit{et al.}, Nature \textbf{414}, 413 (2001)]. The architecture is based on two-photon Hong-Ou-Mandel-type interference which relaxes the long distance stability requirements by about 7 orders of magnitude, from sub wavelength for the single

Jens Christian Claussen, Heinz Georg Schuster

Whileas the Kohonen Self Organizing Map shows an asymptotic level density following a power law with a magnification exponent 2/3, it would be desired to have an exponent 1 in order to provide optimal mapping in the sense of information theory. In this paper, we study analytically and numerically the magnification behaviour of the Elastic Net algorithm as a

P. V. Coveney, R. S. Saksena, S. J. Zasada, M. McKeown

Grid computing is distributed computing performed transparently across multiple administrative domains. Grid middleware, which is meant to enable access to grid resources, is currently widely seen as being too heavyweight and, in consequence, unwieldy for general scientific use. Its heavyweight nature, especially on the client-side, has severely restricted t

C. J. Bomhof, P. J. Mulders

The gauge-links connecting the parton field operators in the hadronic matrix elements appearing in the transverse momentum dependent distribution functions give rise to T-odd effects. Due to the process-dependence of the gauge-links the T-odd distribution functions appear with different pre-factors. A consequence is that in the description of single spin asy

John D. Barrow, Christos G. Tsagas

We examine the effects of spatial inhomogeneities on irrotational anisotropic cosmologies by looking at the average properties of anisotropic pressure-free models. Adopting the Buchert scheme, we recast the averaged scalar equations in Bianchi-type form and close the standard system by introducing a propagation formula for the average shear magnitude. We the

Pedro Silva, Pascal Weil

We revisit the problem of deciding whether a finitely generated subgroup H is a free factor of a given free group F. Known algorithms solve this problem in time polynomial in the sum of the lengths of the generators of H and exponential in the rank of F. We show that the latter dependency can be made exponential in the rank difference rank(F) - rank(H), whic

Akira Ishii, Kazushi Ueda, Hokuto Uehara

We study the spaces of locally-finite stability conditions on the derived categories of coherent sheaves on the minimal resolutions of $A_n$-singularities supported at the exceptional sets. Our main theorem is that they are connected and simply-connected. The proof is based on the study of spherical objects in math.AG/0409151 and the homological mirror symme

Jaroslaw Buczynski

We give the full classification of smooth toric Legendrian subvarieties in projective space. We also prove that under some minor assumptions the group of linear automorphisms preserving given Legendrian subvariety preserves the contact structure of the ambient projective space.

Stephane Schanne, Michel Casse, Patrick Sizun, Bertrand Cordier

According to recent analyses of the type-Ia supernova rate as a function of redshift, delayed and prompt type-Ia supernovae (SN Ia) should explode respectively in the Galactic bulge and in the nuclear bulge, a gas rich structure with ongoing star formation, located in the central region of the Milky Way. We estimate the rate of type-Ia supernovae in the Gala

Abdou Wahidi Bello

A finite-volume method for the one-dimensional shallow-water equations including topographic source terms is presented. Exploiting an original idea by Leroux, the system of partial-differential equations is completed by a trivial equation for the bathymetry. By applying a change of variable, the system is given a celerity-speed formulation, and linearized. A

Luis Fuentes Garcia, Manuel Pedreira Perez

We study the generic linearly normal special scroll of genus g in P^N. Moreover, we give a complete classification of the linearly normal scrolls in P^3 of genus 2 and 3.

H. Mohseni Sadjadi, M. Honardoost

By the assumption that the thermodynamics second law is valid, we study the possibility of $ω=-1$ crossing in interacting holographic dark energy model. Depending on the choice of the horizon and the interaction, the transition from quintessence to phantom regime and subsequently from phantom to quintessence phase may be possible. The second transition avoid

Jan Wiersig

We study the formation of long-lived states near avoided resonance crossings in open systems. For three different optical microcavities (rectangle, ellipse, and semi-stadium) we provide numerical evidence that these states are localized along periodic rays, resembling scarred states in closed systems. Our results shed light on the morphology of long-lived st

David Aldous, Charles Bordenave, Marc Lelarge

We study the relation between the minimal spanning tree (MST) on many random points and the &#34;near-minimal&#34; tree which is optimal subject to the constraint that a proportion $δ$ of its edges must be different from those of the MST. Heuristics suggest that, regardless of details of the probability model, the ratio of lengths should scale as $1 + Θ(δ^2)

M. S. Gronsleth, J. Linder, J. -M. Borven, A. Sudbo

We study tunneling currents in a model consisting of two non-unitary ferromagnetic spin-triplet superconductors separated by a thin insulating layer. We find a novel interplay between ferromagnetism and superconductivity, manifested in the Josephson effect. This offers the possibility of tuning dissipationless currents of charge and spin in a well-defined ma

Zeng-Bing Chen, Bo Zhao, Yu-Ao Chen, Joerg Schmiedmayer

We present a detailed analysis of a new robust quantum repeater architecture building on the original DLCZ protocol [L.M. Duan \textit{et al.}, Nature (London) \textbf{414}, 413 (2001)]. The new architecture is based on two-photon Hong-Ou-Mandel-type interference which relaxes the long-distance interferometric stability requirements by about 7 orders of magn

Y. S. Oh, Kee Hoon Kim, P. A. Sharma, N. Harrison

Temperature- and field-dependent measurements of the Hall effect of pure and 4 % Rh-doped URu$_{2}$Si$_{2}$ reveal low density (0.03 hole/U) high mobility carriers to be unique to the `hidden order&#39; phase and consistent with an itinerant density-wave order parameter. The Fermi surface undergoes a series of abrupt changes as the magnetic field is increase

Kumiko Hayashi, Mitsunori Takano

We report the results of molecular dynamics simulations of the protein myosin carried out with an elastic network model. Quenching the system, we observe glassy behavior of a density correlation function and a density response function that are often investigated in structure glasses and spin glasses. In the equilibrium, the fluctuation-response relation, a

Jihong Qin, Ting Chen, Shiping Feng

Within the kinetic energy driven superconducting mechanism, the effect of the pressure on superconductivity in doped two-leg ladder cuprates is studied. It is shown that the superconducting transition temperature in doped two-leg ladder cuprate superconductors increases with increasing pressure in the underpressure regime, and reaches a maximum in the optima