January 2011 arXiv papers — page 26

Daniel Faessler

We study the geometry and topology of Riemannian 3-orbifolds which are locally volume collapsed with respect to a curvature scale. We show that a sufficiently collapsed closed 3-orbifold without bad 2-suborbifolds either admits a metric of nonnegative sectional curvature or satisfies Thurston's Geometrization Conjecture. We also prove a version with boun

T. P. Polak

We study the mutually coupled, strongly interacting bosonic and non-interacting fermionic, species of unequal masses in the regime were the retardation effects are an important part of the physics. A cloud of neutral atoms experiences a synthetic magnetic field because of a vector potential that imposes a phase shift on the constituents. The magnetic field c

Osamu Iyama, Michael Wemyss

Let R be a normal, equi-codimensional Cohen-Macaulay ring of dimension $d\geq 2$ with a canonical module. We give a sufficient criterion that establishes a derived equivalence between the noncommutative crepant resolutions of R. When $d\leq 3$ this criterion is always satisfied and so all noncommutative crepant resolutions of R are derived equivalent. Our me

Kirsten Martens, Lyderic Bocquet, Jean-Louis Barrat

We present an extensive numerical study of dynamical heterogeneities and their influence on diffusion in an athermal mesoscopic model for actively deformed amorphous solids. At low strain rates the stress dynamics are governed by cooperative regions of plastic events. On the basis of scaling arguments as well as an extensive numerical study of an athermal el

C. C. Lee, W. L. Lee, J. -Y. Lin, C. C. Tsuei

ß-pyrochore KOs2O6, which shows superconductivity below ~ 9.7K, has been converted into KxOs2O6 (x < 2/3 - 1/2) electrochemically to show spin glass-like behavior below ~ 6.1K. Room temperature sample surface potential versus charge transfer scan indicates that there are at least two two-phase regions for x between 1 and 0.5. Rattling model of superconductiv

Gitta Kutyniok

Anisotropic decompositions using representation systems such as curvelets, contourlet, or shearlets have recently attracted significantly increased attention due to the fact that they were shown to provide optimally sparse approximations of functions exhibiting singularities on lower dimensional embedded manifolds. The literature now contains various direct

B. A. Tay, Kazuki Kanki, Satoshi Tanaka, Tomio Petrosky

We consider the eigenvalue problem of a kinetic collision operator for a quantum Brownian particle interacting with a one-dimensional chain. The quantum nature of the system gives rise to a difference operator. For the one-dimensional case, the momentum space separates into infinite sets of disjoint subspaces dynamically independent of one another. The eigen

Xiaobo Yin, Hehu Xie

In this paper, we give a new type of a posteriori error estimators suitable for moving finite element methods under anisotropic meshes for general second-order elliptic problems. The computation of estimators is simple once corresponding Hessian matrix is recovered. Wonderful efficiency indices are shown in numerical experiments.

Kayoomars Karami, M. S. Khaledian, Mubasher Jamil

Here we consider the entropy-corrected version of the holographic dark energy model in the non-flat universe. We obtain the equation of state parameter in the presence of interaction between dark energy and dark matter. Moreover, we reconstruct the potential and the dynamics of the quintessence, tachyon, K-essence and dilaton scalar field models according to

F. Y. Wang, Z. G. Dai

Recent studies suggest that Swift gamma-ray bursts (GRBs) may not trace an ordinary star formation history. Here we show that the GRB rate turns out to be consistent with the star formation history with an evolving stellar initial mass function (IMF). We first show that the latest Swift sample of GRBs reveals an increasing evolution in the GRB rate relative

Vladimir N. Potapov

A latin hypercuboid of order $N$ is an $N\times...\times N\times k$ array filled with symbols from the set $\{0,...,N-1\} $ in such a way that every symbol occurs at most once in every line. If $k=N$, such an array is a latin hypercube. We prove that any latin hypercuboid of order 4 is completable to a latin hypercube. Keywords: latin hypercube, n-ary quasig

Vladimir N. Potapov

A coloring of the Boolean $n$-cube is called perfect if, for every vertex $x$, the collection of the colors of the neighbors of $x$ depends only on the color of $x$. A Boolean function is called correlation-immune of degree $n-m$ if it takes the value 1 the same number of times for each $m$-face of the Boolean $n$-cube. In the present paper it is proven that

X. L. Yan, Z. Q. Qu, D. F. Kong

To better understand the dynamical process of active-region filament eruptions and associated flares and CMEs, we carried out a statistical study of 120 events observed by BBSO, TRACE, and t(SOHO/EIT) from 1998 to 2007 and combined filament observations with the NOAA&#39;s flare reports, MDI magnetograms, and LASCO data, to investigate the relationship betwe

S. W. Saputro, E. T. Baskoro, A. N. M. Salman, D. Suprijanto

A set of vertices $W$ resolves a graph $G$ if every vertex is uniquely determined by its vector of distances to the vertices in $W$. A metric dimension of $G$ is the minimum cardinality of a resolving set of $G$. A bipartite graph G(n,n) is a graph whose vertex set $V$ can be partitioned into two subsets $V_1$ and $V_2,$ with $|V_1|=|V_2|=n,$ such that every

Satoshi Naito, Daisuke Sagaki, Yoshihisa Saito

In the present paper, we give an explicit description of the affine analogs of Berenstein-Zelevinsky data constructed in our previous paper: Toward Berenstein-Zelevinsky data in affine type $A$, I: Construction of affine analogs (arXiv:1009.4526), in terms of certain collections of nonnegative integers, which we call Lusztig data of type $A_{l-1}^{(1)}$.

Laurent Demanet, Pierre-David Létourneau, Nicolas Boumal, Henri Calandra

This paper considers the problem of approximating the inverse of the wave-equation Hessian, also called normal operator, in seismology and other types of wave-based imaging. An expansion scheme for the pseudodifferential symbol of the inverse Hessian is set up. The coefficients in this expansion are found via least-squares fitting from a certain number of ap

Masayuki Asaoka

We show the local rigidity of the natural action of the Borel subgroup of SO_+(n,1) on a cocompact quotient of SO_+(n,1) for n>2.

Motohiko Ezawa

We have investigated electronic and magnetic properties of graphene nanodisks (nanosize triangular graphene) as well as electromechanical properties of graphene nanojunctions. Nanodisks are nanomagnets made of graphene, which are robust against perturbation such as impurities and lattice defects, where the ferromagnetic order is assured by Lieb&#39;s theorem

J. Jang, D. G. Ferguson, V. Vakaryuk, R. Budakian

Spin-triplet superfluids can support exotic objects, such as half-quantum vortices characterized by the nontrivial winding of the spin structure. We present cantilever magnetometry measurements performed on mesoscopic samples of Sr2RuO4, a spin-triplet superconductor. For micron-sized annular-shaped samples, we observe transitions between integer fluxoid sta

Philip A. Casey, Philip W. Anderson

Hidden Fermi liquid theory explicitly accounts for the effects of Gutzwiller projection in the t-J Hamiltonian, widely believed to contain the essential physics of the high-Tc superconductors. We derive expressions for the entire &#34;strange metal&#34;, normal state relating angle-resolved photoemission, resistivity, Hall angle, and by generalizing the form

Xuan Zhong Ni, M. H. Jiang

This paper presents a novel theory for understanding the mechanics behind non-conventional superconductors. It presents the hypothesis that non-conventional superconductors are 2D lattices of super-cells and that the superconductivity mechanism involves the ordered hopping of itinerant electrons along with phase transitions in the edge percolations.

Zhen-Hua Zhang, Jin-Yan Zeng, En-Guang Zhao, Shan-Gui Zhou

The recently observed high-spin rotational bands in odd-$A$ nuclei $^{247, 249}$Cm and $^{249}$Cf [Tandel \textit{et al.}, Phys. Rev. C 82 (2010) 041301R] are investigated by using the cranked shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method in which the blocking effects are taken into account exactly. The

Sergey L. Rumyantsev, Guanxiong Liu, Michael S. Shur, Alexander A. Balandin

We found that the current-voltage characteristics of the single-layer graphene field-effect transistors exhibit an intriguing feature - an abrupt change of the current near zero gate bias at elevated temperatures T > 500 K. The strength of the effect - referred to as the &#34;memory step&#34; by analogy with the &#34;memory dips&#34; - known phenomenon in el

Jin-San Cheng, Xiao-Shan Gao

In this paper, a multiplicity preserving triangular set decomposition algorithm is proposed for a system of two polynomials. The algorithm decomposes the variety defined by the polynomial system into unmixed components represented by triangular sets, which may have negative multiplicities. In the bivariate case, we give a complete algorithm to decompose the

Saijun Wu, Roger C. Brown, William D. Phillips, J. V. Porto

We propose a laser cooling technique in which atoms are selectively excited to a dressed metastable state whose light shift and decay rate are spatially correlated for Sisyphus cooling. The case of cooling magnetically trapped (anti)hydrogen with the 1S-2S-3P transitions using pulsed ultra violet and continuous-wave visible lasers is numerically simulated. W

Mariana Frank, Beste Korutlu

We revisit the Higgs sector of the left-right supersymmetric model. We study the scalar potential in a version of the model in which the minimum is the charge conserving vacuum state, without R-parity violation or additional non-renormalizable terms in the Lagrangian. We analyze the dependence of the potential and of the Higgs mass spectrum on the various pa

Alexander Koldobsky

A comparison problem for volumes of convex bodies asks whether inequalities $f_K(ξ)\le f_L(ξ)$ for all $ξ\in S^{n-1}$ imply that $\vol_n(K)\le \vol_n(L),$ where $K,L$ are convex bodies in $\R^n,$ and $f_K$ is a certain geometric characteristic of $K.$ By linear stability in comparison problems we mean that there exists a constant $c$ such that for every $\e>

Lenka Motlochova, Jiri Patera

Four families of generalizations of trigonometric functions were recently introduced. In the paper the functions are transformed into four families of orthogonal polynomials depending on two variables. Recurrence relations for construction of the polynomials are presented. Orthogonality relations of the four families of polynomials are found together with th

Amos N. Koeller

In Koeller \cite{koerprops} the twelve variants of the Reifenberg properties known to be instrumental in the theory of minimal surfaces were classified with respect to various Hausdorff measure based measure theoretic properties. The classification lead to the consideration of fine geometric properties and a connection to fractal geometry. The current work d

H. Liu, Jack Ng, S. B. Wang, Z. F. Lin

We found that very strong negative optical pressure can be induced in plasmonic cavities by LC resonance. This interesting effect could be described qualitatively by a Lagrangian model which shows that the negative optical pressure is driven by the internal inductance and the kinetic energy of the conduction electrons. If the metal is replaced by perfect con

Tao Zhong, Xing-Gang Wu, Jia-Wei Zhang, Yun-Qing Tang

We present an improved calculation on the pionic twist-3 distribution amplitudes $ϕ^π_{p}$ and $ϕ^π_σ$, which are studied within the QCD sum rules. By adding all the uncertainties in quadrature, it is found that $<ξ^2_p>=0.248^{+0.076}_{-0.052}$, $<ξ^4_p>=0.262^{+0.080}_{-0.055}$, $<ξ^2_σ>=0.102^{+0.035}_{-0.025}$ and $<ξ^4_σ>=0.094^{+0.028}_{-0.020}$. Furth

Jean-Luc Guermond, Peter D. Minev, Abner J. Salgado

We provide a convergence analysis for a new fractional time-stepping technique for the incompressible Navier-Stokes equations based on direction splitting. This new technique is of linear complexity, unconditionally stable and convergent, and suitable for massive parallelization.

Peter L. Capak, Dominik Riechers, Nick Z. Scoville, Chris Carilli

Massive clusters of galaxies have been found as early as 3.9 Billion years (z=1.62) after the Big Bang containing stars that formed at even earlier epochs. Cosmological simulations using the current cold dark matter paradigm predict these systems should descend from &#34;proto-clusters&#34; - early over-densities of massive galaxies that merge hierarchically

Zdenek Stuchlik, Jan Schee

We study optical phenomena related to appearance of Keplerian accretion discs orbiting Kerr superspinars predicted by the string theory. The superspinar exterior is described by the standard Kerr naked singularity geometry breaking the black hole limit on the internal angular momentum (spin). We construct local photon escape cones for a variety of orbiting s

James B. Wilson

Three algorithms of Gram-Schmidt type are given that produce an orthogonal decomposition of finite $d$-dimensional symmetric, alternating, or Hermitian forms over division rings. The first uses $d^3/3+O(d^2)$ ring operations with very simple implementation. Next, that algorithm is adapted in two new directions. One is an optimal sequential algorithm whose co

P. Edward Herman

This paper is a first attempt at getting information on a symmetric power representation of a $GL_2$ automorphic form via a trace formula that is beyond endoscopic techniques. In particular, we study the symmetric third power representation for all forms over $\Q$ adjoined the cube roots of unity. A key tool needed in the study is an identity relating cubic

Ran Li, Frank Gaitan

We show how a robust high-fidelity universal set of quantum gates can be implemented using a single form of non-adiabatic rapid passage whose parameters are optimized to maximize gate fidelity and reward gate robustness. Each gate in the universal set is found to operate with a fidelity F in the range 0.99988 < F < 0.99999, and to require control parameters

Maarten McKubre-Jordens, Phillip L. Wilson

Does combining a finite collection of objects infinitely many times guarantee the construction of a particular object? Here we use recursive function theory to examine the popular scenario of an infinite collection of typing monkeys reproducing the works of Shakespeare. Our main result is to show that it is possible to assign typing probabilities in such a w

Alexander M. G. Cox, David Hobson, Jan Obloj

We pursue an inverse approach to utility theory and consumption & investment problems. Instead of specifying an agent&#39;s utility function and deriving her actions, we assume we observe her actions (i.e. her consumption and investment strategies) and ask if it is possible to derive a utility function for which the observed behaviour is optimal. We work in

Thomas Bloom

Almost surely in an Angelesco ensemble,the normalized counting measure of a random point converges weak* to the equilibrium measure.This result, for orthogonal polynomial ensembles, is well-known.

Francesco Bigazzi, Aldo L. Cotrone, Javier Mas, Daniel Mayerson

We present the string dual to SU(Nc) N=4 SYM, coupled to Nf massless fundamental flavors, at finite temperature and baryon density. The solution is determined by two dimensionless parameters, both depending on the &#39;t Hooft coupling $λ_h$ at the scale set by the temperature T: $ε_h\simλ_h Nf/Nc$, weighting the backreaction of the flavor fields and $\tilde

L. Borsten, M. J. Duff, A. Marrani, W. Rubens

The entanglement classification of four qubits is related to the extremal black holes of the 4-dimensional STU model via a time-like reduction to three dimensions. This correspondence is generalised to the entanglement classification of a very special four-way entanglement of eight qubits and the black holes of the maximally supersymmetric N = 8 and exceptio

Gabor Somogyi

We discuss the evaluation of certain d dimensional angular integrals which arise in perturbative field theory calculations. We find that the angular integral with n denominators can be computed in terms of a certain special function, the so-called H-function of several variables. We also present several illustrative examples of the general result and briefly

Nora Elisa Chisari, Matias Zaldarriaga

On large-scales, comparable to the horizon, the observable clustering properties of galaxies are affected by various general relativistic effects. To calculate these effects one needs to consistently solve for the metric, densities and velocities in a specific coordinate system or gauge. The method of choice for simulating large-scale structure is numerical

Andreas Klein

We formulate certain sufficient conditions for the symplectic monodromy of an isolated quasihomogeneous singularity to be of infinite order in the relative symplectic mapping class group of the Milnor fibre and give a proof using Maslov classes, stability theory for Lagrangian folds resp. stable Morse theory for generating families as well as algebraic resul

Jock McOrist, Andrew B. Royston

We construct the first known example of a near horizon supergravity solution for a pair of NS5-branes, intersecting on R^{1,3} and localised in all directions except a single transverse circle. We do this by establishing an explicit map between the conifold metric and the near horizon geometry of two intersecting NS5-branes, clarifying and correcting a numbe

Robert P. C. Wiersma, Joop Schaye, Tom Theuns

[Abridged] We investigate how a range of physical processes affect the cosmic metal distribution using a suite of cosmological, hydrodynamical simulations. Focusing on z = 0 and 2, we study the metallicities and metal mass fractions for stars as well as for the ISM, and several more diffuse gas phases. We vary the cooling rates, star formation law, structure

M. B. Voloshin

It is argued that the observed enhancement of the hadronic transition Upsilon(4S) -> Upsilon(1S) eta relative to Upsilon(4S) -> Upsilon(1S) pi pi can be explained if the resonance Upsilon(4S) contains an admixture of a four-quark component, possibly due to the coupling to the meson channel B \bar B. A test of the discussed mechanism by searching for the tran

Sudarshan Ananth, Stefano Kovacs, Sarthak Parikh

We derive a manifestly MHV Lagrangian for the N=4 supersymmetric Yang-Mills theory in light-cone superspace. This is achieved by constructing a canonical redefinition which maps the N=4 superfield and its conjugate to a new pair of superfields. In terms of these new superfields the N=4 Lagrangian takes a (non-polynomial) manifestly MHV form, containing verti

Ho-Gyu Lee, Dae-Sik Moon, Bon-Chul Koo, Takashi Onaka

We present the results of infrared (IR; 2.5--160 um) observations of the supernova remnant (SNR) Kes 17 based on the data obtained with the AKARI and Spitzer satellites. We first detect bright continuum emission of its western shell in the mid- and far-IR wavebands together with its near-IR molecular line emission. We also detect hidden mid-IR emission of it

John Ellis, Jae Sik Lee, Apostolos Pilaftsis

The electric dipole moments (EDMs) of heavy nuclei, such as 199Hg, 225Ra and 211Rn, can be enhanced by the Schiff moments induced by the presence of nearby parity-doublet states. Working within the framework of the maximally CP-violating and minimally flavour-violating (MCPMFV) version of the MSSM, we discuss the maximal values that such EDMs might attain, g

E. S. Zhukova, B. P. Gorshunov, V. A. Yuryev, L. V. Arapkina

The terahertz spectra of the dynamic conductivity and radiation absorption coefficient in germanium-silicon heterostructures with arrays of Ge hut clusters (quantum dots) have been measured for the first time in the frequency range of 0.3-1.2 THz at room temperature. It has been found that the effective dynamic conductivity and effective radiation absorption

D. Coronel, A. Navas, M. Ponce

We study skew-maps given by a minimal homeomorphism on the basis and a cocycle of affine isometries on the fibers. We call such a map a cylindrical vortex. We extend to this setting some classical results of Atkinson, Besicovitch, Matsumoto-Shishikura and Schinelman (among other people) about cylindrical cascades. In particular, we show that no cylindrical v

Valentin Bonzom, Laurent Freidel

We discretize the Hamiltonian scalar constraint of three-dimensional Riemannian gravity on a graph of the loop quantum gravity phase space. This Hamiltonian has a clear interpretation in terms of discrete geometries: it computes the extrinsic curvature from dihedral angles. The Wheeler-DeWitt equation takes the form of difference equations, which are actuall

D. Coronel, A. Navas, M. Ponce

We show the following geometric generalization of a classical theorem of W.H. Gottschalk and G.A. Hedlund: a skew action induced by a cocycle of (affine) isometries of a Hilbert space over a minimal dynamics has a continuous invariant section if and only if the cocycle is bounded. Equivalently, the associated twisted cohomological equation has a continuous s

Karoly Urmossy, Tamas S. Biro, Gergely G. Barnaföldi

Resonance production and decay into pion pairs is simulated in a non-extensive quark matter with multi-particle interactions. Final state pion spectra are found to take the form of the Tsallis distribution, in accordance with measurements. It has also been shown that, if a large number of particles with these multi-particle interactions are constrained to a

Amit Hagar, Giuseppe Sergioli

We propose a new interpretation of objective deterministic chances in statistical physics based on physical computational complexity. This notion applies to a single physical system (be it an experimental set--up in the lab, or a subsystem of the universe), and quantifies (1) the difficulty to realize a physical state given another, (2) the `distance&#39; (i

B. Isham, M. T. Rietveld, P. Guio, F. R. E. Forme

Langmuir cavitons have been artificially produced in the earth&#39;s ionosphere, but evidence of naturally-occurring cavitation has been elusive. By measuring and modeling the spectra of electrostatic plasma modes, we show that natural cavitating, or strong, Langmuir turbulence does occur in the ionosphere, via a process in which a beam of auroral electrons

Bence Béky, Gáspár Á. Bakos, Joel Hartman, Guillermo Torres

We report the discovery of HAT-P-27b, an exoplanet transiting the moderately bright G8 dwarf star GSC 0333-00351 (V=12.214). The orbital period is 3.039586 +/- 0.000012 d, the reference epoch of transit is 2455186.01879 +/- 0.00054 (BJD), and the transit duration is 0.0705 +/- 0.0019 d. The host star with its effective temperature 5300 +/- 90 K is somewhat c

Miguel Penadés Ordaz, Jesús Maíz Apellániz, Alfredo Sota Ballano, Emilio J. Alfaro

In this poster we show our preliminary analysis of DIBs (Diffuse Interstellar Bands) and other interstellar absorption lines with the purpose of understanding their origin and their relationship with extinction. We use the biggest Galactic O-star blue-violet spectroscopic sample ever (GOSSS, see contribution by Maíz Apellániz at this meeting). This sample al

Giorgis Petridis

We present a new method to bound the cardinality of triple product sets in groups and give three applications. A new and unexpectedly short proof of the Plunnecke-Ruzsa sumset inequalities for Abelian groups. A new proof of a theorem of Tao on triple products, which generalises these inequalities when no assumption on commutativity is made. A further general

J. G. Rubin, J. Arrington

A recent reanalysis of world proton and deuteron structure function measurements showed that a significant amount of the apparent model dependence in the extraction of the neutron structure function was related to inconsistencies between the kinematics of the data and those assumed for the calculation, suggesting that the true model dependence is smaller tha

Jan van Neerven, Mark Veraar, Lutz Weis

We prove maximal $L^p$-regularity for the stochastic evolution equation \[\{{aligned} dU(t) + A U(t)\, dt& = F(t,U(t))\,dt + B(t,U(t))\,dW_H(t), \qquad t\in [0,T], U(0) & = u_0, {aligned}.\] under the assumption that $A$ is a sectorial operator with a bounded $H^\infty$-calculus of angle less than $\frac12π$ on a space $L^q(\mathcal{O},μ)$. The driving proce

Adam D. Bull

Efficient global optimization is the problem of minimizing an unknown function f, using as few evaluations f(x) as possible. It can be considered as a continuum-armed bandit problem, with noiseless data and simple regret. Expected improvement is perhaps the most popular method for solving this problem; the algorithm performs well in experiments, but little i

László Székelyhidi, Emil Wiedemann

In their seminal paper &#34;Oscillations and concentrations in weak solutions of the incompressible fluid equations&#34;, R. DiPerna and A. Majda introduced the notion of measure-valued solution for the incompressible Euler equations in order to capture complex phenomena present in limits of approximate solutions, such as persistence of oscillation and devel

Matthew Orr, Frank Krennrich, Eli Dwek

Direct measurements of the extragalactic background light (EBL) in the near-IR to mid-IR waveband are extremely difficult due to an overwhelming foreground from the zodiacal light that outshines the faint cosmological diffuse radiation field by more than an order of magnitude. Indirect constraints on the EBL are provided by gamma-ray observations of AGN. Usi

Eric Gourgoulhon, Charalampos Markakis, Koji Uryu, Yoshiharu Eriguchi

A fully geometrical treatment of general relativistic magnetohydrodynamics (GRMHD) is developed under the hypotheses of perfect conductivity, stationarity and axisymmetry. The spacetime is not assumed to be circular, which allows for greater generality than the Kerr-type spacetimes usually considered in GRMHD. Expressing the electromagnetic field tensor sole

L. Andrianopoli, R. D&#39;Auria, S. Ferrara, A. Marrani

We determine the two-centered generic charge orbits of magical N = 2 and maximal N = 8 supergravity theories in four dimensions. These orbits are classified by seven U-duality invariant polynomials, which group together into four invariants under the horizontal symmetry group SL(2,R). These latter are expected to disentangle different physical properties of

Abiy G. Tekola, Petri Vaisanen, Andreas Berlind

This work studies the environments and star formation relationships of local luminous infrared galaxies (LIRG) in comparison to other types of local and distant (z~1) galaxies. The infrared (IR) galaxies are drawn from the IRAS sample. The density of the environment is quantified using 6dF and Point Source Catalogue redshift survey (PSCz) galaxies in a cylin

R B Sandeep

We define a perfect coloring of a graph $G$ as a proper coloring of $G$ such that every connected induced subgraph $H$ of $G$ uses exactly $ω(H)$ many colors where $ω(H)$ is the clique number of $H$. A graph is perfectly colorable if it admits a perfect coloring. We show that the class of perfectly colorable graphs is exactly the class of perfect paw-free gr

Marine Jeanmougin, Mickael Guedj, Christophe Ambroise

Inferring genetic networks from gene expression data is one of the most challenging work in the post-genomic era, partly due to the vast space of possible networks and the relatively small amount of data available. In this field, Gaussian Graphical Model (GGM) provides a convenient framework for the discovery of biological networks. In this paper, we propose

Alexander Schenkel

We summarize our recently proposed approach to quantum field theory on noncommutative curved spacetimes. We make use of the Drinfel&#39;d twist deformed differential geometry of Julius Wess and his group in order to define an action functional for a real scalar field on a twist-deformed time-oriented, connected and globally hyperbolic Lorentzian manifold. Th

Paolo Moretti, Andrea Baronchelli, Alain Barrat, Romualdo Pastor-Satorras

We present a simple mathematical framework for the description of the dynamics of glassy systems in terms of a random walk in a complex energy landscape pictured as a network of minima. We show how to use the tools developed for the study of dynamical processes on complex networks, in order to go beyond mean-field models that consider that all minima are con

Min Sha

We obtain some results about the repeated exponentiation modulo a prime power from the viewpoint of arithmetic dynamical systems. Especially, we extend two asymptotic formulas about periodic points and tails in the case of modulo a prime to the case of modulo a prime power.

Jiun-Cheng Chen, Hsian-Hua Tseng

We present a generalization of the Bogomolov-Miyaoka-Yau inequality to Deligne-Mumford surfaces of general type.

James Conant, Rob Schneiderman, Peter Teichner

The first part of this paper completes the classification of Whitney towers in the 4-ball that was started in three related papers. We provide an algebraic framework allowing the computations of the graded groups associated to geometric filtrations of classical link concordance by order n (twisted) Whitney towers in the 4-ball. Higher-order Sato-Levine invar

James Conant, Rob Schneiderman, Peter Teichner

This paper describes grope and Whitney tower filtrations on the set of concordance classes of classical links in terms of class and order respectively. Using the tree-valued intersection theory of Whitney towers, the associated graded quotients are shown to be finitely generated abelian groups under a (surprisingly) well-defined connected sum operation. Twis

G. A. Ummarino

The phenomenology of iron-pnictides superconductors can be explained in the framework of a three bands s\pm wave Eliashberg theory with only two free parameters plus a feedback effect i.e. the effect of the condensate on the antiferromagnetic spin fluctuactions responsible of the superconductivity in these compounds. I have examined the experimental data of

Alexander Schilke, Claus Zimmermann, Philippe W. Courteille, William Guerin

We experimentally investigate the Bragg reflection of light at one-dimensionally ordered atomic structures by using cold atoms trapped in a laser standing wave. By a fine tuning of the periodicity, we reach the regime of multiple reflection due to the refractive index contrast between layers, yielding an unprecedented high reflectance efficiency of 80%. This

Jonathan Stolle, Nikolas Provatas

This paper studies how solute segregation and its relationship to grain boundary energy in binary alloys is captured in the phase field crystal (PFC) formalism, a continuum method that incorporates atomic scale elasto-plastic effects on diffusional time scales. Grain boundaries are simulated using two binary alloy PFC models --- the original binary model by

Larry Zamick

We find the largest negative value of the expectation of the spin operator for a many nucleon system.

Petr Benes, Jiri Hosek, Adam Smetana

We gauge the experimentally observed flavor (family) index of chiral lepton and quark fields and argue that the resulting non-vectorial SU(3)_F dynamics completely self-breaks. This breakdown generates fermion masses, which in turn trigger electroweak symmetry breaking (EWSB). Suggested asymptotically free dynamics with an assumed non-perturbative infrared f

Hirotake Kurihara

The set of subspaces of a given dimension in an attenuated space has a structure of a symmetric association scheme and this association scheme is called an association scheme based on an attenuated space. Association schemes based on attenuated spaces are generalizations of Grassmann schemes and bilinear forms schemes, and also $q$-analogues of non-binary Jo

L. P. Csernai, V. K. Magas, H. Stöcker, D. D. Strottman

Substantial collective flow is observed in collisions between Lead nuclei at LHC as evidenced by the azimuthal correlations in the transverse momentum distributions of the produced particles. Our calculations indicate that the Global v1-flow, which at RHIC peaked at negative rapidities (named as 3rd flow component or anti-flow), now at LHC is going to turn t

Michael, Bialy, Andrey Mironov

In this paper we deal with the classical question of existence of polynomial in momenta integrals for geodesic flows on the 2-torus. For the quasi-linear system on coefficients of the polynomial integral we consider the region (so called elliptic regions) where there are complex-conjugate eigenvalues. We show that for quartic integrals in the other two eigen

Daniel ben-Avraham

The nonconcensus opinion model (NCO) introduced recently by Shao et al., [Phys. Rev. Lett.103, 018701 (2009)] is solved exactly on the line. Although, as expected, the model exhibits no phase transition in one dimension, its study is interesting because of the connection with invasion percolation with trapping. The system evolves exponentially fast to the st

Alexander Arbieto, Laura Senos, Tatiana Sodero

We prove that if $X|_Λ$ has the weak specification property robustly, where $Λ$ is an isolated set, then $Λ$ is a hyperbolic topologically mixing set and, as a consequence, if $X$ is a vector field that has the weak specification property robustly on a closed manifold $M$, then the flow $X_t$ is a topologically mixing Anosov flow. Also we prove that there ex

C. Emre Koksal, Ozgur Ercetin, Yunus Sarikaya

We consider the problem of cross-layer resource allocation in time-varying cellular wireless networks, and incorporate information theoretic secrecy as a Quality of Service constraint. Specifically, each node in the network injects two types of traffic, private and open, at rates chosen in order to maximize a global utility function, subject to network stabi

C. M. Copperwheat, T. R. Marsh, V. S. Dhillon, S. P. Littlefair

We present ULTRACAM photometry of ES Cet, an ultracompact binary with a 620s orbital period. The mass transfer in systems such as this one is thought to be driven by gravitational radiation, which causes the binary to evolve to longer periods since the semi-degenerate donor star expands in size as it loses mass. We supplement these ULTRACAM+WHT data with obs

Jin Young Kim, Taekoon Lee

We calculate the bending angles of light under the strong electric and magnetic fields by a charged black hole and a magnetized neutron star according to the nonlinear electrodynamics of Euler-Heisenberg interaction. The bending angle of light by the electric field of charged black hole is computed from geometric optics and a general formula is derived for l

F. Bigazzi, A. L. Cotrone, J. Tarrio

We provide a short review of the hydrodynamical properties of a class of strongly coupled thermal gauge theories, coupled to massless fundamental flavor fields, having a dual supergravity description. The analysis is valid for more general classes of nearly conformal holographic plasmas, where the breaking of conformality is driven by marginally (ir)relevant

Stephane Gaubert, Ricardo D. Katz, Sergei Sergeev

Tropical polyhedra have been recently used to represent disjunctive invariants in static analysis. To handle larger instances, tropical analogues of classical linear programming results need to be developed. This motivation leads us to study the tropical analogue of the classical linear-fractional programming problem. We construct an associated parametric me

S. Souma, K. Kosaka, T. Sato, M. Komatsu

We have performed spin- and angle-resolved photoemission spectroscopy of Bi2Te3 and present the first direct evidence for the existence of the out-of-plane spin component on the surface state of a topological insulator. We found that the magnitude of the out-of-plane spin polarization on a hexagonally deformed Fermi surface (FS) of Bi2Te3 reaches maximally 2

Mathieu Faure, Sebastian J. Schreiber

We analyze quasi-stationary distributions $\{μ^{\varepsilon}\}_{\varepsilon>0}$ of a family of Markov chains $\{X^{\varepsilon}\}_{\varepsilon>0}$ that are random perturbations of a bounded, continuous map $F:M\to M$, where $M$ is a closed subset of $\mathbb{R}^k$. Consistent with many models in biology, these Markov chains have a closed absorbing set $M_0\s

Dominique Duval, Rachid Echahed, Frédéric Prost

Rewriting systems are often defined as binary relations over a given set of objects. This simple definition is used to describe various properties of rewriting such as termination, confluence, normal forms etc. In this paper, we introduce a new notion of abstract rewriting in the framework of categories. Then, we define the functoriality property of rewritin

Rastislav Dvornicky, Kazuo Muto, Fedor Simkovic, Amand Faessler

The planned rhenium beta-decay experiment MARE might probe the absolute mass scale of neutrinos with the same sensitivity as the tritium beta-decay experiment KATRIN, which will start data taking in 2011 and will proceed for five years. We present the energy distribution of emitted electrons for the first unique forbidden beta-decay of 187Re. It is found tha

Yuanyuan Zhao, Wei Li, Ruibao Tao

Analytical studies of the effect of edge decoration on the energy spectrum of semi-infinite one-dimensional (1D) lattice chain with Peierls phase transition and zigzag edged graphene (ZEG) are presented by means of transfer matrix method, in the frame of which the sufficient and necessary conditions for the existence of the edge states are determined. For 1D

V. P. Efrosinin

The situation connected with a possibility of CPT violation in neutrino sector is considered.

Russell K. Standish, Stephen L. Keen

We have previously presented a critique of the standard Marshallian theory of the firm, and developed an alternative formulation that better agreed with the results of simulation. An incorrect mathematical fact was used in our previous presentation. This paper deals with correcting the derivation of the Keen equilibrium, and generalising the result to the as

Jianwei Xu

The original definition of quantum discord of bipartite states was defined over one-sided projective measurements, it describes quantum correlation more extensively than entanglement. Dakic, Vedral, and Brukner [Phys. Rev. Lett. 105 (2010) 190502] introduced a geometric measure for this quantum discord, and Luo, Fu [Phys. Rev. A 82 (2010) 034302] simplified