December 2008 arXiv papers — page 29

D. Rubin, S. Hony, S. C. Madden, A. G. G. M Tielens

(abridged) We study photoelectric heating throughout the Large Magellanic Cloud. We quantify the importance of the [CII] cooling line and the photoelectric heating process of various environments in the LMC and investigate which parameters control the extent of photoelectric heating. We use the BICE [CII] map and the Spitzer/SAGE infrared maps. We examine th

Stéphane Mischler

We prove global stability results of {\sl DiPerna-Lions} renormalized solutions for the initial boundary value problem associated to some kinetic equations, from which existence results classically follow. The (possibly nonlinear) boundary conditions are completely or partially diffuse, which includes the so-called Maxwell boundary conditions, and we prove t

Daniel Meyer

A metric space $\mathcal{S}$ is called a \defn{quasisphere} if there is a quasisymmetric homeomorphism $f\colon S^2\to \mathcal{S}$. We consider the elliptic harmonic measure, i.e., the push forward of 2-dimensional Lebesgue measure by $f$. It is shown that for certain self similar quasispheres $\mathcal{S}$ (snowspheres) the dimension of the elliptic harmon

V. I. Yukalov, D. Sornette

The Quantum Decision Theory, developed recently by the authors, is applied to clarify the role of risk and uncertainty in decision making and in particular in relation to the phenomenon of dynamic inconsistency. By formulating this notion in precise mathematical terms, we distinguish three types of inconsistency: time inconsistency, planning paradox, and inc

Noga Alon, Sonny Ben-Shimon, Michael Krivelevich

We prove that there is an absolute constant $C>0$ so that for every natural $n$ there exists a triangle-free \emph{regular} graph with no independent set of size at least $C\sqrt{n\log n}$.

Maximilien Gadouleau, Zhiyuan Yan

Rank metric codes and constant-dimension codes (CDCs) have been considered for error control in random network coding. Since decoder errors are more detrimental to system performance than decoder failures, in this paper we investigate the decoder error probability (DEP) of bounded distance decoders (BDDs) for rank metric codes and CDCs. For rank metric codes

Daowen Qiu, Lvjun Li

The minimum-error probability of ambiguous discrimination for two quantum states is the well-known {\it Helstrom limit} presented in 1976. Since then, it has been thought of as an intractable problem to obtain the minimum-error probability for ambiguously discriminating arbitrary $m$ quantum states. In this paper, we obtain a new lower bound on the minimum-e

Matthias Schuett, Tetsuji Shioda, Ronald van Luijk

We prove that the Neron-Severi groups of several complex Fermat surfaces are generated by lines. Specifically, we obtain these new results for all degrees up to 100 that are relatively prime to 6. The proof uses reduction modulo a supersingular prime. The techniques are developed in detail. They can be applied to other surfaces and varieties as well.

N. Chtchelkatchev, V. Vinokur

We show that there exist a class of nonequilibrium systems for which a non-equilibrium analog of the Ginzburg-Landau (GL) functional can be constructed and propose the procedure for its derivation. As an example, we consider a small superconductor island of the size less than the coherence length in a stationary nonequlibrium state. We find the GL expansion

Dariush Kaviani

The numerical results for the computed moduli of the irreducible three-loop contributions to the thermodynamical pressure of an SU(2) Yang-Mills theory in the effective theory for the deconfinning phase are explained in detail. Irreducible three-loop integrations are compared with two-loop integrations and the different nature of their integrations is scruti

P. Bravi, D. Luna

We give an introduction to the theory of wonderful G-varieties, with many examples when G is simple of type F4. We present results and open problems about these varieties: on their classification, on their isotropy groups, on morphisms between them, and on their relations with the representation theory of G.

Amnon Aharony, Ora Entin-Wohlman, Yasuhiro Tokura, Shingo Katsumoto

We present several new results, extending our recent proposal of a spin filter based on a tight-binding model for a periodic chain of diamond-like loops [Phys. Rev. B {\bf 78}, 125328 (2008)]. In this filter, the Rashba spin-orbit interaction (which can be tuned by a perpendicular gate voltage) and the Aharonov-Bohm flux (due to a perpendicular magnetic fiel

Florian Schaetz

The BFV-formalism was introduced to handle classical systems, equipped with symmetries. It associates a differential graded Poisson algebra to any coisotropic submanifold $S$ of a Poisson manifold $(M,Π)$. However the assignment (coisotropic submanifold) $\leadsto$ (differential graded Poisson algebra) is not canonical, since in the construction several choi

Benjamin McKay

The most commonly encountered types of complex analytic G-structures and Cartan geometries cannot have singularities of complex codimension 2 or more.

Y. Avishai, J. M. Luck

We investigate the persistent currents and magnetization of a mesoscopic system consisting of two clean metallic rings sharing a single contact point in a magnetic field. Many novel features with respect to the single-ring geometry are underlined, including the explicit dependence of wavefunctions on the Aharonov-Bohm fluxes, the complex pattern of twofold a

Jan Kaczmarczyk, Jozef Spalek

Paired state of nonstandard quasiparticles is analyzed in detail in two model situations. Namely, we consider the Cooper-pair bound state and the condensed phase of an almost localized Fermi liquid (ALFL) composed of quasiparticles in a narrow-band with the spin-dependent masses (SDM) and an effective field, both introduced earlier and induced by strong elec

Lachezar S. Georgiev

We demonstrate that the two inequivalent spinor representations of the braid group \B_{2n+2}, describing the exchanges of 2n+2 non-Abelian Ising anyons in the Pfaffian topological quantum computer, are equivalent from computational point of view, i.e., the sets of topologically protected quantum gates that could be implemented in both cases by braiding exact

Lachezar S. Georgiev

We give a rigorous and self-consistent derivation of the elementary braid matrices representing the exchanges of adjacent Ising anyons in the two inequivalent representations of the Pfaffian quantum Hall states with even and odd number of Majorana fermions. To this end we use the distinct operator product expansions of the chiral spin fields in the Neveu-Sch

E. O. Kamenetskii, M. Sigalov, R. Shavit

In a normally magnetized thin-film ferrite disk with magnetic-dipolar modes, one can observe magnetoelectric oscillations. Such magnetoelectric properties of an electrically small sample can be considered as very attractive phenomena in microwaves. In this paper we discuss the question on novel microwave device applications based on ferrite magnetoelectric p

Goulwen Fichou, Masahiro Shiota

Approximation of real analytic functions by Nash functions is a classical topic in real geometry. In this paper, we focus on the Nash approximation of an analytic desingularization of a Nash function germ obtained by a sequence of blowings-up along smooth analytic centers. We apply the result to prove that Nash function germs that are analytically equivalent

Kari Astala, Jarmo Jääskeläinen

We study differential expressions related to linear families of quasiconformal mappings and give a simple and direct proof to a result due to Alessandrini and Nesi arXiv:0707.0727.

A. A. Reshetnyak

We study the properties of nonlinear superalgebras $\mathcal{A}$ and algebras $\mathcal{A}_b$ arising from a one-to-one correspondence between the sets of relations that extract AdS-group irreducible representations $D(E_0,s_1,s_2)$ in AdS$_d$-spaces and the sets of operators that form $\mathcal{A}$ and $\mathcal{A}_b$, respectively, for fermionic, $s_i=n_i+

Francois Le Gall

The group isomorphism problem asks whether two given groups are isomorphic or not. Whereas the case where both groups are abelian is well understood and can be solved efficiently, very little is known about the complexity of isomorphism testing for nonabelian groups. In this paper we study this problem for a class of groups corresponding to one of the simple

Alessandro Cere, Valentina Parigi, Marta Abad, Florian Wolfgramm

We demonstrate a tunable, narrow-band filter based on optical-pumping-induced circular dichroism in rubidium vapor. The filter achieves a peak transmission of 14.6%, a linewidth of 80 MHz, and an out-of-band extinction >35 dB. The transmission peak can be tuned within the range of the Doppler linewidth of the D1 line of atomic rubidium at 795 nm. While other

S. Takeshita, R. Kadono

The presence of macroscopic phase separation into superconducting and magnetic phases in LaFeAsO$_{1-x}$F$_x$ (LFAOF) and CaFe$_{1-x}$Co$_x$AsF (CFCAF) is demonstrated by muon spin rotation (muSR) measurement across their phase boundaries ($x=0.06$ for LFAOF and $x=0.075$--0.15 for CFCAF). In LFAOF, both magnetism and superconductivity develop simultaneously

Fabrice Collard, Fabrice Ardhuin, Bertrand Chapron

Satellite Synthetic Aperture Radar (SAR) observations can provide a global view of ocean swell fields when using a specific "wave mode" sampling. A methodology is presented to routinely derive integral properties of the longer wavelength (swell) portion of the wave spectrum from SAR Level 2 products, and both monitor and predict their evolution acros

Amihay Hanany, Noppadol Mekareeya, Giuseppe Torri

We use the plethystic exponential and the Molien-Weyl formula to compute the Hilbert series (generating funtions), which count gauge invariant operators in N=1 supersymmetric SU(N_c), Sp(N_c), SO(N_c) and G_2 gauge theories with 1 adjoint chiral superfield, fundamental chiral superfields, and zero classical superpotential. The structure of the chiral ring th

D. Döring, J. E. Debs, N. P. Robins, C. Figl

We present results on a free-space atom interferometer operating on the first order magnetically insensitive |F=1,mF=0> -> |F=2,mF=0> transition of Bose-condensed 87Rb atoms. A pulsed atom laser is output-coupled from a Bose-Einstein condensate and propagates through a sequence of two internal state beam splitters, realized via coherent Raman transitions bet

Marcin Marciniak

The paper is devoted to the problem of classification of extremal positive maps acting between $B(K)$ and $B(H)$ where $K$ and $H$ are Hilbert spaces. It is shown that every positive map with the property that $\rank ϕ(P)\leq 1$ for any one-dimensional projection $P$ is a rank 1 preserver. It allows to characterize all decomposable extremal maps as those whi

Patrick Valageas

We study the one-dimensional ballistic aggregation process in the continuum limit for one-sided Brownian initial velocity (i.e. particles merge when they collide and move freely between collisions, and in the continuum limit the initial velocity on the right side is a Brownian motion that starts from the origin $x=0$). We consider the cases where the left si

B. Feigin, E. Feigin, M. Jimbo, T. Miwa

We use the Whittaker vectors and the Drinfeld Casimir element to show that eigenfunctions of the difference Toda Hamiltonian can be expressed via fermionic formulas. Motivated by the combinatorics of the fermionic formulas we use the representation theory of the quantum groups to prove a number of identities for the coefficients of the eigenfunctions.

Stefan Kebekus, Sandor J. Kovacs

Generalizing the well-known Shafarevich hyperbolicity conjecture, it has been conjectured by Viehweg that a quasi-projective manifold that admits a generically finite morphism to the moduli stack of canonically polarized varieties is necessarily of log general type. Given a quasi-projective threefold Y that admits a non-constant map to the moduli stack, we e

Tadashi Toyoda

The magnetoresistance oscillations in GaAs/Al$_x$Ga$_{1-x}$As heterostructures induced by millimeterwave radiation recently observed by Zudov et al. [Phys. Rev. B {\bf 64}, 201311 (2001)] is theoretically reproduced by introducing a model based on the finite temperature Fermi liquid theory of dc conductivity and the electron reservoir hypothesis. The obtaine

Igor A. Tanski

In this article we derive Fokker - Planck equation for incompressible fluid and investigate its properties. In version 2 symmetries of linearized equations and some examples of invariant solutions are added.

Ilmu Byun, Kwang Soon Kim

Cooperative hybrid-ARQ (HARQ) protocols, which can exploit the spatial and temporal diversities, have been widely studied. The efficiency of cooperative HARQ protocols is higher than that of cooperative protocols, because retransmissions are only performed when necessary. We classify cooperative HARQ protocols as three decode-and-forward based HARQ (DF-HARQ)

Robert B. Mann, John J. Oh, Mu-In Park

We study the gravitational collapse problem of rotating shells in three-dimensional Einstein gravity with and without a cosmological constant. Taking the exterior and interior metrics to be those of stationary metrics with asymptotically constant curvature, we solve the equations of motion for the shells from the Darmois-Israel junction conditions in the &#3

Neil F. Johnson, Chen Xu, Zhenyuan Zhao, Nicolas Ducheneaut

Quantifying human group dynamics represents a unique challenge. Unlike animals and other biological systems, humans form groups in both real (offline) and virtual (online) spaces -- from potentially dangerous street gangs populated mostly by disaffected male youths, through to the massive global guilds in online role-playing games for which membership curren

J. E. Debs, D. Döring, N. P. Robins, C. Figl

We present results on a Raman laser-system that resonantly drives a closed two-photon transition between two levels in different hyperfine ground states of 87Rb. The coupler is based on a novel optical design for producing two phase-coherent optical beams to drive a Raman transition. Operated as an outcoupler, it produces an atom laser in a single internal a

Hualing Zeng, Hongbo Zhao, Fu-Chun Zhang, Xiaodong Cui

Single-walled carbon nanotubes (SWCNTs) are quasi-one-dimensional systems with poor Coulomb screening and enhanced electron-phonon interaction, and are good candidates for excitons and exciton-phonon couplings in metallic state. Here we report back scattering reflection experiments on individual metallic SWCNTs. An exciton-phonon sideband separated by 0.19 e

Moshe Babaioff, Yogeshwer Sharma, Aleksandrs Slivkins

We consider a multi-round auction setting motivated by pay-per-click auctions for Internet advertising. In each round the auctioneer selects an advertiser and shows her ad, which is then either clicked or not. An advertiser derives value from clicks; the value of a click is her private information. Initially, neither the auctioneer nor the advertisers have a

Jan Mandel, Jonathan D. Beezley

An Ensemble Kalman Filter (EnKF, the predictor) is used make a large change in the state, followed by a Particle Filer (PF, the corrector) which assigns importance weights to describe non-Gaussian distribution. The weights are obtained by nonparametric density estimation. It is demonstrated on several numerical examples that the new predictor-corrector filte

Ernie Croot, Derrick Hart

We show that under the assumption of a 24-term version of Fermat&#39;s Last Theorem, there exists an absolute constant c > 0 such that if S is a set of n > n_0 positive integers satisfying |S.S| < n^(1+c), then the sumset S.S satisfies |S+S| >> n^2. In other words, we prove a weak form of the Erdos-Szemeredi sum-product conjecture, conditional on an extensio

Oscar Cata, Maarten Golterman, Santiago Peris

We discuss the issue of duality violations in hadronic tau decay. After introducing a physically motivated ansatz for duality violations, we estimate their possible size by fitting this ansatz to the tau experimental data provided by the ALEPH collaboration. Our conclusion is that these data do not exclude significant duality violations in tau decay. This ma

Ram Band, Ori Parzanchevski, Gilad Ben-Shach

We present a method which enables one to construct isospectral objects, such as quantum graphs and drums. One aspect of the method is based on representation theory arguments which are shown and proved. The complementary part concerns techniques of assembly which are both stated generally and demonstrated. For that purpose, quantum graphs are grist to the mi

Angela Kubena, Anne Thomas

Let G be the automorphism group of a regular right-angled building X. The &#34;standard uniform lattice&#34; Γ_0 in G is a canonical graph product of finite groups, which acts discretely on X with quotient a chamber. We prove that the commensurator of Γ_0 is dense in G. This result was also obtained by Haglund. For our proof, we develop carefully a technique

Andrew Das Arulsamy, Kostya &#34;Ken&#34; Ostrikov

Microscopic surface diffusivity theory based on atomic ionization energy concept is developed to explain the variations of the atomic and displacement polarizations with respect to the surface diffusion activation energy of adatoms in the process of self-assembly of quantum dots on plasma-exposed surfaces. These polarizations are derived classically, while t

David Rapetti, Steven W. Allen, Adam Mantz, Harald Ebeling

We use measurements of the growth of cosmic structure, as inferred from the observed evolution of the X-ray luminosity function (XLF) of galaxy clusters, to constrain departures from General Relativity (GR) on cosmological scales. We employ the popular growth rate parameterization, Omega_m(z)^gamma, for which GR predicts a growth index gamma~0.55. We use obs

Vaneet Aggarwal, Lalitha Sankar, A. Robert Calderbank, H. Vincent Poor

The secrecy capacity of relay channels with orthogonal components is studied in the presence of an additional passive eavesdropper node. The relay and destination receive signals from the source on two orthogonal channels such that the destination also receives transmissions from the relay on its channel. The eavesdropper can overhear either one or both of t

Andrea Shindler

We make several observations concerning the low quark mass region with Wilson fermions and how this is connected with the epsilon regime in the continuum. A transition from tiny cutoff effects to rather large discretization errors would take place in general with Wilson fermions if we lower the quark mass at finite lattice spacing. We argue that these two re

Frauke M. Bleher, Giovanna Llosent

Let k be an algebraically closed field of characteristic 2, and let W be the ring of infinite Witt vectors over k. Let S_4 denote the symmetric group on 4 letters. We determine the universal deformation ring R(S_4,V) for every kS_4-module V which has stable endomorphism ring k and show that R(S_4,V) is isomorphic to either k, or W[t]/(t^2,2t), or the group r

J. -H. Chen, C. Jang, M. Ishigami, S. Xiao

We review our recent work on the physical mechanisms limiting the mobility of graphene on SiO2. We have used intentional addition of charged scattering impurities and systematic variation of the dielectric environment to differentiate the effects of charged impurities and short-range scatterers. The results show that charged impurities indeed lead to a condu

S. T. Dye

This paper briefly reviews recent developments in the field of geo-neutrinos. It describes current and future detection projects, discusses modeling projects, suggests an observational program, and visits geo-reactor hypotheses.

Konstantin Goulianos

The diffractive program of the CDF Collaboration at the Fermilab Tevatron p-pbar collider is reviewed with emphasis on recent results from Run II at a c.m.s. energy of 1.96 TeV. Results are presented on the x-Bjorken and Q^2 dependence of the diffractive structure function obtained from di-jet production, on the slope parameter of the t-distribution of diffr

Adam Clay

Let G be a left orderable group and LO(G) the space of all left orderings. We investigate the circumstances under which a left ordering < of G can correspond to an isolated point in LO(G), in particular we extend known results to cover the case of uncountable groups. With minor technical restrictions on the group G, we also find that no dense left ordering i

Jiri Lebl

We study the local geometry of the pullback of a variety via a finite holomorphic map. In particular, we are looking for properties of $V = F^{-1}(W)$ such that if $V$ has the property $A$, then $W$ must have the property $A$. We show that $A$ can be the property of normality or prefactoriality. We also show that $A$ can be the property of smoothness, under

Alan P. Boss

The disk instability mechanism for giant planet formation is based on the formation of clumps in a marginally-gravitationally unstable protoplanetary disk, which must lose thermal energy through a combination of convection and radiative cooling if they are to survive and contract to become giant protoplanets. While there is good observational support for for

Patrick Rinke, Anderson Janotti, Matthias Scheffler, Chris G. Van de Walle

We present an improved method to calculate defect formation energies that overcomes the band-gap problem of Kohn-Sham density-functional theory (DFT) and reduces the self-interaction error of the local-density approximation (LDA) to DFT. We demonstrate for the silicon self-interstitial that combining LDA with quasiparticle energy calculations in the G0W0 app

Aleksandr Azatov, Manuel Toharia, Lijun Zhu

In the context of a warped extra-dimension with Standard Model fields in the bulk, we obtain the general flavor structure of the Radion couplings to fermions and show that the result is independent on the particular nature of the Higgs mechanism (bulk or brane localized). These couplings will be generically misaligned with respect to the fermion mass matrix

S. P. de Alwis

Compactifications of heterotic string theory on Generalized Calabi-Yau manifolds have been expected to give the same type of flexibility that type IIB compactifications on Calabi-Yau orientifolds have. In this note we generalize the work done on half-flat manifolds by other authors, to show how flux quantization occurs in the general case, by starting with a

Maria L. Ekiel-Jezewska, Eligiusz Wajnryb

It is shown that nonsymmetric microobjects orient while settling under gravity in a viscous fluid. To analyze this process, a simple shape is chosen: a non-deformable `chain&#39;. The chain consists of two straight arms, made of touching solid spheres. In the absence of external torques, the spheres are free to spin along the arms. The motion of the chain is

K. Maltman, D. Leinweber, P. Moran, A. Sternbeck

The determination of alpha_s(M_Z) via perturbative analyses of short-distance-sensitive lattice observables is revisited, incorporating new lattice data and performing a modified version of the original analysis. The analysis employs two high-intrinsic-scale observables, log (W_11) and log(W_12), and one lower-intrinsic-scale observable, log(W_12/u_0^6). We

Eleni Katifori, Silas Alben, David R. Nelson

Hydrostatically pressurized circular rings confined to two dimensions (or cylinders constrained to have only z-independent deformations) undergo Euler type buckling when the outside pressure exceeds a critical value. We perform a stability analysis of rings with arc-length dependent bending moduli and determine how weakened bending modulus segments affect th

A. J. Barger, L. L. Cowie, W. -H. Wang

We present a table of redshifts for 2907 galaxies and stars in the 145 square arcmin HST ACS GOODS-North, making this the most spectroscopically complete redshift sample obtained to date in a field of this size. We also include the redshifts, where available, in a table containing just under 7000 galaxies from the ACS area with K_s(AB)<24.5 measured from a d

J. D. Younger, A. Omont, N. Fiolet, J. -S. Huang

We present millimetre observations of a sample of 12 high redshift ultraluminous infrared galaxies (ULIRGs) in the Extended Growth Strip (EGS). These objects were initially selected on the basis of their observed mid--IR colours (0.0 < [3.6]-[4.5] < 0.4 and -0.7 < [3.6]-[8.0] < 0.5) to lie at high redshift 1.5 < z < 3, and subsequent 20-38 micron mid-IR spec

Matthew J. Payne, Eric B. Ford, Mark C. Wyatt, Mark Booth

HD 69830 exhibits radial velocity variations attributed to three planets as well as infrared emission attributed to a warm debris disk. Previous studies have developed models for the planet migration and mass growth (Alibert et al. 2006) and the replenishment of warm grains (Wyatt et al. 2007). We perform n-body integrations in order to explore the implicati

P. K. Pathak, S. Hughes

We present a formal theory of single quantum-dot coupling to a planar photonic crystal that supports quasi-degenerate cavity modes, and use this theory to describe, and optimize, entangled-photon-pair generation via the biexciton-exciton cascade. In the generated photon pairs, either both photons are spontaneously emitted from the dot, or one photon is emitt

Gabriele U. Varieschi

We continue our presentation of an alternative cosmology based on conformal gravity, following our kinematical approach introduced in a recent paper. In line with the assumptions of our model, which proposes a closed-form expression for the cosmic scale factor R(t), we first revise the Hubble and deceleration parameters and also introduce modified cosmologic

A. B. Vorontsov, M. G. Vavilov, A. V. Chubukov

We consider phase transitions and potential co-existence of spin-density-wave (SDW) magnetic order and extended s-wave ($s^+$) superconducting order within a two-band itinerant model of iron pnictides, in which SDW magnetism and $s^+$ superconductivity are competing orders. We show that depending on parameters, the transition between these two states is eith

F. Myhrer

Considerable progress has been made in our knowledge of the spin distribution within the proton. The recently measured limits on polarized gluons in the proton suggest polarized gluons contribute very modestly to the proton spin. We will show that a modern, relativistic and chirally symmetric description of the nucleon structure naturally explain the current

V. A. Abramovsky, N. V. Radchenko

The multiple production processes of secondary hadrons in proton-antiproton scattering are divided into three types. The first type is a shower of secondary hadrons produced from gluon string decay, the second type is a shower of secondary hadrons produced from two quark strings decay and the third is a shower produced from three quark strings decay. At the

Matt Lehnert, Carlos De Breuck, Harald Kuntschner, Martin Zwaan

An overview of the ESO/Radionet workshop devoted to 3D optical/near-infrared and sub-mm/radio observations of gas and stars in galaxies is presented. There will be no published proceedings but presentations are available at http://www.eso.org/sci/meetings/gal3D2008/program.html . The main aim of this ESO/Radionet workshop was to bring together the optical/ n

O. Purevdorj, A. V. Tetenov

The article contains a construction of a self-similar dendryte which cannot be the attractor of any self-similar zipper.

Smarajit Das, B. Sundar Rajan

Space-time block codes from square complex orthogonal designs (SCOD) have been extensively studied and most of the existing SCODs contain large number of zeros. The zeros in the designs result in high peak-to-average power ratio and also impose a severe constraint on hardware implementation of the code while turning off some of the transmitting antennas when

Kim Maltman, Tzahi Yavin

We discuss the extraction of alpha_s using isovector hadronic tau decay data and sum rules constructed specifically to suppress contributions associated with poorly known higher dimension condensates. We show, first, that problems with the treatment of such contributions affect earlier related analyses and, second, that these problems can be brought under go

Oleg N. German, Nikolay G. Moshchevitin

We prove a new quantitative result on the degeneracy of the dimension of the subspace spanned by the best Diophantine approximations for a linear form.

Neri Merhav

Using well-known results from statistical physics, concerning the almost-sure behavior of the free energy of directed polymers in a random medium, we prove that random tree codes achieve the distortion-rate function almost surely under a certain symmetry condition.

Janusz Sadowski, Piotr Dluzewski, Janusz Kanski

GaAs nanowires were grown by molecular beam epitaxy on Si(100) substrates covered with 5 nm SiO2. The growth was performed with As4 at low, close to stoichiometric, As4/Ga flux ratio, using Ga nanodroplets as catalyst. The nanowires are found to be in epitaxial relation to the Si substrate due to contact via pinholes through the SiO2 layer. The nanowires are

Michel Aoun, Annick Hourmant, Jean-Yves Cabon

The protective effect exerted by polyamines (Put and Spd) against cadmium (Cd) stress was investigated in Brassica juncea plants. Treatment with CdCl2 (75 micro-Mole) resulted in a rise of Cd accumulation, a decrease of fresh and dry weights in every plant organ, an increase of free polyamine content at limb and stem levels as well as a decrease at root leve

M. Wolleben, T. L. Landecker, E. Carretti, J. M. Dickey

The Global Magneto-Ionic Medium Survey (GMIMS) is a project to map the diffuse polarized emission over the entire sky, Northern and Southern hemispheres, from 300 MHz to 1.8 GHz. With an angular resolution of 30 - 60 arcmin and a frequency resolution of 1 MHz or better, GMIMS will provide the first spectro-polarimetric data set of the large-scale polarized e

T. Kaizoji, D. Sornette

Episodes of market crashes have fascinated economists for centuries. Although many academics, practitioners and policy makers have studied questions related to collapsing asset price bubbles, there is little consensus yet about their causes and effects. This review and essay evaluates some of the hypotheses offered to explain the market crashes that often fo

T. Storchi-Bergmann, P. J. McGregor, Rogemar A. Riffel, R. Simoes-Lopes

We have used the Gemini Near-infrared Integral Field Spectrograph (NIFS) to map the emission-line intensity distributions and ratios in the Narrow-Line Region (NLR) of the Seyfert galaxy NGC 4151 in the Z, J, H and K bands at a resolving power ~ 5000, covering the inner 200 pc x 300 pc of the galaxy at a spatial resolution of 8 pc. We present intensity distr

C. Reichhardt, C. J. Olson Reichhardt

We study the driving of colloidal molecular crystals over periodic substrates such as those created with optical traps. The n-merization that occurs in the colloidal molecular crystal states produces a remarkably rich variety of distinct dynamical behaviors, including polarization effects within the pinned phase and the formation of both ordered and disorder

Morrel H. Cohen, Adam Wasserman, Roberto Car, Kieron Burke

The recently proposed Partition Theory (PT) [J.Phys.Chem.A 111, 2229 (2007)] is illustrated on a simple one-dimensional model of a heteronuclear diatomic molecule. It is shown that a sharp definition for the charge of molecular fragments emerges from PT, and that the ensuing population analysis can be used to study how charge redistributes during dissociatio

Alexandre F. Roch

In this paper, we study the valuation of American type derivatives in the stochastic volatility model of Barndorff-Nielsen and Shephard (2001). We characterize the value of such derivatives as the unique viscosity solution of an integral-partial differential equation when the payoff function satisfies a Lipschitz condition.

Howard Baer

Gravity-mediated SUSY breaking models with R-parity conservation give rise to dark matter in the universe. I review neutralino dark matter in the minimal supergravity model (mSUGRA), models with non-universal soft SUSY breaking terms (NUSUGRA) which yield a well-tempered neutralino, and models with unified Yukawa couplings at the GUT scale (as may occur in a

Olivier Mousis, Ulysse Marboeuf, Jonathan I. Lunine, Yann Alibert

We calculate the minimum mass of heavy elements required in the envelopes of Jupiter and Saturn to match the observed oversolar abundances of volatiles. Because the clathration efficiency remains unknown in the solar nebula, we have considered a set of sequences of ice formation in which the fraction of water available for clathration is varied between 0 and

S. Kimura, A. Bonasera

We discuss the reaction rate of the muon-catalysed $t$-$t$ fusion. The reaction rate is determined as a function of the temperature using the model of &#34;in flight&#34; fusion. We especially take into account the effect of the fluctuation of the cross section due to the existence of the muon. The obtained reaction rate 5.0$\times10^{-3} μ$s$^{-1}$ is a fac

N. Michel

Coulomb wave functions are difficult to compute numerically for extremely low energies, even with direct numerical integration. Hence, it is more convenient to use asymptotic formulas in this region. It is the object of this paper to derive analytical asymptotic formulas valid for arbitrary energies and partial waves. Moreover, it is possible to extend these

Henry P. Stapp

A recent article in which John Searle claims to refute dualism is examined from a scientific perspective.

C. Galindo, F. Monserrat

We give a characterization theorem for non-degenerated plane foliations of degree different from 1 having a rational first integral. Moreover, we prove that the degree $r$ of a non-degenerated foliation as above provides the minimum number, $r+1$, of points in the projective plane through which infinitely many algebraic leaves of the foliation go.

Jean B Nganou

If K/F is a finite abelian Galois extension of global fields whose Galois group has exponent t, we prove that there exists a short exact sequence that has as a consequence that if t is square free, then Dec(K/F)=Br_{t}(K/F) which we use to show that prime exponent division algebras over Henselian valued fields with global residue fields are isomorphic to a t

Johanna Knapp, Emanuel Scheidegger

We discuss B-type tensor product branes in mirrors of two-parameter Calabi-Yau hypersurfaces, using the language of matrix factorizations. We determine the open string moduli of the branes at the Gepner point. By turning on both bulk and boundary moduli we then deform the brane away from the Gepner point. Using the deformation theory of matrix factorizations

Eva Hackmann, Valeria Kagramanova, Jutta Kunz, Claus Laemmerzahl

The complete analytical solutions of the geodesic equation of massive test particles in higher dimensional Schwarzschild, Schwarzschild-(anti)de Sitter, Reissner-Nordstroem and Reissner-Nordstroem-(anti)de Sitter space--times are presented. Using the Jacobi inversion problem restricted to the theta divisor the explicit solution is given in terms of Kleinian

I. Bierenbaum, J. Blümlein, S. Klein

The heavy quark effects in deep--inelastic scattering in the asymptotic regime $Q^2 \gg m^2$ can be described by heavy flavor operator matrix elements. Complete analytic expressions for these objects are currently known to ${\sf NLO}$. We present first results for fixed moments at ${\sf NNLO}$. This involves a recalculation of fixed moments of the correspond

Alain Bruguières, Alexis Virelizier

The center Z(C) of a spherical fusion category C (over an arbitrary commutative ring) is modular. We give an algorithm for computing the Reshetikhin-Turaev invariant defined with Z(C). It is based on Hopf diagrams and an explicit description of the structure of the coend of Z(C).

M. Saffman, K. Molmer

We present an efficient method for producing $N$ particle entangled states using Rydberg blockade interactions. Optical excitation of Rydberg states that interact weakly, yet have a strong coupling to a second control state is used to achieve state dependent qubit rotations in small ensembles. On the basis of quantitative calculations we predict that an N=8

M. Simon, R. C. Obbie

We report an analysis of twins of spectral types F or later in the 9th Catalog of Spectroscopic Binaries (SB9). Twins, the components of binaries with mass ratio within 2% of 1.0, are found among the binaries with primaries of F and G spectral type. They are most prominent among the binaries with periods less than 43 days, a cutoff first identified by Lucy.

Aleix Ruiz de Villa, Xavier Tolsa

In this paper we prove that, given s> 0, if E is a subset of R^m with positive and bounded s-dimensional Hausdorff measure H^s and the principal values of the s-dimensional signed Riesz transform of H^s|E exist H^s-almost everywhere in E, then s is integer. Other more general variants of this result are also proven.

Michael E. Hoffman

Recent work on perturbative quantum field theory has led to much study of the Connes-Kreimer Hopf algebra. Its (graded) dual, the Grossman-Larson Hopf algebra of rooted trees, had already been studied by algebraists. L. Foissy introduced a noncommutative version of the Connes-Kreimer Hopf algebra, which turns out to be self-dual. Using some homomorphisms def

Kurt Langfeld, Tom Heinzl, Anton Ilderton, Martin Lavelle

A new approach to gauge fixed Yang-Mills theory is derived using the Polyakov-Susskind projection techniques to build gauge invariant states. In our approach, in contrast to the Faddeev-Popov method, the Gribov problem does not prevent the gauge group from being factored out of the partition function. Lattice gauge theory is used to illustrate the method via