June 2009 arXiv papers — page 27

Z. Ammari, S. Breteaux

We consider the semiclassical limit of nonrelativistic quantum many-boson systems with delta potential in one dimensional space. We prove that time evolved coherent states behave semiclassically as squeezed states by a Bogoliubov time-dependent affine transformation. This allows us to obtain properties analogous to those proved by Hepp and Ginibre-Velo (\cit

Andrei Mesinger, Steven Furlanetto

We study the spatial fluctuations in the hydrogen ionizing background in the epoch following reionization (z ~ 5--6). The rapid decrease with redshift in the photon mean free path (m.f.p.), combined with the clustering of increasingly rare ionizing sources, can result in a very inhomogenous ionizing background during this epoch. We systematically investigate

K. Tsigutkin, D. Dounas-Frazer, A. Family, J. E. Stalnaker

Atomic parity violation has been observed in the 6s^2 1S0 - 5d6s 3D1 408-nm forbidden transition of ytterbium. The parity-violating amplitude is found to be two orders of magnitude larger than in cesium, where the most precise experiments to date have been performed. This is in accordance with theoretical predictions and constitutes the largest atomic parity

Andrey A. Shoom

We present a short review on the electric and magnetic black strings in 5D spacetime with one compact dimension. Linear static perturbations of these objects indicate presence of the threshold unstable mode. Analysis of the mode shows that the electric black string is less stable than a neutral one. The situation is opposite for the magnetic black string.

R. Feldmann, C. M. Carollo, L. Mayer, A. Renzini

We trace the evolution of central galaxies in three ~10^13 M_sun galaxy groups simulated at high resolution in cosmological hydrodynamical simulations. The evolution in the group potential leads, at z=0, to central galaxies that are massive, gas-poor early-type systems supported by stellar velocity dispersion resembling either elliptical or S0 galaxies. Thei

Brian Niebergal, Rachid Ouyed, Rodrigo Negreiros, Fridolin Weber

Compact stars made of quark matter rather than confined hadronic matter, are expected to form a color superconductor. This superconductor ought to be threaded with rotational vortex lines, within which the star's interior magnetic field is at least partially confined. The vortices (and thus magnetic flux) would be expelled from the star during stellar sp

Gilles Champenois

Mnesors are defined as elements of a semimodule over the min-plus integers. This two-sorted structure is able to merge graduation properties of vectors and idempotent properties of boolean numbers, which makes it appropriate for hybrid systems. We apply it to the control of an inverted pendulum and design a full logical controller, that is, without the usual

V. Y. Chernyak, N. A. Sinitsyn

We explore quantization of the response of a molecular motor to periodic modulation of control parameters. We formulate the Pumping-Quantization Theorem (PQT) that identifies the conditions for robust integer quantized behavior of a periodically driven molecular machine. Implication of PQT on experiments with catenane molecules are discussed.

Amy E. Kimball, Gillian R. Knapp, Zeljko Ivezic, Andrew A. West

We conduct a search for radio stars by combining radio and optical data from the Faint Images of the Radio Sky at Twenty cm survey (FIRST) and the Sloan Digital Sky Survey (SDSS). The faint limit of SDSS makes possible a homogeneous search for radio emission from stars of low optical luminosity. We select a sample of 112 candidate radio stars in the magnitud

Yonina C. Eldar, Patrick Kuppinger, Helmut Bölcskei

We consider compressed sensing of block-sparse signals, i.e., sparse signals that have nonzero coefficients occurring in clusters. An uncertainty relation for block-sparse signals is derived, based on a block-coherence measure, which we introduce. We then show that a block-version of the orthogonal matching pursuit algorithm recovers block $k$-sparse signals

O. Suárez, J. F. Gómez, L. F. Miranda, J. M. Torrelles

We intended to study the incidence and characteristics of water masers in the envelopes of stars in the post-AGB and PN evolutionary stages. We have used the 64-m antenna in Parkes (Australia) to search for water maser emission at 22 GHz, towards a sample of 74 sources with IRAS colours characteristic of post-AGB stars and PNe, at declination $< -32 °$. In o

Alan D. Sokal

Let R_\alpha be the Riesz distribution on a simple Euclidean Jordan algebra, parametrized by the complex number \alpha. I give an elementary proof of the necessary and sufficient condition for R_\alpha to be a locally finite complex measure (= complex Radon measure).

N. M. Fernandes, B. D. L. Pinto, L. O. B. Almeida, J. F. W. Slaets

We study the reconstruction of visual stimuli from spike trains, recording simultaneously from the two H1 neurons located in the lobula plate of the fly Chrysomya megacephala. The fly views two types of stimuli, corresponding to rotational and translational displacements. If the reconstructed stimulus is to be represented by a Volterra series and correlation

S. Capozziello, L. Izzo

A new method to constrain the cosmological equation of state is proposed by using combined samples of gamma-ray bursts (GRBs) and supernovae (SNeIa). The Chevallier-Polarski-Linder parameterization is adopted for the equation of state in order to find out a realistic approach to achieve the deceleration/acceleration transition phase of dark energy models. As

R. Maier, I. Damião Soares

The dynamics of the gravitational collapse is examined in the realm of string based formalism of D-branes that encompass General Relativity as a low energy limit. A complete analytical solution is given to the spherically symmetric collapse of a pure dust star, including its matching with a corrected Schwarzschild exterior spacetime. The collapse forms a bla

Kristan Jensen, Andreas Karch

We clarify how mirror symmetry acts on 3d theories with N=2,3 or 4 supersymmetries and non-abelian Chern-Simons terms and then construct many new examples. We identify a new duality, geometric duality, that allows us to generate large families of gauge theories, with and without Chern-Simons term, that all flow to the same conformal field theory in the infra

Dmitry Kerner, Victor Vinnikov

A (global) determinantal representation of hypersurface in P^n is a matrix, whose entries are linear forms in homogeneous coordinates and whose determinant defines the hypersurface. We study the properties of such representations for singular (possibly reducible or non-reduced) hypersurfaces. In particular, we obtain the decomposability criteria for determin

Jaume Gomis, Takuya Okuda

We study S-duality in N=4 super Yang-Mills with an arbitrary gauge group by determining the operator product expansion of the circular BPS Wilson and 't Hooft loop operators. The coefficients in the expansion of an 't Hooft loop operator for chiral primary operators and the stress-energy tensor are calculated in perturbation theory using the quantum path-int

Sasha Hinkley, Ben R. Oppenheimer, Remi Soummer, Douglas Brenner

We demonstrate the versatility of a dual imaging polarimeter working in tandem with a Lyot coronagraph and Adaptive Optics to suppress the highly static speckle noise pattern--the greatest hindrance to ground-based direct imaging of planets and disks around nearby stars. Using a double difference technique with the polarimetric data, we quantify the level of

Golam Mortuza Hossain, Viqar Husain, Sanjeev S. Seahra

We consider a polymer quantization of a free massless scalar field in a homogeneous and isotropic cosmological spacetime. This quantization method assumes that field translations are fundamentally discrete, and is related to but distinct from that used in loop quantum gravity. The semi-classical Friedman equation yields a universe that is non-singular and no

K. S. Kawabata, K. Maeda, K. Nomoto, S. Taubenberger

The unusual helium-rich (type Ib) supernova SN 2005E is distinguished from any supernova hitherto observed by its faint and rapidly fading light curve, prominent calcium lines in late-phase spectra and lack of any mark of recent star formation near the supernova location. These properties are claimed to be explained by a helium detonation in a thin surface l

Boudewijn F. Roukema

A local bootstrap method is proposed for the analysis of electoral vote-count first-digit frequencies, complementing the Benford&#39;s Law limit. The method is calibrated on five presidential-election first rounds (2002--2006) and applied to the 2009 Iranian presidential-election first round. Candidate K has a highly significant (p< 0.15%) excess of vote cou

Thomas Chen, Nataša Pavlović

We consider the cubic and quintic Gross-Pitaevskii (GP) hierarchies in $d$ dimensions, for focusing and defocusing interactions. We introduce new higher order energy functionals and prove that they are conserved for solutions of energy subcritical defocusing, and $L^2$ subcritical (de)focusing GP hierarchies, in spaces also used by Erdös, Schlein and Yau in

Yemon Choi

Let $X$ be a Banach space on which a discrete group $Γ$ acts by isometries. For certain natural choices of $X$, every element of the group algebra, when regarded as an operator on $X$, has empty residual spectrum. We show, for instance, that this occurs if $X$ is $\ell^2(\Gm)$ or the group von Neumann algebra $VN(\Gm)$. In our approach, we introduce the noti

Shwetank Kumar, David P. DiVincenzo

We propose a scheme for dispersive readout of stored energy in one mode of a nonlinear superconducting microwave ring resonator by detection of the frequency shift of a second mode coupled to the first via a Kerr nonlinearity. Symmetry is used to enhance the device responsivity while minimizing self nonlinearity of each mode. Assessment of the signal to nois

M. Cuquet, J. Calsamiglia

Quantum networks are essential to quantum information distributed applications, and communicating over them is a key challenge. Complex networks have rich and intriguing properties, which are as yet unexplored in the quantum setting. Here, we study the effect of entanglement percolation as a means to establish long-distance entanglement between arbitrary nod

Keun-young Kim, Jinfeng Liao

In this paper, we calculate analytically the baryonic density and susceptibilities, which are sensitive probes to the fermionic degrees of freedom, in a holographic model of QCD both in its hot QGP phase and in its cold dense phase. Interesting patterns due to strong coupling dynamics will be shown and valuable lessons for QCD will be discussed.

Thibault Damour, Orchidea Maria Lecian

The gravitational polarizability properties of black holes are compared and contrasted with their electromagnetic polarizability properties. The &#34;shape&#34; or &#34;height&#34; multipolar Love numbers h_l of a black hole are defined and computed. They are then compared to their electromagnetic analogs h_l^{EM}. The Love numbers h_l give the height of the

Elena Kulinskaya, Michael B. Dollinger, Kirsten Bjørkestøl

Meta-analysis seeks to combine the results of several experiments in order to improve the accuracy of decisions. It is common to use a test for homogeneity to determine if the results of the several experiments are sufficiently similar to warrant their combination into an overall result. Cochran&#39;s Q statistic is frequently used for this homogeneity test.

Alexander Berkovich, William Jagy

We show that many of Ramanujan&#39;s modular equations of degree 3 can be interpreted in terms of integral ternary quadratic forms. This way we establish that for any n in N |{n= x(x+1)/2 + y^2 +z^2 : x,y,z in Z}| >= |{n= x(x+1)/2 + 3y^2 +3z^2: x,y,zin Z}|, just to mention one among many similar positive results of this type. In particular, we prove the rece

Ian Palmer, Jean Bellissard

Given a random distribution of impurities on a periodic crystal, an equivalent uniquely ergodic tiling space is built, made of aperiodic, repetitive tilings with finite local complexity, and with configurational entropy close to the entropy of the impurity distribution. The construction is the tiling analog of the Jewett-Kreger theorem.

Volker Diekert, Manfred Kufleitner

We give topological and algebraic characterizations as well as language theoretic descriptions of the following subclasses of first-order logic FO[<] for omega-languages: Sigma_2, FO^2, the intersection of FO^2 and Sigma_2, and Delta_2 (and by duality Pi_2 and the intersection of FO^2 and Pi_2). These descriptions extend the respective results for finite wor

Daniel Juteau, Carl Mautner, Geordie Williamson

Given a stratified variety X with strata satisfying a cohomological parity-vanishing condition, we define and show the uniqueness of &#34;parity sheaves&#34;, which are objects in the constructible derived category of sheaves with coefficients in an arbitrary field or complete discrete valuation ring. This construction depends on the choice of a parity funct

Shengshi Pang, Shengjun Wu

Given $n$ linearly independent pure states and their prior probabilities, we study the problem of optimum unambiguous discrimination of these states. We derive the properties of the optimum solution and the equations that must be satisfied by the optimum measurement strategy which achieves the maximum average success probability, and also give the detailed s

Yunseok Seo, Sang-jin Sin, Wei-shui Xu

We consider a holographic model constructed through using the D4/D8-$\bar{\rm D8}$ brane configuration with a background field. We study some properties of the effective field theory in this intersecting brane construction, and calculate the effects of this NS-NS background field on some underlying dynamics. We also discuss some other general brane configura

D. Azagra, R. Fry, L. Keener

Let $X$ be a Banach space with a separable dual $X^{*}$. Let $Y\subset X$ be a closed subspace, and $f:Y\to\mathbb{R}$ a $C^{1}$-smooth function. Then we show there is a $C^{1}$ extension of $f$ to $X$.

R. Rebelo, P. Winternitz

We present an exposition of a method of discretizing ordinary differential equations while preserving their Lie point symmetries. This method is very general and can be applied to any ODE with a nontrivial symmetry group. The method is applied to obtain numerical slutions of second and third order ODEs invariant under two different realizations of $SL(2,\mat

Christian Eder, John Perry

Faugere&#39;s F5 algorithm computes a Groebner basis incrementally, by computing a sequence of (non-reduced) Groebner bases. The authors describe a variant of F5, called F5C, that replaces each intermediate Groebner basis with its reduced Groebner basis. As a result, F5C considers fewer polynomials and performs substantially fewer polynomial reductions, so t

Iftach Nevo, Lotte Holmegaard, Jens H. Nielsen, Jonas L. Hansen

A strong inhomogeneous static electric field is used to spatially disperse a rotationally cold supersonic beam of 2,6-difluoroiodobenzene molecules according to their rotational quantum state. The molecules in the lowest lying rotational states are selected and used as targets for 3-dimensional alignment and orientation. The alignment is induced in the adiab

M. Weides, M. Disch, H. Kohlstedt, D. E. Buergler

The supercurrent transport in metallic Josephson tunnel junctions with an additional interlayer made up by chromium, being an itinerant antiferromagnet, was studied. Uniform Josephson coupling was observed as a function of the magnetic field. The supercurrent shows a weak dependence on the interlayer thickness for thin chromium layers and decays exponentiall

Mark Williams

We report on a study of dimuon events produced in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV, using 0.9fb$^{-1}$ of data recorded by the D0 experiment during 2008. Using information from the inner-layer silicon tracking detector, we observe $712 \pm 462 \pm 942$ events in which one or both muons are produced in the range $1.6 < r \lesssim 10$ cm, which i

Alexander Kusenko

The discovery of neutrino masses suggests the likely existence of gauge singlet fermions that participate in the neutrino mass generation via the seesaw mechanism. The masses of the corresponding degrees of freedom can range from well below the electroweak scale to the Planck scale. If some of the singlet fermions are light, the sterile neutrinos appear in t

Eberhard Jakobi, Nils Blümer, Peter van Dongen

We extend previous studies on orbital-selective Mott transitions in the paramagnetic state of the half-filled degenerate two-band Hubbard model to the general doped case, using a high-precision quantum Monte Carlo dynamical mean-field theory solver. For sufficiently strong interactions, orbital-selective Mott transitions as a function of total band filling a

A. Martinez Torres, L. S. Geng, L. R. Dai, Bao Xi Sun

We present an approach to study the decay modes of the $J/ψ$ into a vector meson and a tensor meson, taking into account the nature of the $f_2(1270)$, $f&#39;_2(1525)$, $\bar{K}^{* 0}_2(1430)$ resonances as dynamically generated states from the vector meson-vector meson interaction. We evaluate four ratios of partial decay widths in terms of a flavor depend

Kay zum Felde

We compute gauge theories of the Lorentz group. We discuss non-interacting, and interacting fermionic systems. The interacting system combines a local with a global Lorentz group, i.e, discusses a $SO(3,1)_{l}\times SO(3,1)_{g}$-theory. We compute the equations of motion and conservation laws for the fermionic matter current. The core of our work is the pred

Pavel Fileviez Perez, Mark B. Wise

We discuss the simplest mechanisms for generating neutrino masses at tree level and one loop level. We find a significant number of new possibilities where one can generate neutrino masses at the one-loop level by adding only two new types of representations. These models have renormalizable interactions that automatically conserve baryon number. Adding to t

Richard J. Szabo

A pedagogical introduction to some of the main ideas and results of field theories on quantized spacetimes is presented, with emphasis on what such field theories may teach us about the problem of quantizing gravity. We examine to what extent noncommutative gauge theories may be regarded as gauge theories of gravity. UV/IR mixing is explained in detail and w

Andreas Holzner, Ian P. McCulloch, Ulrich Schollwöck, Jan von Delft

A magnetic moment in a metal or in a quantum dot is, at low temperatures, screened by the conduction electrons through the mechanism of the Kondo effect. This gives rise to spin-spin correlations between the magnetic moment and the conduction electrons, which can have a substantial spatial extension. We study this phenomenon, the so-called Kondo cloud, by me

Felix Brummer, Sylvain Fichet, Arthur Hebecker, Sabine Kraml

Supersymmetric Gauge-Higgs Unification is a well-motivated new physics scenario, both in heterotic model building and from the perspective of higher-dimensional Grand Unified Theories. When combined with radion mediated supersymmetry breaking, it allows for very specific predictions concerning the high-scale parameters of the MSSM. Using an appropriately mod

Z. Petric, T. Trimble

A new, self-contained, proof of a coherence result for categories equipped with two symmetric monoidal structures bridged by a natural transformation is given. It is shown that this coherence result is sufficient for $ω\timesω$-indexed family of iterated reduced bar constructions based on such a category.

Hong Huang

Let $(M^n,g_0)$ and $(\bar{M}^{n+1},\bar{g})$ be complete Riemannian manifolds with $|\bar{\nabla}^k\bar{Rm}|\le \bar{C}$ for $k \le 2$, and suppose there is an isometric immersion $F_0: M^n \rightarrow \bar{M}^{n+1}$ with bounded second fundamental form. Let $F_t: M^n \rightarrow \bar{M}^{n+1}$ ($t\in [0,T]$) be a family of immersions evolving by mean curva

Benedetto Silvestri

In this work we construct certain general bundles $<\mathfrak{M},\rho,X>$ and $<\mathfrak{B},\eta,X>$ of Hausdorff locally convex spaces associated with a given Banach bundle $<\mathfrak{E},\pi,X>$. Then we present conditions ensuring the existence of bounded sections $\mathcal{U}\in \Gamma^{x_{\infty}}(\rho)$ and $\mathcal{P}\in \Gamma^{x_{\infty}}(\eta)$ b

M. Doring, K. Nakayama

The nature of some baryonic resonances is still an unresolved issue. The case of the N*(1535) is particularly interesting in this respect due to the nearby etaN threshold and interference with the N*(1650). The N*(1535) has been described as a threshold effect, as a genuine 3-quark resonance, or as dynamically generated from the interaction of the octet of b

D. Bazeia, L. Losano, R. Menezes, M. A. M. Souza

This work deals with a new family of models, which includes the sine-Gordon model and the double-sine-Gordon, triple-sine-Gordon and so on. The investigation is based on a deformation procedure, which is used to deform a well-known model, to get to the family of sine-Gordon models. Due to properties of the procedure, we get to the models and find the corresp

Stylianos Basagiannis, Panagiotis Katsaros, Andrew Pombortsis

In this paper, we describe an attack against one of the Oblivious-Transfer-based blind signatures scheme, proposed in [1]. An attacker with a primitive capability of producing specific-range random numbers, while exhibiting a partial MITM behavior, is able to corrupt the communication between the protocol participants. The attack is quite efficient as it lea

Jens O. Andersen, Michael Strickland, Nan Su

We calculate the free energy of a hot gas of electrons and photons to three loops using the hard-thermal-loop perturbation theory reorganization of finite-temperature perturbation theory. We calculate the free energy through three loops by expanding in a power series in m_D/T, m_f/T, and e^2, where m_D and m_f are thermal masses and e is the coupling constan

Benoit Revenu

The CODALEMA experiment detects the cosmic air showers with an hybrid detector composed of an array of scintillators and an array of antennas triggered by the particle array. We will first describe the experiment and the data analysis then we will focus on the sky distribution of the events detected by the antennas which presents a strong asymmetry. We will

L. S. Anusha, K. N. Nagendra, F. Paletou, L. Léger

A robust numerical method called the Preconditioned Bi-Conjugate Gradient (Pre-BiCG)method is proposed for the solution of radiative transfer equation in spherical geometry.A variant of this method called Stabilized Preconditioned Bi-Conjugate Gradient (Pre-BiCG-STAB) is also presented. These are iterative methods based on the construction of a set of bi-ort

Alex Buchel, Robert C. Myers

We study causality violation in holographic hydrodynamics in the gauge theory/string theory correspondence, focussing on Gauss-Bonnet gravity. The value of the Gauss-Bonnet coupling is related to the difference between the central charges of the dual conformal gauge theory. We show that, when this difference is sufficiently large, causality is violated both

Sergey S. Kokarev

Here is presented a concept of centrogeometry which can be seen as a combination of the concept of point-like observer with an idea of Poincaré&#39;s that different geometries are principally equivalent. As it is to be shown later, all centrogeometries are obtained from each other by general deformation (i.e. active coordinate transformations). Isometries of

Antonino Flachi, Takahiro Tanaka

We consider the Casimir effect between two parallel plates localized on a brane. In order to properly compute the contribution to the Casimir energy due to any higher dimensional field, it is necessary to take into account the localization properties of the KK modes. When no massless mode appears in the spectrum, the correction to the Casimir energy is expon

Lavi Karp

The Cauchy problem of the vacuum Einstein&#39;s equations aims to find a semi-metric $g_{αβ}$ of a spacetime with vanishing Ricci curvature $R_{α,β}$ and prescribed initial data. Under the harmonic gauge condition, the equations $R_{α,β}=0$ are transferred into a system of quasi-linear wave equations which are called the reduced Einstein equations. The initi

Michal Zerola, Jérôme Lauret, Roman Barták, Michal Šumbera

For the past decade, HENP experiments have been heading towards a distributed computing model in an effort to concurrently process tasks over enormous data sets that have been increasing in size as a function of time. In order to optimize all available resources (geographically spread) and minimize the processing time, it is necessary to face also the questi

A. A. Raduta, R. Budaca

The energy-weighted sum rule for an electric dipole transition operator of a Schiff type differs from the Thomas-Reiche-Kuhn sum rule by several corrective terms which depend on the number of system components, ${\cal N}$. The deviations are evaluated by two distinct approaches. One of them is based on the charge density expansion around an uniform distribut

M. Centelles, S. K. Patra, X. Roca-Maza, B. K. Sharma

We analyze the influence of the density dependence of the symmetry energy on the average excitation energy of the isoscalar giant monopole resonance (GMR) in stable and exotic neutron-rich nuclei by applying the relativistic extended Thomas-Fermi method in scaling and constrained calculations. For the effective nuclear interaction, we employ the relativistic

Ulrich Vogl, Martin Weitz

The general idea that optical radiation may cool matter was put forward by Pringsheim already in 1929. Doppler cooling of dilute atomic gases is an extremely successful application of this concept, and more recently anti-Stokes cooling in multilevel systems has been explored, culminating in the optical refrigeration of solids. Collisional redistribution of r

N. P. H. Nesvadba

AGN feedback is now a major component of models of galaxy evolution. Using near-infrared imaging spectroscopy on the VLT we identify kpc-sized outflows of few x 10^10 M_s of ionized gas in powerful radio galaxies at z~2-3. Velocity fields are consistent with bipolar outflows, with total velocity offsets of ~1000 km s-1. FWHMs ~1000 km s-1 suggest strong turb

Vladimir Balan, Mircea Neagu

In this paper we construct the jet geometrical extensions of the KCC-invariants, which characterize a given second-order system of differential equations on the 1-jet space $J^1(R,M)$. A generalized theorem of characterization of our jet geometrical KCC-invariants is also presented.

Mubasher Jamil, Emmanuel N. Saridakis, M. R. Setare

We investigate the holographic dark energy scenario with a varying gravitational constant, in flat and non-flat background geometry. We extract the exact differential equations determining the evolution of the dark energy density-parameter, which include $G$-variation correction terms. Performing a low-redshift expansion of the dark energy equation of state,

Velimir M. Ilic, Miomir S. Stankovic, Branimir T. Todorovic

The paper proposes a new message passing algorithm for cycle-free factor graphs. The proposed &#34;entropy message passing&#34; (EMP) algorithm may be viewed as sum-product message passing over the entropy semiring, which has previously appeared in automata theory. The primary use of EMP is to compute the entropy of a model. However, EMP can also be used to

Seth A. Marvel, Steven H. Strogatz, Jon M. Kleinberg

We model a close-knit community of friends and enemies as a fully connected network with positive and negative signs on its edges. Theories from social psychology suggest that certain sign patterns are more stable than others. This notion of social &#34;balance&#34; allows us to define an energy landscape for such networks. Its structure is complex: numerica

Teresa Arias-Marco

This is the appendix of the paper [T. Arias-Marco, Constant Jacobi osculating rank of $U(3)/(U(1) \times U(1) \times U(1))$, Arch. Math. (Brno) 45 (2009), 241--254] where we obtain an interesting relation between the covariant derivatives of the Jacobi operator valid for all geodesic on the flag manifold $M^6=U(3)/(U(1) \times U(1) \times U(1))$. As a conseq

Johan Anderson, Eun-jin Kim

The probability density function (PDF) of flux $R$ is computed in systems with logarithmic non-linearity using a model non-linear dynamical equation. The PDF tails of the first moment flux are analytically predicted to be power law. These PDF tails are shown to be broader than a Gaussian distribution and are a manifestation of intermittency caused by short l

Balazs Hetenyi, Hans Gerd Evertz, Wolfgang von der Linden

The Gutzwiller approximate solution to the Gutzwiller wavefunction yields exact results for the Gutzwiller wavefunction in the infinite dimensional limit. Implicit in the Gutzwiller approximation is an approximate local form of the fermion exchange hole. This approximate form is the same for all dimensions but is incorrect except in infinite dimensions. We i

Petr Chaloupka, Pavel Jakl, Jan Kapitán, Jérôme Lauret

High Energy Nuclear Physics (HENP) collaborations&#39; experience show that the computing resources available at a single site are often neither sufficient nor satisfy the need of remote collaborators. From latencies in the network connectivity to the lack of interactivity, work at distant computing centers is often inefficient. Having fully functional softw

A. Qaiumzadeh, Reza Asgari

We study the effects of an in-plane magnetic field on the ground state properties of both gapless and gapped graphene sheets within Random Phase Approximation. The critical magnetic field which leads to a fully spin polarized phase increases by decreasing the carrier density at zero gap indicating that no spontaneous magnetic phase transition occurs. However

Julien Armijo, Carlos Garrido Alzar, Isabelle Bouchoule

We have studied the thermal properties of atom chips consisting o high thermal conductivity Aluminum Nitride (AlN) substrates on which gold microwires are directly deposited. We have measured the heating of wires of several widths and with different thermal couplings to the copper mount holding the chip. The results are in good agreement with a theoretical m

Julien Scheibert, Claudia Guerra, Fabrice Célarié, Davy Dalmas

Dynamic fracture experiments were performed in PMMA over a wide range of velocities and reveal that the fracture energy exhibits an abrupt 3-folds increase from its value at crack initiation at a well-defined critical velocity, below the one associated to the onset of micro-branching instability. This transition is associated with the appearance of conics pa

K. Lind, F. Primas, C. Charbonnel, F. Grundahl

To alleviate the discrepancy between the prediction of the primordial lithium abundance in the universe and the abundances observed in Pop II dwarfs and subgiant stars, it has been suggested that the stars observable today have undergone photospheric depletion of Li. To constrain the nature of such depletion, we conduct a homogeneous analysis of a very large

P. Zhang, M. W. Wu

Hole spin relaxation in [001] strained asymmetric Si/Si$_{0.7}$Ge$_{0.3}$ (Ge/Si$_{0.3}$Ge$_{0.7}$) quantum wells is investigated in the situation with only the lowest hole subband being relevant. The effective Hamiltonian of the lowest hole subband is obtained by the subband Löwdin perturbation method in the framework of the six-band Luttinger ${\bf k}\cdot

Mubasher Jamil

In the classical relativistic regime, the accretion of phantom energy onto a black hole reduces the mass of the black hole. In this context, we have investigated the evolution of a Schwarzschild black hole in the standard model of cosmology using the phantom-like modified variable Chaplygin gas and the viscous generalized Chaplygin gas. The corresponding exp

Jean-Louis Clerc, Toshiyuki Kobayashi, Bent Ørsted, Michael Pevzner

We find a closed formula for the triple integral on spheres in $\mathbb{R}^{2n}\times\mathbb{R}^{2n}\times\mathbb{R}^{2n}$ whose kernel is given by powers of the standard symplectic form. This gives a new proof to the Bernstein--Reznikov integral formula in the $n=1$ case. Our method also applies for linear and conformal structures.

Jun Lu, M Schmidt, P Lunkenheimer, A Pimenov

The magnetic susceptibility between 1.5 and 800 K, the infrared reflectivity at room temperature and the temperature dependence of the dielectric constant at mm-wavelengths are reported for single crystalline BiFeO3. A well developed anomaly in the magnetic susceptibility signals the onset of antiferromagnetic order close to 640 K. Beside this anomaly, no fu

Scott N. Armstrong, Charles K. Smart

We present a modified version of the two-player &#34;tug-of-war&#34; game introduced by Peres, Schramm, Sheffield, and Wilson. This new tug-of-war game is identical to the original except near the boundary of the domain $\partial Ω$, but its associated value functions are more regular. The dynamic programming principle implies that the value functions satisf

Philip Bett, Vincent Eke, Carlos S. Frenk, Adrian Jenkins

We investigate the magnitude and internal alignment of the angular momentum of cold dark matter haloes in simulations with and without baryons. We analyse the cumulative angular momentum profiles of hundreds of thousands of haloes in the Millennium simulation and in a smaller, but higher resolution, simulation, in total spanning 5 orders of magnitude in mass

R. Staszewski, J. Chwastowski

The measurement of diffractively scattered protons in the ATLAS Forward Physics detector system placed 220 m away from the ATLAS interaction point is studied. A parameterisation of the scattered proton transport through the LHC magnet lattice is presented. The proton energy unfolding and its impact on the centrally produced scalar particle mass resolution ar

A. Fienga, J. Laskar, T. Morley, H. Manche

The latest version of the planetary ephemerides developed at the Paris Observatory and at the Besancon Observatory is presented here. INPOP08 is a 4-dimension ephemeris since it provides to users positions and velocities of planets and the relation between TT and TDB. Investigations leading to improve the modeling of asteroids are described as well as the ne

Christoffer Wittmann, Ulrik L. Andersen, Masahiro Takeoka, Denis Sych

We experimentally demonstrate a new measurement scheme for the discrimination of two coherent states. The measurement scheme is based on a displacement operation followed by a photon number resolving detector, and we show that it outperforms the standard homodyne detector which we, in addition, proof to be optimal within all Gaussian operations including con

Paola Giacconi, Roberto Soldati

We investigate in some detail the structure of the electromagnetic current density for the pseudo-relativistic massless spinor effective model for graphene. It is shown that the pseudo-relativistic massless Dirac field theory in {\em 2+1} space-time dimensions and in the presence of a constant homogeneous electric field actually leads to the measured current

N. Mirabal, J. P. Halpern

We present a multiwavelength study of the unidentified Fermi gamma-ray source 0FGL J1830.3+0617, which exhibits variability above 200 MeV on timescales of days to weeks. Within the Fermi 95% confidence error contour lies B1827+0617, a radio source with spectral index alpha = 0.09 between 1.4 and 4.85 GHz. The flat spectral index and flux density of 443 mJy a

M. Yoshida, M. Takigawa, H. Yoshida, Y. Okamoto

We report 51V-NMR study on a high-quality powder sample of volborthite Cu3V2O7(OH)2/2H2O, a spin-1/2 Heisenberg antiferromagnet on a distorted kagome lattice formed by isosceles triangles. In the magnetic fields below 4.5 T, a sharp peak in the nuclear spin-lattice relaxation rate 1/T1 accompanied with line broadening revealed a magnetic transition near 1 K.

Barkat Ali Bhayo, Matti Vuorinen

R. Fehlmann and M. Vuorinen proved in 1988 that Mori&#39;s constant $M(n,K)$ for $K$-quasiconformal maps of the unit ball in $\mathbf{R}^n$ onto itself keeping the origin fixed satisfies $M(n,K) \to 1$ when $K\to 1 .$ We give here an alternative proof of this fact, with a quantitative upper bound for the constant in terms of elementary functions. Our proof i

Robert Joynt, Dong Zhou, Qiang-Hua Wang

For many implementations of quantum computing, 1/f and other types of broad-spectrum noise are an important source of decoherence. An important step forward would be the ability to back out the characteristics of this noise from qubit measurements and to see if it leads to new physical effects. For certain types of qubits, the working point of the qubit can

Daniel Hennequin, Philippe Verkerk

The dynamics of cold atoms in conservative optical lattices obviously depends on the geometry of the lattice. But very similar lattices may lead to deeply different dynamics. For example, in a 2D optical lattice with a square mesh, the sign of the detuning plays a crucial role: in the blue detuned case, trajectories of an atom inside a well are chaotic for h

A. N. Villano, P. Stoler, P. E. Bosted, S. H. Connell

The process $ep \to e^{\prime}p^{\prime}π^0$ has been measured at $Q^2$ = 6.4 and 7.7 GeV/c$^2$)$^2$ in Jefferson Lab&#39;s Hall C. Unpolarized differential cross sections are reported in the virtual photon-proton center of mass frame considering the process $γ^{\ast}p \to p^{\prime}π^0$. Various details relating to the background subtractions, radiative cor

Chao-Guang Huang, Meng-Sen Ma

In the model of de Sitter gauge theory of gravity, the empty homogenous and isotropic spacetimes with constant curvature scalar and nonvanishing homogenous and isotropic torsion must have de Sitter metrics. The static de Sitter spacetime with static, O(3)-symmetric, vector torsion is the only spherically symmetric, vacuum solution with the metric of the form

Terence Tao

In the previous papers in this series, the global regularity conjecture for wave maps from two-dimensional Minkowski space $\R^{1+2}$ to hyperbolic space $\H^m$ was reduced to the problem of constructing a minimal-energy blowup solution which is almost periodic modulo symmetries in the event that the conjecture fails. In this paper, we show that this problem

Bruno Uchoa, Ling Yang, S. -W. Tsai, N. M. R. Peres

We examine theoretically the signatures of magnetic adatoms in graphene probed by scanning tunneling spectroscopy (STS). When the adatom hybridizes equally with the two graphene sublattices, the broadening of the local adatom level is anomalous and can scale with the cube of the energy. In contrast to ordinary metal surfaces, the adatom local moment can be s

Fred H. Thaheld

Over a period of several decades it has been noticed that most astronauts, either orbiting the earth or on trips to the moon, have observed phosphenes or light flashes (LF) including streaks, spots and clouds of light when their eyes are closed or they are in a darkened cabin. Scientists suspect that two separate components of cosmic rays cause these flashes

J. Ruostekoski

We propose a scheme to implement an optical Kagome lattice for ultra-cold atoms with controllable s-wave interactions between nearest neighbor sites and a gauge potential. The atoms occupy three different internal atomic levels with electromagnetically-induced coupling between the levels. We show that by appropriately shifting the triangular lattice potentia