December 2007 arXiv papers — page 26

R. Centeno, J. Trujillo Bueno, H. Uitenbroek, M. Collados

Two of the most attractive spectral windows for spectropolarimetric investigations of the physical properties of the plasma structures in the solar chromosphere and corona are the ones provided by the spectral lines of the He I 10830 A and 5876 A (or D3) multiplets, whose polarization signals are sensitive to the Hanle and Zeeman effects. However, in order t

Lenny Tevlin

This paper introduces noncommutative analogs of monomial symmetric functions and fundamental noncommutative symmetric functions. The expansion of ribbon Schur functions in both of these basis is nonnegative. With these functions at hand, one can derive a noncommutative Cauchy identity as well as study a noncommutative scalar product implied by Cauchy identit

K. Gallmeister, M. Kaskulov, U. Mosel

The study of the interaction of hadrons, produced by elementary probes in a nucleus, with the surrounding nuclear medium can give insight into two important questions. First, at high energies, the production process, the time-scales connected with it and the prehadronic interactions can be studied by using the nuclear radius as a length-scale. We do this her

Thorsten Emig

The interaction of compact objects with an infinitely extended mirror plane due to quantum fluctuations of a scalar or electromagnetic field that scatters off the objects is studied. The mirror plane is assumed to obey either Dirichlet or Neumann boundary conditions or to be perfectly reflecting. Using the method of images, we generalize a recently developed

Patryk Sofia Lykawka, Tadashi Mukai

Trans-Neptunian objects (TNOs) are remnants of a collisionally and dynamically evolved planetesimal disk in the outer solar system. This complex structure, known as the trans-Neptunian belt (or Edgeworth-Kuiper belt), can reveal important clues about disk properties, planet formation, and other evolutionary processes. In contrast to the predictions of accret

Rainer J. Fries

I discuss some recent progress in our understanding of high energy nuclear collisions. I will focus on two topics which I was lucky to co-pioneer in the recent past. One is recombination of quarks and its interpretation as a signal for deconfinement, the second is electromagnetic radiation from jets passing through a quark gluon plasma. This talk was given d

Sergio Fenley, Renato Feres, Kamlesh Parwani

Let (M, F) be a compact codimension-one foliated manifold whose leaves are equipped with Riemannian metrics, and consider continuous functions on M that are harmonic along the leaves of F . If every such function is constant on leaves we say that (M, F) has the Liouville property. Our main result is that codimension-one foliated bundles over compact negative

V. I. Man'ko, G. Marmo, E. C. G. Sudarshan, F. Zaccaria

Using general construction of star-product the q-deformed Wigner-Weyl-Moyal quantization procedure is elaborated. The q-deformed Groenewold kernel determining the product of quantum observables is given in explicit form for small nonlinearities corresponding to nonlinear vibrations of classical and quantum q-oscillators. The deformations of Groenewold kernel

John D. Barrow, Douglas J. Shaw

We study the asymptotic behaviour of isotropic and homogeneous universes in general scalar-tensor gravity theories containing a p=-rho vacuum fluid stress and other sub-dominant matter stresses. It is shown that in order for there to be approach to a de Sitter spacetime at large 4-volumes the coupling function, omega(phi), which defines the scalar-tensor the

Philippe-Jacques Moreau, Oliviero Barana, Sylvain Brémond, Jérome Bucalossi

The Tore Supra tokamak is the largest superconducting magnetic fusion facility, has been devoted to long-duration high-performance discharge research. With a steady-state magnetic field and water cooled plasma facing components, discharges up to 6 minutes 24 seconds duration with injected / extracted energy up to 1 GJ have been performed. The Tore Supra real

Xianghon Qi, John J. Portman

We analyzed folding routes predicted by a variational model in terms of a generalized formalism of the capillarity scaling theory for 28 two-state proteins. The scaling exponent ranged from 0.2 to 0.45 with an average of 0.33. This average value corresponds to packing of rigid objects.That is, on average the folded core of the nucleus is found to be relative

H. H. Wolter, J. Rizzo, M. Colonna, M. Di Toro

With stochastic transport simulations we study in detail central and peripheral collisions at Fermi energies and suggest new observables, sensitive to the symmetry energy below normal density. As such we identify on one hand the isospin imbalance ratio, i.e. the relative amount of isospin equilibration in binary, peripheral reactions of nuclei with different

Mihai Mihailescu, Vicentiu Radulescu

We study a nonlinear Neumann boundary value problem associated to a nonhomogeneous differential operator. Taking into account the competition between the nonlinearity and the bifurcation parameter, we establish sufficient conditions for the existence of nontrivial solutions in a related Orlicz--Sobolev space.

Marc-Eric Bobiller-Chaumon, Françoise Sandoz-Guermond

This article proposes to describe and compare the contributions of various techniques of evaluation of the accessibility of E-services carried out starting from (i) methods of inspection (on the basis of traditional ergonomic criteria and accessibility) and (ii) of tests of use. It show that these are the latter which show the best rate of identification of

Henk D. L. Hollmann, Ludo M. G. M. Tolhuizen

In 2007, Martinian and Trott presented codes for correcting a burst of erasures with a minimum decoding delay. Their construction employs [n,k] codes that can correct any burst of erasures (including wrap-around bursts) of length n-k. The raised the question if such [n,k] codes exist for all integers k and n with 1<= k <= n and all fields (in particular, for

A. G. Agocs, A. Di Mauro, A. Ben David, B. Clark

We have developed prototypes of GEM-like detectors with resistive electrodes to be used as RICH photodetectors equipped with CsI photocathodes. The main advantages of these detectors are their intrinsic spark protection and possibility to operate at high gain (~10E5) in many gases including poorly quenched ones, allowing for the adoption of windowless config

Andreu Esteban-Pretel, Sergio Pastor, Ricard Tomas, Georg Raffelt

We study two-flavor collective neutrino oscillations in the dense-neutrino region above the neutrino sphere in a supernova (SN). The angular dependence of the neutrino-neutrino interaction potential causes &#34;multi-angle&#34; effects that can lead either to complete kinematical decoherence in flavor space or only to small differences between different traj

Matthew T. Morrow

We present elements of a theory of translation-invariant integration on finite dimensional vector spaces and on GL_n over a valuation field with local field as residue field. We then discuss the case of an arbitrary algebraic group. This extends the work of Fesenko.

Stephane Ouvry

A review on the Anyon model and the lowest Landau level Anyon model is presented.

Piotr Sułkowski

This thesis is concerned with a realisation of topological theories in terms of statistical models known as Calabi-Yau crystals. The thesis starts with an introduction and review of topological field and string theories. Subsequently several new results are presented. The main focus of the thesis is on the topological string theory. In this case crystal mode

Matthew T. Morrow

We present elements of a theory of translation-invariant integration, measure, and harmonic analysis on a valuation field with local field as residue field. This extends the work of Fesenko. Applications to zeta integrals for two-dimensional local fields are then considered.

Luigina Feretti

The most spectacular aspect of cluster radio emission is represented by the large-scale diffuse radio sources, which cannot be obviously associated with any individual galaxy. These sources demonstrate the existence of relativistic particles and magnetic fields in the cluster volume, thus indicating the presence of non-thermal processes in the hot intraclust

Marc-Eric Bobiller-Chaumon, Michel Dubois, Françoise Sandoz-Guermond

The aim of this paper is to determine the expectations that French-speaking disabled persons have for electronic administrative sites (utility). At the same time, it is a matter of identifying the difficulties of use that the manipulation of these E-services poses concretely for blind people (usability) and of evaluating the psychosocial impacts on the way o

Gregory C. Verchota

Positive definite forms $f$ which are sums of squares are constructed to have the additional property that the members of any collection of forms whose squares sum to $f$ must share a nontrivial complex root.

A. Colaiuda, V. Ferrari, L. Gualtieri, J. A. Pons

We find numerical solutions of the coupled system of Einstein-Maxwell&#39;s equations with a linear approach, in which the magnetic field acts as a perturbation of a spherical neutron star. In our study, magnetic fields having both poloidal and toroidal components are considered, and higher order multipoles are also included. We evaluate the deformations ind

R. J. Douglas

This paper proves some results concerning the polar factorisation of an integrable vector-valued function u into the composition of the gradient of a convex function with a measure-preserving mapping. Not every integrable function has a polar factorisation; we extend the class of counterexamples. We introduce a generalisation: u has a polar inclusion if u(x)

Jessy Jose, A. K. Pandey, D. K. Ojha, K. Ogura

We present $UBVI_c$ CCD photometry of the young open cluster Stock 8 with the aim to study the basic properties and star formation scenario in this region. The radius of the cluster is found to be $\sim 6^{\prime}$ ($\sim 3.6$ pc) and the reddening within the cluster region varies from $E(B-V)=0.40$ to 0.60 mag. The cluster is located at a distance of $2.05

Ludmil Hadjiivanov, Paolo Furlan

Global gauge symmetry becomes more intricate in low dimensional QFT. We survey the mathematical concepts leading to the relevant analogues of the (D=4) Doplicher-Haag-Roberts theory of superselection sectors and internal symmetry. We also review a recently uncovered duality between braid and quantum group representations in an extension of the chiral su(2)_k

M. Ebrahim Foulaadvand, Sommayeh Belbasi

We have developed a modified Nagel-Schreckenberg cellular automata model for describing a conflicting vehicular traffic flow at the intersection of two streets. No traffic lights control the traffic flow. The approaching cars to the intersection yield to each other to avoid collision. Closed boundary condition is applied to the streets. Extensive Monte Carlo

A. Radosz, A. T. Augousti, K. Ostasiewicz

The Doppler shift considered in general relativity involves mixed contributions of distinct, gravitational and kinematical origins and for most metrics or trajectories it takes a complex form. The expression for the Doppler shift may simplify due to particular symmetries. In Schwarzschild spacetime it factorizes in the case of radial fall for an observer and

Luis Paris

We prove that the mapping class group of a closed oriented surface of genus $ρ\ge 3$ has no proper subgroup of index $\le 4 ρ+4$.

S. Shklyaev, M. Khenner, A. A. Alabuzhev

Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows

Cliff Spiegelman, William A. Tobin, William D. James, Simon J. Sheather

The assassination of President John Fitzgerald Kennedy (JFK) traumatized the nation. In this paper we show that evidence used to rule out a second assassin is fundamentally flawed. This paper discusses new compositional analyses of bullets reportedly to have been derived from the same batch as those used in the assassination. The new analyses show that the b

Eivind Eriksen

We compute the noncommutative deformations of a family of modules over the first Weyl algebra. This example shows some important properties of noncommutative deformation theory that separates it from commutative deformation theory.

Aurélien Perrin, Craig M. Savage, D. Boiron, V. Krachmalnicoff

We perform a theoretical analysis of atomic four-wave mixing via a collision of two Bose-Einstein condensates of metastable helium atoms, and compare the results to a recent experiment. We calculate atom-atom pair correlations within the scattering halo produced spontaneously during the collision. We also examine the expected relative number squeezing of ato

M. Zofka, J. Bicak

We review and investigate some basic properties of static, cylindrically symmetric spacetimes with non-zero cosmological constant, find non-singular sheet sources of these spacetimes and discuss their characteristics, and clarify their relation to the 4D black-string solutions.

Jakob Jonsson, Volkmar Welker

Let $S$ be a finite alphabet. An injective word over $S$ is a word over $S$ such that each letter in $S$ appears at most once in the word. We study Boolean cell complexes of injective words over $S$ and their commutation classes. This generalizes work by Farmer and by Björner and Wachs on the complex of all injective words.

Rong-Gen Cai

Applying the Clausius relation, $δQ=TdS$, to the apparent horizon of FRW universe in brane world scenarios, we show that an explicit entropy expression associated with the apparent horizon can be obtained. On the apparent horizon, the relation, $dE=TdS +WdV$, also holds in the brane world scenarios. We show these results in the RSII model, warped DGP model a

Eric Chojnacki, Jean Baccou, Sébastien Destercke

The treatment of both aleatory and epistemic uncertainty by recent methods often requires an high computational effort. In this abstract, we propose a numerical sampling method allowing to lighten the computational burden of treating the information by means of so-called fuzzy random variables.

F. Patisson, C. Ablitzer-Thouroude, S. Hebrard, D. Ablitzer

The dry conversion process for making UO2 nuclear fuel pellets consists of two steps: hydrolysis of UF6 to UO2F2, followed by reducing pyrohydrolysis to UO2 in a rotary kiln. The physical characteristics (morphology, particle size distribution) of the powder obtained at the kiln end determine the final properties (sinterability, flow-ability, green strength)

Jordy Bouwman, Wiebke Ludwig, Zainab Awad, Karin I. Oberg

A laboratory study on the band profiles and band strengths of H2O in CO ice, and vice versa, is presented and interpreted in terms of two models. The results show that a mutual interaction takes place between the two species in the solid, which alters the band positions and band strengths. It is found that the band strengths of the H2O bulk stretch, bending

Matyas Koniorczyk, Arpad Varga, Peter Rapcan, Vladimir Buzek

We investigate dynamics of semi-quantal spin systems in which quantum bits are attached to classically and possibly stochastically moving classical particles. The interaction between the quantum bits takes place when the respective classical particles get close to each other in space. We find that with Heisenberg XX couplings quantum homogenization takes pla

Yi-Zhong Fan, Tsvi Piran, Da-Ming Wei

Before 2004, nearly all GRB afterglow data could be understood in the context of the external shocks model. This situation has changed in the past two years, when it became clear that some afterglow components should be attributed to the activity of the central engine; i.e., the {\it central engine afterglow}. We review here the afterglow emission that is di

A. B. Hill, A. J. Dean, R. Landi, V. A. McBride

IGR J16493-4348 was one of the first new sources to be detected by the INTEGRAL gamma-ray telescope in the 18-100 keV energy band. Based upon spatial coincidence the source was originally associated with the free radio pulsar PSR J1649-4349. Presented here are the results of 2.8 Ms of observations made by the INTEGRAL mission and a 5.6 ks observation with th

Dan Polisevski

The Div-Curl Lemma, which is the basic result of the compensated compactness theory in Sobolev spaces, was introduced by F. Murat (1978) with distinct proofs for the $L^2(Ω)$ and $L^p(Ω)$, $p \neq 2$, cases. In this note we present a slightly different proof, relying only on a Green-Gauss integral formula and on the usual Rellich-Kondrachov compactness prope

J. C. Gonzalez-Davila

We study the Jacobi osculating rank of geodesics on naturally reductive homogeneous manifolds and we apply this theory to the 3-dimensional case. Here, each non-symmetric, simply connected naturally reductive 3-manifold can be given as a principal bundle over a surface of constant curvature, such that the curvature of its horizontal distribution is also a co

Lev Klebanov, Andrei Yakovlev

It is well known that correlations in microarray data represent a serious nuisance deteriorating the performance of gene selection procedures. This paper is intended to demonstrate that the correlation structure of microarray data provides a rich source of useful information. We discuss distinct correlation substructures revealed in microarray gene expressio

Olivier Bodini, Alexis Darrasse, Michèle Soria

In this paper, we study the distribution of distances in random Apollonian network structures (RANS), a family of graphs which has a one-to-one correspondence with planar ternary trees. Using multivariate generating functions that express all information on distances, and singularity analysis for evaluating the coefficients of these functions, we describe th

O. Fialko, K. Ziegler

A mixture of spin-1/2 fermionic atoms and molecules of paired fermionic atoms is studied in an optical lattice. The molecules are formed by an attractive nearest-neighbor interaction. A functional integral is constructed for this many-body system and analyzed in terms of a mean-field approximation and Gaussian fluctuations. This provides a phase diagram with

Chao Li, Ute Ebert, W. J. M. Brok, Willem Hundsdorfer

Particle models for streamer ionization fronts contain correct electron energy distributions, runaway effects and single electron statistics. Conventional fluid models are computationally much more efficient for large particle numbers, but create too low ionization densities in high fields. To combine their respective advantages, we here show how to couple b

Giorgio Giacomelli

The results obtained by several experiments on atmospheric neutrino oscillations are summarized and discussed. Then the results obtained by different long baseline neutrino experiments are considered. Finally conclusions and perspectives are made.

Elena A. Erosheva, Stephen E. Fienberg, Cyrille Joutard

Data on functional disability are of widespread policy interest in the United States, especially with respect to planning for Medicare and Social Security for a growing population of elderly adults. We consider an extract of functional disability data from the National Long Term Care Survey (NLTCS) and attempt to develop disability profiles using variations

Andrea Malchiodi

We consider the problem of varying conformally the metric of a four dimensional manifold in order to obtain constant $Q$-curvature. The problem is variational, and solutions are in general found as critical points of saddle type. We show how the problem leads naturally to consider the set of formal barycenters of the manifold.

Elia M. Leibowitz, Liliana Formiggini

We have reanalyzed the long-term optical light curve (LC) of the symbiotic star Z Andromedae, covering 112--yr of mostly visual observations. Two strictly periodic and one quasi-periodic cycles can be identified in this LC. A P1=7550 d quasi periodicity characterizes the repetition time of the outburst episodes of this symbiotic star. Six such events have be

L. L. Kitchatinov, G. Rüdiger

Stability of toroidal magnetic field in a stellar radiation zone is considered for the cases of uniform and differential rotation. In the rigidly rotating radiative core shortly below the tachocline, the critical magnetic field for instability is about 600 G. The unstable disturbances for slightly supercritical fields have short radial scales ~1 Mm. Radial m

S. Messina

We present the results of a long-term photometric monitoring project carried out at Catania Astrophysical Observatory and aimed at studying magnetic activity in close binary systems. We present the complete observations dataset (38,000 photoelectric observations in UBV) and new results of an investigation on the origin of brightness and color variations obse

F. Massaro, A. Tramacere, A. Cavaliere, M. Perri

Many of the extragalactic sources detected in $γ$ rays at TeV energies are BL Lac objects. In particular, they belong to the subclass of ``high frequency peaked BL Lacs&#34; (HBLs), as their spectral energy distributions exhibit a first peak in the X-ray band. At a closer look, their X-ray spectra appear to be generally curved into a log-parabolic shape. In

Zhijin Wu, Rafael A. Irizarry

In microarray technology, a number of critical steps are required to convert the raw measurements into the data relied upon by biologists and clinicians. These data manipulations, referred to as preprocessing, influence the quality of the ultimate measurements and studies that rely upon them. Standard operating procedure for microarray researchers is to use

E. Yu. Korzinin, V. G. Ivanov, S. G. Karshenboim

The Uehling correction to the energy levels is presented in terms of the hypergeometric functions 2F1. This presentation allows to derived various asymptotics and approximations. Further applications of this method to other atomic characteristics are also considered.

Andreas U. Schmidt, Nicolai Kuntze, Michael Kasper

In its recently published TCG Mobile Reference Architecture, the TCG Mobile Phone Work Group specifies a new concept to enable trust into future mobile devices. For this purpose, the TCG devises a trusted mobile platform as a set of trusted engines on behalf of different stakeholders supported by a physical trust-anchor. In this paper, we present our percept

Peter Elias

By a theorem proved by Erdos, Kunen and Mauldin, for any nonempty perfect set $P$ on the real line there exists a perfect set $M$ of Lebesgue measure zero such that $P+M=\mathbb{R}$. We prove a stronger version of this theorem in which the obtained perfect set $M$ is a Dirichlet set. Using this result we show that for a wide range of familes of subsets of th

Peter Tuthill, John Monnier, Nicholas Lawrance, William Danchi

Results from the most extensive study of the time-evolving dust structure around the prototype &#34;Pinwheel&#34; nebula WR 104 are presented. Encompassing 11 epochs in three near-infrared filter bandpasses, a homogeneous imaging data set spanning more than 6 years (or 10 orbits) is presented. Data were obtained from the highly successful Keck Aperture Maski

Steffen Mieske, Helmut Jerjen

With the arrival of wide-field imagers on medium-size telescopes (e.g. SkyMapper, Pan-STARRS) and the future co-existence of LSST with the E-ELT, it is worthwhile to evaluate the scientific potential of a CCD camera with ~1 degree FOV for the VLT. Here we discuss the role that such an instrument could play in resolving persisting fundamental problems in &#34

A. Calabri, C. Ciliberto, F. Flamini, R. Miranda

In this paper we study the Brill-Noether theory of sub-line bundles of a general, stable rank-two vector bundle on a curve C with general moduli. We relate this theory to the geometry of unisecant curves on smooth, non-special scrolls with hyperplane sections isomorphic to C. Most of our results are based on degeneration techniques.

Alberto Calabri, Ciro Ciliberto, Flaminio Flamini, Rick Miranda

In this paper we study smooth, non-special scrolls S of degree d, genus g, with general moduli. In particular, we study the scheme of unisecant curves of a given degree on S. Our approach is mostly based on degeneration techniques.

G. Aranda-Pino, E. Pardo, M. Siles-Molina

In this paper a bijection between the set of prime ideals of a Leavitt path algebra $L_K(E)$ and a certain set which involves maximal tails in $E$ and the prime spectrum of $K[x,x^{-1}]$ is established. Necessary and sufficient conditions on the graph $E$ so that the Leavitt path algebra $L_K(E)$ is primitive are also found.

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

Based on the modified Landau-Lifshitz-Gilbert equation for an arbitrary Stoner particle under an external magnetic field and a spin-polarized electric current, differential equations for the optimal reversal trajectory, along which the magnetization reversal is the fastest one among all possible reversal routes, are obtained. We show that this is a Euler-Lag

Jocelyne Troccaz, Michael Baumann, Peter Berkelman, Philippe Cinquin

Until recently, Computer-Aided Medical Interventions (CAMI) and Medical Robotics have focused on rigid and non deformable anatomical structures. Nowadays, special attention is paid to soft tissues, raising complex issues due to their mobility and deformation. Mini-invasive digestive surgery was probably one of the first fields where soft tissues were handled

V. Daanen, J. Gastaldo, J. Y. Giraud, P. Fourneret

BACKGROUND: Prostate brachytherapy consists in placing radioactive seeds for tumour destruction under transrectal ultrasound imaging (TRUS) control. It requires prostate delineation from the images for dose planning. Because ultrasound imaging is patient- and operator-dependent, we have proposed to fuse MRI data to TRUS data to make image processing more rel

Maurice Courbage, V. I. Nekorkin, L. V. Vdovin

We propose a discrete time dynamical system (a map) as phenomenological model of excitable and spiking-bursting neurons. The model is a discontinuous two-dimensional map. We find condition under which this map has an invariant region on the phase plane, containing chaotic attractor. This attractor creates chaotic spiking-bursting oscillations of the model. W

Ashis Mandal

In this work we compute a versal deformation of the three dimensional nilpotent Leibniz algebra over $\mathbb{C}$, defined by the nontrivial brackets $[e_1,e_3]=e_2$ and $[e_3,e_3]=e_1$.

Timothy G. Abbott, Zachary Abel, David Charlton, Erik D. Demaine

We prove that any finite collection of polygons of equal area has a common hinged dissection. That is, for any such collection of polygons there exists a chain of polygons hinged at vertices that can be folded in the plane continuously without self-intersection to form any polygon in the collection. This result settles the open problem about the existence of

Andrei Kryjevski

Using $\varepsilon$ expansion technique proposed in \cite{Nishida:2006br} we derive an effective Lagrangian (Ginzburg-Landau-like functional) of the degenerate unitary Fermi gas to the next-to-leading (NLO) order in $\varepsilon.$ It is demonstrated that for many realistic situations it is sufficient to retain leading order (LO) terms in the derivative expan

Malwina J. Luczak, Colin McDiarmid

In the supermarket model there are n queues, each with a unit rate server. Customers arrive in a Poisson process at rate λn, where 0<λ<1. Each customer chooses d > 2 queues uniformly at random, and joins a shortest one. It is known that the equilibrium distribution of a typical queue length converges to a certain explicit limiting distribution as n -> oo. We

Yaroslav V. Kartashov, Victor V. Vysloukh, Lluis Torner

We introduce multipole soliton complexes in optical lattices induced by nondiffracting parabolic beams. Despite the symmetry-breaking dictated by the curvature of the lattice channels, we find that complex, asymmetric higher-order states can be stable. The unique topology of parabolic lattices affords new types of soliton motion: single solitons launched int

Byron E. Bell

I studied what role the US stock markets and money markets have possibly played in the Gross Private Domestic Investment (GPDI) of the United States from the year 1959 to the year 2001, Gross Private Domestic Investment refers to the total amount of investment spending by businesses and firms located within the borders of a nation. It includes both the value

Jean Carlos Perez, Stanislav Boldyrev

Recent numerical and observational studies contain conflicting reports on the spectrum of magnetohydrodynamic turbulence. In an attempt to clarify the issue we investigate anisotropic incompressible magnetohydrodynamic turbulence with a strong guide field $B_0$. We perform numerical simulations of the reduced MHD equations in a special setting that allows us

Andrew Hassell, Adam Sikora

We study the boundedness on $L^p$ of the Riesz transform $\nabla L^{-1/2}$, where $L$ is one of several operators defined on $\R$ or $\R_+$, endowed with the measure $r^{d-1} dr$, $d > 1$, where $dr$ is Lebesgue measure. For integer $d$, this mimics the measure on Euclidean $d$-dimensional space, and in this case our setup is equivalent to looking at the Lap

A. Chan, S. C. Liew

Prior work indicates that 802.11 is extremely inefficient for VoIP transport. Only 12 and 60 VoIP sessions can be supported in an 802.11b and an 802.11g WLAN, respectively. This paper shows that the bad news does not stop there. When there are multiple WLANs in the vicinity of each other, the already-low VoIP capacity can be further eroded in a significant m

Marco Antonio Chávez-Rojo, Rigoberto Juárez-Maldonado, Magdaleno Medina-Noyola

A simple manner to describe the diffusive relaxation of a colloidal fluid adsorbed in a porous medium is to model the porous medium as a set of spherical particles fixed in space at random positions with prescribed statistical structural properties. Within this model one may describe the relaxation of concentration fluctuations of the adsorbed fluid by simpl

Dao T. Khoa, Do Cong Cuong

Analyses of the inelastic $α$+$^{12}$C scattering at medium energies have indicated that the strength of the Hoyle state (the isoscalar 0$^+_2$ excitation at 7.65 MeV in $^{12}$C) seems to exhaust only 7 to 9% of the monopole energy weighted sum rule (EWSR), compared to about 15% of the EWSR extracted from inelastic electron scattering data. The full monopol

Ken-ichi Maruyama, Hideaki Oshima

We compute the homotopy groups of the spaces of self maps of Lie groups of rank 2, SU(3), Sp(2), and G_2. We use the cell structures of these Lie groups and the standard methods of homotopy theory.

K. Gemba, Z. T. Hlousek, Z. Papp

In quantum mechanics with minimal length uncertainty relations the Heisenberg-Weyl algebra of the one-dimensional harmonic oscillator is a deformed SU(1,1) algebra. The eigenvalues and eigenstates are constructed algebraically and they form the infinite-dimensional representation of the deformed SU(1,1) algebra. Our construction is independent of prior knowl

Pedro Esequiel Ramírez-González, Rigoberto Juárez-Maldonado, Laura Yeomans-Reyna, Marco Antonio Chávez-Rojo

This letter presents a remarkably simple approach to the first-principles determination of the ergodic-non-ergodic transition in monodisperse colloidal suspensions. It consists of an equation for the long-time asymptotic value $γ$ of the mean squared displacement of the colloidal particles, whose finite real solutions signal the non-ergodic state, and determ

Lalit Ponnala, Donald Bitzer, Anne Stomp, Mladen Vouk

This work applies the methods of signal processing and the concepts of control system design to model the maintenance and modulation of reading frame in the process of protein synthesis. The model shows how translational speed can modulate translational accuracy to accomplish programmed +1 frameshifts and could have implications for the regulation of transla

K. Y. Shin, J. Laverock, Y. Q. Wu, C. L. Condron

The rare earth ($R$) tellurides $R_2$Te$_5$ have a crystal structure intermediate between that of $R$Te$_2$ and $R$Te$_3$, consisting of alternating single and double Te planes sandwiched between $R$Te block layers. We have successfully grown single crystals of Nd$_2$Te$_5$, Sm$_2$Te$_5$ and Gd$_2$Te$_5$ from a self flux, and describe here the first evidence

J. E. Avron, O. Raz

We develop a qualitative geometric approach to swimming at low Reynolds number which avoids solving differential equations and uses instead landscape figures of two notions of curvatures: The swimming curvature and the curvature derived from dissipation. This approach gives complete information for swimmers that swim on a line without rotations and gives the

C. Seoanez

This thesis studies three kinds of mesoscopic systems and how one of their collective degrees of freedom is affected by a dissipative environment: a)Nanoelectromechanical systems based on semiconductor materials, and how surface friction processes limit the quality factor of their vibrational eigenmodes at low temperatures, causing as well a frequency shift;

The LIGO Scientific Collaboration, B. Abbott

We report on the methods and results of the first dedicated search for gravitational waves emitted during the inspiral of compact binaries with spinning component bodies. We analyze 788 hours of data collected during the third science run (S3) of the LIGO detectors. We searched for binary systems using a detection template family designed specially to captur

William H. Kinney, Konstantinos Tzirakis

We study a two-parameter family of exactly solvable inflation models with variable sound speed, and derive a corresponding exact expression for the spectrum of curvature perturbations. We generalize this expression to the slow roll case, and derive an approximate expression for the scalar spectral index valid to second order in slow roll. We apply the result

Jilong Tong

In this papers, we study the geometric and arithmetic properties of the theta divisor associated to the sheaf of locally exact differential forms over a curve in positive characteristic. In this published version, we prove a stronger version of the main result of chapiter 5.

V. P. Konchakovski, B. Lungwitz, M. I. Gorenstein, E. L. Bratkovskaya

Event-by-event multiplicity fluctuations in central C+C, S+S, In+In, and Pb+Pb as well as p+p collisions at bombarding energies from 10 to 160 AGeV are studied within the HSD and UrQMD microscopic transport approaches. Our investigation is directly related to the future experimental program of the NA61 Collaboration at the SPS for a search of the QCD critica

Graham D. Kribs, Erich Poppitz, Neal Weiner

We propose a new solution to the supersymmetric flavor problem without flavor-blind mediation. Our proposal is to enforce a continuous or a suitably large discrete R-symmetry on weak scale supersymmetry, so that Majorana gaugino masses, trilinear A-terms, and the mu-term are forbidden. We find that replacing the MSSM with an R-symmetric supersymmetric model

Kenichi Hatakeyama

Recent results on jet physics at the Fermilab Tevatron $p\bar p$ collider from the CDF Collaboration are presented. The main focus is put on results for the inclusive jet and dijet, $b\bar b$ dijet, $W/Z+$jets and $W/Z+b$-jets production.

Tomoya Takiwaki, Kei Kotake, Katsuhiko Sato

We perform a series of two-dimensional magnetohydrodynamic core-collapse simulations of rapidly rotating and strongly magnetized massive stars. To study the properties of magnetic explosions for a longer time stretch of postbounce evolution, we develop a new code under the framework of special relativity including a realistic equation of state with a multifl

Leonor Cruzeiro

An all-atom model of proteins is used to show that the same sequence of amino acids can have many alternative structures, that are very distant from, and that can be as stable as, the corresponding native structure. Such alternative structures are not easily rationalized as belonging to the native basin and indicate instead that the free energy landscape of

S. Zenitani, M. Hesse

The role of the Weibel instability is investigated for the first time in the context of the large-scale magnetic reconnection problem. A late-time evolution of magnetic reconnection in relativistic pair plasmas is demonstrated by particle-in-cell (PIC) simulations. In the outflow regions, powerful reconnection jet piles up the magnetic fields and then a tang

B. Bigot, S. Galtier, H. Politano

Context : We present a self-consistent model of solar coronal heating, originally developed by Heyvaert & Priest (1992), in which we include the dynamical effect of the background magnetic field along a coronal structure by using exact results from wave MHD turbulence (Galtier et al. 2000). Aims : We evaluate the heating rate and the microturbulent velocity

Karsten Grosse-Brauckmann, Nicholas J. Korevaar, Robert B. Kusner, Jesse Ratzkin

We prove each embedded, constant mean curvature (CMC) surface in Euclidean space with genus zero and finitely many coplanar ends is nondegenerate: there is no nontrivial square-integrable solution to the Jacobi equation, the linearization of the CMC condition. This implies that the moduli space of such coplanar surfaces is a real-analytic manifold and that a

Rouzbeh Allahverdi, Anupam Mazumdar, Tuomas Multamaki

It is plausible that the scalar density perturbations are created by a relatively low scale model of inflation which predicts the CMB anisotropy and excites Standard Model baryon and cold dark matter, but negligible gravity waves. Nevertheless a significantly large tensor perturbations can be observed if there exists a prior phase of high scale inflation sep