September 2007 arXiv papers — page 6

D. Stauffer

Countries like Poland with a recent sharp drop in birth rates still have some time to prepare for the problems of an ageing society. Ater the year 2030 they can become increasingly serious.

N. Bouayed, F. Boudjema

We calculate the electroweak and QCD corrections to W-W+ -> tt and ZZ -> tt. We also consider the interplay of these corrections with the effect of anomalous interactions that affect the massive weak bosons and the top. The results at the VV level fusion are convoluted with the help of the effective vector boson approximation to give predictions for a high e

János Körner, Claudia Malvenuto, Gábor Simonyi

We strengthen and put in a broader perspective previous results of the first two authors on colliding permutations. The key to the present approach is a new non-asymptotic invariant for graphs.

Jean-Pierre Kahane

Exposition of the relation between quasi-independent and Sidon sets, theorems of Pisier according to the method of Bourgain

Roberto Casalbuoni, Joaquim Gomis, Giorgio Longhi

We construct a classical non-relativistic string model in 3+1 dimensions. The model contains a spurion tensor field that is responsible for the non-commutative structure of the model. Under double dimensional reduction the model reduces to the exotic non-relativistic particle in 2+1 dimensions.

Alberto Minguez

In this article, we give a new method for proving Howe correspondence in the case of dual pairs of type $({\rm GL}_n, {\rm GL}_m)$ over a non-Archimedean locally compact field $F$. The proof consists in combining a study on Kudla's filtration with the results of a previous article of the autor about the irreducibility of a parabolically induced represent

Jean-Pierre Kahane

Grid condition and Sidon sets. The grid condition stated by the author in 1957 as a necessary condition for a set of integers to be a Sidon set is neither improvable nor sufficient ; explanations and stronger statements are provided.

Jean-Pierre Kahane

Laplace's views on randomness and determinism. The paper was written for "Cahiers rationalistes" and addresses a rather wide audience. It contains large quotations of Laplace, most of them coming from his introduction to the book "Analytical theory of probabilities".

Jean-Pierre Kahane

Extension to Walsh series of theorems of Helson and Katznelson on trigonometric series, saying that a trigonometric series whose partial sums are positive has its coefficients tend to zero but is not necessarily a Fourier-Lebesgue series

S Collaboration, S. Carrigan, Y. A. Gallant, J. A. Hinton

Motivated by recent detections of pulsar wind nebulae in very-high-energy (VHE) gamma rays, a systematic search for VHE gamma-ray sources associated with energetic pulsars was performed, using data obtained with the H.E.S.S. (High Energy Stereoscopic System) instrument. The search for VHE gamma-ray sources near the pulsar PSR J1718-3825 revealed the new VHE

S. S. Sosin, L. A. Prozorova, A. I. Smirnov, P. Bonville

The spin-liquid phase of two highly frustrated pyrochlore magnets Gd2Ti2O7 and Gd2Sn2O7 is probed using electron spin resonance in the temperature range 1.3 - 30 K. The deviation of the absorption line from the paramagnetic position ν=γH observed in both compounds below the Curie-Weiss temperature Θ_CW ~ 10 K, suggests an opening up of a gap in the excitatio

D. Volchenkov, Ph. Blanchard

We report about universality of rank-integration distributions of open spaces in city space syntax similar to the famous rank-size distributions of cities (Zipf's law). We also demonstrate that the degree of choice an open space represents for other spaces directly linked to it in a city follows a power law statistic. Universal statistical behavior of sp

Andrea Vanossi, Giuseppe E. Santoro, Nicola Manini, Erio Tosatti

This paper is part of a study of the frictional dynamics of a confined solid lubricant film - modelled as a one-dimensional chain of interacting particles confined between two ideally incommensurate substrates, one of which is driven relative to the other through an attached spring moving at constant velocity. This model system is characterized by three inhe

C. Tappert, B. T. Gaensicke, L. Schmidtobreick, A. Aungwerojwit

System parameters of the object LTT560 are determined in order to clarify its nature and evolutionary status. We apply time-series photometry to reveal orbital modulations of the light curve, time-series spectroscopy to measure radial velocities of features from both the primary and the secondary star, and flux-calibrated spectroscopy to derive temperatures

Satyam Mukherjee, Neelima Gupte

We study the efficiency of the gradient mechanism of message transfer in a $2-d$ communication network of regular nodes and randomly distributed hubs. Each hub on the network is assigned some randomly chosen capacity and hubs with lower capacities are connected to the hubs with maximum capacity. The average travel time of single messages traveling on this la

M. Constantinou, H. Panagopoulos

We calculate the relation between the bare coupling constant g_0 and the MSbar-renormalized coupling g_MS: g_0 = Z_g(g_0,a μ) g_MS, to 2 loops in perturbation theory. We employ the standard Wilson action for gluons and the overlap action for fermions. For convenience, we have worked with the background field technique, which only requires evaluation of 2-poi

E. Bozzo, M. Falanga, A. Papitto, L. Stella

4U 2129+47 was discovered in the early 80's and classified as an accretion disk corona source due to its broad and partial X-ray eclipses. The 5.24 hr binary orbital period was inferred from the X-ray and optical light curve modulation, implying a late K or M spectral type companion star. The source entered a low state in 1983, during which the optical m

Prasenjit Ghosh, Raghani Pushpa, Stefano de Gironcoli, Shobhana Narasimhan

We have studied the adsorption of NO on small Rh clusters, containing one to five atoms, using density functional theory in both spin-polarized and non-spin-polarized forms. We find that NO bonds more strongly to Rh clusters than it does to Rh(100) or Rh(111); however, it also quenches the magnetism of the clusters. This (local) effect results in reducing th

Edouard Berg Manoukian, Seckson Sukkhasena

A careful functional treatment of quantum scattering is given using Schwinger's dynamical principle which involves a functional differentiation operation applied to a generating functional written in closed form. For long range interactions, such as for the Coulomb one, it is shown that this expression may be used to obtain explicitly the asymptotic &#34

M. Kanevski, M. Maignan, A. Pozdnoukhov, V. Timonin

The present study deals with the analysis and mapping of Swiss franc interest rates. Interest rates depend on time and maturity, defining term structure of the interest rate curves (IRC). In the present study IRC are considered in a two-dimensional feature space - time and maturity. Geostatistical models and machine learning algorithms (multilayer perceptron

R. Burioni, D. Cassi, F. M. Neri

The decimation map $\mathcal{D}$ for a network of admittances on an $n$-simplex lattice fractal is studied. The asymptotic behaviour of $\mathcal{D}$ for large-size fractals is examined. It is found that in the vicinity of the isotropic point the eigenspaces of the linearized map are always three for $n \geq 4$; they are given a characterization in terms of

Anja Schroeter, Ronny Nawrodt, Roman Schnabel, Stuart Reid

Current interferometric gravitational wave detectors (IGWDs) are operated at room temperature with test masses made from fused silica. Fused silica shows very low absorption at the laser wavelength of 1064 nm. It is also well suited to realize low thermal noise floors in the detector signal band since it offers low mechanical loss, i. e. high quality factors

F. Kh. Abdullaev, R. M. Galimzyanov, Kh. N. Ismatullaev

Collective excitations of a Bose-Einstein condensate under periodic oscillations of a quadratic plus quartic trap position has been studied. A coupled set of variational equations is derived for the width and the condensate wave function center. Analytical expressions for the growth of oscillation amplitudes in the resonance case are derived. It is shown tha

D. Volchenkov, Ph. Blanchard

The encoding of cities into non-planar dual graphs reveals their complex structure. We investigate the statistics of the typical space syntax measures for the five different compact urban patterns. Universal statistical behavior of space syntax measures uncovers the universality of the city creation mechanism.

Yuichi Ikeda, Yoshi Fujiwara, Wataru Souma, Hideaki Aoyama

We have conducted an agent-based simulation of chain bankruptcy. The propagation of credit risk on a network, i.e., chain bankruptcy, is the key to nderstanding largesized bankruptcies. In our model, decrease of revenue by the loss of accounts payable is modeled by an interaction term, and bankruptcy is defined as a capital deficit. Model parameters were est

I. G. Gurtubay, R. J. Needs

We report a study of the electronic dissociation energy of the water dimer using quantum Monte Carlo (QMC) techniques. We have performed variational quantum Monte Carlo (VMC) and diffusion quantum Monte Carlo (DMC) calculations of the electronic ground state of the water monomer and dimer using all-electron and pseudopotential approaches. We have used Slater

Haydar Uncu, Devrim Tarhan, Ersan Demiralp, Ozgur E. Mustecaplioglu

We investigate Bose-Einstein condensation of noninteracting gases in a harmonic trap with an off-center dimple potential. We specifically consider the case of a tight and deep dimple potential which is modelled by a point interaction. This point interaction is represented by a Dirac delta function. The atomic density, chemical potential, critical temperature

Stefan Wolf

We show that the generic Hall algebra of nilpotent representations of an oriented cycle specialised at $q=0$ is isomorphic to the generic extension monoid in the sense of Reineke. This continues the work of Reineke.

Peter Sjögren, Maria Vallarino

Let $G$ be the Lie group given by the semidirect product of $R^2$ and $R^+$ endowed with the Riemannian symmetric space structure. Let $X_0, X_1, X_2$ be a distinguished basis of left-invariant vector fields of the Lie algebra of $G$ and define the Laplacian $Δ=-(X_0^2+X_1^2+X_2^2)$. In this paper we consider the first order Riesz transforms $R_i=X_iΔ^{-1/2}

J. I. Vestgarden, D. V. Shantsev, Y. M. Galperin, T. H. Johansen

Flux penetration into type-II superconducing films is simulated for transverse applied magnetic field and flux creep dynamics. The films contain macroscopic, non-conducting holes and we suggest a new method to introduce the holes in the simulation formalism. The method implies reconstruction of the magnetic field change inside the hole. We find that in the r

Ihor Lubashevsky, Namik Gusein-zade, Dmitry Klochkov, Sergey Zuev

The airborne traffic monitoring system forms a novel technology of detecting vehicle motion. An optical digital camera located on an airborne platform produces a series of images which then are processed to recognized the fixed vehicles. In this way the video data are converted into the time sequence of frames containing the vehicle coordinates. In the prese

Diego Guadagnoli

I discuss how the novel experimental data on D0 - D0bar mixing can be combined to provide information on the fundamental theoretical quantities describing the mixing itself. I then discuss the theoretical impact of the new data, focusing in particular on the MSSM.

J. Dawson, R. Ramaswamy, C. Reeve, J. R. Wilson

For the first time an extensive search for various double beta decay modes of 124Sn and 112Sn has been performed. A total exposure of 43.29 kg.days has been accumulated. New half-life limits of 124Sn into excited states of 124Te have been obtained; the lower half-life limit for the first excited 2+ state at 602.7keV is T_1/2 > 3.1 *10^{18}yrs (90 % CL) and f

Ganna Kudryavtseva, Volodymyr Mazorchuk

We compare three approaches to the notion of conjugacy for semigroups, the first one via the transitive closure of the $uv\sim vu$ relation, the second one via an action of inverse semigroups on themselves by partial transformations, and the third one via characters of finite-dimensional representations.

Francis Billaud, Julien Gornay, Lucie Coniglio

A totally green chemistry alternative that would lead both to energy production from renewable feedstocks and to solutions of parts of ecological problems related to waste disposals would be very attractive. Pyrolysis of used frying oils seems to be one option for this attractive alternative as we propose to demonstrate in this study. Since 2002, the whole p

Shigeki Matsumoto, Takeo Moroi

We consider decay processes of scalar-field condensation in the framework of well-established quantum field theory. We postulate that the quantum state corresponding to the scalar-field condensation is so-called coherent state with discussing the validity of such a treatment. We show that, by using the unitarity relation of the scattering matrix, decay rate

A. V. Minkevich

Poincaré gauge theory of gravity offers opportunities to solve some principal problems of general relativity theory and modern cosmology. In the frame of this theory the gravitational interaction can have the repulsion character in the case of usual gravitating matter with positive values of energy density and pressure satisfying energy dominance condition.

Pietro Giudice, Ferdinando Gliozzi, Stefano Lottini

Random percolation can be fully interpreted as a confining pure gauge theory. With numerical high-precision measurements of Polyakov-Polyakov correlators at finite temperature, we could well observe the presence of shape effects due to rough fluctuations of the confining string, in complete agreement with the universality predictions up to the next-to-leadin

Sevilay Sevincli, R. O. Umucalilar, M. O. Oktel

We investigate the behavior of a single particle hopping on a three dimensional cubic optical lattice in the presence of a Mott insulator of bosons in the same lattice. We calculate the critical interaction strength between the impurity and background bosons, beyond which there is bound state (polaron) formation. We give exact results in the limit of a perfe

Romuald Lenczewski, Rafal Salapata

We introduce and study a noncommutative two-parameter family of noncommutative Brownian motions in the free Fock space. They are associated with Kesten laws and give a continuous interpolation between Brownian motions in free probability and monotone probability. The combinatorics of our model is based on ordered non-crossing partitions, in which to each suc

M. Ajello, A. Rau, J. Greiner, G. Kanbach

In this concluding part of the series of three papers dedicated to the Swift/BAT hard X-ray survey (BXS), we focus on the X-ray spectral analysis and statistical properties of the source sample. Using a dedicated method to extract time-averaged spectra of BAT sources we show that Galactic sources have, generally, softer spectra than extragalactic objects and

Reynier F. Peletier, Katia Ganda, Jesus Falcon-Barroso, Roland Bacon

We discuss some recent integral field spectroscopy using the SAURON instrument of a sample consisting of 24 early-type spirals, part of the SAURON Survey, and 18 late-type spirals. Using 2-dimensional maps of their stellar radial velocity, velocity dispersion, and absorption line strength, it is now much easier to understand the nature of nearby galactic bul

W. Weber, S. Seidl, S. N. Danilov, W. Prettl

The magneto-gyrotropic photogalvanic and spin-galvanic effects are observed in (0001)-oriented GaN/AlGaN heterojunctions excited by terahertz radiation. We show that free-carrier absorption of linearly or circularly polarized terahertz radiation in low-dimensional structures causes an electric photocurrent in the presence of an in-plane magnetic field. Micro

Xin-Ding Zhang, Z. D. Wang, Liang-Bin Hu, Zhi-Ming Zhang

We propose for the first time an experimentally feasible scheme to disclose the noncommutative effects induced by a light-induced non-Abelian gauge structure with trapped ions. Under an appropriate configuration, a true non-Abelian gauge potential naturally arises in connection with the geometric phase associated with two degenerated dark states in a four-st

Eric Voutier

The deeply virtual Compton scattering reaction has been investigated in the Hall A of the Jefferson Laboratory by measuring longitudinally polarized (e,e'gamma) cross sections, in the valence quark region, for protons and neutrons. In the proton channel, experimental results strongly support the factorization of the cross section at Q2 as low as 2 GeV2,

Christian Maes, Karel Netočný, Bram Wynants

How is it that entropy derivatives almost in their own are characterizing the state of a system close to equilibrium, and what happens further away from it? We explain within the framework of Markov jump processes why fluctuation theory can be based on considerations involving entropy production alone when perturbing around the detailed balance condition. Va

Shlomo Gelaki, Deepak Naidu

We first show that every group-theoretical category is graded by a certain double coset ring. As a consequence, we obtain a necessary and sufficient condition for a group-theoretical category to be nilpotent. We then give an explicit description of the simple objects in a group-theoretical category (following Ostrik, arXiv:math/0202130) and of the group of i

Hadj-Ali Gueniche, Pierre-Alexandre Glaude, René Fournet, Frédérique Battin-Leclerc

In line with the study presented in the part I of this paper, the structure of a laminar rich premixed methane flame doped with 1,3-butadiene has been investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen and 3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a ratio C4H6 / CH4 of 16 %. The flame has been stabilized

Christian Bonatti, Sylvain Crovisier, Gioia Vago, Amie Wilkinson

Given any compact manifold M, we construct a non-empty open subset O of the space of C^1-diffeomorphisms of M and a dense subset D of O such that the centralizer of every diffeomorphism in D is uncountable, hence non-trivial.

Eunhyeuk Kim, Ilsang Yoon, Hyung Mok Lee, Rainer Spurzem

We have carried out N-body simulations for rotating star clusters with equal mass and compared the results with Fokker-Planck models. These two different approaches are found to produce fairly similar results, although there are some differences with regard to the detailed aspects. We confirmed the acceleration of the core collapse of a cluster due to an ini

Sang Pyo Kim

The common interpretation of the Hawking radiation as quantum tunneling has some ambiguity such as coordinate-dependence of tunneling rate and non-invariance of the action under canonical transformations. It is shown that the tunneling process of black holes can be successfully described by Rindler coordinates in analogy with the Schwinger mechanism for pair

Tulsi Dass

Operating in the framework of `supmech' (a scheme of mechanics which aims at providing a concrete setting for the axiomatization of physics and probability theory as required in Hilbert's sixth problem; integrating noncommutative symplectic geometry and noncommutative probability in an algebraic setting, it associates, with every `experimentally acce

Ho Seong Hwang, Myung Gyoon Lee, Hong Soo Park, Sang Chul Kim

We present a kinematic analysis of the globular cluster (GC) system in the giant elliptical galaxy (gE) M60 in the Virgo cluster. Using the photometric and spectroscopic database of 121 GCs (83 blue GCs and 38 red GCs), we have investigated the kinematics of the GC system. We have found that the M60 GC system shows a significant overall rotation. The rotatio

Myung Gyoon Lee, Ho Seong Hwang, Hong Soo Park, Jang-Hyun Park

We present the measurement of radial velocities for globular clusters in M60, giant elliptical galaxy in the Virgo cluster. Target globular cluster candidates were selected using the Washington photometry based on the deep $16\arcmin \times 16\arcmin$ images taken at the KPNO 4m and using the $VI$ photometry derived from the HST/WFPC2 archive images. The spe

N. Kumada, K. Iwata, K. Tagashira, Y. Shimoda

We study effects of tilted magnetic fields on energy levels in a double-quantum-well (DQW) system, focusing on the coupling of subbands and Landau levels (LLs). The subband-LL coupling induces anticrossings between LLs, manifested directly in the magnetoresistance. The anticrossing gap becomes larger than the spin splitting at the tilting angle $θ\sim 20^\ci

Florian Otto, Emmalee K. Riegler, Greg A. Voth

Granular particles vibrated in a fluid have been found to exhibit self-organization with attractive and repulsive interactions between the particles. These interactions have been attributed to the steady streaming flow around oscillating particles. Here we examine the steady streaming flow surrounding a vertically oscillating sphere using three dimensional p

V. A. Khitrov, A. M. Sukhovoj, Pham Dinh Khang, Vuong Huu Tan

The model-free analysis of experimental data in the intensities of two-step cascades into 163Dy shows, that the basically special features of the cascade gamma-decay of its compound-state completely correspond to those observed in other nuclei. Thus, the density of the levels in this nucleus with good precision it is reproduced as sum of three, five, seven-q

V. A. Khitrov, A. M. Sukhovoj, Pham Dinh Khang, Vuong Huu Tan

The direct determination of the excitation level density and radiative strength functions of their exciting gamma-transitions is impossible for the larger part of the stable and long-life radioactive target nuclei. This circumstance is uniquely determined by the fact, that the level spacing much less than the resolution of the existing spectrometers of gamma

D. R. Lorimer, M. Bailes, M. A. McLaughlin, D. J. Narkevic

Pulsar surveys offer one of the few opportunities to monitor even a small fraction (~0.00001) of the radio sky for impulsive burst-like events with millisecond durations. In analysis of archival survey data, we have discovered a 30-Jy dispersed burst of duration <5 ms located three degrees from the Small Magellanic Cloud. The burst properties argue against a

VERITAS Collaboration, J. Grube

Due to the strong and steady TeV gamma-ray emission from the Crab Nebula supernova remnant, its measured flux and energy spectrum can be used to verify the calibration and data reduction methods applied to IACT data acquired over many observing seasons. This gives us confidence in the results obtained on variable TeV sources observed over the same period and

VERITAS Collaboration, A. Smith

Between September 2006 and February 2007, the galactic binary LS I +61 303 was monitored in the TeV band with the VERITAS array of imaging Cherenkov telescopes. These observations confirm LS I +61 303 as a variable TeV gamma-ray source, with emission peaking between orbital phase 0.6 and 0.7. During this observational period, monitoring in the X-ray regime w

VERITAS Collaboration, T. B. Humensky

Shell-type supernova remnants (SNRs) accelerate particles at the shock front between the expanding remnant and the swept-up interstellar medium. If these particles include protons and nuclei, very-high-energy gamma-ray emission may result from the decay of pions produced in interactions between cosmic rays and the local insterstellar medium. For SNRs that ar

B. Zilbergleyt

The article introduces a new relationship between the chemical system complexity and deviation of its bifurcation point from thermodynamic equilibrium. In the formalism of discrete thermodynamics of chemical equilibria, simulation of numerous equilibrium cases with regards to complexity of the reaction hosting systems has lead to a conclusion that the system

F. Shi, G. Zhao, Y. C. Liang

To calibrate the relationship between Ne3O2 (Ne3O2 = log(\neiii$\lambda3869$/\oii$\lambda3727$)) and oxygen abundances, we present a sample of $\sim$3000 $\hii$ galaxies from the Sloan Digital Sky Survey (SDSS) data release four. They are associated with a sample from the literature intended to enlarge the oxygen abundance region. We calculated the electron

A. Afanasev, M. Strikman, C. Weiss

Inclusive DIS with unpolarized beam exhibits a subtle dependence on the transverse target spin, arising from the interference of one-photon and two-photon exchange amplitudes in the cross section. We argue that this observable probes mainly the quark helicity-flip amplitudes induced by the non-perturbative vacuum structure of QCD (spontaneous chiral symmetry

Jorge Melendez, Ivan Ramirez

For more than a decade, 18 Sco (HD 146233) has been considered the star that most closely resembles the Sun, even though significant differences such as its Li content, which is about three times solar, exist. Using high resolution, high S/N spectra obtained at McDonald Observatory, we show that the stars HIP 56948 and HIP 73815 are very similar to the Sun i

Mariana Frank, Ismail Turan, Ismet Yurdusen

We systematically analyze the integrability of a Pauli system in Lorentz violating background at the non-relativistic level both in two- and three-dimensions. We consider the non-relativistic limit of the Dirac equation from the QED sector of the so-called Standard Model Extension by keeping only two types of background couplings, the vector a_mu and the axi

T. Birol, T. Dereli, Ö. E. Müstecaplıoğlu, L. You

We study the quantum coherence properties of a finite sized atomic condensate using a toy-model and the thin spectrum model formalism. The decoherence time for a condensate in the ground state, nominally taken as a variational symmetry breaking state, is investigated for both zero and finite temperatures. We also consider the lifetimes for Bogoliubov quasi-p

A. M. Bratkovsky, A. P. Levanyuk

In a recent Letter [N.A. Pertsev and H. Kohlstedt, Phys. Rev. Lett. 98, 257603 (2007)] the authors claim that &#34;even nanoscale capacitors and tunnel junctions may have out of plane polarization sufficient for memory applications.&#34; Here we show in an elementary way that this conclusion is not substantiated by their calculations and that they should hav

Stephen A. Vavasis

Nonnegative matrix factorization (NMF) has become a prominent technique for the analysis of image databases, text databases and other information retrieval and clustering applications. In this report, we define an exact version of NMF. Then we establish several results about exact NMF: (1) that it is equivalent to a problem in polyhedral combinatorics; (2) t

M. Massi, M. Kaufman Bernado

Context: Very high magnetic fields at the surface of neutron stars or in the accretion disk of black holes inhibit the production of jets. Aims: We quantify here the magnetic field strength for jet formation. Methods: By using the Alfven Radius, R_A, we study what we call {\it the basic condition}, R_A/R_*=1 or R_A/R_{LSO}=1 (LSO, last stable orbit), in its

M. Ruzzi

This article presents a squeezing transformation for quantum systems associated to finite vector spaces. The physical idea of squeezing here is taken from the action of the usual squeezing operator over wave functions defined on a real line, that is, a transformation capable to diminish (or enhance) the mean square deviation of a centered distribution. As it

V. M. Acosta, M. Auzinsh, W. Gawlik, P. Grisins

Anisotropy of atomic states is characterized by population differences and coherences between Zeeman sublevels. It can be efficiently created and probed via resonant interactions with light, the technique which is at the heart of modern atomic clocks and magnetometers. Recently, nonlinear magneto-optical techniques have been developed for selective productio

M. A. Pérez-Torres, S. Mattila, A. Alberdi, L. Colina

We report a radio detection of supernova SN 2004ip in the circumnuclear region of the luminous infrared galaxy IRAS 18293-3413, using Very Large Array (VLA) observations at 8.4 GHz on 11 June 2007. SN 2004ip had been previously discovered at near-infrared wavelengths using adaptive optics observations, but its nature (core-collapse or thermonuclear) could no

J. W. Moffat

An electroweak model is formulated in a finite, four-dimensional quantum field theory without a Higgs particle. The W and Z masses are induced from the electroweak symmetry breaking of one-loop vacuum polarization graphs. The theory contains only the observed particle spectrum of the standard model. In terms of the observed twelve lepton and quark masses, a

Jay Gambetta, Alexandre Blais, M. Boissonneault, A. A. Houck

We present a theoretical study of a superconducting charge qubit dispersively coupled to a transmission line resonator. Starting from a master equation description of this coupled system and using a polaron transformation, we obtain an exact effective master equation for the qubit. We then use quantum trajectory theory to investigate the measurement of the q

M. Dziemianczuk

Kwasniewski&#39;s cobweb posets uniquely represented by directed acyclic graphs are such a generalization of the Fibonacci tree that allows joint combinatorial interpretation for all of them under admissibility condition. This interpretation was derived in the source papers and it entailes natural enquieres already formulated therein. In our note we response

Gary T. Horowitz, Jacopo Orgera, Joe Polchinski

We study the AdS/CFT correspondence with boundary conditions AdS_5 x S^5/Z_k, where the Z_k acts freely but breaks all supersymmetry. While there are closed string tachyons at small &#39;t Hooft coupling, there are no tachyons at large coupling. Nevertheless, we show that there is a nonperturbative instability directly analogous to the decay of the Kaluza-Kl

Alexis Larranaga

In this paper we study the first law of thermodynamics for the (2+1) dimensional BTZ rotating black hole considering a pair of thermodinamical systems constructed with the two horizons of this solution. We show that these two systems are similar to the right and left movers of string theory and that the temperature associated with the black hole is the harmo

Cristian D. Gonzalez-Aviles

In this paper we obtain a Poitou-Tate exact sequence for finite and flat group schemes over a global function field. We also extend the duality theorems for 1-motives over number fields obtained by D.Harari and T.Szamuely to the function field case.

Francois Huard, Marcelo Lanzilotta, Octavio Mendoza

We show that an artin algebra having at most three radical layers of infinite projective dimension has finite finitistic dimension, generalizing the known result for algebras with vanishing radical cube.

Suhas Gangadharaiah, Jianmin Sun, Oleg A. Starykh

We present analysis of the interacting quantum wire problem in the presence of magnetic field and spin-orbital interaction. We show that an interesting interplay of Zeeman and spin-orbit terms, facilitated by the electron-electron interaction, results in the spin-density wave (SDW) state when the magnetic field and spin-orbit axes are orthogonal. We show tha

Cong-Feng Qiao

The newly found states Y(4260), Y(4361), Y(4664) and Z$^\pm$(4430) stir broad interest in the study of spectroscopy in a typical charmonium scale. The Y(4260) which was observed earlier has been interpreted as hybrid, molecular state, and baryonium, etc. In this note we show for the first time that these new structures, which are hard to be interpreted as ch

Christophe Hohlweg, Carsten Lange, Hugh Thomas

Given a finite Coxeter system $(W,S)$ and a Coxeter element $c$, we construct a simple polytope whose outer normal fan is N. Reading&#39;s Cambrian fan $F_c$, settling a conjecture of Reading that this is possible. We call this polytope the $c$-generalized associahedron. Our approach generalizes Loday&#39;s realization of the associahedron (a type $A$ $c$-ge

Jonathan Walgate, A. J. Scott

A subspace of a multipartite Hilbert space is completely entangled if it contains no product states. Such subspaces can be large with a known maximum size, S, approaching the full dimension of the system, D. We show that almost all subspaces with dimension less than or equal to S are completely entangled, and then use this fact to prove that n random pure qu

F. Krauss, T. E. J. Underwood, R. Zwicky

The process gg -> h_0 -> gamma gamma is studied in the Lee-Wick extension of the Standard Model (LWSM) proposed by Grinstein, O&#39;Connell and Wise. In this model negative norm partners for each SM field are introduced with the aim to cancel quadratic divergences in the Higgs mass. All sectors of the model relevant to gg -> h_0 -> gamma gamma are diagonaliz

Tao Mei

We study tent spaces on general measure spaces $(Ω, μ)$. We assume that there exists a semigroup of positive operators on $L^p(Ω, μ)$ satisfying a monotone property but do not assume any geometric/metric structure on $Ω$. The semigroup plays the same role as integrals on cones and cubes in Euclidean spaces. We then study BMO spaces on general measure spaces

Mark D. Hamilton

When geometric quantization is applied to a manifold using a real polarization which is &#34;nice enough&#34;, a result of Sniatycki says that the quantization can be found by counting certain objects, called Bohr-Sommerfeld leaves. Subsequently, several authors have taken this as motivation for counting Bohr-Sommerfeld leaves when studying the quantization

P. Cogan

VERITAS employs a 12m segmented mirror and pixellated photomultiplier tube camera to detect the brief pulse of Cherenkov radiation produced by the extensive air shower initiated by a cosmic high-energy gamma ray. The VERITAS data acquisition system consists of a 500 Mega-Sample-Per-Second custom-built flash ADC system, which samples the Cherenkov light pulse

H. Dimov, R. C. Rashkov

We study rigid string solutions rotating in $AdS_5\times S^5$ background. For particular values of the parameters of the solutions we find multispin solutions corresponding to giant magnons and single spike strings. We present an analysis of the dispersion relations in the case of three spin solutions distributed only in $S^5$ and the case of one spin in $Ad

Chiun-Chuan Chen, Robert M. Strain, Tai-Peng Tsai, Horng-Tzer Yau

Consider axisymmetric strong solutions of the incompressible Navier-Stokes equations in $\R^3$ with non-trivial swirl. Let $z$ denote the axis of symmetry and $r$ measure the distance to the z-axis. Suppose the solution satisfies either $|v (x,t)| \le C_*{|t|^{-1/2}} $ or, for some $\e > 0$, $|v (x,t)| \le C_* r^{-1+ε} |t|^{-ε/2}$ for $-T_0\le t < 0$ and $0<

R. Bonciani, G. Degrassi, A. Vicini

We consider the gluon fusion production cross section of a scalar Higgs boson in models where fermion and scalar massive colored particles are present. We report analytic expressions for the matrix elements of $gg\to Hg$, $q\bar{q}\to Hg$, and $qg\to Hq$ processes completing the calculation of the NLO QCD corrections in these extended scenarios. The formulas

Wojciech Kaminski, Jerzy Lewandowski, Lukasz Szulc

This letter is motivated by the recent papers by Dittrich and Thiemann and, respectively, by Rovelli discussing the status of Quantum Geometry in the dynamical sector of Loop Quantum Gravity. Since the papers consider model examples, we also study the issue in the case of an example, namely on the Loop Quantum Cosmology model of space-isotropic universe. We

X. Chen, P. W. Leung, R. J. Gooding

We have obtained the exact ground state wave functions of the Anderson-Hubbard model for different electron fillings on a 4x4 lattice with periodic boundary conditions - for 1/2 filling such ground states have roughly 166 million states. When compared to the uncorrelated ground states (Hubbard interaction set to zero) we have found strong evidence of the ver

Ion Dinca

We establish a link between Archimedes&#39; method of integration for calculating areas, volumes and centers of mass of segments of parabolas and quadrics of revolution by factorization via the moments of a balance and an integration technique for a particular integrable system, namely Bianchi&#39;s Bäcklund transformation for quadrics.

Jean-Paul Allouche, Jonathan Sondow

Let $N_{1,B}(n)$ denote the number of ones in the $B$-ary expansion of an integer $n$. Woods introduced the infinite product $P :=\prod_{n \geq 0} (\frac{2n+1}{2n+2})^{(-1)^{N_{1,2}(n)}}$ and Robbins proved that $P = 1/\sqrt{2}$. Related products were studied by several authors. We show that a trick for proving that $P^2 = 1/2$ (knowing that $P$ converges) c

Charles D. Hill, J. F. Ralph

In this paper we show how weak joint measurement and local feedback can be used to control entanglement generation between two qubits. To do this, we make use of a decoherence free subspace (DFS). Weak measurement and feedback can be used to drive the system into this subspace rapidly. Once within the subspace, feedback can generate entanglement rapidly, or

N. Crokidakis, F. D. Nobre

The phase transitions that occur in an infinite-range-interaction Ising ferromagnet in the presence of a double-Gaussian random magnetic field are analyzed. Such random fields are defined as a superposition of two Gaussian distributions, presenting the same width $σ$. Is is argued that this distribution is more appropriate for a theoretical description of re

H. J. Pirner, D. Grunewald, E. -M. Ilgenfritz, E. V. Prokhvatilov

We give a status report of our work on light cone Hamiltonian lattice QCD. We have derived an effective Hamiltonian $H_{eff}$ which is only quadratic in the momenta and therefore can be simulated by standard methods. For this Hamiltonian we determine variationally an approximate ground state wave functional in the light cone limit.

G. Quintana-Lacaci, F. Jiménez-Esteban, V. Bujarrabal, A. Castro-Carrizo

High spatial resolution images of PNe have shown their extremely complex morphology. However, the circumstellar envelopes of their progenitors, the AGB stars, are strikingly spherical. In order to understand the carving processes leading to axisymmetric nebulae, we are carrying out a study of a large sample of pre-PNe. Our emission model of the nebular molec