July 2009 arXiv papers — page 31

O. Corradini

Completely regular tensionful codimension-n brane world solutions are discussed, where the core of the brane is chosen to be a thin codimension-(n-1) shell in an infinite volume flat bulk, and an Einstein-Hilbert term localized on the brane is included (Dvali-Gabadadze-Porrati models). In order to support such localized sources we enrich the vacuum structure

Barbara Betz, Jorge Noronha, Giorgio Torrieri, Miklos Gyulassy

We use (3+1)-dimensional ideal hydrodynamics to describe a variety of different jet energy loss scenarios for a jet propagating through an opaque medium. The conical correlations obtained for fully stopped jets, revealing a Bragg peak, are discussed as well as results from pQCD and AdS/CFT. Moreover, we investigate transverse flow deflection. It is demonstra

Ross C. McPhedran Lindsay C. Botten, Nicolae-Alexandru P. Nicorovici

We present further results on a class of sums which involve complex powers of the distance to points in a two-dimensional square lattice and trigonometric functions of their angle, supplementing those in a previous paper (McPhedran et al, Porc. Roy. Soc., 2008). We give a general expression which permits numerical evaluation of members of the class of sums t

Bastien Mallaroni, Pierre-Olivier Mattei, Jean Kergomard

Radiation by solid or fluid bodies can be characterized by resonance modes. They are complex, as well as resonance frequencies, because of the energy loss due to radiation. For ducts, they can be computed from the knowledge of the radiation impedance matrix. For the case of a flanged duct of finite length radiating on one side in an infinite medium, the expr

A. Gauguet, Benjamin Canuel, Thomas Lévèque, Walid Chaibi

We present the full evaluation of a cold atom gyroscope based on atom interferometry. We have performed extensive studies to determine the systematic errors, scale factor and sensitivity. We demonstrate that the acceleration noise can be efficiently removed from the rotation signal allowing to reach the fundamental limit of the quantum projection noise for s

Laurent Meersseman

Consider the following uniformization problem. Take two holomorphic (parametrized by some analytic set defined on a neighborhood of $0$ in $\Bbb C^p$, for some $p>0$) or differentiable (parametrized by an open neighborhood of $0$ in $\Bbb R^p$, for some $p>0$) deformation families of compact complex manifolds. Assume they are pointwise isomorphic, that is fo

Sang-Woon Jeon, Sae-Young Chung

Characterizing the capacity region of multi-source wireless relay networks is one of the fundamental issues in network information theory. The problem is, however, quite challenging due to inter-user interference when there exist multiple source--destination (S--D) pairs in the network. By focusing on a special class of networks, we show that the capacity ca

Ciprian Tudor

We study when a given Gaussian random variable on a given probability space $(Ω, {\cal{F}}, P) $ is equal almost surely to $β_{1}$ where $β$ is a Brownian motion defined on the same (or possibly extended) probability space. As a consequences of this result, we prove that the distribution of a random variable (satisfying in addition a certain property) in a f

Masakazu Sano, Hisao Suzuki

We consider brane gas models based on type II string theories and analyze the mass, the Ramond-Ramond charge and the charge on moduli fluctuations of branes wrapping over cycles of a compactified space in the four-dimensional Einstein frame. A six-dimensional torus and Calabi-Yau threefolds are considered for the Kaluza-Klein reduction. A large volume of the

Florin P. Boca

We study the statistics of the linear flow in a punctured honeycomb lattice, or equivalently the free motion of a particle on a regular hexagonal billiard table with holes of equal size at the corners and obeying the customary reflection rules. In the small-scatterer limit we prove the existence of the limiting distribution of the free path length with rando

Nam Q. Le

This paper has been withdrawn by the author due to a coming paper completely superseding it.

Stuart Marongwe, Stuart Kauffman

In this paper we consider clumped baryonic matter as a spherically symmetric barotropic fluid associated with a compact four-dimensional Einstein manifold with a four-radius that is determined by the fluid density. We further investigate the properties of these matter generated manifolds and show that because of their homogeneity and isotropy they exhibit FL

A. Sheykhi

Scalar-field dark energy models like tachyon are often regarded as an effective description of an underlying theory of dark energy. In this Letter, we implement the interacting agegraphic dark energy models with tachyon field. We demonstrate that the interacting agegraphic evolution of the universe can be described completely by a single tachyon scalar field

Joseph A. Cima, Stephan Ramon Garcia, William T. Ross, Warren R. Wogen

A truncated Toeplitz operator is the compression $A_ϕ:\K_Θ \to \K_Θ$ of a Toeplitz operator $T_ϕ:H^2\to H^2$ to a model space $\K_Θ := H^2 \ominus ΘH^2$. For $Θ$ inner, let $\T_Θ$ denote the set of all bounded truncated Toeplitz operators on $\K_Θ$. Our main result is a necessary and sufficient condition on inner functions $Θ_1$ and $Θ_2$ which guarantees th

Alexandros Marinos, Gerard Briscoe

Cloud Computing is rising fast, with its data centres growing at an unprecedented rate. However, this has come with concerns over privacy, efficiency at the expense of resilience, and environmental sustainability, because of the dependence on Cloud vendors such as Google, Amazon and Microsoft. Our response is an alternative model for the Cloud conceptualisat

Ronald G. Douglas, Ciprian Foias, Jaydeb Sarkar

Let H^2_m be the Drury-Arveson (DA) module which is the reproducing kernel Hilbert space with the kernel function (z, w) \in B^m \times B^m \raro (1 - <z,w>)^{-1}. We investigate for which multipliers θ: \mathbb{B}^m \raro \cll(\cle, \cle_*) the quotient module \clh_θ is similar to H^2_m \otimes \clf for some Hilbert space \clf, where M_θ is the correspondin

Charles Santori, David Fattal, Kai-Mei C. Fu, Paul E. Barclay

We provide a theoretical framework to study the effect of dephasing on the quantum indistinguishability of single photons emitted from a coherently driven cavity QED $Λ$-system. We show that with a large excited-state detuning, the photon indistinguishability can be drastically improved provided that the fluctuation rate of the noise source affecting the exc

Yuji Suwa, Ryotaro Arita, Kazuhiko Kuroki, Hideo Aoki

While the periodic Anderson model (PAM) has been recognized as a good model for various heavy f-electron systems, here we design a purely organic polymer whose low-energy physics can be captured by PAM. By means of the spin density functional calculation, we show that polymer of dimethylaminopyrrole is a candidate, where its ground state can indeed be magnet

Ken-ichi Sasaki, Masayuki Yamamoto, Shuichi Murakami, Riichiro Saito

The quantum corrections to the energies of the $Γ$ point optical phonon modes (Kohn anomalies) in graphene nanoribbons are investigated. We show theoretically that the longitudinal optical modes undergo a Kohn anomaly effect, while the transverse optical modes do not. In relation to Raman spectroscopy, we show that the longitudinal modes are not Raman active

Hiroki Matui

We consider Z-actions (single automorphisms) on a unital simple AH algebra with real rank zero and slow dimension growth and show that the uniform outerness implies the Rohlin property under some technical assumptions. Moreover, two Z-actions with the Rohlin property on such a C^*-algebra are shown to be cocycle conjugate if they are asymptotically unitarily

Alejandro Cabo, Francisco Claro

Eigenstates of the FQHE hamiltonian problem after to be projected on the LLL are determined for filling factors 1/q, with q an odd number. The solutions are found for an infinite class of finite samples in which the Coulomb potential is periodically extended. Therefore, a thermodynamic limit solution is also identified. The results suggest the presence of in

Hideo Mabuchi

Quantum optical input-output models are described for a class of optical switches based on cavity quantum electrodynamics (cavity QED) with a single multilevel atom (or comparable bound system of charges) coupled simultaneously to several resonant field modes. A recent limit theorem for quantum stochastic differential equations is used to show that such mode

Jonathan Touboul, Olivier Faugeras

Temporal lobe epilepsy is one of the most common chronic neurological disorder characterized by the occurrence of spontaneous recurrent seizures which can be observed at the level of populations through electroencephalogram (EEG) recordings. This paper summarizes some preliminary works aimed to understand from a theoretical viewpoint the occurrence of this t

S. Boettcher, J. L. Cook, R. M. Ziff

The bond-percolation properties of the Hanoi networks are analyzed with the renormalization group. Unlike scale-free networks, they are meant to provide an analytically tractable interpolation between finite dimensional, lattice-based models and their mean-field limits. In percolation, the hierarchical small-world bonds in the Hanoi networks impose a new for

Michael J. Ramsey-Musolf

Fundamental symmetry tests with neutrons can provide unique information about whatever will be the new Standard Model of fundamental interactions. I review two aspects of this possibility: searches for the permanent electric dipole moment of the neutron and its relation to the origin of baryonic matter, and precision studies of neutron decay that can probe n

Alan J. Barr, Claire Gwenlan

We describe how one may employ a very simple event selection, using only the kinematic variable mT2, to search for new particles at the LHC. The method is useful when searching for evidence of models (such as R-parity conserving supersymmetry) which have a Z2 parity and a weakly-interacting lightest parity-odd particle. We discuss the kinematic properties wh

Fabrice Baudoin

These notes focus on the applications of the stochastic Taylor expansion of solutions of stochastic differential equations to the study of heat kernels in small times. As an illustration of these methods we provide a new heat kernel proof of the Chern-Gauss-Bonnet theorem.

Jan-Fredrik Olsen, Eero Saksman

A range of Hardy-like spaces of ordinary Dirichlet series, called the Dirichlet-Hardy spaces $\Hp^p$, $p \geq 1$, have been the focus of increasing interest among researchers following a paper of Hedenmalm, Lindqvist and Seip in Duke Math. J 86 (1997), 1-37. The Dirichlet series in these spaces converge on a certain half-plane, where one may also define the

J. L. Goity, C. Jayalath, N. N. Scoccola

The partial decay widths of positive parity baryons belonging to 56-plets of SU(6) are analyzed in the framework of the 1/Nc expansion. The channels considered are those with emission of a single pion, K or K-bar mesons, and the analysis is carried out to subleading order in 1/Nc and to first order in SU(3) symmetry breaking. The results for the multiplet [5

K. Bardakci, M. B. Halpern

We briefly recall the historical environment around our 1971 and 1975 constructions of current-algebraic internal symmetry on the open string. These constructions included the introduction of world sheet fermions, the independent discovery of affine Lie algebra in physics (level one of affine su(3)), the first examples of the affine-Sugawara and coset constr

Gianluca Giovannetti, Sanjeev Kumar, Daniel Khomskii, Silvia Picozzi

We show that charge ordered rare-earth nickelates of the type RNiO3 (R= Ho, Lu, Pr and Nd) are multiferroic with very large magnetically induced ferroelectric (FE) polarizations. This we determine from first principles electronic structure calculations. The emerging FE polarization is directly tied to the long-standing puzzle of which kind of magnetic orderi

Vasily E. Tarasov

The quantum analogs of the derivatives with respect to coordinates q_k and momenta p_k are commutators with operators P_k and $Q_k. We consider quantum analogs of fractional Riemann-Liouville and Liouville derivatives. To obtain the quantum analogs of fractional Riemann-Liouville derivatives, which are defined on a finite interval of the real axis, we use a

Hannes Guhl, Wolfram Miller, Karten Reuter

We present a density-functional theory study addressing the energetics and electronic structure properties of isolated oxygen adatoms at the SrTiO3(001) surface. Together with a surface lattice oxygen atom, the adsorbate is found to form a peroxide-type molecular species. This gives rise to a non-trivial topology of the potential energy surface for lateral a

Andreas P. Braun, Rainer Ebert, Arthur Hebecker, Roberto Valandro

We study in detail the degeneration of K3 to T^4/Z_2. We obtain an explicit embedding of the lattice of collapsed cycles of T^4/Z_2 into the lattice of integral cycles of K3 in two different ways. Our first method exploits the duality to the heterotic string on T^3. This allows us to describe the degeneration in terms of Wilson lines. Our second method is ba

Klaus Halterman, Oriol T. Valls

We study triplet pairing correlations induced in an SFS trilayer (where F is a ferromagnet and S an ordinary s-wave superconductor) by spin flip scattering at the interfaces. We derive and solve self consistently the appropriate Bogoliubov-de Gennes equations in the clean limit. We find that the spin flip scattering generates $m=\pm 1$ triplet correlations,

Lorenz Bartosch, Peter Kopietz, Alvaro Ferraz

We use the functional renormalization group approach with partial bosonization in the particle-particle channel to study the effect of order parameter fluctuations on the BCS-BEC crossover of superfluid fermions in three dimensions. Our approach is based on a new truncation of the vertex expansion where the renormalization group flow of bosonic two-point fun

STAR collaboration, David Kettler

We have measured the $p_t$-integrated quadrupole component of two-particle azimuth correlations (related to quantity $v_2$, denoted in this case by $v_2 \{2D\}$) via two-dimensional (2D) angular autocorrelations on $(η, ϕ)$ for unidentified hadrons in Au-Au collisions at 62 and 200 GeV. The 2D autocorrelation provides a method to remove non-quadrupole contri

Antonella Marini, Thomas H. Otway

Linear and nonlinear Hodge-like systems for 1-forms are studied, with an assumption equivalent to complete integrability substituted for the requirement of closure under exterior differentiation. The systems are placed in a variational context and properties of critical points investigated. Certain standard choices of energy density are related by Backlund t

Jiri Kvita

We report on measurements of the ttbar production cross section at a center-of-mass energy of 1.96 TeV at the D0 experiment during Run II of the Fermilab Tevatron collider. We use candidate events in lepton+jets and dilepton final states. In the most sensitive channel (lepton+jets channel), a neural network algorithm that uses lifetime information to identif

Torleiv Kløve, Te-Tsung Lin, Shi-Chun Tsai, Wen-Guey Tzeng

An (n,d) permutation array (PA) is a set of permutations of length n with the property that the distance (under some metric) between any two permutations in the array is at least d. They became popular recently for communication over power lines. Motivated by an application to flash memories, in this paper the metric used is the Chebyshev metric. A number of

M. Hempel, G. Pagliara, J. Schaffner-Bielich

We investigate the qualitative properties of phase transitions in a general way, if not the single particle numbers of the system but only some particular charges like e.g. baryon number are conserved. In addition to globally conserved charges we analyze the implications of locally conserved charge fractions, like e.g. local electric charge neutrality or loc

Sanjubala Sahoo, Alfred Hucht, Markus E. Gruner, Peter Entel

Theoretical studies on M$_{13}$ (M = Fe, Co, Ni) and M$_{13}$Pt$_n$ (for $n$ = 3, 4, 5, 20) clusters including the spin-orbit coupling are done using density functional theory. The magnetic anisotropy energy (MAE) along with the spin and orbital moments are calculated for M$_{13}$ icosahedral clusters. The angle-dependent energy differences are modelled usin

Miloslav Znojil

The direct observability of coordinates x is often lost in PT-symmetric quantum theories. A manifestly non-local Hilbert-space metric $Θ$ enters the double-integral normalization of wave functions $ψ(x)$ there. In the context of scattering, the (necessary) return to the asymptotically fully local metric has been shown feasible, for certain family of PT-symme

Corey A. Hoelscher

In this paper we give a full diffeomorphism characterization of compact simply connected cohomogeneity one manifolds in dimension six.

J. Leconte, I. Baraffe, G. Chabrier, T. Barman

We present detailed structure and evolution calculations for the first transiting extrasolar planets discovered by the space-based CoRoT mission. Comparisons between theoretical and observed radii provide information on the internal composition of the CoRoT objects. We distinguish three different categories of planets emerging from these discoveries and from

J. -F. Mathiot

We propose a new approach to describe baryonic structure in terms of an effective chiral Lagrangian. The state vector of a baryon is defined on the light front of general position ω. x=0, where ωis an arbitrary light-like four vector. It is then decomposed in Fock components including an increasing number of pions. The maximal number of particles in the stat

Boris Kayser

We briefly explain how the present baryon-antibaryon asymmetry of the universe could have arisen through leptogenesis, and then discuss a new version of leptogenesis in which CP violation in electromagnetic decays plays the central role.

I. A. Merkulov, G. Alvarez, D. R. Yakovlev, T. C. Schulthess

A quasi-classical theoretical description of polarization and relaxation of nuclear spins in a quantum dot with one resident electron is developed for arbitrary mechanisms of electron spin polarization. The dependence of the electron-nuclear spin dynamics on the correlation time $τ_c$ of electron spin precession, with frequency $Ω$, in the nuclear hyperfine

K. Byckling, J. P. Osborne, P. J. Wheatley, G. A. Wynn

The second known outburst of the WZ Sge type dwarf nova GW Lib was observed in April 2007. We have obtained unique multiwavelength data of this outburst which lasted ~ 26 days. AAVSO observers recorded the outburst in the optical, which was also monitored by WASP, with a peak V magnitude of ~ 8. The outburst was followed in the UV and X-ray wavelengths by th

L3 Collaboration

Results are presented from a study of the structure of hadronic events in high-energy e+e- interactions detected by the L3 detector at LEP. Various event shape distributions and their moments are measured at several energy points at and above the Z-boson mass. The event flavour is tagged by using the decay characteristics of b-hadrons. Measurements of distri

David Conlon

The Ramsey number r(H) of a graph H is the smallest number n such that, in any two-colouring of the edges of K_n, there is a monochromatic copy of H. We study the Ramsey number of graphs H with t vertices and density \r, proving that r(H) \leq 2^{c \sqrt{\r} \log (2/\r) t}. We also investigate some related problems, such as the Ramsey number of graphs with t

Jian Liu, B. J. Kirby, M. Kareev, J. W. Freeland

The interfacial properties of Y0.6Pr0.4Ba2Cu3O7/La2/3Ca1/3MnO3 superlattices have been studied by resonant soft x-rays and diffuse scattered neutrons. Linearly polarized X-ray absorption at Cu L3 -edge reveals dramatic interfacial changes from the bulk including charge transfer between LCMO and YPBCO and an orbital reconstruction in the interface CuO2 plane.

El Hassan Saidi

Complex tetrahedral surface $\mathcal{T}$ is a non planar projective surface that is generated by four intersecting complex projective planes $CP^{2}$. In this paper, we study the family $\{\mathcal{T}_{m}\} $ of blow ups of $\mathcal{T}$ and exhibit the link of these $\mathcal{T}_{m}$s with the set of del Pezzo surfaces $dP_{n}$ obtained by blowing up n iso

H. J. Deeg, M. Gillon, A. Shporer, D. Rouan

The motivation, techniques and performance of the ground-based photometric follow-up of transit detections by the CoRoT space mission are presented. Its principal raison d&#39;être arises from the much higher spatial resolution of common ground-based telescopes in comparison to CoRoT&#39;s cameras. This allows the identification of many transit candidates as

Penny Thorn, Laurence Campbell, Michael Brunger

Recent measurements of the cross sections for electronic state excitations in H2O have made it possible to calculate rates applicable to these excitation processes. We thus present here calculations of electron energy transfer rates for electronic and vibrational state excitations in H2O, as well as rates for excitation of some of these states by atmospheric

Steven R. Cranmer, William H. Matthaeus, Benjamin A. Breech, Justin C. Kasper

We analyze measured proton and electron temperatures in the high-speed solar wind in order to calculate the separate rates of heat deposition for protons and electrons. When comparing with other regions of the heliosphere, the fast solar wind has the lowest density and the least frequent Coulomb collisions. This makes the fast wind an optimal testing ground

J. Poncela, J. Gomez-Gardenes, A. Traulsen, Y. Moreno

We discuss a model for evolutionary game dynamics in a growing, network-structured population. In our model, new players can either make connections to random preexisting players or preferentially attach to those that have been successful in the past. The latter depends on the dynamics of strategies in the game, which we implement following the so-called Fer

Stefan Bretzel, Gerrit E. W. Bauer, Yaroslav Tserkovnyak, Arne Brataas

The Barnett effect refers to the magnetization induced by rotation of a demagnetized ferromagnet. We describe the location and stability of stationary states in rotating nanostructures using the Landau-Lifshitz-Gilbert equation. The conditions for an experimental observation of the Barnett effect in different materials and sample geometries are discussed.

Gleb Arutyunov, Sergey Frolov

We use the recently found integral representation for the dressing phase in the kinematic region of the mirror theory to simplify the TBA equations for the AdS_5 x S^5 mirror model. The resulting set of equations provides an efficient starting point for both analytic and numerical studies.

Juergen Ehlers, Thomas Buchert

In this note we wish to complement some recent work in the cosmological literature concerning the Weyl conformal curvature tensor and its parts. In particular, we shall give a clear-cut definition of the Newtonian limits of electric and magnetic parts of the Weyl tensor. We also discuss that only a subset of the relativistic equations is needed to obtain a c

M. A. Perez-Torres, A. Alberdi, L. Colina, J. M. Torrelles

We present the results of an eight-year long monitoring of the radio emission from the Luminous Infrared Galaxy (LIRG) NGC 7469, using 8.4 GHz Very Large Array (VLA) observations at 0.3&#39;&#39; resolution. Our monitoring shows that the late time evolution of the radio supernova SN 2000ft follows a decline very similar to that displayed at earlier times of

F. Della Valle, G. Di Domenico, U. Gastaldi, E. Milotti

Nonlinear effects in vacuum have been predicted but never observed yet directly. The PVLAS collaboration has long been working on an apparatus aimed at detecting such effects by measuring vacuum magnetic birefringence. Unfortunately the sensitivity has been affected by unaccounted noise and systematics since the beginning. A new small prototype ellipsometer

Te Wu, Feng Fu, Long Wang

Most of previous studies concerning the Public Goods Game assume either participation is unconditional or the number of actual participants in a competitive group changes over time. How the fixed group size, prescribed by social institutions, affects the evolution of cooperation is still unclear. We propose a model where individuals with heterogeneous social

M. -A Dupret, A. Miglio, J. Montalban, A. Grigahcene

We study the energetic aspects of hybrid pressure-gravity modes pulsations. The case of hybrid beta Cephei-SPB pulsators is considered with special attention. In addition to the already known sensitivity of the driving mechanism to the heavy elements mixture (mainly the iron abundance), we show that the characteristics of the propagation and evanescent regio

Marcel Jackson, Mikhail Volkov

We establish a surprisingly close relationship between universal Horn classes of directed graphs and varieties generated by so-called adjacency semigroups which are Rees matrix semigroups over the trivial group with the unary operation of reversion. In particular, the lattice of subvarieties of the variety generated by adjacency semigroups that are regular u

Ana D Folgueras, Kazumi Maki

The symmetry of the superconductivity in Bechgaard salts is still unknown, though the triplet pairing has been established by Hc2 and NMR for (TMTSF)2PF6. The large upper critical field at T = 0K (Hc2 ~ 5 Tesla) both for H || a and H || b also indicates strongly the triplet pairing. Here we start with a low energy effective Hamiltonian and study the temperat

Alexander A Tulub

The Schlegel-Frisch ab initio molecular dynamics (ADMP) (DFT:B3LYP), T = 310 K, is used to study complexation between adenosinetriphosphate (ATP), ATP subsystem, and magnesium cofactor [Mg(H2O)6]2+, Mg subsystem, in a water pool, modeled with 78 water molecules, in singlet (S) and triplet (T) states. The computations prove that the way of ATP cleavage is gov

Dieter Gromes

We generalize and simplify an earlier approach. In three dimensions we present the most general averaging formula in lowest order which respects the requirements of covariance. It involves a bitensor, made up of a basis of six tensors, and contains three arbitrary functions, which are only restricted by their behavior near the origin. The averaging formula c

Juri Poutanen

Radiation of X-ray bursts and of accretion shocks in weakly magnetized neutron stars in low-mass X-ray binaries is produced in plane-parallel atmospheres dominated by electron scattering. We first discuss polarization produced by single (non-magnetic) Compton scattering, in particular the depolarizing effect of high electron temperature, and then the polariz

Paul Bonsma, Felix Breuer

We consider the following question, motivated by the enumeration of fullerenes. A fullerene patch is a 2-connected plane graph G in which inner faces have length 5 or 6, non-boundary vertices have degree 3, and boundary vertices have degree 2 or 3. The degree sequence along the boundary is called the boundary code of G. We show that the question whether a gi

C. T. M. Clack, I. Ballai

In the context of resonant absorption, nonlinearity has two different manifestations. The first is the reduction in amplitude of perturbations around the resonant point (wave energy absorption). The second is the generation of mean shear flows outside the dissipative layer surrounding the resonant point. Ruderman et al. [Phys. Plasmas 4, 75 (1997)] studied b

Rene P. Breton

This thesis focuses on the study of binary radio pulsars, their evolution and some specific use of their properties to investigate fundamental physics such as general relativity and other gravitational theories. The work that we present here is organized in three main parts. First, we report on the study of PSR J1744-3922, a binary pulsar presenting a peculi

J. M. Taylor, G. D. Love

Optical binding interactions between laser-trapped spherical microparticles are familiar in a wide range of trapping configurations. Recently it has been demonstrated that these experiments can be accurately modeled using Mie scattering or coupled dipole models. This can help confirm the physical phenomena underlying the inter-particle interactions, but does

Pavel Hrubes, Amir Yehudayoff

We investigate the arithmetic formula complexity of the elementary symmetric polynomials S(k,n). We show that every multilinear homogeneous formula computing S(k,n) has size at least k^(Omega(log k))n, and that product-depth d multilinear homogeneous formulas for S(k,n) have size at least 2^(Omega(k^{1/d}))n. Since S(n,2n) has a multilinear formula of size O

Sintayehu Tesfa

Effect of biased noise fluctuations on the degree of squeezing as well as the intensity of a radiation generated by a one-photon coherent beat laser is presented. It turns out that the radiation exhibits squeezing inside and outside the cavity under certain conditions. The degree of squeezing is enhanced by the biased noise input significantly in both region

Elisa Manrique, Martin Reuter

In the average action approach to the quantization of gravity the fundamental requirement of "background independence" is met by actually introducing a background metric but leaving it completely arbitrary. The associated Wilsonian renormalization group defines a coarse graining flow on a theory space of functionals which, besides the dynamical metric, depen

I. Bierenbaum, J. Blümlein, S. Klein

We calculate moments of the $O(α_s^3)$ heavy flavor contributions to the Wilson coefficients of the structure function $F_2(x,Q^2)$ in the region $Q^2\gg m^2$. The massive Wilson coefficients are obtained as convolutions of massive operator matrix elements (OMEs) and the known light flavor Wilson coefficients. The calculation of moments of the massive OMEs i

Hallstein Hogaasen, Jean-Marc Richard, Paul Sorba

The quantum mechanics of two-electron systems is reviewed, starting with the ground state of the helium atom and helium-like ions, with central charge $Z\ge 2$. For Z=1, demonstrating the stability of the negative hydrogen ion, H$^-$, cannot be achieved using a mere product of individual electron wave functions, and requires instead an explicit account for t

T. Spadaro

Kaon decay studies seeking new-physics (NP) effects in leptonic (K_l2) or semileptonic (K_l3) decays are discussed. A unitarity test of the first row of the CKM mixing matrix is obtained from the KLOE precision measurements of Kl3 widths for K^+-, K_L, and (unique to KLOE) K_S, complemented with the absolute branching ratio for the K_mu2 decay. KLOE results

Y. J. Du, R. X. Xu, G. J. Qiao, J. L. Han

Pulsars have been recognized as normal neutron stars, but sometimes argued as quark stars. {\it Sub-millisecond pulsars, if detected, would play an essential and important role in distinguishing quark stars from neutron stars.} We focus on the formation of such sub-millisecond pulsars in this paper. A new approach to form a sub-millisecond pulsar (quark star

D. P. Menezes, M. Benghi Pinto, S. S. Avancini, C. Providencia

In the present work we use the mean field approximation to investigate quark matter described by the su(3) Nambu-Jona-Lasinio model subject to a strong magnetic field. We consider two cases: pure quark matter and quark matter in beta-equilibrium possibly present in magnetars. The results are compared with the ones obtained with the su(2) version of the model

Futoshi Hayasaka, Eero Hyry

In this article we prove that the Buchsbaum-Rim multiplicity $e(F/N)$ of a parameter module $N$ in a free module $F=A^r$ is bounded above by the colength $\ell_A(F/N)$. Moreover, we prove that once the equality $\ell_A(F/N)=e(F/N)$ holds true for some parameter module $N$ in $F$, then the base ring $A$ is Cohen-Macaulay.

Salem Said, Christian Lageman, Nicolas Le Bihan, Jonathan H. Manton

Noncommutative harmonic analysis is used to solve a nonparametric estimation problem stated in terms of compound Poisson processes on compact Lie groups. This problem of decompounding is a generalization of a similar classical problem. The proposed solution is based on a char- acteristic function method. The treated problem is important to recent models of t

Hung D. Ly, Tie Liu, Yingbin Liang

This paper considers the problem of the multiple-input multiple-output (MIMO) Gaussian broadcast channel with two receivers (receivers 1 and 2) and two messages: a common message intended for both receivers and a confidential message intended only for receiver 1 but needing to be kept asymptotically perfectly secure from receiver 2. A matrix characterization

V. N. Zverev, A. V. Korobenko, G. L. Sun, D. L. Sun

The transport and superconducting properties of Ba_{1-x}K_xFe_2As_2 single crystals with T_c = 31 K were studied. Both in-plane and out-of plane resistivity was measured by modified Montgomery method. The in-plane resistivity for all studied samples, obtained in the course of the same synthesis, is almost the same, unlike to the out-of plane resistivity, whi

Christian Krattenthaler, Tanguy Rivoal

We prove Obnservation 2 in arXiv:math/0402386 by Gert Almkvist and Wadim Zudilin.

HERMES Collaboration

Exclusive electroproduction of pi+ mesons was studied by scattering 27.6 GeV positrons or electrons off a transversely polarized hydrogen target. The single-spin azimuthal asymmetry with respect to target polarization was measured as a function of the Mandelstam variable t, the Bjorken scaling variable x_B, and the virtuality Q^2 of the exchanged photon. The

Tobias H. Colding, William P. Minicozzi

We prove a smooth compactness theorem for the space of embedded self-shrinkers in $\RR^3$. Since self-shrinkers model singularities in mean curvature flow, this theorem can be thought of as a compactness result for the space of all singularities and it plays an important role in studying generic mean curvature flow.

Nadav Drukker, David R. Morrison, Takuya Okuda

We study Wilson-&#39;t Hooft loop operators in a class of N=2 superconformal field theories recently introduced by Gaiotto. In the case that the gauge group is a product of SU(2) groups, we classify all possible loop operators in terms of their electric and magnetic charges subject to the Dirac quantization condition. We then show that this precisely matches

Jean-Marc Richard

We investigate the domain of masses for which a state with total orbital momentum L=1 and unnatural parity $P=+1$ exists for the Coulomb systems $(m_1^+,m_2^-,m_3^-)$.

P. Bechtle, K. Desch, M. Uhlenbrock, P. Wienemann

We investigate the constraints on Supersymmetry arising from available precision measurements using a global fit approach. When interpreted within minimal supergravity (mSUGRA), the data provide significant constraints on the masses of supersymmetric particles, which are predicted to be light enough for an early discovery at the Large Hadron Collider (LHC).

Simon Arridge, John Schotland

This paper is a review of recent mathematical and computational advances in optical tomography. We discuss the physical foundations of forward models for light propagation on microscopic, mesoscopic and macroscopic scales. We also consider direct and numerical approaches to the inverse problems that arise at each of these scales. Finally, we outline future d

Emden R. Gansner, Yifan Hu, Stephen G. Kobourov

Information visualization is essential in making sense out of large data sets. Often, high-dimensional data are visualized as a collection of points in 2-dimensional space through dimensionality reduction techniques. However, these traditional methods often do not capture well the underlying structural information, clustering, and neighborhoods. In this pape

Toufik Mansour, Matthias Schork

As a first step towards a theory of differential equations involving para-Grassmann variables the linear equations with constant coefficients are discussed and solutions for equations of low order are given explicitly. A connection to n-generalized Fibonacci numbers is established. Several other classes of differential equations (systems of first order, equa

E. Molnár, H. Niemi, D. H. Rischke

We present numerical methods to solve the Israel-Stewart (IS) equations of causal relativistic dissipative fluid dynamics with bulk and shear viscosities. We then test these methods studying the Riemann problem in (1+1)-- and (2+1)-dimensional geometry. The numerical schemes investigated here are applicable to realistic (3+1)--dimensional modeling of a relat

Razvan Gurau

Group field theories are higher dimensional generalizations of matrix models. Their Feynman graphs are fat and in addition to vertices, edges and faces, they also contain higher dimensional cells, called bubbles. In this paper, we propose a new, fermionic Group Field Theory, posessing a color symmetry, and take the first steps in a systematic study of the to

G. P. Vacca

A novel perturbative analysis for the 2+1 local supercritical field theory of pomerons is developed. It is based on the PT symmetry of the model which allows to study a similar Hamiltonian with the same real perturbative spectrum. In the lowest non trivial order of perturbation theory the pomeron interactions are shown to lead to the renormalization of the s

I. V. Anikin, I. O. Cherednikov, N. G. Stefanis, O. V. Teryaev

We discuss duality in ``two-photon&#39;&#39;-like processes in the scalar $φ^3_E$ model and also in the process $γ^*γ\toππ$ in QCD. Duality implies the equivalence between two distinct nonperturbative mechanisms. These two mechanisms, one involving a twist-3 Generalized Distribution Amplitude, the other employing a leading-twist Transition Distribution Ampli

B. G. Zakharov

A quasiclassical theory of the synchrotron-like gluon emission is discussed. We show that the synchrotron emission may be important in the jet quenching if the plasma instabilities generate a chromomagnetic field about $m^{2}_{D}/g$. Our gluon spectrum disagrees with that obtained by Shuryak and Zahed within Schwinger&#39;s proper time method.

Yuan Liu, Shuang Nan Zhang

The gravitational collapse of a star is an important issue both for general relativity and astrophysics, which is related to the well known &#34;frozen star&#34; paradox. This paradox has been discussed intensively and seems to have been solved in the comoving-like coordinates. However, to a real astrophysical observer within a finite time, this problem shou