August 2005 arXiv papers — page 14

T. V. Dudnikova, A. I. Komech, E. A. Kopylova, Yu. M. Suhov

Consider the Klein-Gordon equation (KGE) in $\R^n$, $n\ge 2$, with constant or variable coefficients. We study the distribution $μ_t$ of the random solution at time $t\in\R$. We assume that the initial probability measure $μ_0$ has zero mean, a translation-invariant covariance, and a finite mean energy density. We also asume that $μ_0$ satisfies a Rosenblatt

Victor Guba

Let $G$ be a group generated by a finite set $A$. An element $g\in G$ is a strict dead end of depth $k$ (with respect to $A$) if $|g|>|ga_1|>|ga_1a_2|>...>|ga_1a_2... a_k|$ for any $a_1,a_2, ..., a_k\in A^{\pm1}$ such that the word $a_1a_2... a_k$ is freely irreducible. (Here $|g|$ is the distance from $g$ to the identity in the Cayley graph of $G$.) We show

Abdelmalek Abdesselam

We obtain an alternate proof of an injectivity result by Beauville for a map from the moduli space of quartic del Pezzo surfaces to the set of conjugacy classes of certain subgroups of the Cremona group. This amounts to showing that a projective configuration of five distinct unordered points on the line can be reconstructed from its five projective four-poi

Stephan Baier

We prove an estimate for the large sieve with square moduli which improves a recent result of L. Zhao. Our method uses an idea of D. Wolke and some results from Fourier analysis.

Stephan Baier

Extending a method of D. Wolke, we establish a general result on the large sieve with sparse sets S of moduli which are in a sense well-distributed in arithmetic progressions. We then apply our result to the case when S consists of sqares. In this case we obtain an estimate which improves a recent result by L. Zhao.

Brian Hartwig

Let (A,B) and (C,D) denote Leonard pairs on V. We say these pairs are adjacent whenever each basis for V which is standard for (A,B) (resp. (C,D)) is split for (C,D) (resp. (A,B)). Our main results are as follows: Theorem 1. There exists at most 3 mutually adjacent Leonard pairs on V provided the dimension of V is at least 2. Theorem 2. Let (A,B), (C,D), and

Boris Tsirelson

We compare two examples of random dense countable sets, `Brownian local minima' and `unordered uniform infinite sample'. They appear to be identically distributed. A framework for such notions is proposed. In addition, random elements of other singular spaces (especially, reals modulo rationals) are considered.

Luigi Santocanale

A $μ$-algebra is a model of a first order theory that is an extension of the theory of bounded lattices, that comes with pairs of terms $(f,μ_{x}.f)$ where $μ_{x}.f$ is axiomatized as the least prefixed point of $f$, whose axioms are equations or equational implications. Standard $μ$-algebras are complete meaning that their lattice reduct is a complete latti

M. Draief, A. Ganesh

In recent work, Jon Kleinberg considered a small-world network model consisting of a d-dimensional lattice augmented with shortcuts. The probability of a shortcut being present between two points decays as a power of the distance between them. Kleinberg studied the efficiency of greedy routing depending on the value of the power. The results were extended to

Kazumasa Nomura, Paul Terwilliger

Let $K$ denote a field, and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \to V$ and $A^*:V \to V$ that satisfy (i), (ii) below: (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is irreducible tridiagonal and the matrix representing $A^*$ is diagonal.

Thomas Huettemann

If Y is a diagram of spectra indexed by an arbitrary poset C together with a specified sub-poset D, we define the total cofibre Γ(Y) of Y as the strict cofibre of the map from hocolim_D (Y) to hocolim_C (Y). We construct a comparison map from the homotopy limit of Y to a looping of a fibrant replacement of Gamma (Y), and characterise those poset pairs (C,D)

Alison Parker

Let $k$ be an algebraically closed field of characteristic $p$, possibly zero, and $G=q$-$\GL_3(k)$, the quantum group of three by three matrices as defined by Dipper and Donkin. We may also take $G$ to be $\GL_3(k)$. We first determine the extensions between simple $G$-modules for both $G$ and $G_1$, the first Frobneius kernel of $G$. We then determine the

Le Anh Vinh

In this paper we study random walks on the hypergroup of circles in a finite field of prime order p = 4l + 3. We investigating the behavior of random walks on this hypergroup, the equilibrium distribution and the mixing times. We use two different approaches - comparision of Dirichlet forms (geometric bound of eigenvalues), and coupling methods, to show that

Michael G. Eastwood, Nuno M. Romão

We establish a combinatorial formula for homogeneous moments and give some examples where it can be put to use. An application to the statistical mechanics of interacting gauged vortices is discussed.

John S. Caughman, Mark S. MacLean, Paul M. Terwilliger

Let $Y$ denote a $D$-class symmetric association scheme with $D \geq 3$, and suppose $Y$ is almost-bipartite P- and Q-polynomial. Let $x$ denote a vertex of $Y$ and let $T=T(x)$ denote the corresponding Terwilliger algebra. We prove that any irreducible $T$-module $W$ is both thin and dual thin in the sense of Terwilliger. We produce two bases for $W$ and de

Jörgen Backelin

The confluent binomial posets with the atomic function A(n) = max (1,2^(n-2)) are classified. In particular, it is shown that in general there are non-isomorphic intervals of the same length.

Olivier Gues, Guy Metivier, Mark Williams, Kevin Zumbrun

Answering a question left open in \cite{MZ2}, we show for general symmetric hyperbolic boundary problems with constant coefficients, including in particular systems with characteristics of variable multiplicity, that the uniform Lopatinski condition implies strong $L^2$ well-posedness, with no further structural assumptions. The result applies, more generall

Pierre Jammes

We study the small eigenvalues of the Hodge Laplacian on collaping torus bundles with bounded curvature. In the first part of this dissertation, we consider examples of bundles on S^1 and T^2 with homogeneous structure. In the second part, we give a lower bound of the first non-zero eigenvalue of the 1-form Laplacian on principal torus bundles.

Omer Angel, Alexander E Holroyd, James B Martin

Initially a car is placed with probability p at each site of the two-dimensional integer lattice. Each car is equally likely to be East-facing or North-facing, and different sites receive independent assignments. At odd time steps, each North-facing car moves one unit North if there is a vacant site for it to move into. At even time steps, East-facing cars m

Moez Draief

We consider the coupling of a single server queue and a storage model defined as a Queue/Store model in Draief et al. 2004. We establish that if the input variables, arrivals at the queue and store, satisfy large deviations principles and are linked through an {\em exponential tilting} then the output variables (departures from each system) satisfy large dev

A. N. Aliev, Cihan Saçlioğlu

We present a new exact solution for self-dual Abelian gauge fields living on the space of the Kerr-Taub-bolt instanton, which is a generalized example of asymptotically flat instantons with non-self-dual curvature, by constructing the corresponding square integrable harmonic form on this space.

V. Caudrelier

This article is based on recent works done in collaboration with M. Mintchev, E. Ragoucy and P. Sorba. It aims at presenting the latest developments in the subject of factorization for integrable field theories with a reflecting and transmitting impurity.

Biswajit Chakraborty, Sunandan Gangopadhyay, Arindam Ghosh Hazra, Frederik G. Scholtz

Non(anti)commutativity in an open free superstring and also one moving in a background anti-symmetric tensor field is investigated. In both cases, the non(anti)commutativity is shown to be a direct consequence of the non-trivial boundary conditions which, contrary to several approaches, are not treated as constraints. The above non(anti)commutative structure

Shyamoli Chaudhuri

This is the transcript of a talk given at the 3rd Simons Workshop in Mathematics and Physics on July 26, 2005. We review the genesis of the CHL (Chaudhuri-Hockney-Lykken) project, explaining both its phenomenological goals and theoretical justification in light of the known vast proliferation of N=1 string vacua. We explain what a CHL compactification is, re

Charles A. S. Young

The construction of flat currents, and hence conserved non-local charges, for the superstring on AdS_5 x S^5 is generalised. It is shown that such currents exist for sigma-model type actions on all coset (super-)spaces G/H in which, at the level of the Lie algebras, h is the grade-zero subspace of a Zm grading of g. This is true for an essentially unique cho

E. Mendels

The near threshold expansion of Feynman diagrams is derived from their configuration space representation, by performing all x integrations. The general scalar Feynman diagram is considered, with an arbitrary number of external momenta, an arbitrary number of internal lines and an arbitrary number of loops, in n dimensions and all masses may be different. Th

Zurab Berezhiani

We briefly review the concept of a parallel `mirror' world which has the same particle physics as the observable world and couples to the latter by gravity and perhaps other very weak forces. The nucleosynthesis bounds demand that the mirror world should have a smaller temperature than the ordinary one. By this reason its evolution should substantially d

Chong-Xing Yue, Feng Zhang, Li-Na Wang, Li Zhou

In the framework of the littlest Higgs($LH$) model, we study single production of the standard model($SM$) gauge boson $W_{s}^{-}$ and the heavy gauge boson $W_{H}^{-}$ via polarized $e^{-}γ$ collisions. We find that the corrections of the $LH$ model to the cross section $σ(W_{s}^{-})$ might be observed only for the scale parameter $f\leq 1.5TeV$ and the mix

E. Asakawa, O. Brein, S. Kanemura

It is important to explore the Higgs sector in order to identify the model beyond the standard model. We study the charged Higgs production in the $γγ$ mode of a linear collider (LC) with 1000 GeV center of mass energy. We show that the cross sections for the $γγ\to H^\pm W^\mp$ processes can be significantly enhanced in the two Higgs doublet model (THDM). T

V. I. Zhdanov, M. S. Borshch

We study solutions of the relativistic hydrodynamical equations, which describe spherical or cylindrical expansion of ideal fluid. We derived approximate solutions involving two arbitrary functions, which describe asymptotic behavior of expanding fireballs in ultra-relativistic limit. In case of a sufficiently stiff linear equation of state the solution may

Stefan Kretzer, Fredrick I. Olness

We present the CTEQ6HQ parton distribution set which is determined in the general variable flavor number scheme which incorporates heavy flavor mass effects; hence, this set provides advantages for precision observables which are sensitive to charm and bottom quark masses. We describe the analysis procedure, examine the predominant features of the new distri

Stefan Berge, Pavel M. Nadolsky, Fredrick I. Olness, C. -P. Yuan

Analysis of semi-inclusive DIS hadroproduction suggests broadening of transverse momentum distributions at small x below 1E-3 ~ 1E-2 which can be modeled in the Collins-Soper-Sterman formalism by a modification of impact parameter dependent parton densities. We investigate these consequences for the production of electroweak bosons at the Tevatron and the LH

Christian M. Arnesen, Joydip Kundu, Iain W. Stewart

A complete basis for the next-to-next-to leading order heavy-to-light currents in the soft-collinear effective theory is constructed. Reparameterization invariance is imposed by deriving constraint equations. Their solutions give the set of allowed Dirac structures as well as relations between the Wilson coefficients of operators that appear at different ord

Takeshi Fukuyama, Amon Ilakovac, Tatsuru Kikuchi, Stjepan Meljanac

We explicitly show that minimal SUSY SO(10) Higgs-Higgsino mass matrices evaluated by various groups are mutually consistent and correct. We comment on the corresponding results of other authors. We construct one-to-one mappings of our approach to the approaches of other authors.

Raghunath Ratabole

This thesis describes work done by me during my tenure as a Ph.D. student at the Centre for High Energy Physics, Indian Institute of Science, Bangalore. Chapter 1 is a brief introduction to QCD. In Chapter 2, we formulate QCD in the large-$N_{c}$ and strong transverse coupling limits, and then exactly integrate out all the gauge degrees of freedom to obtain

The BABAR Collaboration, B. Aubert

We present preliminary measurements of branching fractions for the charmless two-body decays B0 -> pi+pi- and K+pi-, and a search for B0 -> K+K- using a data sample of approximately 227 million BBbar decays. Signal yields are extracted with a multi-dimensional maximum likelihood fit, and the efficiency is corrected for the effects of final-state radiation. W

J. E. Campagne, A. Cazes, the OPERA Collaboration

The poster presented the OPERA experiment and the SPL-Fréjus neutrino super beam project. OPERA (1) is an experiment willing to see tau neutrino appearance. The detector is described in section 2 and the expected results are given. Section 3 is devoted to the SPL neutrino super beam (2), which search for $θ\_{13}$. An optimisation of the SPL energy is propos

S. Balestra, S. Cecchini, F. Fabbri, G. Giacomelli

The search for magnetic monopoles in the cosmic radiation remains one of the main aims of non-accelerator particle astrophysics. Experiments at high altitude allow lower mass thresholds with respect to detectors at sea level or underground. The SLIM experiment is a large array of nuclear track detectors at the Chacaltaya High Altitude Laboratory (5290 m a.s.

Styrmir Sigurjonsson, Young-Han Kim

We extend Shannon's result on the capacity of channels with state information to multiple user channels. More specifically, we characterize the capacity (region) of degraded broadcast channels and physically degraded relay channels where the channel state information is causally available at the transmitters. We also obtain inner and outer bounds on the

Rohit Negi, Arjunan Rajeswaran

Throughput capacity is a critical parameter for the design and evaluation of ad-hoc wireless networks. Consider n identical randomly located nodes, on a unit area, forming an ad-hoc wireless network. Assuming a fixed per node transmission capability of T bits per second at a fixed range, it has been shown that the uniform throughput capacity per node r(n) is

Kai Chen, Hoi-Kwong Lo

We propose a wide class of distillation schemes for multi-partite entangled states that are CSS-states. Our proposal provides not only superior efficiency, but also new insights on the connection between CSS-states and bipartite graph states. We then consider the applications of our distillation schemes for two cryptographic tasks--namely, (a) conference key

Dana Porrat, Urbashi Mitra

The acquisition, or synchronization, of the multipath profile for an ultrawideband pulse position modulation (PPM) communication systems is considered. Synchronization is critical for the proper operation of PPM based For the multipath channel, it is assumed that channel gains are known, but path delays are unknown. In the limit of large bandwidth, W, it is

Stergos D. Afantenos, Vangelis Karkaletsis, Panagiotis Stamatopoulos

We present an approach for summarization from multiple documents which report on events that evolve through time, taking into account the different document sources. We distinguish the evolution of an event into linear and non-linear. According to our approach, each document is represented by a collection of messages which are then used in order to instantia

Susana Munoz-Hernandez, Claudio Vaucheret

Incomplete information is a problem in many aspects of actual environments. Furthermore, in many sceneries the knowledge is not represented in a crisp way. It is common to find fuzzy concepts or problems with some level of uncertainty. There are not many practical systems which handle fuzziness and uncertainty and the few examples that we can find are used b

Sariel Har-Peled, Manor Mendel

We present a near linear time algorithm for constructing hierarchical nets in finite metric spaces with constant doubling dimension. This data-structure is then applied to obtain improved algorithms for the following problems: Approximate nearest neighbor search, well-separated pair decomposition, compact representation scheme, doubling measure, and computat

Zuxin Ye, W. D. Si, Qiang Li, Y. Hu

Nano-scaled substrate surface roughness is shown to strongly influence the critical current density Jc in YBCO films made by pulse-laser-deposition on the crystalline LaAlO3 substrates consisting of two separate twin-free and twin-rich regions. The nano-scaled corrugated surface was created in the twin-rich region during the deposition process. Using magneto

Cary L. Pint, Michael W. Roth

We present the results of molecular dynamics simulations of odd alkane impurities present within the hexane (even alkane) monolayer. We simulate various temperatures at ca. 3%, 5%, 10%, and 15% impurities of propane, pentane, heptane, nonane, and undecane, each having a low-temperature solid phase belonging to a different space group as compared to hexane, t

Craig E. Maloney, Daniel J. Lacks

Energy landscape mappings are performed for two different molecular systems under mechanical loads. Barrier heights are observed to scale as $ΔU\simδ^{3/2}$, where $δ$ is a residual load. Catastrophe theory predicts that this scaling should arise for vanishing $δ$, however, this region is irrelevant in physical processes at finite temperature because thermal

Abhik Basu

We elucidate the universal properties of the nonequilibrium steady states (NESS) in a driven symmetric binary fluid mixture, an example of active advection, in its miscible phase. We use the symmetries of the equations of motion to establish the appropriate form of the structure functions which characterise the statistical properties of the NESS of a driven

H. Hartmann, K. Berggold, S. Jodlauk, I. Klassen

We present a study of the magnetoresistance, the specific heat and the magnetocaloric effect of equiatomic $RET$Mg intermetallics with $RE = {\rm La}$, Eu, Gd, Yb and $T = {\rm Ag}$, Au and of GdAuIn. Depending on the composition these compounds are paramagnetic ($RE = {\rm La}$, Yb) or they order either ferro- or antiferromagnetically with transition temper

Robert E. Rudd, Jeremy Q. Broughton

Coarse-grained molecular dynamics (CGMD) is a technique developed as a concurrent multiscale model that couples conventional molecular dynamics (MD) to a more coarse-grained description of the periphery. The coarse-grained regions are modeled on a mesh in a formulation that generalizes conventional finite element modeling (FEM) of continuum elasticity. CGMD

A. Ossipov, V. E. Kravtsov

A new super-symmetric representation for quantum disordered systems is derived. This representation is exact and is dual to that of the nonlinear sigma-model. The new formalism is tested by calculating the distribution of wave function amplitudes in the 1d Anderson model. The deviation from the distribution found for a thick wire is detected near the band ce

Wei Gan, Dan Wu, Zhen Zhang, Hong-fei Wang

Analysis of SFG vibrational spectra of OH stretching bands in four experimental configurations shows that orientational motion of water molecule at air/water interface is libratory within a limited angular range. This picture is significantly different from the previous conclusion that the interfacial water molecule orientation varies over a broad range with

J. Rissler, R. M. Noack, S. R. White

Quantum information theory gives rise to a straightforward definition of the interaction of electrons $I_{p,q}$ in two orbitals $p$, $q$ for a given many-body wave function. A convenient way to calculate the von Neumann entropies needed is presented in this work, and the orbital interaction $I_{p,q}$ is successfully tested for different types of chemical bon

V. Blavatska, M. Dudka, R. Folk, Yu. Holovatch

We study an influence of the quenched extended defects on the critical dynamics of the d=3-dimensional systems with m-component non-conserved order parameter (model A dynamics). Considering defects to be correlated in ε_d dimensions and randomly distributed in d-ε_d dimensions we obtain reliable numerical values for the critical exponents governing divergenc

Amandine Aftalion, Xavier Blanc, Francis Nier

We study the vortex distribution of the wave functions minimizing the Gross Pitaevskii energy for a fast rotating condensate in the Lowest Landau Level (LLL): we prove that the minimizer cannot have a finite number of zeroes thus the lattice is infinite, but not uniform. This uses the explicit expression of the projector onto the LLL. We also show that any s

Arup Banerjee, Manoranjan P. Singh

We study the properties of the vortex state of a trapped Bose gas in the large-gas-parameter regime. To test validity of the Gross-Pitaevskii theory in this regime for the vortex states we compare the results of the Gross-Pitaevskii and the modified Gross-Pitaevskii calculations for the total energy, the chemical potential, the density profile and the freque

M. Ferrier, A. Yu. Kasumov, V. Agache, L. Buchaillot

We have altered the superconductivity of a suspended rope of single walled carbon nanotubes, by coating it with organic polymers. Upon coating, the normal state resistance of the rope changes by less than 20 percent. But superconductivity, which on the bare rope shows up as a substantial resistance decrease below 300 mK, is gradualy suppressed. We correlate

Hai-Hu Wen, Lei Shan, Xiao-Gang Wen, Yue Wang

Through the measurements of magnetic field dependence of specific heat in $La_{2-x}Sr_xCuO_4$ in zero temperature limit, we determined the nodal slope $v_Δ$ of the quasiparticle gap. It is found that $v_Δ$ has a very similar doping dependence of the pseudogap temperature $T^*$ or value $Δ_p$. Meanwhile the virtual maximum gap at ($π,0$) derived from $v_Δ$ is

H. Fu, E. Zaremba

We consider a rapidly rotating Bose-condensed gas in an harmonic plus quartic trap. At sufficiently high rotation rates the condensate acquires an annular geometry with the superposition of a vortex lattice. With increasing rotation rate the lattice evolves into a single ring of vortices. Of interest is the transition from this state to the giant vortex stat

Debasish Chaudhuri, Surajit Sengupta

We investigate by direct numerical solution of appropriate renormalization flow equations, the validity of a recent dislocation unbinding theory for laser induced freezing/melting in two dimensions. The bare elastic moduli and dislocation fugacities which are inputs to the flow equations are obtained for three different 2-d systems (hard disk, inverse $12^{t

Debasish Chaudhuri, Surajit Sengupta

Starting from a commensurate triangular thin solid strip, confined within two hard structureless walls, a stretch along its length introduces a rectangular distortion. Beyond a critical strain the solid fails through nucleation of "smectic"-like bands. We show using computer simulations and simple density functional based arguments, how a solid-smect

Ashok Razdan

Specific heat is calculated using Tsallis statistics. It is observed that it is possible to explain some low temperature specific heat properties of glasses using non-extensive approach. A similarity between temperature dependence of non-extensive specific heat and fractal specific heat is also discussed.

Satoshi Morita, Yukiyasu Ozeki, Hidetoshi Nishimori

The gauge theory for random spin systems is extended to quantum spin glasses to derive a number of exact and/or rigorous results. The transverse Ising model and the quantum gauge glass are shown to be gauge invariant. For these models, an identity is proved that the expectation value of the gauge invariant operator in the ferromagnetic limit is equal to the

Sayani Majumdar, Himadri S. Majumdar, Reino Laiho, Ronald Osterbacka

We report giant magnetoresistance up to 150 percent at low bias current and low temperature as well as room temperature magnetoresistance in polymeric spin-valves having the structure LSMO/conjugated polymer/Co. The conjugated polymers, regiorandom and regioregular P3HT were used as the spacer materials. We observed an asymmetric bias voltage dependence of d

I. Pallecchi, V. Ferrando, E. Galleani D'Agliano, D. Marre'

In this paper we present normal state magnetoresistivity data of magnesium diboride epitaxial thin films with different levels of disorder, measured at 42K in magnetic fields up to 45 Tesla. Disorder was introduced in a controlled way either by means of neutron irradiation or by carbon doping. From a quantitative analysis of the magnetoresistivity curves wit

G. C. Marques, V. S. Bagnato, S. R. Muniz, D. Spehler

In this paper we extend previous hydrodynamic equations, governing the motion of Bose-Einstein-condensed fluids, to include temperature effects. This allows us to analyze some differences between a normal fluid and a Bose-Einstein-condensed one. We show that, in close analogy with superfluid He-4, a Bose-Einstein-condensed fluid exhibits the mechanocaloric a

Y. V. Sushko, S. O. Leontsev, O. B. Korneta, A. Kawamoto

Static susceptibility of kappa-[(BEDT-TTF)1-x(BEDSe-TTF)x]2Cu[N(CN)2]Br alloys with the BEDSe-TTF content near the border-line of ambient pressure superconductivity (x~0.3) has been measured as a function of temperature, magnetic field, and pressure. A non-monotonic pressure dependence is observed for both the superconducting critical temperature and superco

Kazuhiko Kuroki, Seiichiro Onari, Yukio Tanaka, Ryotaro Arita

Motivated by recent experiments and band calculation results, we investigate the possibility of superconductivity originating from the $a_{1g}$ band of Na$_x$CoO$_2\cdot y$H$_2$O assuming the absence of $e_g'$ pockets. We adopt a single band $U$-$V$ model that takes into account the local minimum of the $a_{1g}$ band dispersion at the $Γ$ point. Using th

Pio Baettig, Claude Ederer, Nicola A. Spaldin

We present results of an {\it ab initio} density functional theory study of three bismuth-based multiferroics, BiFeO$_{3}$, Bi$_{2}$FeCrO$_{6}$, and BiCrO$_{3}$. We disuss differences in the crystal and electronic structure of the three systems, and we show that the application of the LDA+$U$ method is essential to obtain realistic structural parameters for

L. Levrel, A. C. Maggs

We consider Monte Carlo algorithms for the simulation of charged lattice gases with purely local dynamics. We study the mobility of particles as a function of temperature and show that the poor mobility of particles at low temperatures is due to "trails" or "strings" left behind after particle motion. We introduce modified updates which subst

C. Mora, A. Komnik, R. Egger, A. O. Gogolin

The four-body problem for an interacting two-species Fermi gas is solved analytically in a confined quasi-one-dimensional geometry, where the two-body atom-atom scattering length $a_{aa}$ displays a confinement-induced resonance. We compute the dimer-dimer scattering length $a_{dd}$, and show that this quantity completely determines the many-body solution of

Florian Schuetz, Lorenz Bartosch, Peter Kopietz

We develop a new formulation of the functional renormalization group (RG) for interacting fermions. Our approach unifies the purely fermionic formulation based on the Grassmannian functional integral, which has been used in recent years by many authors, with the traditional Wilsonian RG approach to quantum systems pioneered by Hertz [Phys. Rev. B 14, 1165 (1

M. V. Mostovoy, F. M. Marchetti, B. D. Simons, P. B. Littlewood

We study effects of nonmagnetic impurities on the competition between the superconducting and electron-hole pairing. We show that disorder can result in coexistence of these two types of ordering in a uniform state, even when in clean materials they are mutually exclusive.

Jose Franco, Guillermo Garcia-Segura, Stan Kurtz

The dynamical evolution of HII regions with and without stellar motion in dense, structured molecular clouds is studied. Clouds are modeled in hydrostatic equilibrium, with gaussian central cores and external halos that obey r**-2 and r**-3 density power laws. The cloud gravity is included as a time-independent, external force. Stellar velocities of 0, 2, 8,

The Pierre Auger Collaboration

The surface detector of the Pierre Auger Observatory is a 1600 water Cherenkov tank array on a triangular 1.5 km grid. The signals from each tank are read out using three 9'' photomultipliers and processed at a sampling frequency of 40 MHz, from which a local digital trigger efficiently selects shower candidates. GPS signals are used for time synchro

D. Allard, E. Parizot, A. V. Olinto, E. Khan

We consider the stochastic propagation of high-energy protons and nuclei in the cosmological microwave and infrared backgrounds, using revised photonuclear cross-sections and following primary and secondary nuclei in the full 2D nuclear chart. We confirm earlier results showing that the high-energy data can be fit with a pure proton extragalactic cosmic ray

Milos Milosavljevic, Ehud Nakar

Models for the synchrotron emission of gamma-ray burst afterglows suggest that the magnetic field is generated in the shock wave that forms as relativistic ejecta plow through the circum-burst medium. Transverse Weibel instability efficiently generates magnetic fields near equipartition with the post-shock energy density. The detailed saturated state of the

Peter Yoachim, Julianne J. Dalcanton

We analyze the global structure of 34 late-type, edge-on, undisturbed, disk galaxies spanning a wide range of mass. We measure structural parameters for the galaxies using two-dimensional least-squares fitting to our $R$-band photometry. The fits require both a thick and a thin disk to adequately fit the data. The thick disks have larger scale heights and lo

Tina Kahniashvili

In present talk I show that primordial helical turbulence produced during a first-order phase transition induces circularly polarized cosmological gravitational waves (GWs). The degree of polarization as well as the characteristic frequency and the amplitude of these GWs depend crucially on phase-transition model of primordial turbulence. I present a brief d

J. M. Rathborne, J. M. Jackson, E. T. Chambers, R. Simon

We present a multiwavelength study of the infrared dark cloud MSXDC G034.43+00.24. Dust emission, traced by millimeter/submillimeter images obtained with the IRAM, JCMT, and CSO telescopes, reveals three compact cores within this infrared dark cloud with masses of 170--800 Msun and sizes < 0.5 pc. Spitzer 3.6-8.0 um images show slightly extended emission tow

Nitya Kallivayalil, Roeland P. van der Marel, Charles Alcock, Tim Axelrod

We present a measurement of the systemic proper motion of the Large Magellanic Cloud (LMC) from astrometry with the High Resolution Camera (HRC) of the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). We observed LMC fields centered on 21 background QSOs that were discovered from their optical variability in the MACHO database. The QSOs

E. Hatziminaoglou, P. Cassata, G. Rodighiero, I. Perez-Fournon

We present results of a morphological analysis of a small subset of the Spitzer Wide-area InfraRed Extragalactic survey (SWIRE) galaxy population. The analysis is based on public ACS data taken inside the SWIRE N1 field, which are the deepest optical high-resolution imaging available within the SWIRE fields as of today. Our reference sample includes 156 gala

P. Eggenberger, A. Maeder, G. Meynet

We examine the generation of a magnetic field in a solar-like star and its effects on the internal distribution of the angular velocity. We suggest that the evolution of a rotating star with magnetic fields leads to an equilibrium value of the differential rotation. This equilibrium is determined by the magnetic coupling, which favours a constant rotation pr

C. Angulo, E. Casarejos, M. Couder, P. Demaret

The WMAP satellite, devoted to the observations of the anisotropies of the Cosmic Microwave Background (CMB) radiation, has recently provided a determination of the baryonic density of the Universe with unprecedented precision. Using this, Big Bang Nucleosynthesis (BBN) calculations predict a primordial 7Li abundance which is a factor 2-3 higher than that ob

Laure Barrière-Fouchet, Jean-François Gonzalez, James R. Murray, Robin J. Humble

We present the results of a three dimensional, locally isothermal, non-self-gravitating SPH code which models protoplanetary disks with two fluids: gas and dust. We ran simulations of a 1 Msun star surrounded by a 0.01 Msun disk comprising 99% gas and 1% dust in mass and extending from 0.5 to ~300 AU. The grain size ranges from 0.001 mm to 10 m for the low r

James V. Lindesay, H. Pierre Noyes

Examining the reverse evolution of the universe from the present, long before reaching Planck density dynamics one expects major modifications from the de-coherent thermal equations of state, suggesting a prior phase that has macroscopic coherence properties. The assumption that the phase transition occurs during the radiation dominated epoch, and that zero-

D. B. Guenther, T. Kallinger, P. Reegen, W. W. Weiss

Eight consecutive low-frequency radial p-modes are identified in the G0 IV star eta Bootis based on 27 days of ultraprecise rapid photometry obtained by the MOST (Microvariability & Oscillations of Stars) satellite. The MOST data extend smoothly to lower overtones the sequence of radial p-modes reported in earlier groundbased spectroscopy by other groups. Th

L. M. Dray, J. E. Dale, M. E. Beer, R. Napiwotzki

We present numerical simulations of the runaway fractions expected amongst O and Wolf-Rayet star populations resulting from stars ejected from binaries by the supernova of the companion. Observationally the runaway fraction for both types of star is similar, prompting the explanation that close dynamical interactions are the main cause of these high-velocity

R. Valdettaro, F. Palla, J. Brand, R. Cesaroni

We report the results of a multi-epoch survey of water maser observations at 22.2 GHz with the Medicina radiotelescope from 44 bright rimmed clouds (BRCs) of the northern hemisphere identified by Sugitani et al. (1989) as potential sites of star formation. The data span 16 years of observations and allow to draw conclusions about the maser detection rate in

Shinji Horiuchi, David L. Meier, Robert A. Preston, Steven J. Tingay

We present the results of a VLBI Space Observatory Programme (VSOP) observation of the subparsec structure in Centaurus A at 4.9 GHz. Owing to its proximity, our Centaurus A space-VLBI image is one of the highest spatial resolution images of an AGN ever made -- 0.01 pc per beam. The elongated core region is resolved into several components over 10 milli-arcs

Andrew Cumming, Jared Macbeth, J. J. M. in &#39;t Zand, Dany Page

Superbursts are very energetic Type I X-ray bursts discovered in recent years by long term monitoring of X-ray bursters, believed to be due to unstable ignition of carbon in the deep ocean of the neutron star. A number of &#34;intermediate duration&#34; bursts have also been observed, probably associated with ignition of a thick helium layer. We investigate

S. D. Huegelmeyer, S. Dreizler, K. Werner, J. Krzesinski

We present a model atmosphere analysis of ten new DO white dwarfs and five new PG 1159 stars discovered in the Sloan Digital Sky Survey DR1, DR2 and DR3. This is a significant increase in the number of known DOs and PG 1159 stars. DO white dwarfs are situated on the white dwarf cooling sequence from the upper hot end Teff ~ 120 000 K down to the DB gap (Teff

J. Bagchi, Florence Durret, Gastao B. Lima Neto, Surajit Paul

We describe multiwavelength optical, X-ray and radio evidences of energetic mergers in southern galaxy cluster Abell 3376 (A3376, redshift z=0.046, X-ray luminosity $ \rm L_{X}(0.1-2.4 keV)= 2.48 \times 10^{44} erg s^{-1}$). Here we report the rare discovery of gigantic, Mpc-scale non-thermal radio structures (`radio-arcs&#39;), shaped like a pair of bow-sho

Wojciech Kaminski, Jerzy Lewandowski, Marcin Bobienski

We are concerned with the issue of quantization of a scalar field in a diffeomorphism invariant manner. We apply the method used in Loop Quantum Gravity. It relies on the specific choice of scalar field variables referred to as the polymer variables. The quantization, in our formulation, amounts to introducing the `quantum&#39; polymer *-star algebra and loo

Diego Conti, Simon Salamon

We study the intrinsic geometry of hypersurfaces in Calabi-Yau manifolds of real dimension 6 and, more generally, SU(2)-structures on 5-manifolds defined by a generalized Killing spinor. We prove that in the real analytic case, such a 5-manifold can be isometrically embedded as a hypersurface in a Calabi-Yau manifold in a natural way. We classify nilmanifold

Dietrich Bodeker

QCD plasma instabilities, caused by an anisotropic momentum distributions of the particles in the plasma, are likely to play an important role in thermalization in heavy ion collisions. We consider plasmas with two different components of particles, one strongly anisotropic and one isotropic or nearly isotropic. The isotropic component does not eliminate ins

Rafael Diaz, Eddy Pariguan

We introduce perturbative Feynman integrals in the context of q-calculus generalizing the Gaussian q-integrals introduced by Diaz and Teruel. We provide analytic as well as combinatorial interpretations for the Feynman-Jackson integrals.

P. Koroteev, A. V. Zayakin

We describe correlations functions of topological quantum mechanics (TQM) in terms of Morse theory. We review the basics of topological field theories and discuss geometric and algebraic interpretations of TQM. We prove that correlators in TQM can be expressed via intersection numbers of certain submanifolds of the target space with paths of steepest descent

Katherine E. McGowan, Silvia Zane, Mark Cropper, W. Thomas Vestrand

We report on the first XMM-Newton observation of the Vela-like pulsar PSR B2334+61. Spectral analysis reveals soft X-ray emission, with the bulk of the photons emitted at energies below ~1.5 keV. We find that the spectrum has a thermal origin and is well-fitted with either a blackbody or a magnetized, pure H atmospheric model. In the latter case, for a neutr