May 2009 arXiv papers — page 43

A. J. Berkley, M. W. Johnson, P. Bunyk, R. Harris

We have designed, fabricated and tested an XY-addressable readout system that is specifically tailored for the reading of superconducting flux qubits in an integrated circuit that could enable adiabatic quantum optimization. In such a system, the flux qubits only need to be read at the end of an adiabatic evolution when quantum mechanical tunneling has been

Benjamin P. Lanyon, James D. Whitfield, Geoff G. Gillet, Michael E. Goggin

The fundamental problem faced in quantum chemistry is the calculation of molecular properties, which are of practical importance in fields ranging from materials science to biochemistry. Within chemical precision, the total energy of a molecule as well as most other properties, can be calculated by solving the Schrodinger equation. However, the computational

B. Leeb, C. Ramos-Cuevas

We prove that a convex subcomplex of a spherical building of type F4 or E6 is a subbuilding or the automorphisms of the subcomplex fix a point on it. Our approach is differential-geometric and based on the theory of metric spaces with curvature bounded above. We use these techniques also to give another proof of the same result for the spherical buildings of

Jayanth Chennamangalam, Yogesh Maan, Avinash A. Deshpande

Although several existing and upcoming telescopes have imaging as their primary mode, they also have a sensitive phased-array mode with a multiple-beam forming capability enabling high time resolution studies of several types of objects, including pulsars. For example, the potentially wide coverage in frequency, combined with its collecting area, makes the M

M. Czakon, C. G. Papadopoulos, M. Worek

We extend the massless dipole formalism of Catani and Seymour, as well as its massive version as developed by Catani, Dittmaier, Seymour and Trocsanyi, to arbitrary helicity eigenstates of the external partons. We modify the real radiation subtraction terms only, the primary aim being an improved efficiency of the numerical Monte Carlo integration of this co

Reza Seyyedali

In 1980, I. Morrison proved that slope stability of a vector bundle of rank 2 over a compact Riemann surface implies Chow stability of the projectivization of the bundle with respect to certain polarizations. Using the notion of balanced metrics and recent work of Donaldson, Wang, and Phong-Sturm, we show that the statement holds for higher rank vector bundl

N. C. Bristowe, Emilio Artacho, P. B. Littlewood

The physics of oxide superlattices is considered for pristine (001) multilayers of the band insulators LaAlO3 and SrTiO3 with alternating p and n interfaces. First principles results and a model of capacitor plates offer a simple paradigm to understand their dielectric properties and the insulator to metal transition (IMT) at interfaces with increasing layer

Yoh Tanimoto

The group Diff(S^1) of the orientation preserving diffeomorphisms of the circle S^1 plays an important role in conformal field theory. We consider a subgroup B_0 of Diff(S^1) whose elements stabilize "the point of infinity". This subgroup is of interest for the actual physical theory living on the punctured circle, or the real line. We investigate th

Michael Uhlmann, Ralf Schützhold, Uwe R. Fischer

We present an analytical derivation of the winding number counting topological defects created by an O(N) symmetry-breaking quantum quench in N spatial dimensions. Our approach is universal in the sense that we do not employ any approximations apart from the large-$N$ limit. The final result is nonperturbative in N, i.e., it cannot be obtained by %the usual

Rong-Gen Cai, Li-Ming Cao, Nobuyoshi Ohta

By using the canonical Hamiltonian method, we obtain the mass and entropy of the black holes with general dynamical coupling constant $λ$ in Hoř ava-Lifshitz Gravity. Regardless of whether the horizon is sphere, plane or hyperboloid, we find these black holes are thermodynamically stable in some parameter space and unstable phase also exists in other paramet

The BABAR Collaboration, B. Aubert

We describe searches for $B^0$ meson decays to the charmless final states $π^0 K^0_SK^0_S$, $ηK^0_S K^0_S$, and $η^{\prime}K^0_SK^0_S$. The data sample corresponds to $467 \times 10^{6}$ $B\bar{B}$ pairs produced in $e^+e^-$ annihilation and collected with the BABAR detector at the SLAC National Accelerator Laboratory. We find no significant signals and dete

Masayoshi Ushio, Takaaki Tanaka, Grzegorz Madejski, Tadayuki Takahashi

We present the results of X-ray observations of the well-studied TeV blazar Mrk 421 with the Suzaku satellite in 2006 April 28. During the observation, Mrk 421 was undergoing a large flare and the X-ray flux was variable, decreasing by ~ 50 %, from 7.8x10^{-10} to 3.7x10^{-10} erg/s/cm^2 in about 6 hours, followed by an increase by ~ 35 %. Thanks to the broa

Fedor Nazarov, Fedor Petrov, Dmitry Ryabogin, Artem Zvavitch

We prove that the unit cube $B^n_{\infty}$ is a strict local minimizer for the Mahler volume product $vol_n(K)vol_n(K^*)$ in the class of origin symmetric convex bodies endowed with the Banach-Mazur distance.

Roberta Armillis, Claudio Coriano, Luigi Delle Rose, Marco Guzzi

We analyze the role played by anomaly poles in an anomalous gauge theory by discussing their signature in the corresponding off-shell effective action. The origin of these contributions, in the most general kinematical case, is elucidated by performing a complete analysis of the anomaly vertex at perturbative level. We use two independent (but equivalent) re

S. Hubrig, B. Stelzer, M. Schoeller, C. Grady

Among the 21 Herbig Ae/Be stars studied, new detections of a magnetic field were achieved in six stars. For three Herbig Ae/Be stars, we confirm previous magnetic field detections. The largest longitudinal magnetic field, <B_z> = -454+-42G, was detected in the Herbig Ae/Be star HD101412 using hydrogen lines. No field detection at a significance level of 3sig

Z. G. Chen, G. Xu, W. Z. Hu, X. D. Zhang

BaNi$_2$As$_2$ exhibits a first order structural transition at 130 K. Understanding this structural transition is a crucial step towards understanding the electronic properties of the material. We present a combined optical spectroscopy and band structure calculation study on the compound across the transition. The study reveals that BaNi$_2$As$_2$ is a good

Alex Roxin, Ernest Montbrio

Synaptic, dendritic and single-cell kinetics generate significant time delays that shape the dynamics of large networks of spiking neurons. Previous work has shown that such effective delays can be taken into account with a rate model through the addition of an explicit, fixed delay [Roxin et al. PRL 238103 (2005)]. Here we extend this work to account for ar

Fabian Schmidt

We perform cosmological N-body simulations of the Dvali-Gabadadze-Porrati braneworld model, by solving the full non-linear equations of motion for the scalar degree of freedom in this model, the brane bending mode. While coupling universally to matter, the brane-bending mode has self-interactions that become important as soon as the density field becomes non

Fu-Jiun Jiang, Brian C. Tiburzi

We use two-flavor heavy baryon chiral perturbation theory to investigate the isovector axial charges of the spin one-half hyperons. Expressions for these hyperon axial charges are derived at next-to-leading order in the chiral expansion. We utilize phenomenological and lattice QCD inputs to assess the convergence of the two-flavor theory, which appears to be

Daniel S. Freed, Michael J. Hopkins, Jacob Lurie, Constantin Teleman

It is a long-standing question to extend the definition of 3-dimensional Chern-Simons theory to one which associates values to 1-manifolds with boundary and to 0-manifolds. We provide a solution in case the gauge group is a torus. We also develop from different points of view an associated 4-dimensional invertible topological field theory which encodes the a

Horace P. Yuen, Ranjith Nair

The general problem of performance advantage obtainable by the use of nonclassical transmitted states over classical ones is considered. Attention is focused on the situation where system loss is significant and additive Gaussian noise may be present at the receiver. Under the assumption that the total received state is classical, rigorous output density ope

Leonardo Campanelli, Marco Ruggieri

We study the response of the QCD vacuum to an external abelian chromomagnetic field in the framework of a non local Nambu-Jona Lasinio model with the Polyakov loop. We use the Lattice results on the deconfinement temperature of the pure gauge theory to compute the same quantity in the presence of dynamical quarks. We find a linear relationship between the de

David Hoffman, Brian White

For any prescribed closed subset of a line segment in Euclidean 3-space, we construct a sequence of minimal disks that are properly embedded in an open solid cylinder around the segment and that have curvatures blowing up precisely at the points of the closed set.

Cenalo Vaz, L. C. R. Wijewardhana

Although all popular approaches to quantum gravity are able to recover the Bekenstein-Hawking entropy-area law in the thermodynamic limit, there are significant differences in their descriptions of the microstates and in the application of statistics. Therefore they can have significantly different phenomenological implications. For example, requiring indist

Gou Shinkai, Toshiaki Hayashi, Takeshi Ota, Toshimasa Fujisawa

Designing coherent processes is essential for developing quantum information technologies. We study coherent dynamics of two spatially separated electrons in a coupled semiconductor double quantum dot (DQD), in which various two-qubit operations are demonstrated just by adjusting the gate voltages. Especially, second-order correlated coherent oscillations pr

Filipe Paccetti Correia, Michael G. Schmidt

We investigate the viability of F-term uplift in heterotic M-theory. With this aim we explore a natural ingredient of heterotic compactifications, namely vector bundle moduli. It is shown that it is generically possible to obtain stable de Sitter vacua with broken supersymmetry provided the little Kahler potential and the prefactors of the non-perturbative s

Giampiero Esposito, Pietro Santorelli

In the application of potential models, the use of the Dirac equation in central potentials remains of phenomenological interest. The associated set of decoupled second-order ordinary differential equations is here studied by exploiting the phase-integral technique, following the work of Froman and Froman that provides a powerful tool in ordinary quantum mec

Armin Rainer

We study the regularity of the roots of multiparameter families of complex univariate monic polynomials $P(x)(z) = z^n + \sum_{j=1}^n (-1)^j a_j(x) z^{n-j}$ with fixed degree $n$ whose coefficients belong to a certain subring $\mathcal C$ of $C^\infty$-functions. We require that $\mathcal C$ includes polynomial but excludes flat functions (quasianalyticity)

Ahmad Ghodsi

Recently a new four-dimensional non relativistic renormalizable theory of gravity was proposed by Horava. This gravity reduces to Einstein gravity at large distances. In this paper by using the new action for gravity we present different toroidal solutions to the equations of motion. Our solutions describe the near horizon geometry with slow rotating paramet

Vadim Shcherbakov, Stanislav Volkov

We study stability of a growth process generated by sequential adsorption of particles on a one-dimensional lattice torus, that is, the process formed by the numbers of adsorbed particles at lattice sites, called heights. Here the stability of process, loosely speaking, means that its components grow at approximately the same rate. To assess stability quanti

R. Maul, W. Wenzel

Structural disorder is present in almost all experimental measurements of electronic transport through single molecules or molecular wires. To assess its influence on the conductance is computationally demanding, because a large number of conformations must be considered. Here we analyze an approximate recursive layer Green function approach for the ballisti

Igor Goychuk

We study viscoelastic subdiffusion in bistable and periodic potentials within the Generalized Langevin Equation approach. Our results justify the (ultra)slow fluctuating rate view of the corresponding bistable non-Markovian dynamics which displays bursting and anti-correlation of the residence times in two potential wells. The transition kinetics is asymptot

Charles H. -T. Wang, Paolo M. Bonifacio, Robert Bingham, J. Tito Mendonca

We identify a new dynamical mechanism for a strong scalar gravitational field effect. To illustrate this mechanism, we investigate the parametric excitation and emission of scalar gravitational waves by a radially pulsating model neutron star.

Theo van Uem

We obtain expected number of arrivals, absorption probabilities and expected time before absorption for a discrete random walk on the integers with an infinite set of equidistant multiple function barriers

Daniel J. Thompson

Let $(X,d)$ be a compact metric space, $f:X \mapsto X$ be a continuous map satisfying a property we call almost specification (which is slightly weaker than the $g$-almost product property of Pfister and Sullivan), and $ϕ$ be a continuous function on $X$. We show that the set of points for which the Birkhoff average of $ϕ$ does not exist (which we call the i

Erich Gaertig, Kostas D. Kokkotas

We study the g-modes of fast rotating stratified neutron stars in the general relativistic Cowling approximation, where we neglect metric perturbations and where the background models take into account the buoyant force due to composition gradients. This is the first paper studying this problem in a general relativistic framework. In a recent paper by Passam

Valery Marenich

With the help of a new type of functionals we study manifolds diffeomorphic to $S^2\times S^2$ and establish, in particular, the Hopf conjecture.

Richard J. Parker, Simon P. Goodwin

We examine the effects of dynamical evolution in clusters on planetary systems or protoplanetary disks orbiting the components of binary stars. In particular, we look for evidence that the companions of host stars of planetary systems or disks could have their inclination angles raised from zero to between the threshold angles (39.23 degrees and 140.77 degre

Leonid Ya. Glozman, C. B. Lang, Markus Limmer

The variational method allows one to study the mixing of interpolators with different chiral transformation properties in the non-perturbatively determined physical state. It is then possible to define and calculate in a gauge-invariant manner the chiral as well as the partial wave content of the quark-antiquark component of a meson in the infrared, where ma

Karl Svozil

Despite provable unknowables in recursion theory, indeterminism and randomness in physics is confined to conventions, subjective beliefs and preliminary evidence. The history of the issue is very briefly reviewed, and answers to five questions raised by Hector Zenil are presented.

Janine Splettstoesser, Michael Moskalets, Markus Büttiker

We propose a mesoscopic circuit in the quantum Hall effect regime comprising two uncorrelated single-particle sources and two distant Mach-Zehnder interferometers with magnetic fluxes, which allows in a controllable way to produce orbitally entangled electrons. Two-particle correlations appear as a consequence of erasing of which path information due to coll

Georgi Dzhelepov, Iva Dokuzova, Dimitar Razpopov

We consider a 3-dimensional Riemannian manifold with additional structure q. We find a condition that the affine structure q is parallel with respect to the Riamannian connection.We prove the sectional curvatures of three 2-sections formed linearly independent vectors are equal among them.

Arthur Hipke, Sven Lubeck, Haye Hinrichsen

The conserved Manna model with a planar absorbing boundary is studied in various space dimensions. We present a heuristic argument that allows one to compute the surface critical exponent in one dimension analytically. Moreover, we discuss the mean field limit that is expected to be valid in d>4 space dimensions and demonstrate how the corresponding partial

Qing-Guo Huang, Miao Li, Xiao-Dong Li, Shuang Wang

In this work, we explore the cosmological consequences of the recently released Constitution sample of 397 Type Ia supernovae (SNIa). By revisiting the Chevallier-Polarski-Linder (CPL) parameterization, we find that, for fitting the Constitution set alone, the behavior of dark energy (DE) significantly deviate from the cosmological constant $Λ$, where the eq

WeiGuo Zhang, GuoZhen Xiao

In this paper, a technique on constructing nonlinear resilient Boolean functions is described. By using several sets of disjoint spectra functions on a small number of variables, an almost optimal resilient function on a large even number of variables can be constructed. It is shown that given any $m$, one can construct infinitely many $n$-variable ($n$ even

Salvatore Antoci

The propagation of waves in two space dimensions exhibited by two exact solutions to the field equations of Einstein&#39;s unified field theory is investigated under the assumption that the metric s_{ik} is the one already chosen by Kursunoglu and by Hély in the years 1952-1954. It is shown that, for both exact solutions, with this choice of the metric the p

Peter Imkeller, Goncalo dos Reis

We consider backward stochastic differential equations with drivers of quadratic growth (qgBSDE). We prove several statements concerning path regularity and stochastic smoothness of the solution processes of the qgBSDE, in particular we prove an extension of Zhang&#39;s path regularity theorem to the quadratic growth setting. We give explicit convergence rat

Jaroslaw Klos, Maciej Krawczyk

We calculate the band structure of a two-dimensional GaAs/AlGaAs superlattice and estimate the ultimate efficiency of solar cells using this type of structure for solar energy conversion. The superlattice under consideration consists of gallium arsenide rods forming a square lattice and embedded in aluminium gallium arsenide. The ultimate efficiency is deter

Mikhail Voropaev

High precision analytical approximation is proposed for variance-covariance based risk allocation in a portfolio of risky assets. A general case of a single-period multi-factor Merton-type model with stochastic recovery is considered. The accuracy of the approximation as well as its speed are compared to and shown to be superior to those of Monte Carlo simul

C. Giannetti, F. Banfi, D. Nardi, G. Ferrini

The use of femtosecond laser pulses to impulsively excite thermal and mechanical transients in matter has led, in the last years, to the development of picosecond acoustics. Recently, the pump-probe approach has been applied to nano-engineered materials to optically generate and detect acoustic waves in the GHz-THz frequency range. In this paper, we review t

Wei Wei, Hong Guo

We propose a new approach to nondeterministic random number generation. In theory, the randomness originated from the uncorrelated nature of consecutive laser pulses with Poissonian photon number distribution and that of the consecutive single photon detections is used to generate random bit. In experiment, von Neumann correction method is applied to extract

Gniewomir Sarbicki

A general formulation of the problem of detection for a pair of two cones is presented. The special case is the detection of entangled states by entanglement witnesses. Having defined what means &#34;to detect&#34;, one can identify the subset of elements, which detect optimally. I will present the properties of this set for a general pair of cones. In parti

Felix M. Lev

We consider a possibility that gravity is not an interaction but a manifestation of a symmetry based on a Galois field.

Chun-Kun Jiao, Wei Chen, Hua-Xing Chen, Shi-Lin Zhu

In order to explore the possible existence of the exotic $0^{--}$ state, we have constructed the tetraquark interpolating operators systematically. As a byproduct, we notice the $0^{+-}$ tetraquark operators without derivatives do not exist. The special Lorentz structure of the $0^{--}$ currents forbids the four-quark correction to the spectral density. Now

J. P. D&#39;Incao, B. D. Esry

We present a comprehensive collection of ultracold three-body collisions properties near overlapping Feshbach resonances. Our results incorporate variations of all scattering lengths and demonstrate novel collisional behavior, such as atom-molecule interference effects. Taking advantage of the unique ways in which these collisions reflect Efimov physics, new

Timothy J. Hollowood, Graham M. Shore, Ross J. Stanley

This work considers the way that quantum loop effects modify the propagation of light in curved space. The calculation of the refractive index for scalar QED is reviewed and then extended for the first time to QED with spinor particles in the loop. It is shown how, in both cases, the low frequency phase velocity can be greater than c, as found originally by

Gonzalo Navarro, Kunihiko Sadakane

We propose new succinct representations of ordinal trees, which have been studied extensively. It is known that any $n$-node static tree can be represented in $2n + o(n)$ bits and a number of operations on the tree can be supported in constant time under the word-RAM model. However the data structures are complicated and difficult to dynamize. We propose a s

Rostam Moradian

We added an extra condition, original lattice symmetry of chosen cluster around cluster central site, to the cluster approximation methods with periodic boundary condition such as dynamical cluster approximation (DCA), effective medium approximation (EMSCA) and nonlocal coherent potential approximation (NLCPA). For each cluster size, this condition leads to

Stephen R. Williams, Denis J. Evans

We examine the question of whether fluids and crystals are differentiated on the basis of their zero frequency shear moduli or their limiting zero frequency shear viscosity. We show that while fluids, in contrast with crystals, do have a zero value for their shear modulus, in contradiction to a widespread presumption, a crystal does not have an infinite or e

Belle Collaboration, S. -H. Kyeong, Y. -J. Kwon

We report measurements of charmless hadronic B^0 decays into the pi+pi-K+pi+ final state. The analysis uses a sample of 657x10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider at the Y(4S) resonance. The decay B^0 -> rho0 Kpi is observed for the first time; the significance is 5.0sigma and the corresponding partial

Wei-Feng Tsai, Yan-Yang Zhang, Chen Fang, Jiangping Hu

Using both the self-consistent Bogoliubov-de Gennes formulation and non-self-consistent T-matrix approach, we perform a comprehensive investigation of the in-gap bound states induced by a localized single impurity in iron-based superconductors. We focus on studying signatures associated with the unconventional sign-changed s-wave pairing symmetry. For a non-

James Z. M. Gao, Linda Y. M. Li, Christian M. Reidys

Background: RNA exhibits a variety of structural configurations. Here we consider a structure to be tantamount to the noncrossing Watson-Crick and \pairGU-base pairings (secondary structure) and additional cross-serial base pairs. These interactions are called pseudoknots and are observed across the whole spectrum of RNA functionalities. In the context of st

Hayato Motohashi, Alexei A. Starobinsky, Jun&#39;ichi Yokoyama

For a class of viable cosmological models in $f(R)$ gravity which deviation from the Einstein gravity decreases as a inverse power law of the Ricci scalar $R$ for large $R$, an analytic solution for density perturbations in the matter component during the matter dominated stage is obtained in terms of hypergeometric functions. An analytical expression for th

Bahman Davoudi, Babak Pourbohloul, Joel Miller, Rafael Meza

When an infectious disease strikes a population, the number of newly reported cases is often the only available information that one can obtain during early stages of the outbreak. An important goal of early outbreak analysis is to obtain a reliable estimate for the basic reproduction number, $R_{0}$, from the limited information available. We present a nove

Elif Cincioglu, Alper Hayreter, Asli Sabanci, Levent Solmaz

Using the effective potential method, we computed one-loop corrections to the mass matrix of neutral Higgs bosons of the Non-Holomorphic Supersymmetric Standard Model (NHSSM) with explicit CP violation, where the radiative corrections due to the quarks and squarks of the third generation were taken into account. We observed that the non-holomorphic trilinear

Florentin Smarandache

In this article we present the two classical negations of Euclid&#39;s Fifth Postulate (done by Lobachevski-Bolyai-Gauss, and respectively by Riemann), and in addition of these we propose a partial negation (or a degree of negation) of an axiom in geometry. The most important contribution of this article is the introduction of the degree of negation (or part

Aveek Sarkar, Robert W Walsh

Determining the preferred spatial location of the energy input to solar coronal loops would be an important step forward towards a more complete understanding of the coronal heating problem. Following on from Sarkar & Walsh (2008) this paper presents a short 10e9 cm &#34;global loop&#34; as 125 individual strands, where each strand is modelled independently

Volker Bromm, Naoki Yoshida, Lars Hernquist, Christopher F. McKee

Observations made using large ground-based and space-borne telescopes have probed cosmic history all the way from the present-day to a time when the Universe was less than a tenth of its present age. Earlier on lies the remaining frontier, where the first stars, galaxies, and massive black holes formed. They fundamentally transformed the early Universe by en

Roberto De Leo

Wextend the results obtained recently by G. D&#39;Ambra and A. Loi towards the proof of a conjecture of M.Gromov on isometric immersions via non-free maps.

M. Uplaznik, B. Bercic, M. Remskar, D. Mihailovic

Charge transport measurements on flexible Mo$_{6}$S$_{3}$I$_{6}$ (MoSI) nanowires with different diameters in highly imperfect 2-terminal circuits reveal systematic power law behaviour of the conductivity $σ(T,V)$ as a function of temperature and voltage. On the basis of measurements on a number of circuits we conclude that the behaviour in \emph{thin} wires

Tiago P. Peixoto, Barbara Drossel

We investigated the properties of Boolean networks that follow a given reliable trajectory in state space. A reliable trajectory is defined as a sequence of states which is independent of the order in which the nodes are updated. We explored numerically the topology, the update functions, and the state space structure of these networks, which we constructed

Jorge Penarrubia, Matthew G. Walker, Gerard Gilmore

We use N-body simulations to study the tidal evolution of globular clusters (GCs) in dwarf spheroidal (dSph) galaxies. Our models adopt a cosmologically motivated scenario in which the dSph is approximated by a static NFW halo with a triaxial shape. We apply our models to five GCs spanning three orders of magnitude in stellar density and two in mass, chosen

Jozef H. Przytycki

It was asked by J.Birman, Williams, and L.Rudolph whether nontrivial Lorentz knots have always positive signature. Lorentz knots are examples of positive braids (in our convention they have all crossings negative so they are negative links). It was shown by L.Rudolph that positive braids have positive signature (if they represent nontrivial links). K.Murasug

N. R. Moloney, J. Davidsen

We study extremal statistics and return intervals in stationary long-range correlated sequences for which the underlying probability density function is bounded and uniform. The extremal statistics we consider e.g., maximum relative to minimum are such that the reference point from which the maximum is measured is itself a random quantity. We analytically ca

Masamune Oguri

We show that the ability to probe primordial non-Gaussianity with cluster counts is drastically improved by adding the excess variance of counts which contains information on the clustering. The conflicting dependences of changing the mass threshold and including primordial non-Gaussianity on the mass function and biasing indicate that the self-calibrated cl

A. Nordlund, G. B. Scharmer

Numerical simulations have by now revealed that the fine scale structure of the penumbra in general and the Evershed effect in particular is due to overturning convection, mainly confined to gaps with strongly reduced magnetic field strength. The Evershed flow is the radial component of the overturning convective flow visible at the surface. It is directed o

G. A. J. Hussain, A. Collier Cameron, M. M. Jardine, N. Dunstone

We have produced brightness and magnetic field maps of the surfaces of CV Cha and CR Cha: two actively accreting G and K-type T Tauri stars in the Chamaeleon I star-forming cloud with ages of 3-5 Myr. Our magnetic field maps show evidence for strong, complex multi-polar fields similar to those obtained for young rapidly rotating main sequence stars. Brightne

Andrei Gruzinov

We show that the first structures that form in the universe should spontaneously generate magnetic fields. No primordial seed field is required for this &#34;first dynamo&#34;. Although the first dynamo starts with kinetic plasma instabilities, we argue that an adequate magnetohydrodynamic description might be possible via a simple trick. This should allow a

M. A. Falkenberg, R. Kotulla, U. Fritze

In a previous paper (Falkenberg, Kotulla & Fritze 2009, arXiv:0901.1665) we have shown that the classical definition of E+A galaxies excludes a significant number of post-starburst galaxies. We suggested that analysing broad-band spectral energy distributions (SEDs) is a more comprehensive method to select and distinguish poststarburst galaxies than the clas

Kai Sun, Hong Yao, Eduardo Fradkin, Steven A. Kivelson

We investigate the stability of a quadratic band-crossing point (QBCP) in 2D fermionic systems. At the non-interacting level, we show that a QBCP exists and is topologically stable for a Berry flux $\pm 2π$, if the point symmetry group has either fourfold or sixfold rotational symmetries. This putative topologically stable free-fermion QBCP is marginally uns

Katie M. Chynoweth, Glen I. Langston, Kelly Holley-Bockelmann, Felix J. Lockman

We have observed the NGC 2403 group of galaxies using the Robert C. Byrd Green Bank Telescope (GBT) in a search for faint, extended neutral hydrogen clouds similar to the clouds found around the M81/M82 group, which is located approximately 250 kpc from the NGC 2403 group along the same filament of galaxies. For an HI cloud with a size < 10 kpc within 50 kpc

Tsvi Piran, Nir J. Shaviv, Ehud Nakar

Recent measurements of the positron/electron ratio in the cosmic ray (CR) flux exhibits an apparent anomaly, whereby this ratio increases between 10 and 100 GeV. In contrast, this ratio should decrease according to the standard scenario, in which CR positrons are secondaries formed by hadronic interactions between the primary CR protons and the interstellar

Aleksey Cherman, Thomas D. Cohen, Abhinav Nellore

We show that the squared speed of sound v_{s}^{2} is bounded from above at high temperatures by the conformal value of 1/3 in a class of strongly coupled four-dimensional field theories, given some mild technical assumptions. This class consists of field theories that have gravity duals sourced by a single scalar field. There are no known examples to date of

Kaspar Sakmann, Alexej I. Streltsov, Ofir E. Alon, Lorenz S. Cederbaum

The quantum dynamics of a one-dimensional bosonic Josephson junction is studied by solving the time-dependent many-boson Schr\"odinger equation numerically exactly. Already for weak interparticle interactions and on short time scales, the commonly-employed mean-field and many-body methods are found to deviate substantially from the exact dynamics. The system

Jan Pflamm-Altenburg, Pavel Kroupa

Star formation is mainly determined by the observation of H$α$ radiation which is related to the presence of short lived massive stars. Disc galaxies show a strong cutoff in H$α$ radiation at a certain galactocentric distance which has led to the conclusion that star formation is suppressed in the outer regions of disc galaxies. This is seemingly in contradi

Ren Guo, Xiaobo Liu

Kashaev algebra associated to a surface is a noncommutative deformation of the algebra of rational functions of Kashaev coordinates. For two arbitrary complex numbers, there is a generalized Kashaev algebra. The relationship between the shear coordinates and Kashaev coordinates induces a natural relationship between the quantum Teichmüller space and the gene

E. J. Nicol, J. P. Carbotte

We study how phonon structure manifests itself in the electronic density of states of graphene. A procedure for extracting the value of the electron-phonon renormalization $λ$ is developed. In addition, we identify direct phonon structures. With increasing doping, these structures, along with $λ$, grow in amplitude and no longer display particle-hole symmetr

Yoichi Tamura, Kotaro Kohno, Kouichiro Nakanishi, Bunyo Hatsukade

Lyman-alpha emitters are thought to be young, low-mass galaxies with ages of ~10^8 yr. An overdensity of them in one region of the sky (the SSA 22 field) traces out a filamentary structure in the early Universe at a redshift of z = 3.1 (equivalent to 15 per cent of the age of the Universe) and is believed to mark a forming protocluster. Galaxies that are bri

P. J. van Zwol, G. Palasantzas, J. Th. M. De Hosson

In this article we present calculations of van der Waals/Casimir forces, described by Lifshitz theory, for the solid-liquid-solid system using measured dielectric functions of all involved materials for the wavelength range from millimeters down to subnanometers. It is shown that even if the dielectric function is known over all relevant frequency ranges, th

Jeffrey Yepez, George Vahala, Linda Vahala

The dynamics of vortex solitons in a BEC superfluid is studied. A quantum lattice-gas algorithm (localization-based quantum computation) is employed to examine the dynamical behavior of vortex soliton solutions of the Gross-Pitaevskii equation (phi^4 interaction nonlinear Schroedinger equation). Quantum turbulence is studied in large grid numerical simulatio

Wanli Li, C. L. Vicente, J. S. Xia, W. Pan

The quantum Hall plateau transition was studied at temperatures down to 1 mK in a random alloy disordered high mobility two-dimensional electron gas. A perfect power-law scaling with κ=0.42 was observed from 1.2K down to 12mK. This perfect scaling terminates sharply at a saturation temperature of T_s~10mK. The saturation is identified as a finite-size effect

Karine Bertin, Erwan Le Pennec, Vincent Rivoirard

This paper deals with the problem of density estimation. We aim at building an estimate of an unknown density as a linear combination of functions of a dictionary. Inspired by Candès and Tao&#39;s approach, we propose an $\ell_1$-minimization under an adaptive Dantzig constraint coming from sharp concentration inequalities. This allows to consider a wide cla

O. Ogievetsky, T. Popov

We describe a quantum Lie algebra based on the Cremmer-Gervais R-matrix. The algebra arises upon a restriction of an infinite-dimensional quantum Lie algebra.

Arvind Nayak, Soobash Daiboo, N. Udaya Shankar

The Mauritius Radio Telescope (MRT) images show systematics in the positional errors of sources when compared to source positions in the Molonglo Reference Catalogue (MRC). We have applied two-dimensional homography to correct positional errors in the image domain and avoid re-processing the visibility data. Positions of bright (above 15-$σ$) sources, common

F. Gómez-Cubillo, Z. Suchanecki

Spectral representations of the dilation and translation operators on $L^2({\mathbb R})$ are built through appropriate bases. Orthonormal wavelets and multiresolution analysis are then described in terms of rigid operator-valued functions defined on the functional spectral spaces. The approach is useful for computational purposes.

A. P. Balachandran, Anosh Joseph, Pramod Padmanabhan

Quantum theories constructed on the noncommutative spacetime called the Groenewold-Moyal plane exhibit many interesting properties such as Lorentz and CPT noninvariance, causality violation and twisted statistics. We show that such violations lead to many striking features that may be tested experimentally. These theories predict Pauli forbidden transitions

Mario N. Berberan-Santos

A different view of Henri-Michaelis-Menten (HMM) enzyme kinetics is presented. In the first part of the paper, a simplified but useful description that stresses the cyclic nature of the catalytic process is introduced. The time-dependence of the substrate concentration after the initial transient phase is derived in a simple way that dispenses the mathematic

A. S. Wills

A considerable challenge is faced by researchers wishing to identify the propagation vector(s) associated with a magnetic structure or a lattice distortion from powder diffraction data, due to the severe destruction of information by powder averaging and search algorithms based on extracted peak positions. In this article a new method is introduced that is b

Bin Luo, Hua Tang, Hong Guo

The rigorous dark-sate conditions, i.e., two-photon resonance, for a Lambda-type electromagnetically induced transparency (EIT) are extended with the system controlled by a microwave field. The extended dark-states are found to be extremely sensitive to the phase of the microwave field in a narrow interval. However, the dark-state is no longer the requiremen

John Smillie, Corinna Ulcigrai

We consider a symbolic coding of linear trajectories in the regular octagon with opposite sides identified (and more generally in regular 2n-gons). Each infinite trajectory gives a cutting sequence corresponding to the sequence of sides hit. We give an explicit characterization of these cutting sequences. The cutting sequences for the square are the well stu