arXiv papers from March 2004

M. Sharif

The energy and momentum for different cosmological models using various prescriptions are evaluated. In particular, we have focused our attention on the energy and momentum for gravitational waves and discuss the results. It is concluded that there are methods which can provide physically acceptable results.

J. Melbourne, P. Guhathakurta

We present 3 methods for measuring the Galactic dust extinction law slope R_V and a method for quantifying fine structure in dust clouds in the direction of differentially-reddened globular clusters. We apply these methods to the low- latitude globular cluster NGC4833 which displays variable extinction/reddening about a mean <A_V> ~ 1. A set of Monte Carlo s

Shantanu Basu, Glenn E. Ciolek

We extend our earlier work on ambipolar diffusion induced formation of protostellar cores in isothermal sheet-like magnetic interstellar clouds, by studying nonaxisymmetric collapse for the physically interesting regime of magnetically critical and supercritical model clouds ($\mui \geq 1$, where $\mui$ is the initial mass-to-magnetic flux ratio in units of

David Kruml, Pedro Resende

The functor Max of Mulvey assigns to each unital C*-algebra A the unital involutive quantale Max A of closed linear subspaces of A, and it has been remarked that it classifies unital C*-algebras up to *-isomorphism. In this paper we provide a proof of this and of the stronger fact that for every isomorphism u : Max A -> Max B of unital involutive quantales t

G. D. Fuchs, N. C. Emley, I. N. Krivorotov, P. M. Braganca

We report measurements of magnetic switching and steady-state magnetic precession driven by spin-polarized currents in nanoscale magnetic tunnel junctions with low-resistance, < 5 Ohm-micron-squared, barriers. The current densities required for magnetic switching are similar to values for all-metallic spin-valve devices. In the tunnel junctions, spin-transfe

J. M. Wrobel, M. A. Garrett, J. J. Condon, R. Morganti

The NRAO Very Long Baseline Array (VLBA) was used at 1.4 GHz to image 20 compact sources in the inner 1-degree radius of the Spitzer VLA First-Look Survey. Twelve sources were detected with the VLBA, with peak flux densities above 2 mJy at 9-mas resolution. The positions of these VLBA detections have been measured in the International Celestial Reference Fra

Brent Tully, Roya Mohayaee

The observed infall of galaxies into the Virgo Cluster puts strong constraints on the mass of the cluster. A non-parametric fully non-linear description of the infall can be made with orbit reconstructions based on Numerical Action Methods. The mass of the cluster is determined to be $1.2 \times 10^{15} M_{\odot}$. The mass-to-light ratio for the cluster is

N. C. Giebink, E. R. Johnson, S. R. Saucedo, E. W. Miles

We first report that, for planar nematic MBBA, the electroconvection threshold voltage has a nonmonotonic temperature dependence, with a well-defined minimum, and a slope of about 0.12 V/degree near room temperature. Motivated by this observation, we have designed an experiment in which a weak continuous-wave absorbed laser beam with a diameter comparable to

Axel Krause

We describe how 4d de Sitter vacua might emerge from 11d heterotic M-theory. Non-perturbative effects and $G$-fluxes play a crucial role leading to vacua with F-term supersymmetry breaking and a positive energy density. Charged scalar matter fields are no longer massless in these vacua thus solving one of the problems of the heterotic string. Moreover, inter

J. Christopher Howk, Arthur M. Wolfe, Jason X. Prochaska

We discuss interstellar temperature determinations using the excitation equilibrium of the ^2P levels of Si II and C II. We show how observations of the ^2P_3/2 fine structure levels of Si II and C II (which have significantly different excitation energies, corresponding to ~413 and 92 K, respectively) can be used to limit gas kinetic temperatures. We apply

C. Pinkenburg

The PHENIX experiment at RHIC should be sensitive to decays of the the anti--pentaquark $\bar{\Theta}^-$ via the K$^-$ $\bar{n}$ channel. Charged kaons can be identified using the standard tracking and time of flight up to a momentum of 1.5 GeV/c. Anti--neutron candidates are detected via their annihilation signal in the highly segmented electromagnetic calo

N. J. Turner, H. W. Yorke, A. Socrates, O. M. Blaes

Spectroscopic studies indicate that gas in the photospheres of young O stars moves at speeds up to the sound speed. We show, using two-dimensional radiation MHD calculations and results from a local linear analysis, that the motions may be due to photon bubble instability if young O stars have magnetic fields.

Paul Martini, Luis C. Ho

We present velocity dispersion measurements of 14 globular clusters in NGC 5128 (Centarus A) obtained with the MIKE echelle spectrograph on the 6.5m Magellan Clay telescope. These clusters are among the most luminous globular clusters in NGC 5128 and have velocity dispersions comparable to the most massive clusters known in the Local Group, ranging from 10 -

M. Rodriguez-Achach, G. Perez, H. Cerdeira

The effects of quantum and thermal corrections on the dynamics of a damped nonlinearly kicked harmonic oscillator are studied. This is done via the Quantum Langevin Equation formalism working on a truncated moment expansion of the density matrix of the system. We find that the type of bifurcations present in the system change upon quantization and that chaot

Geoffrey C. Bower, Heino Falcke, Robeson M. Herrnstein, Jun-Hui Zhao

We have detected the intrinsic size of Sagittarius A*, the Galactic Center radio source associated with a supermassive black hole, showing that the short-wavelength radio emission arises from very near the event horizon of the black hole. Radio observations with the Very Long Baseline Array show that the source has a size of $24 \pm 2$ Schwarzschild radii at

Andre Diatta

A result from Gromov ensures the existence of a contact structure on any connected non-compact odd dimensional Lie group. But in general such structures are not invariant under left translations of the Lie group. The problem of finding which Lie groups admit a left invariant contact structure (contact Lie groups), is then still open. While Lie groups with le

Konstantinos Zoubos

We apply our previous work on Green's functions for the four-dimensional quaternionic Taub-NUT manifold to obtain a scalar two-point function on the homogeneously squashed three-sphere (otherwise known as the Berger sphere), which lies at its conformal infinity. Using basic notions from conformal geometry and the theory of boundary value problems, in particu

H. Davoudiasl, J. L. Hewett, B. Lillie, T. G. Rizzo

We examine a warped Higgsless $SU(2)_L\times SU(2)_R\times U(1)_{B-L}$ model in 5--$d$ with IR(TeV)--brane kinetic terms. It is shown that adding a brane term for the $U(1)_{B-L}$ gauge field does not affect the scale ($\sim 2-3$ TeV) where perturbative unitarity in $W_L^+ W_L^- \to W_L^+ W_L^-$ is violated. This term could, however, enhance the agreement of

Frank Quinn

The main result is that an s-cobordism (topological or smooth) of 4-manifolds has a product structure outside a ``core'' sub s-cobordism. These cores are arranged to have quite a bit of structure, for example they are smooth and abstractly (forgetting boundary structure) diffeomorphic to a standard neighborhood of a 1-complex. The decomposition is highly non

Yoav Achiman

In the framework of a SUSY SO(10) model a phase is generated spontaneously for the B-L breaking VEV. Fitting this phase to the observed CP violating K,B decays all other CP breaking effects are uniquely predicted. In particular, the amount of Leptogenesis can be explicitly calculated and found to be in the right range and sign for the BAU.

K. E. Belle, N. Sanghi, S. B. Howell, J. B. Holberg

Circumbinary (CB) disks have been proposed as a mechanism to extract orbital angular momentum from cataclysmic variables (CVs) during their evolution. As proposed by Taam & Spruit, these disks extend outwards to several a.u. and should be detected observationally via their infrared flux or by absorption lines in the ultraviolet spectra of the CV. We have mad

Arsen Elkin

Let $K$ be a field of characteristic $p \neq 2$, and let $f(x)$ be a sextic polynomial irreducible over $K$ with no repeated roots, whose Galois group is isomorphic to $\A_5$. If the jacobian $J(C)$ of the hyperelliptic curve $C:y^2=f(x)$ admits real multiplication over the ground field from an order of a real quadratic field $D$, then either its endomorphis

S. L. Dubovsky

We consider the infrared modification of gravity by ghost condensate. Naively, in this scenario one expects sizeable modification of gravity at distances of order 1000 km, provided that the characteristic time scale of the theory is of the order of the Hubble time. However, we argue that this is not the case. The main physical reason for the conspiracy is a

A. Mortensen, J. J. T. Lindballe, I. S. Jensen, P. Staanum

Using a technique based on production of ion Coulomb crystals, the isotope shifts of the 4s2 1S0 -> 4s5p 1P1 transition for all naturally occurring isotopes of calcium as well as the hyperfine splitting of the 4s5p 1P1 state in Ca-43 have been measured. The field shift and specific mass shift coefficients as well as the hyperfine structure constants for Ca-4

D. Schurig, D. R. Smith

We examine the Seidel aberrations of thin spherical lenses composed of media with refractive index not restricted to be positive. We find that consideration of this expanded parameter space allows reduction or elimination of more aberrations than is possible with only positive index media. In particular we find that spherical lenses possessing real aplanatic

Alberto Abbondandolo, Pietro Majer

Let f be a smooth Morse function on an infinite dimensional separable Hilbert manifold, all of whose critical points have infinite Morse index and co-index. For any critical point x choose an integer a(x) arbitrarily. Then there exists a Riemannian structure on M such that the corresponding gradient flow of f has the following property: for any pair of criti

Jan Manschot, Arne Brataas, Gerrit E. W. Bauer

The current induced magnetization reversal in nanoscale spin valves is a potential alternative to magnetic field switching in magnetic memory devices. We show that the critical switching current can be decreased by an order of magnitude by strategically distributing the resistances in the magnetically active region of the spin valve. In addition, we simulate

O. Cakir, A. Yilmaz, S. Sultansoy

We analyzed the potential of the LC with $\sqrt{s}=0.5$ TeV, LC$\times$LHC based ep collider with $\sqrt{s}=3.74$ TeV and LHC with $\sqrt{s}=14$ TeV to search for excited electrons through transition magnetic type couplings with gauge bosons. The $e^{\star}\to e\gamma$ signal and corresponding backgrounds are studied in detail.

R. R. Gal, L. M. Lubin

We present spectroscopic confirmation of the Cl 1604 supercluster at z~0.9. Originally detected as two individual clusters, Cl 1604+4304 at z = 0.90 and Cl 1604+4321 at z = 0.92, which are closely separated in both redshift and sky position, subsequent imaging revealed a complex of red galaxies bridging the two clusters, suggesting that the region contained

Julia Gordon

It is shown that the values of Harish-Chandra distribution characters on definable compact subsets of the set of topologically unipotent elements of symplectic or special orthogonal p-adic groups can be expressed as the trace of Frobenius action on virtual Chow motives. The result is restricted to a class of depth-zero representations that can be obtained by

K. Kundu

IN-DNLS, considered here is a countable infinite set of coupled one dimensional nonlinear ordinary differential difference equations with a tunable nonlinearity parameter, $\nu$. This equation is continuous in time and discrete in space with lattice translational invariance and has global gauge invariance. When $\nu = 0$, it reduces to the famous integrable

Mike Develin, Jeremy L. Martin, Victor Reiner

K. Ding studied a class of Schubert varieties X_\lambda in type A partial flag manifolds, corresponding to integer partitions \lambda and in bijection with dominant permutations. He observed that the Schubert cell structure of X_\lambda is indexed by maximal rook placements on the Ferrers board B_\lambda, and that the integral cohomology groups H^*(X_\lambda

Stuart Wyithe, Abraham Loeb

The observed number counts of quasars may be explained either by long-lived activity within rare massive hosts, or by short-lived activity within smaller, more common hosts. It has been argued that quasar lifetimes may therefore be inferred from their clustering length, which determines the typical mass of the quasar host. Here we point out that the relation

Punyabrata Pradhan, Apoorva Nagar

We study the probability distribution of residence time, $T$, of the sand grains in the one dimensional abelian sandpile model on a lattice of $L$ sites, for $T<<L^2$ and $T>>L^2$. The distribution function decays as $\exp(-\frac{K_LT}{L^2})$. We numerically calculate the coefficient $K_L$ for the value of $L$ upto 150 . Interestingly the distribution functi

R. M. Green, J. Losonczy

We give a simple necessary and sufficient condition for a Schubert variety $X_w$ to be smooth when $w$ is a freely braided element of a simply laced Weyl group; such elements were introduced by the authors in a previous work (math.CO/0301104). This generalizes in one direction a result of Fan concerning varieties indexed by short-braid avoiding elements. We

Chad Schoen

An example is given in which specialization is not injective.

Will Loinaz, Naotoshi Okamura, Saifuddin Rayyan, Tatsu Takeuchi

In previous studies we found that models with flavor-universal suppression of the neutrino-gauge couplings are compatible with NuTeV and Z-pole data. In this paper we expand our analysis to obtain constraints on flavor-dependent coupling suppression by including lepton universality data from W, tau, pi and K decays in fits to model parameters. We find that t

Dominic Brecher, Kazuyuki Furuuchi, Henry Ling, Mark Van Raamsdonk

We develop a formalism that allows us to write actions for multiple D-branes with manifest general covariance. While the matrix coordinates of the D-branes have a complicated transformation law under coordinate transformations, we find that these may be promoted to (redundant) matrix fields on the transverse space with a simple covariant transformation law.

Volker Braun, Sakura Schafer-Nameki

We present an encompassing treatment of D-brane charges in supersymmetric SO(3) WZW models. There are two distinct supersymmetric CFTs at each even level: the standard bosonic SO(3) modular invariant tensored with free fermions, as well as a novel twisted model. We calculate the relevant twisted K-theories and find complete agreement with the CFT analysis of

Benjin Xuan

In this paper, we consider the existence and non-existence of non-trivial solution to a Brezis-Nirenberg type problem with singular weights. First, we obtain a compact imbedding theorem which is an extension of the classical Rellich-Kondrachov compact imbedding theorem, and consider the corresponding eigenvalue problem. Secondly, we deduce a Pohozaev type id

M. S. Oey, G. Garcia-Segura

High ambient interstellar pressure is suggested as a possible factor to explain the ubiquitous observed growth-rate discrepancy for supernova-driven superbubbles and stellar wind bubbles. Pressures of P/k ~ 1e5 cm-3 K are plausible for regions with high star formation rates, and these values are intermediate between the estimated Galactic mid-plane pressure

R. C. Bohlin, R. L. Gilliland

The Space Telescope Imaging Spectrograph has measured the absolute flux for Vega from 0.17-1.01 microns on the HST White Dwarf flux scale. These data are saturated by up to a factor of 80 overexposure but retain linearity to a precision of 0.2%, because the charge bleeds along the columns and is recovered during readout of the CCD. The S/N per pixel exceeds

David Joyner, Salahoddin Shokranian

Expository paper discussing AG or Goppa codes arising from curves, first from an abstract general perspective then turning to concrete examples associated to modular curves. We will try to explain these extremely technical ideas using a special case at a level to a typical graduate student with some background in modular forms, number theory, group theory, a

Luc Blanchet

The equations of motion of two point masses in harmonic coordinates are derived through the third post-Newtonian (3PN) approximation. The problem of self-field regularization (necessary for removing the divergent self-field of point particles) is dealt with in two separate steps. In a first step the extended Hadamard regularization is applied, resulting in e

Zoltan Eisler, Janos Kertesz

Multifractal processes are a relatively new tool of stock market analysis. Their power lies in the ability to take multiple orders of autocorrelations into account explicitly. In the first part of the paper we discuss the framework of the Lux model and refine the underlying phenomenological picture. We also give a procedure of fitting all parameters to empir

Dzo Mikulovic

In this paper we construct the Seiberg-Witten maps for superfields on the theta-theta deformed superspaces with N=(1/2,0) and N=(1/2,1/2) supersymmety. We show that on the N=(1/2,0) deformed superspace there is no Seiberg-Witten map for antichiral superfields which is at the same time antichiral, local and which preserves the N=(1/2,0) supersymmetry. Solutio

K. Filimonov

Jet quenching in the matter created in high energy nucleus-nucleus collisions provides a tomographic tool to probe the medium properties. Recent experimental results on jet production at the Relativistic Heavy-Ion Collider (RHIC) are reviewed. Jet properties in p+p and d+Au collisions have been measured, establishing the baseline for studying jet modificatio

R. Belusevic, G. Jikia

To establish the Higgs mechanism experimentally, one has to determine the Higgs self-interaction potential responsible for the electroweak symmetry breaking. This requires a measurement of the trilinear and quadrilinear self-couplings of the Higgs particle, as predicted by the Standard Model (SM). We propose to measure the trilinear Higgs self-coupling in ga

Mario J. Pinheiro

A non-markovian stochastic model is shown to lead to a universal relationship between particle's energy, driven frequency and a frequency of interaction with the medium. It is briefly discussed the possible relevance of this general structure to various phenomena in the context of the formation of patterns in granular media, computation in a Brownian-type co

J. Wenger, J. Fiurasek, R. Tualle-Brouri, N. J. Cerf

Direct photon detection is experimentally implemented to measure the squeezing and purity of a single-mode squeezed vacuum state without an interferometric homodyne detection. Following a recent theoretical proposal [arXiv quant-ph/0311119], the setup only requires a tunable beamsplitter and a single-photon detector to fully characterize the generated Gaussi

I. Dorsner, A. Yu. Smirnov

We suggest an approach to explain the observed pattern of the neutrino masses and mixing which employs the weakly broken quark-lepton symmetry and does not require introduction of an ad hoc symmetry of the neutrino sector. The mass matrices are nearly equal for all quarks and leptons. They have very small determinants and hierarchical form with expansion par

Steven Furlanetto, Matias Zaldarriaga, Lars Hernquist

Recently, there has been a great deal of interest in understanding the reionization of hydrogen in the intergalactic medium (IGM). One of the major outstanding questions is how this event proceeds on large scales. Motivated by numerical simulations, we develop a model for the growth of HII regions during the reionization era. We associate ionized regions wit

Colin Guillarmou

On an asymptotically hyperbolic manifold (X,g), we show that the resolvent resonances coincide, with multiplicities, with the poles of the renormalized scattering operator, except for the special points n/2-k (with k>0 integer) where an additional term appears: this is the dimension of the kernel of the k-conformal Laplacian on the boundary when (X,g) is Ein

H1 Collaboration

The cross section for anti-deuteron photoproduction is measured at HERA at a mean centre-of-mass energy of W_{\gamma p} = 200 GeV in the range 0.2 < p_T/M < 0.7 and |y| < 0.4, where M, p_T and y are the mass, transverse momentum and rapidity in the laboratory frame of the anti-deuteron, respectively. The numbers of anti-deuterons per event are found to be si

Chongying Dong, Kefeng Liu, Xiaonan Ma, Jian Zhou

We introduce two $K$-theories, one for vector bundles whose fibers are modules of vertex operator algebras, another for vector bundles whose fibers are modules of associative algebras. We verify the cohomological properties of these $K$-theories, and construct a natural homomorphism from the VOA K-theory to the associative algebra K-theory.

Herbert E. Scarf, Kevin M. Woods

Given a_1,a_2,...,a_n in Z^d, we examine the set, G, of all non-negative integer combinations of these a_i. In particular, we examine the generating function f(z)=\sum_{b\in G} z^b. We prove that one can write this generating function as a rational function using the neighborhood complex (sometimes called the complex of maximal lattice-free bodies or the Sca

Yutaka Sakamura

We investigate SUSY breaking mediated through the deformation of the space-time geometry due to the backreaction of a nontrivial configuration of a bulk scalar field. To illustrate its features, we work with a toy model in which the bulk is four dimensions. Using the superconformal formulation of SUGRA, we provide a systematic method of deriving the 3D effec

M. Horne, P. Strange, W. M. Temmerman, Z. Szotek

The electronic structure of some europium chalcogenides and pnictides is calculated using the {\it ab-initio} self-interaction corrected local-spin-density approximation (SIC-LSD). This approach allows both a localised description of the rare earth $f-$electrons and an itinerant description of $s$, $p$ and $d$-electrons. Localising different numbers of $f$-e

Julien Lesgourgues, Sergio Pastor, Laurence Perotto

We perform a new study of future sensitivities of galaxy redshift surveys to the free-streaming effect caused by neutrino masses, adding the information on cosmological parameters from measurements of primary anisotropies of the cosmic microwave background (CMB). Our reference cosmological scenario has nine parameters and three different neutrino masses, wit

T. P. Devereaux, T. Cuk, Z. -X. Shen, N. Nagaosa

We explore manifestations of electron-phonon coupling on the electron spectral function for two phonon modes in the cuprates exhibiting strong renormalizations with temperature and doping. Applying simple symmetry considerations and kinematic constraints, we find that the out-of-plane, out-of-phase O buckling mode (B_1g) involves small momentum transfers and

Ronaldo Garcia, Romildo Pina

In this paper is considered the differential equation Ric(g)=T, where Ric(g) is the Ricci tensor of the metric g and T is a rotational symmetric tensor on R^n. A new, geometric, proof of the existence of smooth solutions of this equation, based on qualitative theory of implicitdifferential equations, is presented here. This result was obtained previously by

Krzysztof Byczuk, Walter Hofstetter, Dieter Vollhardt

The phase diagram of correlated, disordered electrons is calculated within dynamical mean--field theory using the geometrically averaged (''typical'') local density of states. Correlated metal, Mott insulator and Anderson insulator phases, as well as coexistence and crossover regimes are identified. The Mott and Anderson insulators are found to be continuous

A. V. Smilga

We consider the theories obtained by dimensional reduction to D=1,2,3 of 4D supersymmetric Yang--Mills theories and calculate there the effective low-energy lagrangia describing moduli space dynamics -- the low-dimensional analogs of the Seiberg--Witten effective lagrangian. The effective theories thus obtained are rather beautiful and interesting from mathe

H. Nikolic

It is often argued that superluminal velocities and nontrivial spacetime topologies, allowed by the theory of relativity, may lead to causal paradoxes. By emphasizing that the notion of causality assumes the existence of a time arrow (TA) that points from the past to the future, the apparent paradoxes appear to be an artefact of the wrong tacit assumption th

E. Artal, J. Carmona, J. I. Cogolludo, M. A. Marco

Following the general strategy proposed by G.Rybnikov, we present a proof of his well-known result, that is, the existence of two arrangements of lines having the same combinatorial type, but non-isomorphic fundamental groups. To do so, the Alexander Invariant and certain invariants of combinatorial line arrangements are presented and developed for combinato

V. C. Geers, J. -C. Augereau, K. M. Pontoppidan, H. U. Kaufl

We present preliminary results of spectroscopic data obtained with the La Silla 3.6m TIMMI2 and the VLT-ISAAC instruments. We have obtained 23 TIMMI2 N-band and 18 Q-band spectra for our total sample of 36 stars in March 2003 to investigate the evolution of the grain properties in circumstellar disks. Our sample consists of Herbig stars, T Tauri stars and Ve

W. Escoffier, C. Chapelier, N. Hadacek, J-C. Villegier

By combining very low temperature scanning tunneling microscopy and spectroscopy on a TiN film we have observed a non uniform state comprising of superconducting (S) and normal (N) areas. The local density of states displays a spatial dependence between S and N different from the usual proximity effect. We conclude that mesoscopic fluctuations might play a m

The OPAL collaboration, G. Abbiendi

Bose-Einstein correlation between like-sign charged-particle pairs in e+e- -> W+W- events recorded with the OPAL detector at LEP at centre-of-mass energies between 183 GeV and 209 GeV are studied. Recently proposed methods which allow direct searches for correlations in the data via distributions of test variables are used to investigate the presence of corr

Shun-ichi Yoshida, Koji Nemoto, Koh Wada

We find that the true ground state of the dipolar spin ice system under [110]-magnetic fields is the ``Q=X'' structure, which is consistent with both experiments and Monte Carlo simulations. We then perform a Monte Carlo simulation to confirm that there exists a first order phase transition under the [110]-field. In particular this result indicates the exist

Jeffrey H Schenker

H\"older continuity, $|N_\lambda(E)-N_\lambda(E')|\le C |E-E'|^\alpha$, with a constant $C$ independent of the disorder strength $\lambda$ is proved for the integrated density of states $N_\lambda(E)$ associated to a discrete random operator $H = H_o + \lambda V$ consisting of a translation invariant hopping matrix $H_o$ and i.i.d. single site potentials $V$

B. L. Ioffe, I. A. Shushpanov, K. N. Zyablyuk

The antideuteron and antihelium-3 production rates at high-energy heavy ion collisions are calculated in the framework of fusion mechanism. It is supposed, that anti-p,n,d,^3He participating in the fusion are moving in the mean field of other fireball constituents. It is demonstrated that at high energies, where many pions are present in the fireball, the nu

Alonso Botero, Benni Reznik

We study the structure of vacuum entanglement for two complimentary segments of a linear harmonic chain, applying the modewise decomposition of entangled gaussian states discussed in \cite {modewise}. We find that the resulting entangled mode shape hierarchy shows a distinctive layered structure with well defined relations between the depth of the modes, the

Victor Abrashkin

Suppose O is a complete discrete valuation ring of positive characteristic with perfect residue field. The category of finite flat strict modules was introduced recently by Faltings and appears as an equal characteristic analogue of the classical category of finite flat group schemes. In this paper we obtain a classification of these modules and apply it to

Ralph Blumenhagen, Timo Weigand

In this note we generalize the description of simple current extended Gepner Model orientifolds as presented in hep-th/0401148 to the case of even levels and non-trivial dressings of the parity transformation. We provide a comprehensive list of all the important ingredients for the construction of such orientifolds. Namely we present explicit expressions for

K. Barro-Bergflödt, R. Rosenfelder, M. Stingl

We determine the lowest bound-state pole of the density-density correlator in the scalar Wick-Cutkosky model where two equal-mass constituents interact via the exchange of mesons. This is done by employing the worldline representation of field theory together with a variational approximation as in Feynman's treatment of the polaron. Unlike traditional method

Sergei Fedotov, Abby Tan

The aim of this paper is to present a simple stochastic model that accounts for the effects of a long-memory in volatility on option pricing. The starting point is the stochastic Black-Scholes equation involving volatility with long-range dependence. We consider the option price as a sum of classical Black-Scholes price and random deviation describing the ri

James P. Norman

We calculate the one-loop effective action of a scalar field with general mass and coupling to the curvature in the detuned Randall-Sundrum brane world scenario, where the four-dimensional branes are anti-de Sitter. We make use of conformal transformations to map the problem to one on the direct product of the hyperbolic space H^4 and the interval. We also i

M. A. C. Lamont

We report measurements of the ratios of identified hadrons (pi,K,p,Lambda) in Au+Au collisions at sqrt(s_NN) = 200 GeV as a function of both collision centrality and transverse momentum (p_T). Ratios of anti-baryon to baryon yields are independent of p_T within 2<p_T <6 GeV/c indicating that, for such a range, our measurements are inconsistent with theoretic

Francois Bergeron, Riccardo Biagioli, Mercedes H. Rosas

We prove that a conjecture of Fomin, Fulton, Li, and Poon, associated to ordered pairs of partitions, holds for many infinite families of such pairs. We also show that the bounded height case can be reduced to checking that the conjecture holds for a finite number of pairs, for any given height. Moreover, we propose a natural generalization of the conjecture

H. H. von Grünberg, M. Kollmann

We present a method to quantify spatial fluctuations of the substitution rate on different length scales throughout genomes of eukaryotes. The fluctuations on large length scales are found to be predominantly a consequence of a coarse-graining effect of fluctuations on shorter length scales. This is verified for both the mouse and the human genome. We also f

Olivier Feron, Ali Mohammad-Djafari

In this work we propose a Bayesian framework for fully automated image fusion and their joint segmentation. More specifically, we consider the case where we have observed images of the same object through different image processes or through different spectral bands. The objective of this work is then to propose a coherent approach to combine these data sets

Amitabha Roy, K. Gopinath

The IEEE 802.11 protocol is a popular standard for wireless local area networks. Its medium access control layer (MAC) is a carrier sense multiple access with collision avoidance (CSMA/CA) design and includes an exponential backoff mechanism that makes it a possible target for probabilistic model checking. In this work, we identify ways to increase the scope

Olivier Feron, Ali Mohammad-Djafari

In this work we propose a Bayesian framework for data fusion of multivariate signals which arises in imaging systems. More specifically, we consider the case where we have observed two images of the same object through two different imaging processes. The objective of this work is then to propose a coherent approach to combine these data sets to obtain a seg

H. Waalkens, A. Burbanks, S. Wiggins

A computational procedure that allows the detection of a new type of high-dimensional chaotic saddle in Hamiltonian systems with three degrees of freedom is presented. The chaotic saddle is associated with a so-called normally hyperbolic invariant manifold (NHIM). The procedure allows to compute appropriate homoclinic orbits to the NHIM from which we can inf

Martin Jakob

Using geometric homology and cohomology we give a simple and conceptual proof of the Thom isomorphism theorem.

Rafal Demkowicz-Dobrzanski, Marek Kus

We study global entangling properties of the system of coupled kicked tops testing various hypotheses and predictions concerning entanglement in quantum chaotic systems. In order to analyze the averaged initial entanglement production rate and the averaged asymptotic entanglement different ensembles of initial product states are evolved. Two different ensemb

L. M. Oskinova, A. Feldmeier, W. -R. Hamann

It is commonly adopted that X-rays from O stars are produced deep inside the stellar wind, and transported outwards through the bulk of the expanding matter which attenuates the radiation and affects the shape of emission line profiles. None of the existing models was able to fit the observationed lines consistently. The possible caveat of these models was t

Joel Merker

In the present paper, we associate the techniques of the Lewy-Pinchuk reflection principle with the Behnke-Sommer continuity principle. Extending a so-called reflection function to a parameterized congruence of Segre varieties, we are led to studying the envelope of holomorphy of a certain domain covered by a smooth Levi-flat ``hat''. In our main theorem, we

Ali Mohammad-Djafari, Olivier Feron

In this work we consider time series with a finite number of discrete point changes. We assume that the data in each segment follows a different probability density functions (pdf). We focus on the case where the data in all segments are modeled by Gaussian probability density functions with different means, variances and correlation lengths. We put a prior

Carl Graham

We consider N single server infinite buffer queues with service rate \beta. Customers arrive at rate N\alpha, choose L queues uniformly, and join the shortest. We study the processes R^N for large N, where R^N_t(k) is the fraction of queues of length at least k at time t. Laws of large numbers (LLNs) are known. We consider certain Hilbert spaces with the wea

Peter Schmitteckert

We extended the Density Matrix Renormalization Group method to study the real time dynamics of interacting one dimensional spinless Fermi systems by applying the full time evolution operator to an initial state. As an example we describe the propagation of a density excitation in an interacting clean system and the transport through an interacting nano struc

D. Quigley, M. I. J Probert

The advantages of performing Langevin Dynamics in extended systems are discussed. A simple Langevin Dynamics scheme for producing the canonical ensemble is reviewed, and is then extended to the Hoover ensemble. We show that the resulting equations of motion generate the isobaric-isothermal ensemble. The Parrinello-Rahman ensemble is then discussed and we sho

B. H. Samset

The BRAHMS experiment at RHIC has measured the production of charged hadrons as a function of pseudorapidity and transverse momentum in Au+Au, d+Au and p+p collisions at a common energy of sqrt(s_NN)=200GeV, and from these spectra we construct the nuclear modification factors for both ``hot'' and ``cold'' nuclear matter. In this contribution I will show how

Petter Callin, Finn Ravndal

The general formalism for calculating the Newtonian potential in fine-tuned or critical Randall-Sundrum braneworlds is outlined. It is based on using the full tensor structure of the graviton propagator. This approach avoids the brane-bending effect arising from calculating the potential for a point source. For a single brane, this gives a clear understandin

X. X. Yi, Erik Sjöqvist

The influence of intersubsystem coupling on the cyclic adiabatic geometric phase in bipartite systems is investigated. We examine the geometric phase effects for two uniaxially coupled spin$-{1/2}$ particles, both driven by a slowly rotating magnetic field. It is demonstrated that the relation between the geometric phase and the solid angle enclosed by the m

P. Palaniyandi, M. Lakshmanan

We propose a simple method to estimate the parameters involved in discrete dynamical systems from time series. The method is based on the concept of controlling chaos by constant feedback. The major advantages of the method are that it needs a minimal number of time series data and is applicable to dynamical systems of any dimension. The method also works ex

Da-Heng He, Ke Qian, Yi-Bing Ding, Xue-Qian Li

In this work, we evaluate the energy spectra of baryons which consist of two heavy and one light quarks in the MIT bag model. The two heavy quarks constitute a heavy scalar or axial vector diquark. Concretely, we calculate the spectra of $|q(QQ')>_{1/2}$ and $|q(QQ')>_{3/2}$ where $Q$ and $Q'$ stand for $b$ and/or $c$ quarks. Especially, for $|q(bc)>_{1/2}$

Nicolae Cotfas

We show that the well known two-dimensional Penrose tiling admits an infinite number of independent scaling factors and an infinite number of inflation centers.

Maciej Blaszak, Krzysztof Marciniak

A new notion of a dual Poisson-presymplectic pair is introduced and its properties are examined. The procedure of Dirac reduction of Poisson operators onto submanifolds proposed by Dirac is in this paper embedded in a geometric procedure of reduction of dual Poisson-presymplectic pairs. The method presented generalizes those used by Marsden and Ratiu for red

J. Korbicz, J. Tafel

We calculate the Hilbert action for the Bondi-Sachs metrics. It yields the Einstein vacuum equations in a closed form. Following the Dirac approach to constrained systems we investigate the related Hamiltonian formulation.