February 2005 arXiv papers — page 4

Roldao da Rocha, Jayme Vaz

This paper is intended to describe twistors via the paravector model of Clifford algebras and to relate such description to conformal maps in the Clifford algebra over R(4,1), besides pointing out some applications of the pure spinor formalism. We construct twistors in Minkowski spacetime as algebraic spinors associated with the Dirac-Clifford algebra, using

Judith A. Packer

We continue the study of projective module wavelet frames corresponding to diagonal dilation matrices on $\mathbb R^n$ with integer entries, focusing on the construction of a projective multi-resolution analysis corresponding to dilations whose domains are finitely generated projective modules over continuous complex-valued functions on $n$-tori, $n\geq 3$.

Jinjia Li

Let $M$ be a finitely generated module over a local complete intersection $R$ of characteristic $p>0$. The property that $M$ has finite projective dimension can be characterized by the vanishing of $\ext_R^i({}^{f^n} R,M)$ for some $i>0$ and for some $n>0$.

Kevin P. Knudson

We compute the completion of the special linear group over the coordinate ring of a curve over a number field $k$ relative to its representation in $\slnk$, and relate this to the study of $K_2$ of the curve.

Brian Dean, Giuseppe Tinaglia

In this paper, we prove a generalization of Rado's Theorem, a fundamental result of minimal surface theory, which says that minimal surfaces over a convex domain with graphical boundaries must be disks which are themselves graphical. We will show that, for a minimal surface of any genus, whose boundary is "almost graphical" in some sense, that th

J. V. Beltran, J. Monterde

A polynomial curve of degree 5, $α$, is a helix, if and only if both $||α^'||$ and $||α^'\wedge α^{''}||$ are polynomial functions.

I. Egorova, L. Golinskii

The discrete spectrum of complex Jacobi matrices that are compact perturbations of the discrete laplacian is under consideration. The rate of stabilization for the the matrix entries which provides finiteness of the discrete spectrum and is sharp in the sense of order is found. The Jacobi matrix with the discrete spectrum having a single limit point is const

Abdelmalek Abdesselam, Jaydeep Chipalkatti

This paper is a sequel to math.AG/0411110. Let P denote the projective space of degree d forms in n+1 variables. Let e denote an integer < d/2, and consider the subvariety X of forms which factor as L^{d-e} M^e for some linear forms L,M. In the language of our earlier paper, this is the Brill-Gordan locus associated to the partition (d-e,e). In this paper we

M. Ladisa, A. Lamura, T. Laudadio, G. Nico

A filter based on the Hankel Lanczos Singular Value Decomposition (HLSVD) technique is presented and applied for the first time to X-ray diffraction (XRD) data. Synthetic and real powder XRD intensity profiles of nanocrystals are used to study the filter performances with different noise levels. Results show the robustness of the HLSVD filter and its capabil

Jean-Louis Colliot-Th&#39;el`ene

Given a smooth, projective irreducible variety over the reals, various algebraic formulas have been given for the number of real connected components of the set of real points. In this note I compare a formula of E. Becker and D. Gondard (1995) with a formula I gave in 1978. I show how one may deduce one from the other by using a purity theorem of M. Rost (1

Bogdan Alexandrov

We prove a lower estimate for the first eigenvalue of the Dirac operator on a compact locally reducible Riemannian spin manifold with positive scalar curvature. We determine also the universal covers of the manifolds on which the smallest possible eigenvalue is attained.

W. Hachem, P. Loubaton, J. Najim

Consider a $N\times n$ random matrix $Z_n=(Z^n_{j_1 j_2})$ where the individual entries are a realization of a properly rescaled stationary gaussian random field. The purpose of this article is to study the limiting empirical distribution of the eigenvalues of Gram random matrices such as $Z_n Z_n ^*$ and $(Z_n +A_n)(Z_n +A_n)^*$ where $A_n$ is a determinist

David Callan

We establish combinatorial interpretations of several identities for the Catalan and Fine numbers and, along the way, we present some new bijections of independent interest. Briefly, we show that C_{n} = 1/(n+1) Sum_{k} (n+1)choose(2k+1) (n+k)choose(k) counts ordered trees on n edges by number of interior vertices adjacent to a leaf, and C_{n} = 2/(n+1) Sum_

Dmitri Alekseevsky, Yoshinobu Kamishima

The purpose of this paper is to introduce a geometric structure called pseudo-conformal quaternionic CR structure on a (4n+3)-dimensional mamnifold and then exhibit a quaternionic analogue of Chern-Moser&#39;s CR structure and uniformization.

Stephen Berman, Jun Morita

Let F be a field of characteristic not 2 and assume all algebras are over F. We establish several conjugacy theorems for the special linear Lie algebra sl_2 over an F-algebra which is a UFD. We find the structure of the full automorphism group as well as conditions for when two such algebras are isomorphic. We also study the structure of their derivation alg

Francois Courtes

Let $F$ be a local complete field with discrete valuation, and let $G$ be a quasi-split group over $F$ which splits over some unramified extension of $F$. Let $P$ be a parahoric subgroup of the group $G(F)$ of $F$-points of $G$; t he open normal pro-nilpotent subgroups of $P$ can be classified using the standa rd normal filtration subgroups of Prasad and Rag

Rashit T. Faizullin, Alexander V. Prolubnikov

We propose an algorithm for solving of the graph isomorphism problem. Also, we introduce the new class of graphs for which the graph isomorphism problem can be solved polynomially using the algorithm.

Ronald J. Stern

These notes are adapted from two talks given at the 2004 Clay Institute Summer School on Floer homology, gauge theory, and low dimensional topology at the Alfred Renyi Institute. We will quickly review what we do and do not know about the existence and uniqueness of smooth and symplectic structures on closed, simply-connected 4-manifolds. We will then list t

M. Alimohammady, R. Saadati

In this paper, we show that D-compactness in Generalized Šerstnev spaces implies D-boundedness and as in the classical case, a D-bounded and closed subset of a characteristic Generalized Šerstnev is not D-compact in general. Finally, in the finite dimensional Generalized Šerstnev spaces a subset is D-compact if and only if is D-bounded and closed.

Jeremy Marzuola

In this paper, the results of Burq and Zworski are further developed to study nonconcentration of eigenfunctions for billiards which have rectangular components: these include the Buminovich billiard, the Sinai billiard, and certain pseudointegrable billiards. The results presented are an application of using a &#34;black box&#34; point of view as presented

William Heinzer, Mee-Kyoung Kim, Bernd Ulrich

Let I be an m-primary ideal of a Noetherian local ring (R,m). We consider the Gorenstein and complete intersection properties of the associated graded ring G(I) and the fiber cone F(I) of I as reflected in their defining ideals as homomorphic images of polynomial rings over R/I and R/m respectively. In case all the higher conormal modules of I are free over

C. A. M. de Melo, B. M. Pimentel, P. J. Pompeia

A manifestly covariant treatment of the free quantum eletromagnetic field, in a linear covariant gauge, is implemented employing the Schwinger&#39;s Variational Principle and the B-field formalism. It is also discussed the abelian Proca&#39;s model as an example of a system without constraints.

J. M. Laget

Primakoff effect offers us with a way to determine the radiative decay width of pseudo-scalar mesons when they are photo-produced in the electromagnetic field of hadronic systems. Taking advantage of recent developments in the Regge description of the production of mesons in the strong hadronic field, this paper evaluates the relative importance of the elect

F. Giuliani, TA Girard

Spin-dependent WIMP searches have traditionally presented results within an odd group approximation and by suppressing one of the spin-dependent interaction cross sections. We here elaborate on a model-independent analysis in which spin-dependent interactions with both protons and neutrons are simultaneously considered. Within this approach, equivalent curre

Cheng-Wei Chiang

We show that information on the weak phase gamma can be extracted from the K* pi and rho K decays. Less hadronic uncertainty is involved when the observables of four of these modes are combined together. We further point out two approximate relations in these decay modes can help determine whether there are new physics contributions in Delta I = 1 transition

HyperCP Collaboration, Y. C. Chen, R. A. Burnstein, A. Chakravorty

We have measured the alpha parameter of the Omega- to Lambda K- decay using data collected with the HyperCP spectrometer during the 1997 fixed-target run at Fermilab. Analyzing a sample of 0.96 million Omega- to Lambda K^-, Lambda to p pi- decays, we obtain alpha_Omega*alpha_Lambda = [1.33+/-0.33(stat)+/-0.52(syst)] x 10^{-2}. With the accepted value of alph

Slava G. Turyshev, Michael Shao, Kenneth L. Nordtvedt

This paper discusses the Laser Astrometric Test Of Relativity (LATOR) mission. By using a combination of independent time-series of highly accurate gravitational deflection of light in the immediate proximity to the Sun along with measurements of the Shapiro time delay on the interplanetary scales (to a precision respectively better than $10^{-13}$ radians a

Martin Zofka, Jiri Langer

We construct a general relativistic analogy of an infinite solenoid, i.e., of an infinite cylinder with zero electric charge and non-zero electric current in the direction tangential to the cylinder and perpendicular to its axis. We further show that the solution has a good weak-field limit.

M. Martinis, V. Mikuta-Martinis

We consider dynamics of a quantum scalar field, minimally coupled to classical gravity, in the near-horizon region of a Schwarzschild black-hole. It is described by a static Klein-Gordon operator which in the near-horizon region reduces to a scale invariant Hamiltonian of the system. This Hamiltonian is not essentially self-adjoint, but it admits a one-param

Dagny Kimberly, Joao Magueijo

These notes summarize a set of lectures on phenomenological quantum gravity which one of us delivered and the other attended with great diligence. They cover an assortment of topics on the border between theoretical quantum gravity and observational anomalies. Specifically, we review non-linear relativity in its relation to loop quantum gravity and high ener

Claude Barrabes, Werner Israel

This paper gives a new, simple and concise derivation of brane actions and brane dynamics in general relativity and in Einstein-Gauss-Bonnet gravity. We present a unified treatment, applicable to timelike surface layers and spacelike transition layers, and including consideration of the more difficult lightlike case.

L. C. Garcia de Andrade

The necessity of a newly proposed (PRD 70 (2004) 64004) non-Riemannian acoustic spacetime structure called acoustic torsion of sound wave equation in fluids with vorticity are discussed. It is shown that this structure, although not always necessary is present in fluids with vorticity even when the perturbation is rotational. This can be done by solving the

Erwan Deriaz, Valérie Perrier

In this paper, we investigate the use of compactly supported divergence-free wavelets for the representation of the Navier-Stokes solution. After reminding the theoretical construction of divergence-free wavelet vectors, we present in detail the bases and corresponding fast algorithms for 2D and 3D incompressible flows. In order to compute the nonlinear term

D. Meiser, P. Meystre

We investigate the potential of the so-called XFROG cross-correlation technique originally developed for ultrashort laser pulses for the recovery of the amplitude and phase of the condensate wave function of a Bose-Einstein condensate. Key features of the XFROG method are its high resolution, versatility and stability against noise and some sources of system

Grace Brannigan, Peter F. Philips, Frank L. H. Brown

A minimalist simulation model for lipid bilayers is presented. Each lipid is represented by a flexible chain of beads in implicit solvent. The hydrophobic effect is mimicked through an intermolecular pair potential localized at the ``water&#39;&#39;/hydrocarbon tail interface. This potential guarantees realistic interfacial tensions for lipids in a bilayer g

David Pekker, Swagatam Mukhopadhyay, Nandini Trivedi, Paul M. Goldbart

The analytical zero-temperature phase diagram of the double exchange model for classical background spins as a function of the carrier density and Hund&#39;s coupling in the entire range of these parameters is presented. By constructing a continuum field theory we explore the possibility of a continuous phase transition from ferromagnetic state to a gently v

S. Ghosh, V. Sih, W. H. Lau, D. D. Awschalom

Time-resolved optical techniques are used to explore electron spin dynamics in bulk and epilayer samples of n-type ZnO as a function of temperature and magnetic field. The bulk sample yields a spin coherence time T2* of 20 ns at T = 30 K. Epilayer samples, grown by pulsed laser deposition, show a maximum T2* of 2 ns at T = 10 K, with spin precession persisti

M. Kaczmarski, O. N. Bedoya-Martinez, E. R. Hernandez

In this letter we present a calculation of the temperature-pressure phase diagram of Si in a range of pressures covering from -5 to 20 GPa and temperatures up to the melting point. The phase boundaries and triple points between the diamond, liquid, $β$-Sn and ${Si}_{34}$ clathrate phases are reported. We have employed efficient simulation techniques to calcu

Michele Casula, Gaetano Senatore

We present a variational Monte Carlo study of a model one dimensional electron gas on the continuum, with long-range interaction (1/r decay). At low density the reduced dimensionality brings about pseudonodes of the many-body wavefunction, yielding non-ergodic behavior of naive Monte Carlo sampling, which affects the evaluation of pair correlations and the r

Nicolas Giovambattista, Pablo G. Debenedetti, Francesco Sciortino, H. Eugene Stanley

We investigate structural order in glassy water by performing classical molecular dynamics simulations using the extended simple point charge (SPC/E) model of water. We perform isochoric cooling simulations across the glass transition temperature at different cooling rates and densities. We quantify structural order by orientational and translational order m

V. A. Ryzhov, A. V. Lazuta, O. P. Smirnov, I. A. Kiselev

Results of structural neutron diffraction study, magnetization and ESR measure-ments are presented for insulating Nd0.75Ba0.25MnO3, Tc = 129 K. The crystal structure is refined in the range 4.2-300 K. The compound is found to exhibit the Jahn-Teller (JT) transition at 250 K. The field cooled (FC) magnetization data are in a reasonable agreement with the pred

P. Van Dorpe, W. Van Roy, J. De Boeck, G. Borghs

The spin polarization of the electron current in a p-(Ga,Mn)As-n-(Al,Ga)As-Zener tunnel diode, which is embedded in a light-emitting diode, has been studied theoretically. A series of self-consistent simulations determines the charge distribution, the band bending, and the current-voltage characteristics for the entire structure. An empirical tight-binding m

N. A. Goncharuk, L. Smrcka, J. Kucera, K. Vyborny

Full quantum-mechanical description of electrons moving in 3D structures with unidirectional periodic modulation subject to tilted magnetic fields requires an extensive numerical calculation. To understand magneto-oscillations in such systems it is in many cases sufficient to use the quasi-classical approach, in which the zero-magnetic-field Fermi surface is

H. R. Schober

The dynamics of a soft sphere model glass, studied by molecular dynamics, is investigated. The vibrational density of states divided by $ω^2$ shows a pronounced boson peak. Its shape is in agreement with the universal form derived for soft oscillators interacting with sound waves. The excess vibrations forming the boson peak have mainly transverse character.

H. R. Schober

We report results of molecular dynamics simulations of a binary Lennard-Jones system at zero pressure in the undercooled liquid and glassy states. We first follow the evolution of diffusivity and dynamic heterogeneity with temperature and show their correlation. In a second step we follow the ageing of a quenched glass. As diffusivity decreases with ageing,

M. Kluge, H. R. Schober

Using molecular dynamics simulation, we calculate the distribution of atomic jum ps in Cu$_{33}$Zr$_{67}$ in the liquid and glassy states. In both states the distribution of jump lengths can be described by a temperature independent exponential of the length and an effective activation energy plus a contribution of elastic displacements at short distances. U

Ugur Tirnakli, Constantino Tsallis

Chaos thresholds of the $z$-logistic maps $x_{t+1}=1-a|x_t|^z$ $(z>1; t=0,1,2,...)$ are numerically analysed at accumulation points of cycles 2, 3 and 5. We verify that the nonextensive $q$-generalization of a Pesin-like identity is preserved through averaging over the entire phase space. More precisely, we computationally verify $\lim_{t \to\infty}< S_{q_{s

P. S. Cornaglia, D. R. Grempel

The effect of a magnetic field on the equilibrium spectral and transport properties of a single-molecule junction is studied using the numerical renormalization group method. The molecule is described by the Anderson-Holstein model in which a single vibrational mode is coupled to the electron density. The effect of an applied magnetic field on the conductanc

U. Klein

Thermodynamically stable vortex-antivortex structures in a quasi-two-dimensional superconductor in a tilted magnetic field are predicted. For this geometry, both orbital and spin pair-breaking effects exist, with their relative strength depending on the tilt angle Θ. The spectrum of possible states contains as limits the ordinary vortex state (for large Θ) a

Erwin Frey, Klaus Kroy

This is a pedagogical introduction to Brownian motion on the occasion of the 100th anniversary of Einstein&#39;s 1905 paper on the subject. After briefly reviewing Einstein&#39;s work in its contemporary context, we pursue some lines of further developments and applications in soft condensed matter and biology. Over the last century Brownian motion became pr

Igor V. Ovchinnikov, Daniel Neuhauser

We reformulate 1D boson-fermion duality in path-integral terms. The result is a 1D counterpart of the boson-fermion duality in the 2D Chern-Simons gauge theory. The theory is consistent and enables, using standard resummation techniques, to obtain the long-wave-length asymptotics of the collective mode in 1D boson systems at the Tonks-Girardeau regime. The c

I. Y. Polishchuk, P. Fulde, A. L. Burin, Y. Sereda

Recently it has been experimentally demonstrated that certain glasses display an unexpected magnetic field dependence of the dielectric constant. In particular, the echo technique experiments have shown that the echo amplitude depends on the magnetic field. The analysis of these experiments results in the conclusion that the effect seems to be related to the

M. A. Cazalilla, A. F. Ho, T. Giamarchi

We study the phase diagram of one dimensional spin one-half fermionic cold atoms. The two ``spin&#39;&#39; species can have different hopping or mass. The phase diagram at equal densities of the species is found to be very rich, Mott insulators as well as superfluids. We also briefly discuss coupling 1D systems together, and some experimental signatures of t

Z. Y. Weng, Y. Zhou, V. N. Muthukumar

We propose a class of wave functions that provide a unified description of antiferromagnetism and d-wave superconductivity in (doped) Mott insulators. The wave function has a Jastrow form and prohibits double occupancies. In the absence of holes, the wave function describes antiferromagnetism accurately. Off diagonal long range order develops at finite dopin

A. M. Soderberg, S. R. Kulkarni, D. B. Fox, E. Berger

We present the results from an Hubble Space Telescope/ACS search for supernovae associated with X-ray flashes 020903, 040701, 040812 and 040916. We find strong evidence that XRF 020903 (z=0.25) was associated with a SN 1998bw-like supernova and confirm this using optical spectroscopy at t ~ 25 days. We find no evidence, however, for SN 1998bw-like supernovae

Peter Schneider, Peter Watts

Galaxy-galaxy lensing (GGL) measures the 2-point cross-correlation between galaxies and mass in the Universe. In this work we seek to generalise this effect by considering the third-order correlations between galaxies and mass: galaxy-galaxy-galaxy lensing. Third-order correlations in the cosmic shear field have recently been reported in the VIRMOS-DESCART a

Lior Shamir, Robert J. Nemiroff

Accurate automatic identification of astronomical objects in an imperfect world of non-linear wide-angle optics, imperfect optics, inaccurately pointed telescopes, and defect-ridden cameras is not always a trivial first step. In the past few years, this problem has been exacerbated by the rise of digital imaging, providing vast digital streams of astronomica

A. Beresnyak, A. Lazarian, J. Cho

We study the statistics of density for supersonic turbulence in a medium with magnetic pressure larger than the gaseous pressure. This study is motivated by molecular cloud research. Our simulations exhibit clumpy density structures, which contrast increases with the Mach number. At 10 Machs densities of some clumps are three orders of magnitude higher than

E. Kerins, M. J. Darnley, J. Duke, A. Gould

The Andromeda Galaxy Stellar Robotic Microlensing Project (The Angstrom Project) aims to use stellar microlensing events to trace the structure and composition of the inner regions of the Andromeda Galaxy (M31). We present microlensing rate and timescale predictions and spatial distributions for stellar and sub-stellar lens populations in combined disk and b

W. R. F. Dent, J. S. Greaves, I. M. Coulson

We describe results from a survey for J=3-2 12CO emission from visible stars with an infrared excess. The line is clearly detected in 21 objects, with molecular gas (>10^-3 Jupiter masses) common in targets with infrared excesses >0.01 (>56% of objects). Such high excesses indicate the presence of a disc of opening angle >12 degrees; within this, the optical

Steven H. Pravdo, Yohko Tsuboi

We report the discovery of X-rays from both components of Cepheus A, East and West, with the XMM-Newton Observatory. HH 168 joins the ranks of other energetic Herbig Haro objects that are sources of T~10^6 K X-ray emission. The HH 168 effective temperature is T = 5.8 (+3.5,-2.3) x 10^6 K and its unabsorbed luminosity is 1.1 x 10^29 erg s^-1, making it hotter

V. Mainieri, P. Rosati, P. Tozzi, J. Bergeron

We provide important new constraints on the nature and redshift distribution of optically faint (R>25) X-ray sources in the Chandra Deep Field South Survey. We show that we can derive accurate photometric redshifts for the spectroscopically unidentified sources thus maximizing the redshift completeness for the whole X-ray sample. Our new redshift distributio

E. P. Mazets, T. L. Cline, R. L. Aptekar, D. D. Frederiks

The giant outburst from SGR 1806-20 was observed on 2004 December 27 by many spacecraft. This extremely rare event exhibits a striking similarity to the two giant outbursts thus far observed, on 1979 March 5 from SGR 0526-66 and 1998 August 27 from SGR 1900+14. All the three outbursts start with a short giant radiation pulse followed by a weaker tail. The ta

Anna Geminale, Piotr Popowski

We present an analysis of 436 lines of sight with extinction data covering wavelength range from near-infrared (NIR) to ultraviolet (UV). We use J, H, K photometry from 2MASS database, the IR intrinsic colors from Wegner (1994), and UV extinction data from Wegner (2002). We exclude 19 lines of sight (4%) from the original sample because of suspected photomet

L. F. Olsen, C. Benoist, L. da Costa, L. Hansen

We have carried out an investigation of the properties of low redshift EIS clusters using both spectroscopy and imaging data. We present new redshifts for 738 galaxies in 21 ESO Imaging Survey (EIS) Cluster fields. We use the ``gap&#39;&#39;-technique to search for significant overdensities in redshift space and to identify groups/clusters of galaxies corres

E. Schmutzer

In this treatise the well-known 2-body problem with a rotating central body is systematically reinvestigated on the basis of the Projective Unified Field Theory (PUFT) under the following aspects (including the special case of the Newton mechanics): First, equation of motion with abstract additional terms being appropriate for the interpretation of the vario

R. J. Wilman, A. C. Edge, R. M. Johnstone

We present near-infrared integral field spectroscopy of the central kiloparsec of NGC 1275 at the heart of the Perseus cluster of galaxies, obtained with the UIST IFU on UKIRT. The nuclear ro-vibrational H_2 emission is spatially resolved and is likely to originate approximately 50 pc from the active nucleus. The Pa-alpha emission is, by contrast, spatially

Jorick S. Vink, Janet E. Drew, Tim J. Harries, Rene D. Oudmaijer

We present Halpha spectropolarimetry observations of a sample of 10 bright T Tauri stars, supplemented with new Herbig Ae/Be star data. A change in the linear polarisation across Halpha is detected in most of the T Tauri (9/10) and Herbig Ae (9/11) objects, which we interpret in terms of a compact source of line photons that is scattered off a rotating accre

H. Meusinger, D. Froebrich, M. Haas, M. Irwin

We report the discovery of the highly peculiar, radio-loud quasar VPMS J1342+2840 (z ~ 1.3) from the variability and proper motion survey. We present spectroscopic, imaging and photometric observations. The unusual spectrum shows a strong depression of the continuum over a wide wavelength range in the blue part without the typical structures of broad absorpt

M. H. Christopher, N. Z. Scoville, S. R. Stolovy, Min S. Yun

We present high spatial resolution (5.1&#34; x 2.7&#34;) OVRO millimeter array observations of HCN (J=1-0) and HCO+ (J=1-0) emission in the inner 3 pc of the galaxy. The HCN and HCO+ emission of the circumnuclear disk (CND) is distributed in a well-defined ring with a peak at a radius of 1.6pc. The HCO+/HCN emission ratio is typically ~0.4 but with significa

P. A. Mazzali, S. Benetti, G. Altavilla, G. Blanc

Evidence of high-velocity features such as those seen in the near-maximum spectra of some Type Ia Supernovae (eg SN 2000cx) has been searched for in the available SNIa spectra observed earlier than one week before B maximum. Recent observational efforts have doubled the number of SNeIa with very early spectra. Remarkably, all SNeIa with early data (7 in our

C. M. Boily, A. Lacon, S. Deiters, D. C. Heggie

We point out a strong time-evolution of the mass-to-light conversion factor ηcommonly used to estimate masses of dense star clusters from observed cluster radii and stellar velocity dispersions. We use a gas-dynamical model coupled with the Cambridge stellar evolution tracks to compute line-of-sight velocity dispersions and half-light radii weighted by the l

G. Benko, G. Erdos, S. I. Nikolsky, N. M. Nesterova

Analysis of the experimental data of joint Russian - Hungarian research was carried out at Tien Shan station on the search of sources of primary cosmic rays (PCR) at energies 0.1-1.0 PeV. Maps of extensive air shower arrival directions were presented where the standard deviation of mean event numbers in equatorial co-ordinates exceeded a definite value. The

Moshe Gai

Recent claims of the Seattle group of evidence of &#34;slope difference between CD [Coulomb Dissociation] and direct [capture] results&#34; are based on wrong and selective data. When the RIKEN2 data are included correctly, and previously published Direct Capture (DC) data are also included, we observe only a 1.9 sigma difference in the extracted so called &

A. Rebhan, R. Schöfbeck, P. van Nieuwenhuizen, R. Wimmer

Quantum corrections to the magnetic central charge of the monopole in N=4 supersymmetric Yang-Mills theory are free from the anomalous contributions that were crucial for BPS saturation of the two-dimensional supersymmetric kink and the N=2 monopole. However these quantum corrections are nontrivial and they require infinite renormalization of the supersymmet

A. Romanelli, A. Auyuanet, R. Donangelo

We present a continuous time quantum search algorithm analogous to Grover&#39;s. In particular, the optimal search time for this algorithm is proportional to $\sqrt{N}$, where $N$ is the database size. This search algorithm can be implemented using any Hamiltonian with a discrete energy spectrum through excitation of resonances between an initial and the sea

J. I. Read, Neil Trentham

In the Big Bang about 5% of the mass that was created was in the form of normal baryonic matter (neutrons and protons). Of this about 10% ended up in galaxies in the form of stars or of gas (that can be in molecules, can be atomic, or can be ionised). In this work, we measure the baryonic mass function of galaxies, which describes how the baryonic mass is di

M. M. Glazov, E. Ya. Sherman

We investigate the spin dynamics of electrons in quantum wells where the Rashba type of spin-orbit coupling is present in the form of random nanosize domains. We study the effect of magnetic field on the spin relaxation in these systems and show that the spatial randomness of spin-orbit coupling limits the minimum relaxation rate and leads to a Gaussian time

Maxime Dion, Kieron Burke

The coupling constant dependence is derived in time-dependent {\em current} density functional theory. The scaling relation can be used to check approximate functionals and in conjunction with the adiabatic connection formula to obtain the ground-state energy from the exchange-correlation kernel. The result for the uniform gas using the Vignale-Kohn approxim

Zhongzhi Zhang, Lili Rong, Francesc Comellas

We propose a simple algorithm which produces a new category of networks, high dimensional random Apollonian networks, with small-world and scale-free characteristics. We derive analytical expressions for their degree distributions and clustering coefficients which are determined by the dimension of the network. The values obtained for these parameters are in

Tomoyuki Maruyama, Takumi Muto, Toshitaka Tatsumi, Kazuo Tsushima

The possibility of kaon condensation in high-density symmetric nuclear matter is investigated including both s- and p-wave kaon-baryon interactions within the relativistic mean-field (RMF) theory. Above a certain density, we have a collective ${\bar K}_s$ state carrying the same quantum numbers as the antikaon. The appearance of the ${\bar K}_s$ state is cau

Maciej Dunajski, Paul Tod

We characterise $n$th order ODEs for which the space of solutions $M$ is equipped with a particular paraconformal structure in the sense of \cite{BE}, that is a splitting of the tangent bundle as a symmetric tensor product of rank-two vector bundles. This leads to the vanishing of $(n-2)$ quantities constructed from of the ODE. If $n=4$ the paraconformal str

James Grime

We derive a new expression for the diagonal matrix elements of irreducible representations of the symmetric group. We obtain this new expression using Cherednik&#39;s fusion procedure. However, instead of splitting Young diagrams into their rows or columns, we consider their principal hooks. This minimises the number of auxiliary parameters needed in the fus

R. D'Auria, S. Ferrara, M. Trigiante, S. Vaula'

We consider consistent truncations of N=2 supergravites in the presence of tensor multiplets (dual to hypermultiplets) as they occur in type IIB compactifications on Calabi--Yau orientifolds. We analyze in detail the scalar potentials encompassing these reductions when fluxes are turned on and study vacua of the N=1 phases.

M. B. Silva Neto, L. Benfatto, V. Juricic, C. Morais Smith

The magnetic and thermodynamic properties of the two-dimensional quantum Heisenberg antiferromagnet that incorporates both a Dzyaloshinskii-Moriya and pseudo-dipolar interactions are studied within the framework of a generalized nonlinear sigma model (NLSM). We calculate the static uniform susceptibility and sublattice magnetization as a function of temperat

Mostafa Sahrai, Habib Tajalli, Kishore T. Kapale, M. Suhail Zubairy

We propose a scheme for subwavelength localization of an atom conditioned upon the absorption of a weak probe field at a particular frequency. Manipulating atom-field interaction on a certain transition by applying drive fields on nearby coupled transitions leads to interesting effects in the absorption spectrum of the weak probe field. We exploit this fact

M. Burgay, A. Possenti, R. N. Manchester, M. Kramer

Analysis of 20 months of observations at the Parkes radio telescope shows secular changes in the pulsed emission from J0737-3039B, the 2.77 s pulsar of the double-pulsar system. Pulse profiles are becoming single-peaked in both bright phases of the orbital modulation although there is no clear variation in overall pulse width. The shape of the orbital modula

Takeshi Tayagaki, Andre Mysyrowicz, Makoto Kuwata-Gonokami

We report on the observation of the yellow exciton Lyman series up to the fourth term in Cu2O by time-resolved mid-infrared spectroscopy. The dependence of the oscillator strength on the principal quantum number n can be well reproduced using the hydrogenic model including an AC dielectric constant, and precise information on the electronic structure of the

Daniel Proga

We present results from axisymmetric, time-dependent hydrodynamical (HD) and magnetohydrodynamical (MHD) simulations of a gaseous envelope collapsing onto a black hole (BH). We consider gas with so small angular momentum that after an initial transient, the flow in the HD case, accretes directly onto a BH without forming a rotationally support torus. However

J. G. Cederquist, R. Corin, M. A. C. Dekker, S. Etalle

We describe and implement a policy language. In our system, agents can distribute data along with usage policies in a decentralized architecture. Our language supports the specification of conditions and obligations, and also the possibility to refine policies. In our framework, the compliance with usage policies is not actively enforced. However, agents are

Morten Brun, Winfried Bruns, Tim Roemer

We study local cohomology of rings of global sections of sheafs on the Alexandrov space of a partially ordered set. We give a criterion for a splitting of the local cohomology groups into summands determined by the cohomology of the poset and the local cohomology of the stalks. The face ring of a rational pointed fan can be considered as the ring of global s

Andrew R. Zentner, Andrey V. Kravtsov, Oleg Y. Gnedin, Anatoly A. Klypin

We present a study of the spatial distribution of subhalos in galactic dark matter halos using dissipationless cosmological simulations of the concordance LCDM model. We find that subhalos are distributed anisotropically and are preferentially located along the major axes of the triaxial mass distributions of their hosts. The Kolmogorov-Smirnov probability f

Gábor Somogyi, Zoltán Trócsányi, Vittorio Del Duca

We describe how to disentangle the singly- and doubly-unresolved (soft and/or collinear) limits of tree-level QCD squared matrix elements. Using the factorization formulae presented in this paper, we outline a viable general subtraction scheme for computing next-to-next-to-leading order corrections for electron-positron annihilation into jets.

Nora Breton

We study the stability of static spherically symmetric exact solutions of Einstein equations coupled with nonlinear electrodynamics, in the magnetic sector. These solutions satisfy the heuristic model proposed by Ashtekar-Corichi-Sudarsky for hairy black holes, meaning that the horizon mass is related to their Arnowitt-Deser-Misner (ADM) mass and to the corr

Soojoon Lee, Jaewoo Joo, Jaewan Kim

We define an entanglement measure, called the partial tangle, which represents the residual two-qubit entanglement of a three-qubit pure state. By its explicit calculations for three-qubit pure states, we show that the partial tangle is closely related to the faithfulness of a teleportation scheme over a three-qubit pure state.

A. Cervellino, C. Giannini, A. Guagliardi, M. Ladisa

A new procedure aiming at disentangling the instrumental profile broadening and the relevant X-ray powder diffraction (XRPD) profile shape is presented. The technique consists of three steps: denoising by means of wavelet transforms, background suppression by morphological functions and deblurring by a Lucy--Richardson damped deconvolution algorithm. Real XR

A. Gomboc, C. G. Mundell, C. Guidorzi, A. Monfardini

We present the first optical observations of a Gamma Ray Burst (GRB) afterglow using the 2-m robotic Liverpool Telescope (LT), which is owned and operated by Liverpool John Moores University and situated on La Palma. We briefly discuss the capabilities of LT and its suitability for rapid follow-up observations of early optical and infrared GRB light curves.

Eli Aljadeff

Let R be any ring (with 1), Γa group and RΓthe corresponding group ring. Let Ext_{RΓ}^{*}(M,M) be the cohomology ring associated to the RΓ-module M. Let H be a subgroup of finite index of Γ. The following is a special version of our main Theorem: Assume the profinite completion of Γis torsion free. Then an element ζin Ext_{RΓ}^{*}(M,M) is nilpotent (under Yo

B. S. Zou, D. O. Riska

A complete analysis is given of the implications of the empirical indications for a positive strangeness magnetic moment $μ_s$ of the proton on the possible configurations of the $uuds\bar s$ component of the proton. A positive value for $μ_s$ is obtained in the $s\bar s$ configuration where the $uuds$ subsystem is in an orbitally excited state with $[4]_{[F

Thomas Heinzl, Tobias Kaestner, Andreas Wipf

We compare different Polyakov loop actions yielding effective descriptions of finite-temperature SU(2) Yang-Mills theory on the lattice. The actions are motivated by a simultaneous strong-coupling and character expansion obeying center symmetry and include both Ising and Ginzburg-Landau type models. To keep things simple we limit ourselves to nearest-neighbo