March 2009 arXiv papers — page 52

Yong Zhou, Hua Liang

We study semiparametric varying-coefficient partially linear models when some linear covariates are not observed, but ancillary variables are available. Semiparametric profile least-square based estimation procedures are developed for parametric and nonparametric components after we calibrate the error-prone covariates. Asymptotic properties of the proposed

Gregory Sallen, Adrien Tribu, Thomas Aichele, Régis André

Photoluminescence of a single CdSe quantum dot embedded in a ZnSe nanowire has been investigated. It has been found that the dark exciton has a strong influence on the optical properties. The most visible influence is the strongly reduced excitonic emission compared to the biexcitonic one. Temperature dependent lifetime measurements have allowed us to measur

M. Mierla, R. Schwenn, L. Teriaca, G. Stenborg

The purpose of this paper is to analyze the variation in the line width with height in the inner corona (region above 1.1 Rsun), by using the spectral data from LASCO-C1 aboard SOHO. We used data acquired at activity minimum (August - October 1996) and during the ascending phase of the solar cycle (March 1998). Series of images acquired at different waveleng

Marco Valerio Battisti, Giovanni Montani

The Bianchi IX cosmological model (through Bianchi I and II) is analyzed in the framework of a generalized uncertainty principle. In particular, the anisotropies of the Universe are described by a deformed Heisenberg algebra. Three main results are in order. (i) The Universe can not isotropize because of the deformed Kasner dynamics. (ii) The triangular allo

J. W. T. Hessels

We consider the currently observed spin distributions of various types of neutron stars, including isolated and binary radio millisecond pulsars in the Galactic plane and globular cluster system as well as neutron stars in low-mass X-ray binary systems where the spin rate is known either through coherent pulsations or burst oscillations. We find that the spi

P. Roulleau, F. Portier, P. Roche, A. Cavanna

We present an experiment where we tune the decoherence in a quantum interferometer using one of the simplest object available in the physic of quantum conductors : an ohmic contact. For that purpose, we designed an electronic Mach-Zehnder interferometer which has one of its two arms connected to an ohmic contact through a quantum point contact. At low temper

C. M. Carloni Calame, S. Moretti, F. Piccinini, D. A. Ross

We compute the full one-loop Electro-Weak (EW) contributions of O(alpha_S alpha_EM^3) entering the electron-positron into a quark-antiquark pair plus one gluon cross section at the Z peak and LC energies in presence of polarisation of the initial state and by retaining the event orientation of the final state. We include both factorisable and non-factorisabl

A. Husakou, J. Herrmann

We study the suppression of noise degradation in high-power soliton-induced supercontinuum generation under the influence of plasma contributions in metallic dielectric-coated hollow waveguides. The high coherence of the supercontinuum is related to the coherent seed components formed by the abruptly rising plasma density. We predict the generation of highly

Yanqing Sun, Peter B. Gilbert, Ian W. McKeague

For time-to-event data with finitely many competing risks, the proportional hazards model has been a popular tool for relating the cause-specific outcomes to covariates [Prentice et al. Biometrics 34 (1978) 541--554]. This article studies an extension of this approach to allow a continuum of competing risks, in which the cause of failure is replaced by a con

R. J. Simpson

In this article I present some special astronomical scripts created for Google Earth, Google Sky and Twitter. These 'hacks' are examples of the ways in which such tools can be used either alone, in on conjunction with online services. The result of a combination of multiple, online services to form a new facility is called a mash-up. Some of what fol

Lars Holden, Ragnar Hauge, Marit Holden

We propose an adaptive independent Metropolis--Hastings algorithm with the ability to learn from all previous proposals in the chain except the current location. It is an extension of the independent Metropolis--Hastings algorithm. Convergence is proved provided a strong Doeblin condition is satisfied, which essentially requires that all the proposal functio

Francisco M. Fernández

In this comment we point out some wrong statements in the paper by Inc and Cavlak, Phys. Scr. 78 (2008) 045008

Fang Fang, Quan Hong, Jun Shao

Nonresponse is common in surveys. When the response probability of a survey variable $Y$ depends on $Y$ through an observed auxiliary categorical variable $Z$ (i.e., the response probability of $Y$ is conditionally independent of $Y$ given $Z$), a simple method often used in practice is to use $Z$ categories as imputation cells and construct estimators by im

Gwendolyn Meeus

The dust in the interstellar medium, that provides the material for forming stars - and circumstellar discs as a natural by-product - is known to have submicron sizes. As these discs are the sites of planet formation, those small grains are predicted to grow to larger entities when the stars are still young. will review evidence for the first steps in grain

George Katsirelos, Nina Narodytska, Toby Walsh

We propose a new family of constraints which combine together lexicographical ordering constraints for symmetry breaking with other common global constraints. We give a general purpose propagator for this family of constraints, and show how to improve its complexity by exploiting properties of the included global constraints.

H. Oda, M. Machida, K. E. Nakamura, R. Matsumoto

We present new thermal equilibrium solutions for optically thin and thick disks incorporating magnetic fields. The purpose of this paper is to explain the bright hard state and the bright/slow transition observed in the rising phases of outbursts in BHCs. On the basis of the results of 3D MHD simulations, we assume that magnetic fields inside the disk are tu

G. Ganbold

We provide a new, independent, and analytic estimate of the lowest glueball mass, and we found it at 1661 MeV within a relativistic quantum-field model based on analytic confinement. The conventional mesons and the weak decay constants are described to extend the consideration. For the spectra of two-gluon and two-quark bound states we solve the ladder Bethe

George Katsirelos, Nina Narodytska, Toby Walsh

An attractive mechanism to specify global constraints in rostering and other domains is via formal languages. For instance, the Regular and Grammar constraints specify constraints in terms of the languages accepted by an automaton and a context-free grammar respectively. Taking advantage of the fixed length of the constraint, we give an algorithm to transfor

Daniel J. Nordman

Because the stationary bootstrap resamples data blocks of random length, this method has been thought to have the largest asymptotic variance among block bootstraps Lahiri [Ann. Statist. 27 (1999) 386--404]. It is shown here that the variance of the stationary bootstrap surprisingly matches that of a block bootstrap based on nonrandom, nonoverlapping blocks.

Jianqiang Zhao

In this note we shall study the Witten multiple zeta function associated to the Lie algebra so(5) defined by Matsumoto. Our main result shows that its special values at nonnegative integers are always expressible by alternating Euler sums. More precisely, every such special value of weight w>2 is a finite rational linear combination of alternating Euler sums

Christian Bessiere, Emmanuel Hebrard, Brahim Hnich, Zeynep Kiziltan

We study the CardPath constraint. This ensures a given constraint holds a number of times down a sequence of variables. We show that SLIDE, a special case of CardPath where the slid constraint must hold always, can be used to encode a wide range of sliding sequence constraints including CardPath itself. We consider how to propagate SLIDE and provide a comple

Claude-Guy Quimper, Toby Walsh

A wide range of constraints can be compactly specified using automata or formal languages. In a sequence of recent papers, we have shown that an effective means to reason with such specifications is to decompose them into primitive constraints. We can then, for instance, use state of the art SAT solvers and profit from their advanced features like fast unit

L. V. Il'ichov, S. V. Anishchik

We address the problem of relative frequencies of singlet and triplet recombinations in a multiparticle system, which consists of spin-correlated radical ion pairs. The nonlocal swapping of spin correlations due to cross-recombinations is taken into account. It is shown that this swapping does not contribute to singlet and triplet recombination frequencies i

Gui-Yun Liu, Le-Man Kuang

We propose an optical scheme to generate genuine entangled states of four atomic qubits in optical cavities using a single-photon source, beam splitters and single photon detectors. We show how to generate deterministically sixteen orthonormal and independent genuine entangled states of four atomic qubits. It is found that the sixteen genuine entangled state

Christian Bessiere, Emmanuel Hebrard, Brahim Hnich, Zeynep Kiziltan

We argue that parameterized complexity is a useful tool with which to study global constraints. In particular, we show that many global constraints which are intractable to propagate completely have natural parameters which make them fixed-parameter tractable and which are easy to compute. This tractability tends either to be the result of a simple dynamic p

C. Fortmann, R. Thiele, R. R. Fäustlin, Th. Bornath

Collective X-ray Thomson scattering has become a versatile tool for the diagnostics of dense plasmas. Assuming homogeneous density and temperature throughout the target sample, these parameters can be determined directly from the plasmon dispersion and the ratio of plasmon amplitudes via detailed balance. In inhomogeneous media, the scattering signal is an a

Toby Walsh

Symmetry is an important factor in solving many constraint satisfaction problems. One common type of symmetry is when we have symmetric values. In a recent series of papers, we have studied methods to break value symmetries. Our results identify computational limits on eliminating value symmetry. For instance, we prove that pruning all symmetric values is NP

Sandy Clarke, Peter Hall

An important aspect of multiple hypothesis testing is controlling the significance level, or the level of Type I error. When the test statistics are not independent it can be particularly challenging to deal with this problem, without resorting to very conservative procedures. In this paper we show that, in the context of contemporary multiple testing proble

Hartmut Führ

The construction of generalized continuous wavelet transforms on locally compact abelian groups $A$ from quasi-regular representations of a semidirect product group $G = A \rtimes H$ acting on ${\rm L}^2(A)$ requires the existence of a square-integrable function whose Plancherel transform satisfies Calderón-type resolution of the identity. The question then

Péter Lajkó

We introduce variants of the Ma-Dasgupta renormalization-group approach for random quantum spin chains, in which the energy-scale is reduced by decimation built on either perturbative or non-perturbative principles. In one non-perturbative version of the method, we require the exact invariance of the lowest gaps, while in a second class of perturbative Ma-Da

S. Albeverio, S. V. Kozyrev

A multidimensional basis of p-adic wavelets is constructed. The relation of the constructed basis to a system of coherent states (i.e. orbit of action) for some $p$-adic group of linear transformations is discussed. We show that the set of products of the vectors from the constructed basis and p-roots of one is the orbit of the corresponding p-adic group of

Alan Frisch, Brahim Hnich, Zeynep Kiziltan, Ian Miguel

Constraint programming (CP) has been used with great success to tackle a wide variety of constraint satisfaction problems which are computationally intractable in general. Global constraints are one of the important factors behind the success of CP. In this paper, we study a new global constraint, the multiset ordering constraint, which is shown to be useful

G. S. Danilov

The capture of trapped ultracold neutrons (UCNs) by closed hydrogenous impurities within a solid coating of the trap is discussed as a possible cause of observed anomalously large losses of UCNs in solid material UCN traps. Then significant losses of UCNs arise only if resonances occur in the UCN-impurity scattering amplitude. For a large size impurity, high

V. N. Berestovskii, E. V. Nikitenko, Yu. G. Nikonorov

The authors give a short survey of previous results on $δ$-homogeneous Riemannian manifolds, forming a new proper subclass of geodesic orbit spaces with non-negative sectional curvature, which properly includes the class of all normal homogeneous Riemannian manifolds. As a continuation and an application of these results, they prove that the family of all co

Jung Hoon Lee

We give a parity condition of a Heegaard diagram to show that it is unstabilized. This improves the result of [5]. As an application, we construct unstabilized Heegaard splittings by Dehn twists on any given Heegaard splitting.

J. F. Fernandez, J. J. Alonso

We study partially occupied lattice systems of classical magnetic dipoles which point along randomly oriented axes. Only dipolar interactions are taken into account. The aim of the model is to mimic collective effects in disordered assemblies of magnetic nanoparticles. From tempered Monte Carlo simulations, we obtain the following equilibrium results. The ze

Spyros Basilakos

We study the dynamics of the FLRW flat cosmological models in which the vacuum energy varies with time, $Λ(t)$. In this model we find that the main cosmological functions such as the scale factor of the universe and the Hubble flow are defined in terms of exponential functions. Applying a joint likelihood analysis of the recent supernovae type Ia data, the C

Enrico Robutti

An overview is given on recent progress in the study of quarkonium spectroscopy at the B-factories. In particular, an updated status report is presented of the long list of "charmonium-like" resonances newly discovered, whose assignment as true charmonium states is in most cases at least controversial. Also, new measurements on the decay properties o

Josselin Garnier, Knut Sølna

In this paper the reflection and transmission of waves by a three-dimensional random medium are studied in a white-noise and paraxial regime. The limit system derives from the acoustic wave equations and is described by a coupled system of random Schrödinger equations driven by a Brownian field whose covariance is determined by the two-point statistics of th

Fatemah Alqallaf, Stefan Van Aelst, Victor J. Yohai, Ruben H. Zamar

We investigate the performance of robust estimates of multivariate location under nonstandard data contamination models such as componentwise outliers (i.e., contamination in each variable is independent from the other variables). This model brings up a possible new source of statistical error that we call "propagation of outliers." This source of er

A. A. Abdujabbarov, B. J. Ahmedov

We perform a study to describe motion of charged particles under the influence of electromagnetic and gravitational fields of a slowly rotating wormhole with nonvanishing magnetic moment. We present analytic expression for potentials of electromagnetic field for an axially symmetric slowly rotating magnetized wormholes. While addressing important issues rega

Salah A. Aly, Zhenning Kong, Emina Soljanin

We consider a distributed storage problem in a large-scale wireless sensor network with $n$ nodes among which $k$ acquire (sense) independent data. The goal is to disseminate the acquired information throughout the network so that each of the $n$ sensors stores one possibly coded packet and the original $k$ data packets can be recovered later in a computatio

Leiba Rodman, Hakan Seyalioglu, Ilya M. Spitkovsky

The existence and construction of common invariant cones for families of real matrices is considered. The complete results are obtained for 2x2 matrices (with no additional restrictions) and for families of simultaneously diagonalizable matrices of any size. Families of matrices with a shared dominant eigenvector are considered under some additional conditio

Xiangyun Zhou, Parastoo Sadeghi, Tharaka A. Lamahewa, Salman Durrani

In this paper, we study the optimal training and data transmission strategies for block fading multiple-input multiple-output (MIMO) systems with feedback. We consider both the channel gain feedback (CGF) system and the channel covariance feedback (CCF) system. Using an accurate capacity lower bound as a figure of merit, we investigate the optimization probl

The KamLAND Collaboration

We have successfully built and operated a source deployment system for the KamLAND detector. This system was used to position radioactive sources throughout the delicate 1-kton liquid scintillator volume, while meeting stringent material cleanliness, material compatibility, and safety requirements. The calibration data obtained with this device were used to

K. A. Collins, C. A. Grady, K. Hamaguchi, J. P. Wisniewski

HD 100453 has an IR spectral energy distribution (SED) which can be fit with a power-law plus a blackbody. Previous analysis of the SED suggests that the system is a young Herbig Ae star with a gas-rich, flared disk. We reexamine the evolutionary state of the HD 100453 system by refining its age (based on a candidate low-mass companion) and by examining limi

Lyderic Bocquet, Annie Colin, Armand Ajdari

A kinetic model for the elasto-plastic dynamics of a flowing jammed material is proposed, which takes the form of a non-local -- Boltzmann-like -- kinetic equation for the stress distribution function. Coarse-graining this equation yields a non-local constitutive law for the flow, introducing as a key dynamic quantity the local rate of plastic events. This q

L. Koralov

We consider the motion of a particle in a periodic two dimensional flow perturbed by small (molecular) diffusion. The flow is generated by a divergence free zero mean vector field. The long time behavior corresponds to the behavior of the homogenized process - that is diffusion process with the constant diffusion matrix (effective diffusivity). We obtain the

L. Koralov

It is well known that for a regular stable potential of pair interaction and a small value of activity one can define the corresponding Gibbs field (a measure on the space of configurations of points in $\mathbb{R}^d$). In this paper we consider a converse problem. Namely, we show that for a sufficiently small constant $\overlineρ_1$ and a sufficiently small

L. Koralov

Given a potential of pair interaction and a value of activity, one can consider the Gibbs distribution in a finite domain $Λ\subset \mathbb{Z}^d$. It is well known that for small values of activity there exist the infinite volume ($Λ\to \mathbb{Z}^d$) limiting Gibbs distribution and the infinite volume correlation functions. In this paper we consider the con

X. R. Wang, P. Yan, J. Lu

A thory of field-induced domain wall (DW) propagation is developed. The theory not only explains why a DW in a defect-free nanowire must propagate at a finite velocity, but also provides a proper definition of DW propagation velocity. This definition, valid for an arbitrary DW structure, allows one to compute the instantaneous DW velocity in a meaningful way

Jun Ji, Jimmy A. Irwin, Alex Athey, Joel N. Bregman

The source of hot gas in elliptical galaxies is thought to be due to stellar mass loss, with contributions from supernova events and possibly from infall from a surrounding environment. This picture predicts supersolar values for the metallicity of the gas toward the inner part of the galaxy, which can be tested by measuring the gas phase abundances. We use

Gabriela Murguia, Matias Moreno, Manuel Torres

A well known example in quantum electrodynamics (QED) shows that Coulomb scattering of unpolarized electrons, calculated to lowest order in perturbation theory, yields a results that exactly coincides (in the non-relativistic limit) with the Rutherford formula. We examine an analogous example, the classical and perturbative quantum scattering of an electron

Dmitry Dolgopyat, Leonid Koralov

We consider the motion of a particle in a random isotropic force field. Assuming that the force field arises from a Poisson field in $\mathbb{R}^d$, $d \geq 4$, and the initial velocity of the particle is sufficiently large, we describe the asymptotic behavior of the particle.

Igor Chilingarian

After several years of intensive technological development Virtual Observatory resources have reached a level of maturity sufficient for their routine scientific exploitation. The Virtual Observatory is starting to be used by astronomers in a transparent way. In this article I will review several research projects making use of the VO at different levels of

J. M. Silva, R. E. de Souza, J. A. S. Lima

The structure of globular clusters and elliptical galaxies are described in an unified way through a new class of lowered models inspired on the nonextensive kinetic theory. These power law models are specified by a single parameter q which quantifies to what extent they depart from the class of lowered stellar distributions discussed by Michie and King. For

Kazuhisa Makino, Hirotaka Ono

In this paper, we investigate the deductive inference for the interiors and exteriors of Horn knowledge bases, where the interiors and exteriors were introduced by Makino and Ibaraki to study stability properties of knowledge bases. We present a linear time algorithm for the deduction for the interiors and show that it is co-NP-complete for the deduction for

Gourab Ghoshal, Vinko Zlatic, Guido Caldarelli, M. E. J. Newman

In the last few years we have witnessed the emergence, primarily in on-line communities, of new types of social networks that require for their representation more complex graph structures than have been employed in the past. One example is the folksonomy, a tripartite structure of users, resources, and tags -- labels collaboratively applied by the users to

Masayuki Kawakita

We introduce an approach of Riemann--Roch theorem to the boundedness problem of minimal log discrepancies in fixed dimension. After reducing it to the case of a Gorenstein terminal singularity, firstly we prove that its minimal log discrepancy is bounded if either multiplicity or embedding dimension is bounded. Secondly we recover the characterisation of a G

Eric D. Feigelson

Perhaps more than other physical sciences, astronomy is frequently statistical in nature. The objects under study are inaccessible to direct manipulation in the laboratory, so the astronomer is restricted to observing a few external characteristics and inferring underlying properties and physics. Astronomy played a profound role in the historical development

Wenzhong Bao, Feng Miao, Zhen Chen, Hang Zhang

Graphene is the nature's thinnest elastic membrane, with exceptional mechanical and electrical properties. We report the direct observation and creation of one-dimensional (1D) and 2D periodic ripples in suspended graphene sheets, using spontaneously and thermally induced longitudinal strains on patterned substrates, with control over their orientations

Alireza Saffarzadeh, Mahdi Ghorbani Asl

Using the tight-binding approximation and the nonequilibrium Green's function approach, we investigate the coherent spin-dependent transport in planar magnetic junctions consisting of two ferromagnetic (FM) electrodes separated by a graphene flake (GF) with zigzag or armchair interfaces. It is found that the electron conduction strongly depends on the ge

S. T. Myers, C. Pfrommer, J. Aguirre, J. R. Bond

We are learning much about how structure forms, in particular how clusters as nodes in the cosmic web evolve and accrete matter, and about the physical processes within these objects. In the next decade, the study of clusters will enable us to tackle important questions regarding the nature of Dark Matter and Dark Energy, how clusters co-evolve with super-ma

C. Tortora, V. Antonuccio-Delogu, S. Kaviraj, J. Silk

We study the feedback from an AGN on stellar formation within its host galaxy, mainly using one high resolution numerical simulation of the jet propagation within the interstellar medium of an early-type galaxy. In particular, we show that in a realistic simulation where the jet propagates into a two-phase ISM, star formation can initially be slightly enhanc

Colin Adams, William George, Rachel Hudson, Ralph Morrison

Two new invariants that are closely related to Milnor's curvature-torsion invariant are introduced. The first, the spiral index of a knot, captures the minimum number of maxima among all knot projections that are free of inflection points. This invariant is closely related to both the bridge and braid index of the knot. The second, the projective superbr

Taeyoung Lee, Melvin Leok, N. Harris McClamroch

This paper presents an analytical model and a geometric numerical integrator for a rigid body connected to an elastic string, acting under a gravitational potential. Since the point where the string is attached to the rigid body is displaced from the center of mass of the rigid body, there exist nonlinear coupling effects between the string deformation and t

Charles L. Epstein, Leslie Greengard

In this paper, we develop a new representation for outgoing solutions to the time harmonic Maxwell equations in unbounded domains in $\bbR^3.$ This representation leads to a Fredholm integral equation of the second kind for solving the problem of scattering from a perfect conductor, which does not suffer from spurious resonances or low frequency breakdown, a

Mathieu Vienney

Given two newforms $f$ and $g$ of respective weights $k$ and $l$ with $k<l$, Hida constructed a $p$-adic $L$-function interpolating the values of the Rankin convolution of $f$ and $g$ in the critical strip $l \leq s \leq k$. However, this construction works only if $f$ is an ordinary form. Using a method developed by Panchishkin to construct $p$-adic $L$-fun

Kay Jin Lim

Let w be the p-weight of a hook partition μand E be an elementary abelian p-subgroup generated by w disjoint p-cycles. We compute the generic Jordan type of the Specht module corresponding to the partition μrestricted to E. In particular, we show that the complexity of the Specht module is precisely the p-weight of the partition μ.

Atilla Yilmaz

We consider large deviations for nearest-neighbor random walk in a uniformly elliptic i.i.d. environment. It is easy to see that the quenched and the averaged rate functions are not identically equal. When the dimension is at least four and Sznitman&#39;s transience condition (T) is satisfied, we prove that these rate functions are finite and equal on a clos

Ameet Deshpande

Using the tools of optimal control, semiconvex duality and \maxp algebra, this work derives a unifying representation of the solution for the matrix differential Riccati equation (DRE) with time-varying coefficients. It is based upon a special case of the \maxp fundamental solution, first proposed in \cite{FlemMac}. Such fundamental solution can extend a spe

Ralf Ulrich, Johannes Blümer, Ralph Engel, Fabian Schüssler

The analysis of high-energy air shower data allows one to study the proton-air cross section at energies beyond the reach of fixed target and collider experiments. The mean depth of the first interaction point and its fluctuations are a measure of the proton-air particle production cross section. Since the first interaction point in air cannot be measured di

Ian Ellwood

We show that the existence of a tachyon vacuum puts tight restrictions on the form of solutions to the equations of motion of string field theory. In particular, we demonstrate that every solution can be written as a - formal - gauge transformation of the tachyon vacuum. In order for a solution to be non-trivial, this gauge transformation must be singular an

Hannah Petersen, Michael Mitrovski, Tim Schuster, Marcus Bleicher

We present results on the centrality and system size dependence of (multi-strange)hyperons in Pb+Pb collisions at 40$A$ and 158$A$ GeV from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD-v2.3) model and a coupled Boltzmann+hydrodynamics calculation. The second approach is realized in a hybrid fashion based on UrQMD with an intermediate hydrodynamic

James Damon

For compact regions Omega in R^3 with generic smooth boundary B, we consider geometric properties of Omega which lie midway between their topology and geometry and can be summarized by the term &#34;geometric complexity&#34;. The &#34;geometric complexity&#34; of Omega is captured by its Blum medial axis M, which is a Whitney stratified set whose local struc

Fengquan Wu, Xuelei Chen

Using the covariant formalism developed in a companion paper (paper I), we derive observational constraint on the Brans-Dicke model in a flat FLRW universe with cosmological constant and cold dark matter. The CMB observations we use include the WMAP five year data, the ACBAR 2007 data, the CBI polarization data, and the BOOMERanG 2003 flight data. For the la

Fengquan Wu, Li-e Qiang, Xin Wang, Xuelei Chen

In the covariant cosmological perturbation theory, a 1+3 decomposition ensures that all variables in the frame-independent equations are covariant, gauge-invariant and have clear physical interpretations. We develop this formalism in the case of Brans-Dicke gravity, and apply this method to the calculation of cosmic microwave background (CMB) anisotropy and

Michael Kiermaier, Stephen G. Naculich

We present a supersymmetric generalization of the MHV vertex expansion for all tree amplitudes in N=4 SYM theory. In addition to the choice of a reference spinor, this super MHV vertex expansion also depends on four reference Grassmann parameters. We demonstrate that a significant fraction of diagrams in the expansion vanishes for a judicious choice of these

Nikolay M. Nikolov

In this paper we study systematically the Euclidean renormalization in configuration spaces. We investigate also the deviation from commutativity of the renormalization and the action of all linear partial differential operators. This deviation is the source of the anomalies in quantum field theory, including the renormalization group action. It also determi

Benjamin Doyon

This is the first part of a work aimed at constructing the stress-energy tensor of conformal field theory as a local &#34;object&#34; in conformal loop ensembles (CLE). This work lies in the wider context of re-constructing quantum field theory from mathematically well-defined ensembles of random objects. The goal of the present paper is two-fold. First, we

Hyung Do Kim, Ji-Hun Kim

The light Higgs mass in the MSSM is highly constrained and is predicted to be close to M_Z which causes a tension between the LEP II Higgs mass bound 114 GeV and the natural electroweak symmetry breaking in the MSSM. The usual way to increase the light CP even Higgs mass was to increase the quartic coupling of the up type Higgs. We point out that the light H

Mikhail V. Bondarko

This is a survey of author&#39;s results on weight structures and Voevodsky&#39;s motives. Weight structures are natural counterparts of t-structures (for triangulated categories) introduced by the author. They allow to construct weight complexes, weight filtrations, and weight spectral sequences for various cohomology theories. Partial cases of the latter a

John C. Baez, Mike Stay

In physics, Feynman diagrams are used to reason about quantum processes. In the 1980s, it became clear that underlying these diagrams is a powerful analogy between quantum physics and topology: namely, a linear operator behaves very much like a "cobordism". Similar diagrams can be used to reason about logic, where they represent proofs, and computation, wher

Shane T. Jensen, Ibrahim Erkan, Erna S. Arnardottir, Dylan S. Small

Substantial statistical research has recently been devoted to the analysis of large-scale microarray experiments which provide a measure of the simultaneous expression of thousands of genes in a particular condition. A typical goal is the comparison of gene expression between two conditions (e.g., diseased vs. nondiseased) to detect genes which show differen

Paul H. Frampton, Pham Q. Hung

It is commonly assumed that dark matter may be composed of one or at most a few elementary particles. PAMELA data present a window of opportunity into a possible relationship between luminous and dark matter. Along with ATIC data the two positron excesses are interpreted as a reflection of dark matter family structure. In a unified model it is predicted that

Eli Aljadeff, Alexei Kanel-Belov

Let W be an associative PI algebra over a field F of characteristic zero, graded by a finite group G. Let id_{G}(W) denote the T-ideal of G-graded identities of W. We prove: 1. {[G-graded PI equivalence]} There exists a field extension K of F and a finite dimensional Z/2ZxG-graded algebra A over K such that id_{G}(W)=id_{G}(A^{*}) where A^{*} is the Grassman

Giordano Pola, Pierdomenico Pepe, Maria D. Di Benedetto, Paulo Tabuada

Time-delay systems are an important class of dynamical systems which provide a solid mathematical framework to deal with many application domains of interest ranging from biology, chemical, electrical, and mechanical engineering, to economics. However, the inherent complexity of such systems poses serious difficulties to control design, when control objectiv

Rui Carvalho, Lubos Buzna, Flavio Bono, Eugenio Gutierrez

Here we uncover the load and fault-tolerant backbones of the trans-European gas pipeline network. Combining topological data with information on inter-country flows, we estimate the global load of the network and its tolerance to failures. To do this, we apply two complementary methods generalized from the betweenness centrality and the maximum flow. We find

Jonathan L. Feng, Jean-Francois Grivaz, Jane Nachtman

This review summarizes the state of the art in searches for supersymmetry at colliders on the eve of the LHC era. Supersymmetry is unique among extensions of the standard model in being motivated by naturalness, dark matter, and force unification, both with and without gravity. At the same time, weak-scale supersymmetry encompasses a wide range of experiment

B. C. Tiburzi

We determine the electromagnetic properties of decuplet resonances using chiral perturbation theory at next-to-leading order. Utilizing a partially quenched charge matrix, we isolate and remove the quark disconnected contractions. This allows us to compare the physical meson loop contributions to the connected contributions, of which the latter are currently

P. Draggiotis, M. V. Garzelli, C. G. Papadopoulos, R. Pittau

We compute the complete set of Feynman Rules producing the Rational Terms of kind R_2 needed to perform any QCD 1-loop calculation. We also explicitly check that in order to account for the entire R_2 contribution, even in case of processes with more than four external legs, only up to four-point vertices are needed. Our results are expressed both in the 't

J. L. F. Barbon, J. R. Espinosa

We critically examine the recent claim that the Standard Model Higgs boson ${\cal H}$ could drive inflation in agreement with observations if $|{\cal H}|^2$ has a strong coupling $ξ\sim 10^4$ to the Ricci curvature scalar. We first show that the effective theory approach upon which that claim is based ceases to be valid beyond a cutoff scale $Λ=m_p/ξ$, where

Mihai Mariş

For a large class of nonlinear Schrödinger equations with nonzero conditions at infinity and for any speed $c$ less than the sound velocity, we prove the existence of nontrivial finite energy traveling waves moving with speed $c$ in any space dimension $N\geq 3$. Our results are valid as well for the Gross-Pitaevskii equation and for NLS with cubic-quintic n

H. Masui

The elliptic flow (v2) pattern in terms of hadron mass and transverse momentum pT is qualitatively described for pT < 2 GeV/c by ideal hydrodynamics in Au + Au collisions at RHIC. In addition, for pT = 2 - 6 GeV/c the measured v2 follow a universal scaling by the number of quarks explained by quark coalescence/recombination models. These observations suggest

I. A. Shuda, S. S. Borysov, A. I. Olemskoi

We consider effect of stochastic sources upon self-organization process being initiated with creation of the limit cycle. General expressions obtained are applied to the stochastic Lorenz system to show that departure from equilibrium steady state can destroy the limit cycle at certain relation between characteristic scales of temporal variation of principle

Shlomo Dado, Arnon Dar

The flux of the diffuse gamma-ray background radiation (GBR) does not confirm that the excess in the flux of cosmic ray electrons between 300-800 GeV, which was measured locally with the ATIC instrument in balloon flights over Antartica, is universal as expected from dark matter annihilation. Neither does the increase with energy of the fraction of positrons

Carmine Cuofano, Alessandro Drago

In millisecond pulsars the existence of the Coriolis force allows the development of the so-called Rossby oscillations (r-modes) which are know to be unstable to emission of gravitational waves. These instabilities are mainly damped by the viscosity of the star or by the existence of a strong magnetic field. A fraction of the observed millisecond pulsars are

B. C. Allanach, C. H. Kom, H. Päs

In the event of an observation of neutrinoless double beta decay, a relevant question would be: what lepton number violating physics is responsible for the decay? The exchange of Majorana neutrinos and/or supersymmetric particles may contribute. We point out that measurements of supersymmetric signals at the LHC, including single slepton production, could be

R. Iengo

We show how easy it is to get the Sommerfeld enhancement for a Yukawa potential, for definite partial waves, beyond the S wave analyzed in previous literature. In particular, we report results for the P wave (for which there is a resonant pattern and the enhancement can be of several orders of magnitude even far from the resonance) that could be relevant for

Mathieu Florence, Frédéric Meunier

The paper deals with sigma-games on grid graphs (in dimension 2 and more) and conditions under which any completely symmetric configuration of lit vertices can be reached -- in particular the completely lit configuration -- when starting with the all-unlit configuration. The answer is complete in dimension 2. In dimension greater than or equal to 3, the answ