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September 2006 arXiv papers — page 11

Showing 1,0011,100 of 4,533 papers

  1. Magda Peligrad, Sergey Utev

    We establish the central limit theorem for linear processes with dependent innovations including martingales and mixingale type of assumptions as defined in McLeish [Ann. Probab. 5 (1977) 616--621] and motivated by Gordin [Soviet Math. Dokl. 10 (1969) 1174--1176]. In doing so we shall preserve the generality of the coefficients, including the long range depe

  2. Philip Foth, Michael Otto

    Let G be a complex semisimple Lie group and τa complex antilinear involution that commutes with the Cartan involution. If H denotes the connected subgroup of τ-fixed points in G, and K is maximally compact, each H-orbit in G/K can be equipped with a Poisson structure as described by Evens and Lu. We consider symplectic leaves of certain such H-orbits with a

  3. B. Goldys, B. Maslowski

    A formula for the transition density of a Markov process defined by an infinite-dimensional stochastic equation is given in terms of the Ornstein--Uhlenbeck bridge and a useful lower estimate on the density is provided. As a consequence, uniform exponential ergodicity and $V$-ergodicity are proved for a large class of equations. We also provide computable bo

  4. Jason Lotay

    In this paper we introduce the area of 2-ruled 4-folds in R^n (n=7 or 8), that is, submanifolds M of R^n that admit a fibration over some 2-fold Sigma such that each fibre is an affine 2-plane in R^n. This is motivated by the paper math.DG/0012060 by Joyce on ruled special Lagrangian 3-folds in C^3 and the work of the author in math.DG/0401123 on ruled assoc

  5. S. Zohren

    We describe the motivation behind the recent formulation of a nonperturbative path integral for Lorentzian quantum gravity defined through Causal Dynamical Triangulations (CDT). In the case of two dimensions the model is analytically solvable, leading to a genuine continuum theory of quantum gravity whose ground state describes a two-dimensional "univers

  6. E. A. Ivanov

    This is a brief review of the BLTP activity in supersymmetry initiated by V.I. Ogievetsky (1928-1996) and lasting for more than 30 years. The main emphasis is made on the superspace geometric approaches and unconstrained superfield formulations. Alongside such milestones as the geometric formulation of N=1 supergravity and the harmonic superspace approach to

  7. Stefano Chiantese

    We compute the anomalies of the topological A and B models with target space geometry of Hitchin's generalized type. The dimension of the moduli space of generalized holomorphic maps is also computed, which turns out to be equal to the total anomaly if the moduli space is unobstructed. We obtain this result by identifying the infinitesimal deformations o

  8. Anastasios Psinas

    We study the geodesic motion of an unstable brane moving in a higher dimensional bulk spacetime. The tachyon which is coupled to a U(1) gauge field induces a non-trivial cosmological evolution. Interestingly enough, this system exhibits a much smoother initial cosmological singularity in comparison with former works.

  9. Yacine Dolivet, Miguel Tierz

    Employing the random matrix formulation of Chern-Simons theory on Seifert manifolds, we show how the Stieltjes-Wigert orthogonal polynomials are useful in exact computations in Chern-Simons matrix models. We construct a biorthogonal extension of the Stieltjes-Wigert polynomials, not available in the literature, necessary to study Chern-Simons matrix models w

  10. A. R. Haghpayma

    We consider THETA+ pentaquark as a bound state of two vector diquarks and one anti-quark and calculate its magnetic moment.

  11. Reinhold A. Bertlmann, Beatrix C. Hiesmayr

    The nonlocal property of quantum mechanics can be nicely tested in high energy physics; in particular, the neutral kaon pairs as produced at DA$Φ$NE, Frascati, are very well suited. The analogies of kaons as compared to polarized photons or spin--1/2 particles --the kaonic qubit feature-- are reviewed. However, there are also fundamental differences which oc

  12. Toru Kanzaki, Masahiro Kawasaki, Kazunori Kohri, Takeo Moroi

    We study the scenario where a sneutrino is the next lightest supersymmetric particle (NLSP) and decays into a gravitino and standard model particles. The daughter particles such as neutrinos and quarks cause electro- and hadronic showers and affect big-bang nucleosynthesis. It is found that despite a small branching ratio, four-body processes including quark

  13. S. Gardner

    I present an exact relationship between the electric dipole moment and anomalous magnetic moment of the nucleon in the light-front formalism of QCD and consider its consequences.

  14. A. Mondragon

    We briefly review some recent developments in theoretical models of fermion masses, mixings and CP violation with discrete non-Abelian symmetries. Then, we explain the main ideas of a recently proposed Minimal S_3 Invariant Extension of the Standard Model and its application to a unified analysis of masses, mixings and CP violation in the leptonic and quark

  15. D0 Collaboration, V. M. Abazov

    We present a measurement of the fraction f_+ of right-handed W bosons produced in top quark decays, based on a candidate sample of ttbar events in the l+jets and dilepton decay channels corresponding to an integrated luminosity of 370 pb^-1 collected by the DO detector at the Fermilab Tevatron ppbar Collider at sqrt{s}=1.96 TeV. We reconstruct the decay angl

  16. B. Epp, E. Kneringer, H. Duer, P. Jussel

    An estimation of the sensitivity to measure Bs-Bsbar oscillations with the ATLAS detector is given for the detector geometry of initial layout. The delta ms reach is derived from unbinned maximum likelihood amplitude fits using Bs0 events generated with a simplified Monte Carlo method.

  17. I. S. Goncharenko, V. D. Ivashchuk, S. Rudametkin-Aguilar, D. Singleton

    We generalize the previously studied cosmological solutions in D-dimensional gravity with an antisymmetric (p+2)-form to the case when the spatial part of the metric is Ricci-flat rather than flat. These generalized solutions are characterized by a parallel self-dual or anti-self-dual charge density form Q of rank 2m and satisfy the condition Q^2 >0. As with

  18. Peter T. Beyersdorf

    Future interferometric gravitational wave detectors will make use of the coupling between shot noise and radiation pressure noise that produces a squeezed output for the quantum noise at the dark-port of the interferometer allowing these interferometers to operate with a sensitivity that exceeds the standard quantum limit at certain frequencies. The ability

  19. K. A. Arnaud, S. Babak, J. G. Baker, M. J. Benacquista

    The LISA International Science Team Working Group on Data Analysis (LIST-WG1B) is sponsoring several rounds of mock data challenges, with the purpose of fostering development of LISA data-analysis capabilities, and of demonstrating technical readiness for the maximum science exploitation of the LISA data. The first round of challenge data sets were released

  20. K. A. Arnaud, S. Babak, J. G. Baker, M. J. Benacquista

    The LISA International Science Team Working Group on Data Analysis (LIST-WG1B) is sponsoring several rounds of mock data challenges, with the purposeof fostering the development of LISA data analysis capabilities, and of demonstrating technical readiness for the maximum science exploitation of the LISA data. The first round of challenge data sets were releas

  21. Iosif Pinelis

    An O(n) test for polygon convexity is stated and proved. It is also proved that the test is minimal in a certain exact sense.

  22. Sekhar Tatikonda, Sanjoy Mitter

    We introduce a general framework for treating channels with memory and feedback. First, we generalize Massey's concept of directed information and use it to characterize the feedback capacity of general channels. Second, we present coding results for Markov channels. This requires determining appropriate sufficient statistics at the encoder and decoder.

  23. Teemu Roos, Petri Myllymäki, Jorma Rissanen

    We refine and extend an earlier MDL denoising criterion for wavelet-based denoising. We start by showing that the denoising problem can be reformulated as a clustering problem, where the goal is to obtain separate clusters for informative and non-informative wavelet coefficients, respectively. This suggests two refinements, adding a code-length for the model

  24. Oskar Hallatschek, Erwin Frey, Klaus Kroy

    Based on the wormlike chain model, a coarse-grained description of the nonlinear dynamics of a weakly bending semiflexible polymer is developed. By means of a multiple scale perturbation analysis, a length-scale separation inherent to the weakly-bending limit is exploited to reveal the deterministic nature of the spatio-temporal relaxation of the backbone te

  25. D. M. Wang, Y. H. Ren, X. Liu, J. K. Furdyna

    Coherent oscillations associated with spin precessions were observed in ultrafast optical experiments on ferromagnetic (Ga,Mn)As films. Using a complete theoretical description of the processes by which light couples to the magnetization, values for the exchange and anisotropy constants were obtained from the field-dependence of the magnon frequencies and th

  26. S. Adam, Gh. Adam

    The mean field Green function solution of the two-band singlet-hole Hubbard model for high-$T\sb{c}$ superconductivity in cuprates (Plakida, N.M. et al., Phys. Rev. B51, 16599 (1995), JETP 97, 331 (2003)) involves expressions of higher order correlation functions describing respectively the singlet hopping and the superconducting pairing. Rigorous derivation

  27. G. Buscarino, S. Agnello, F. M. Gelardi

    We report a study by electron paramagnetic resonance (EPR) on the E'_αpoint defect in amorphous silicon dioxide (a-SiO2). Our experiments were performed on gamma-ray irradiated oxygen-deficient materials and pointed out that the 29Si hyperfine structure of the E'_alpha consists in a pair of lines split by 49 mT. On the basis of the experimental resul

  28. S. J. Woo, S. Choi, L. O. Baksmaty, N. P. Bigelow

    In a rotating two-component Bose-Einstein condensate (BEC), the traditional triangular vortex lattice can be replaced by a rectangular vortex lattice or even a structure characterized in terms of vortex sheets, depending on the interspecies interactions. We study the dynamics of this system by analyzing the Bogoliubov excitation spectrum. Excitations familia

  29. G. Oshanin, H. S. Wio, K. Lindenberg, S. F. Burlatsky

    We study the search kinetics of an immobile target by a concentration of randomly moving searchers. The object of the study is to optimize the probability of detection within the constraints of our model. The target is hidden on a one-dimensional lattice in the sense that searchers have no a priori information about where it is, and may detect it only upon e

  30. B. Militzer

    The properties of hot dense helium at megabar pressures were studied with two first-principles computer simulation techniques, path integral Monte Carlo and density functional molecular dynamics. The simulations predicted that the compressibility of helium is substantially increased by electronic excitations that are present in the hot fluid at thermodynamic

  31. P. Sodano, A. Trombettoni, P. Silvestrini, R. Russo

    We show that some of the Josephson couplings of junctions arranged to form an inhomogeneous network undergo a non-perturbative renormalization provided that the network's connectivity is pertinently chosen. As a result, the zero-voltage Josephson critical currents $I_c$ turn out to be enhanced along directions selected by the network's topology. This

  32. Oskar Hallatschek, Erwin Frey, Klaus Kroy

    In Part I of this contribution, a systematic coarse-grained description of the dynamics of a weakly-bending semiflexible polymer was developed. Here, we discuss analytical solutions of the established deterministic partial integro-differential equation for the spatio-temporal relaxation of the backbone tension. For prototypal experimental situations, such as

  33. Kyung Hyuk Kim

    We study the non-equilibrium thermodynamics of single Brownian macromolecules immersed in water solvent. They are under both a hydrodynamic interaction and a feedback control on their movement by an external agent. The macromolecules are described by a Langevin equation with a multiplicative noise. Work done by the macromolecules on the water solvent is diss

  34. K. P. Neupane, J. L. Cohn, H. Terashita, J. J. Neumeier

    Measurements of the low-frequency (f<= 100 kHz) permittivity at T<= 160 K and dc resistivity (T<= 430 K) are reported for La(1-x)Ca(x)MnO(3) (0<= x<= 0.15). Static dielectric constants are determined from the low-T limiting behavior of the permittivity. The estimated polarizability for bound holes ~ 10^{-22} cm^{-3} implies a radius comparable to the interat

  35. C. Yuce, A. Kilic

    Gross-Pitaevskii equation with gain is used to model Bose Einstein condensation (BEC) fed by the surrounding thermal cloud. It is shown that the number of atoms continuously injected into BEC from the reservoir can be controlled by applying the external magnetic field via Feshbach resonance.

  36. Richard Bouzerar, Georges Bouzerar, Timothy Ziman

    We comment on the recent paper &#34;Magnetic Percolation and the Phase Diagram of the disordered RKKY model.&#34; D.J. Priour and S. Das Sarma, Phys Rev. Lett.{\bf 97}, 127201 (2006); cond-mat/0606532)

  37. P. Paci, M. Capone, E. Cappelluti, S. Ciuchi

    We study the isotope effects arising from the coupling of correlated electrons with dispersionless phonons by considering the Hubbard-Holstein model at half-filling within the dynamical mean-field theory. In particular we calculate the isotope effects on the quasi-particle spectral weight $Z$, the renormalized phonon frequency, and the static charge and spin

  38. Bikas K. Chakrabarti

    This chapter introduces the fracture nucleation process, their (extreme) statistics in disordered solids, in fiber bundle models, and in the two fractal overlap models of earthquake.

  39. Christos Panagopoulos

    Following the direct observation of abrupt changes in the superconducting ground state in doped low dimensional antiferromagnets, we have identified a phase transition where superconductivity is optimal. The experiments indicate the presence of a putative quantum critical point associated with the emergence of a glassy state. This mechanism is argued to be a

  40. A. O. Niskanen, K. Harrabi, F. Yoshihara, Y. Nakamura

    We have carried out spectroscopic measurements of a system of three strongly coupled four-junction flux qubits. The samples studied cover a wide range of parameters with the coupling energy between neighboring qubits varying between 0.75 GHz and 6.05 GHz. The observed complicated spectra agree well with eight-level theory. The experiments are relevant for th

  41. V. Markovich, I. Fita, R. Puzniak, C. Martin

    Magnetic properties of polycrystalline Sm0.1Ca0.84Sr0.06MnO3 in pristine and metastable states have been investigated in wide range of temperatures and magnetic fields. It was found that below Curie temperature TC = 105 K the pristine state exhibits phase separation comprising ferromagnetic and antiferromagnetic phases. The metastable states with reduced mag

  42. Andrea Alu, Nader Engheta

    Here we apply the optical nanocircuit concepts to design and analyze in detail a three-dimensional (3-D) plasmonic nanotransmission line network that may act as a negative-refraction broadband metamaterial at infrared and optical frequencies. After discussing the heuristic concepts at the basis of our theory, we show full-wave analytical results of the expec

  43. M. Titov, A. Ossipov, C. W. J. Beenakker

    We calculate the density of states of electron-hole excitations in a superconductor/normal-metal/superconductor (SNS) junction in graphene, in the long-junction regime that the superconducting gap is much larger than the Thouless energy. If the normal region is undoped, the excitation spectrum consists of neutral modes that propagate along the boundaries - t

  44. Sang-Hoon Kim

    We suggested a method to estimate the quantum depletion of interacting Bose particles confined by a three dimensional harmonic trap.

  45. K. Byczuk, M. Kollar, K. Held, Y. -F. Yang

    The properties of condensed matter are determined by single-particle and collective excitations and their interactions. These quantum-mechanical excitations are characterized by an energy E and a momentum \hbar k which are related through their dispersion E_k. The coupling of two excitations may lead to abrupt changes (kinks) in the slope of the dispersion.

  46. Timothy D. Andersen, Chjan C. Lim

    Systems of nearly parallel, slender vortex filaments in which angular momentum is conserved are an important simplification of the Navier-Stokes equations where turbulence can be studied in statistical equilibrium. We study the canonical Gibbs distribution based on the Klein-Majda-Damodaran (KMD) model and find a divergence in the mean square vortex position

  47. Soumen Roy, Debasis Dan, A. M. Jayannavar

    We study the noise-induced currents and reliability or coherence of transport in two different classes of rocking ratchets. For this, we consider the motion of Brownian particles in the over damped limit in both adiabatic and non-adiabatic regimes subjected to unbiased temporally symmetric and asymmetric periodic driving force. In the case of a time symmetri

  48. F. K. Roepke, S. E. Woosley

    We explore the evolution of thermonuclear supernova explosions when the progenitor white dwarf star ignites asymmetrically off-center. Several numerical simulations are carried out in two and three dimensions to test the consequences of different initial flame configurations such as spherical bubbles displaced from the center, more complex deformed configura

  49. B. J. Maughan, C. Jones, L. R. Jones, L. Van Speybroeck

    Deep XMM and Chandra observations of ClJ1226.9+3332 at z=0.89 have enabled the most detailed X-ray mass analysis of any such high-redshift galaxy cluster. The XMM temperature profile of the system shows no sign of central cooling, with a hot core and a radially declining profile. A temperature map shows asymmetry with a hot region that appears to be associat

  50. James R. Wilson, Grant J. Mathews, George M. Fuller

    We discuss a cosmology in which cold dark-matter particles decay into relativistic particles. We argue that such decays could lead naturally to a bulk viscosity in the cosmic fluid. For decay lifetimes comparable to the present hubble age, this bulk viscosity enters the cosmic energy equation as an effective negative pressure. We investigate whether this neg

  51. Jaan Einasto

    A review of the study of superclusters based on the 2dFGRS and SDSS is given. Real superclusters are compared with models using simulated galaxies of the Millennium Run. We show that the fraction of very luminous superclusters in real samples is about five times greater than in simulated samples. Superclusters are generated by large-scale density perturbatio

  52. P. S. Barklem

    Aims: To calculate transition rates from ground and excited states in neutral oxygen atoms due to electron collisions for non-LTE modelling of oxygen in late-type stellar atmospheres, thus enabling reliable interpretation of oxygen lines in stellar spectra. Methods: A 38-state R-matrix calculation in LS-coupling has been performed. Basis orbitals from the li

  53. Javier Grande, Joan Sola, Hrvoje Stefancic

    We explore the possibility of having a composite (self-conserved) dark energy (DE) whose dynamics is controlled by the quantum running of the cosmological parameters. We find that within this scenario it is feasible to find an explanation for the cosmological coincidence problem and at the same time a good qualitative description of the present data.

  54. G. Malloci, C. Joblin, G. Mulas

    Aims. We present a systematic theoretical study on 40 polycyclic aromatic hydrocarbons dications (PAHs++) containing up to 66 carbon atoms. Methods. We performed our calculations using well established quantum-chemical techniques in the framework of the density functional theory (DFT) to obtain the electronic ground-state properties, and of the time-dependen

  55. J. Machalski, K. T. Chyzy, L. Stawarz, D. Koziel

    We propose a new approach in determining ages of FR II type radio sources. We apply the assumed dynamical model of Kaiser et al. (1997) to a number of FR II type radio galaxies observed at different radio frequencies, and fit - for each frequency separately - the model free parameters to the observed sources&#39; quantities. Such a procedure, using enlarged

  56. Lee Hartmann, Andreas Burkert

    We suggest that the Orion A cloud is gravitationally collapsing on large scales, and is producing the Orion Nebula Cluster due to the focusing effects of gravity acting within a finite cloud geometry. In support of this suggestion, we show how an elliptical rotating sheet of gas with a modest density gradient along the major axis can collapse to produce a st

  57. Christophe Martayan, Dietrich Baade, Anne-Marie Hubert, Michele Floquet

    We report on the study of the population of B and Be stars in SMC young clusters, performed with the Wide Field Imager in slitless spectroscopic mode at ESO/T2.2m with a filter centered at Halpha. First, we explain the reduction methods we used and our selection of different types of objects. Second, we present results on the proportion of Be stars in SMC cl

  58. Christophe Martayan, Yves Frémat, Anne-Marie Hubert, Michele Floquet

    We search for effects of metallicity on B and Be stars in the Small and Large Magellanic Clouds (SMC and LMC) and in the Milky Way (MW). We extend our previous analysis of B and Be stars populations in the LMC to the SMC. The rotational velocities of massive stars and the evolutionary status of Be stars are examined with respect to their environments. Spectr

  59. A. M. Bykov, A. M. Krassilchtchikov, Yu. A. Uvarov, J. A. Kennea

    We found a very likely counterpart to the recently discovered hard X-ray source IGR J2018+4043 in the multi-wavelength observations of the source field. The source, originally discovered in the 20-40 keV band, is now confidently detected also in the 40-80 keV band, with a flux of (1.4 +/- 0.4) x 10(-11) erg cm(-2) s(-1). A 5 ks Swift observation of the IGR J

  60. G. Gräfener, W. -R. Hamann

    Recent results with the Potsdam Wolf-Rayet (PoWR) models have shown that Wolf-Rayet mass loss can be explained by radiative wind driving. An inspection of the galactic WR sample, however, reveals that a significant part of the observed WR stars are in conflict with our models. This group is chiefly formed by intermediate spectral subtypes. Among the populati

  61. J. X. Cheng, M. D. Ding, J. P. Li

    We have calculated the H$α$ and Ca {\sc ii} 8542 Å line profiles based on four different atmospheric models, including the effects of nonthermal electron beams with various energy fluxes. These two lines have different responses to thermal and nonthermal effects, and can be used to diagnose the thermal and nonthermal heating processes. We apply our method to

  62. G. Gräfener, W. -R. Hamann

    We present recent results for galactic WNL stars, obtained with the new Potsdam Wolf-Rayet (PoWR) hydrodynamic model atmospheres. Based on a combination of stellar wind modeling and spectral analysis we identify the galactic WNL subtypes as a group of extremely luminous stars close to the Eddington limit. Their luminosities imply progenitor masses around 120

  63. G. Gräfener, W. -R. Hamann

    We present new atmosphere models for Wolf-Rayet stars that include a self-consistent solution of the wind hydrodynamics. We demonstrate that the formation of optically thick WR winds can be explained by radiative driving on Fe line opacities, implying a strong dependence on metallicity (Z). Z-dependent model calculations for late-type WN stars show that thes

  64. K. F. Schuster, C. Kramer, M. Hitschfeld, S. Garcia-Burillo

    The mechanisms governing the star formation rate in spiral galaxies are not yet clear. The nearby, almost face-on, and interacting galaxy M51 offers an excellent opportunity to study at high spatial resolutions the local star formation laws. In this first paper, we investigate the correlation of H2, HI, and total gas surface densities with the star forming a

  65. J. M. Oliveira, J. Th van Loon, S. Stanimirovic

    We present our recent work on the conditions under which star formation occurs in a metal-poor environment, the Large Magellanic Cloud ([Fe/H] ~ -0.4). Water masers are used as beacons of the current star formation in HII regions. Comparing their location with the dust morphology imaged with the Spitzer Space Telescope, and additional Halpha imaging and grou

  66. S. G. Gregory, M. Jardine, A. Collier Cameron, J. -F. Donati

    We have modelled the rotational modulation of X-ray emission from T Tauri stars assuming that they have isothermal, magnetically confined coronae. By extrapolating surface magnetograms we find that T Tauri coronae are compact and clumpy, such that rotational modulation arises from X-ray emitting regions being eclipsed as the star rotates. Emitting regions ar

  67. Cs. Kiss, P. Abraham, R. J. Laureijs, A. Moor

    The far-infrared (FIR) emissivity of dust is an important parameter characterizing the physical properties of the grains. With the availability of stellar databases and far-infrared data from Infrared Space Observatory (ISO) it is possible to compare the optical and infrared properties of dust, and derive the far-infrared emissivity with respect to the optic

  68. J. M. Oliveira, R. D. Jeffries, J. Th van Loon

    We present IZJHKL&#39; photometry of the core of the cluster NGC 6611 in the Eagle Nebula. This photometry is used to constrain the Initial Mass Function (IMF) and the circumstellar disk frequency of the young stellar objects. Optical spectroscopy of 258 objects is used to confirm membership and constrain contamination as well as individual reddening estimat

  69. M. Forot, W. Hermsen, M. Renaud, P. Laurent

    We present observations with the INTEGRAL/IBIS telescope of the wind nebula powered by the young pulsar B1509-58 and we discuss the spatial and spectral properties of the unpulsed emission in the 20-200 keV energy band. The source extension and orientation along the northwest-southeast axis corresponds to the jet emission seen at keV and TeV energies. The ha

  70. S. Andreon

    We have measured the 3.6 micron luminosity and mass evolution of about 1000 galaxies in 32 clusters at 0.2<z<1.25 with a special attention to methodological issues, as emphasized in this proceeding contribution. We find that the luminosity of our galaxies evolves as an old and passively evolving population formed at high redshift without any need for additio

  71. Glenn J. White, C. W. M. Fridlund, P. Bergman, A. Beardsmore

    We report observations of gaseous methanol in an edge-on torus surrounding the young stellar object L1551 IRS5. The peaks in the torus are separated by ~ 10,000 AU from L1551 IRS5, and contain ~ 0.03 earth masses of cold methanol. We infer that the methanol abundance increases in the outer part of the torus, probably as a result of methanol evaporation from

  72. A. V. Kasparova, A. V. Zasov

    A sample of 66 galaxies from the catalog of Bettoni et al. (CISM) with anomalously high molecular-to-atomic hydrogen mass ratios (M_{mol}/M_{HI}>2) is considered. The sample galaxies do not differ systematically from other galaxies in the catalog with the same morphological types, in terms of their photometric parameters, rotational velocities, dust contents

  73. M. Tosi, A. Aloisi, J. Mack, M. Maio

    IZw18 has been recurrently claimed to be a young galaxy, but stars of increasingly older ages are found every time deeper magnitude levels are reached with high-resolution photometry: from the original few Myrs to, possibly, several Gyrs. We summarize the history of IZw18&#39;s age and an HST project which will allow us to derive both its distance and age.

  74. Andras Pal, Gaspar Bakos

    We present a robust and fast algorithm for performing astrometry and source cross-identification on two dimensional point lists, such as between a catalogue and an astronomical image, or between two images. The method is based on minimal assumptions: the lists can be rotated, magnified and inverted with respect to each other in an arbitrary way. The algorith

  75. O. Kargaltsev, G. G. Pavlov

    We present the UV spectroscopy and timing of three nearby pulsars (Vela, B0656+14 and Geminga) recently observed with the Space Telescope Imaging Spectrograph. We also review the optical and X-ray properties of these pulsars and establish their connection with the UV properties. We show that the multiwavelengths properties of neutron stars (NSs) vary signifi

  76. James Liebert, Kurtis A. Williams, J. B. Holberg, D. K. Sing

    Because of the similarity of the primary star of HS 1136+6646 to the planetary nebula central star BE Ursae Majoris, we did wide field imaging of the former with an H-alpha filter. No nebulosity was detected. On the other hand, the point spread function of the star appeared extended. A partially-resolved red component is detected in the image with the five-b

  77. Miguel A. Sanchez-Conde, Francisco Prada, Ewa L. Lokas

    A new revision of the gamma flux that we expect to detect in Imaging Atmospheric Cherenkov Telescopes (IACTs) from SUSY dark matter annihilation in the Draco dSph is presented using the dark matter density profiles compatible with the latest observations. This revision takes also into account the important effect of the Point Spread Function (PSF) of the Che

  78. A. Sollima, F. R. Ferraro, M. Bellazzini, L. Origlia

    We present the results of a deep photometric survey performed with FORS1@VLT aimed at investigating the complex Main Sequence structure of the stellar system omega Centauri. We confirm the presence of a double Main Sequence and identify its blue component (bMS) over a large field of view up to 26&#39; from the cluster center. We found that bMS stars are sign

  79. Naoki Seto

    We show that isotropic component of circular polarization of stochastic gravitational wave background can be explored by breaking two dimensional configuration of multiple laser interferometers for correlation analysis. By appropriately selecting orbital parameters for the proposed BBO mission, the circular polarization degree Pi can be measured down to Pi ~

  80. R. Tantalo, C. Chiosi, L. Piovan

    Basing on the huge library of 1-A resolution spectra calculated by Munari et al. over a large range of logT, log g, [Fe/H] and both for solar and a-enhanced abundance ratios [a/Fe], we present theoretical absorption-line indices on the Lick system. First we derive the so-called response functions (RFs) of Tripicco & Bell for a wide range of logT, log g, [Fe/

  81. Annalisa Panati

    We consider a model describing $N$ non-relativistic particles coupled to a massless quantum scalar field, called \emph{Nelson model}, under a binding condition on the external potential. We prove that this model does not admit ground state in the Fock representation of the canonical commutation relations, but it does in another not unitarily equivalent coher

  82. J. D. Hague, J. A. J. Matthews, B. R. Becker, M. S. Gold

    The majority of the highest energy cosmic rays are thought to be electrically charged: protons or nuclei. Charged particles experience angular deflections as they pass through galactic and extra-galactic magnetic fields. As a consequence correlation of cosmic ray arrival directions with potential sources has proved to be difficult. This situation is not help

  83. Jeppe C. Dyre

    Ten &#34;themes&#34; of viscous liquid physics are discussed with a focus on how they point to a general description of equilibrium viscous liquid dynamics (i.e., fluctuations) at a given temperature. This description is based on standard time-dependent Ginzburg-Landau equations for the density fields, stress tensor fields, potential energy density field, an

  84. L. A. Tracy, J. P. Eisenstein, L. N. Pfeiffer, K. W. West

    The transition from partial to complete spin polarization of two-dimensional electrons at half filling of the lowest Landau level has been studied using resistively-detected nuclear magnetic resonance (RDNMR). The nuclear spin-lattice relaxation time is observed to be density independent in the partially polarized phase but to increase sharply at the transit

  85. Guido Bacciagaluppi, Antony Valentini

    We reconsider the crucial 1927 Solvay conference in the context of current research in the foundations of quantum theory. Contrary to folklore, the interpretation question was not settled at this conference and no consensus was reached; instead, a range of sharply conflicting views were presented and extensively discussed. Today, there is no longer an establ

  86. Claire Christensen, Reka Albert

    Complex networks are universal, arising in fields as disparate as sociology, physics, and biology. In the past decade, extensive research into the properties and behaviors of complex systems has uncovered surprising commonalities among the topologies of different systems. Attempts to explain these similarities have led to the ongoing development and refineme

  87. Ruyong Wang, Yi Zheng, Aiping Yao

    With a Michelson interferometer using a phase-conjugate mirror (PCM) that reverses the uniform phase shift in a light path, we can conduct a first-order experiment of Special Relativity. Utilization of the PCM changes the basic concepts of an interference experiment. Placing a conventional partially reflecting mirror just in front of the PCM at the end of a

  88. Z. Zanolli, F. Fuchs, J. Furthmueller, U. von Barth

    We report the first quasiparticle calculations of the newly observed wurtzite polymorph of InAs and GaAs. The calculations are performed in the GW approximation using plane waves and pseudopotentials. For comparison we also report the study of the zinc-blende phase within the same approximations. In the InAs compound the In 4d electrons play a very important

  89. Giuseppe Mingione

    We consider non-linear elliptic equations having a measure in the right hand side, of the type $ \divo a(x,Du)=μ, $ and prove differentiability and integrability results for solutions. New estimates in Marcinkiewicz spaces are also given, and the impact of the measure datum density properties on the regularity of solutions is analyzed in order to build a sui

  90. H. Kashiwaya, T. Matsumoto, H. Shibata, S. Kashiwaya

    The switching dynamics of current-biased Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+δ}$ intrinsic Josephson junctions (IJJs) was studied to clarify the effect of d-wave superconductivity and the stack structure on the switching properties. High quality IJJs were fabricated, and then the temperature dependence of the switching probability distribution was measured for t

  91. Michel Brion

    Given a complete nonsingular algebraic variety $X$ and a divisor $D$ with normal crossings, we say that $X$ is log homogeneous with boundary $D$ if the logarithmic tangent bundle $T_X(- \log D)$ is generated by its global sections. We then show that the Albanese morphism $α$ is a fibration with fibers being spherical (in particular, rational) varieties. It f

  92. E. Isasi, Gil Schieber

    We start with a given modular invariant M of a two dimensional su(n)_k conformal field theory (CFT) and present a general method for solving the Ocneanu modular splitting equation and then determine, in a step-by-step explicit construction, 1) the generalized partition functions corresponding to the introduction of boundary conditions and defect lines; 2) th

  93. Jiansong Gao, Benjamin A. Mazin, Peter K. Day, Jonas Zmuidzinas

    We have measured noise in thin-film superconducting coplanar waveguide resonators. This noise appears entirely as phase noise, equivalent to a jitter of the resonance frequency. In contrast, amplitude fluctuations are not observed at the sensitivity of our measurement. The ratio between the noise power in the phase and amplitude directions is large, in exces

  94. Agung Budiyono

    We develop a class of traveling-envelope solutions of Schrödinger equation for a free particle whose amplitude is moving with constant group velocity while keeping its shape undistorted. We show that solution with arbitrary finite group velocity is obtained by Lorentz boosting the solution with vanishing group velocity, if the quantum average energy $E$ and

  95. W. T. Chen

    $K^0_SK^0_S$ production in two-photon collisions has been studied using a 397.6 fb$^{-1}$ data sample collected with the Belle detector at the KEKB $e^+e^-$ collider. For the first time the cross sections are measured in the two-photon center-of-mass energy range between 2.4 GeV and 4.0 GeV and angular range $|\cos\theta^*|<0.6$. Combining the results with m

  96. Guihua Chen, Zhibing Li, Jie Peng, Chunshan He

    The field electron emission from the single-walled carbon nanotubes with their open ends terminated by -BH, -NH, and -O has been simulated. The apex-vacuum barrier and the emission current have been calculated. It has been found that -BH and -NH suppress the apex-vacuum barrier significantly and lead to higher emission current in contrast to the -O terminate

  97. Thierry Giordano, Hiroki Matui, Ian F. Putnam, Christian F. Skau

    We show that every minimal, free action of the group Z^2 on the Cantor set is orbit equivalent to an AF-relation. As a consequence, this extends the classification of minimal systems on the Cantor set up to orbit equivalence to include AF-relations, Z-actions and Z^2-actions.

  98. Marian Anghel, Kenneth A. Werley, Adilson E. Motter

    We introduce a stochastic model that describes the quasi-static dynamics of an electric transmission network under perturbations introduced by random load fluctuations, random removing of system components from service, random repair times for the failed components, and random response times to implement optimal system corrections for removing line overloads

  99. Gabriel Murariu

    In our days, the necessity of laboratory apparatus accustoming by building up specific software objects for studying the virtual evolution of physical phenomena is a major request. In this respect, the aim of the present paper is to present a developed set of electricity interactive simulation computer applica-tions. By following an Object Oriented Programmi

  100. Chengshi Liu

    Complete discrimination system for polynomial and direct integral method were discussed systematically. In particularly, we pointed out some mistaken viewpoints. Combining with complete discrimination system for polynomial, direct integral method was developed to become a powerful method and was applied to a lot of nonlinear mathematical physics equations. A