October 2006 arXiv papers — page 11
Showing 1,001–1,100 of 5,236 papers
Robert O. Bauer
We study the probability that chordal $\text{SLE}_{8/3}$ in the unit disk from $\exp(ix)$ to 1 avoids the disk of radius $q$ centered at zero. We find the initial/boundary-value problem satisfied by this probability as a function of $x$ and $a=\ln q$, and show that asymptotically as $q$ tends to one this probability decays like $\exp(-cx/(1-q))$ with $c=5π/8
Kevin McGerty
The quantum Frobenius map and it splitting are shown to descend to corresponding maps for generalized $q$-Schur algebras at a root of unity. We also define analogs of $q$-Schur algebras for any affine algebra, and prove the corresponding results for them.
Daniel Baumann, Liam McAllister
We derive a microscopic bound on the maximal field variation of the inflaton during warped D-brane inflation. By a result of Lyth, this implies an upper limit on the amount of gravitational waves produced during inflation. We show that a detection at the level $r > 0.01$ would falsify slow roll D-brane inflation. In DBI inflation, detectable tensors may be p
Domenico Orlando
This thesis is almost entirely devoted to studying string theory backgrounds characterized by simple geometrical and integrability properties. The archetype of this type of system is given by Wess-Zumino-Witten models, describing string propagation in a group manifold or, equivalently, a class of conformal field theories with current algebras. We study the m
J. M. Drummond, L. Gallot, E. Sokatchev
Using the form of N=2 superconformal invariants we derive the explicit relation between the bottom and top components of the correlator of four stress-tensor multiplets in N=4 Super Yang-Mills. The result is given in terms of an eighth order differential operator acting on the function of two variables which characterises these correlators. It allows us to s
Hiroyuki Abe, Yutaka Sakamura
We reinterpret the Scherk-Schwarz (SS) boundary condition for SU(2)_R in a compactified five-dimensional (5D) Poincare supergravity in terms of the twisted SU(2)_U gauge fixing in 5D conformal supergravity. In such translation, only the compensator hypermultiplet is relevant to the SS twist, and various properties of the SS mechanism can be easily understood
J. L. Chkareuli, Z. R. Kepuladze
The spontaneous Lorentz invariance violation (SLIV) developing in QED type theories with the nonlinear four-vector field constraint $A_μ^{2}=M^{2}$ (where $M$ is a proposed scale of the Lorentz violation) is considered in the case when the internal U(1) charge symmetry is also spontaneously broken. We show that such a SLIV pattern induces the genuine vector
Riccardo Apreda, Johanna Erdmenger, Dieter Lust, Christoph Sieg
As an extension of holography with flavour, we analyze in detail the embedding of a D7-brane probe into the Polchinski-Strassler gravity background, in which the breaking of conformal symmetry is induced by a 3-form flux G_3. This corresponds to giving masses to the adjoint chiral multiplets. We consider the N=2 supersymmetric case in which one of the adjoin
Maxim Perelstein, Andrew Spray
Little Higgs models with T parity contain an attractive dark matter candidate, the heavy photon. We compute the cross section of the heavy photon annihilation into Z-photon pairs, which turns out to be substantially higher than the previously computed cross section for the two photon final state. Unfortunately, even with this enhancement, the monochromatic p
Stefan Leupold
In thermal field theory selfconsistent (Phi-derivable) approximations are used to improve (resum) propagators at the level of two-particle irreducible diagrams. At the same time vertices are treated at the bare level. Therefore such approximations typically violate the Ward identities connected to internal symmetries. Examples are presented how such violatio
B. Loiseau, B. El-Bennich, A. Furman, R. Kaminski
To describe the weak three-body B decays into pi+ pi- K, we recently derived amplitudes based on two-body QCD factorization followed by pi+ pi- final state interactions in isoscalar S- and isovector P-waves. We study here the sensitivity of the results to the values of the B to f0(980) transition form factor and to the effective decay constant of the f0(980)
C. Garcia-Recio, J. Nieves, L. L. Salcedo
Starting from a consistent SU(6) extension of the Weinberg-Tomozawa (WT) meson-baryon chiral Lagrangian (Phys. Rev. D74 (2006) 034025), we study the s-wave meson-baryon resonances in the strangeness S=-3 and negative parity sector. Those resonances are generated by solving the Bethe-Salpeter equation with the WT interaction used as kernel. The considered mes
I. de Medeiros Varzielas
The observed neutrino mixing, having a near maximal atmospheric neutrino mixing angle and a large solar mixing angle, is close to tri-bi-maximal, putting leptonic mixing in contrast with the small mixing of the quark sector. We discuss a model in which Delta(27) (a subgroup of SU(3)) is the family symmetry, and tri-bi-maximal mixing directly follows from the
Axel Maas, Attilio Cucchieri, Tereza Mendes
Green's functions are gauge-dependent quantities. Thus, the manifestation of confinement in these correlation functions also depends on the gauge. Here we use lattice gauge theory to study the gluon and the ghost propagators in a gauge (the so-called lambda-gauge) interpolating between the Landau and the Coulomb gauge. Results are compared to the usual m
M. Engelhardt, B. Sperisen
The random vortex world-surface model is extended to the gauge groups SU(4) and Sp(2). Compared to the SU(2) and SU(3) models studied previously, which reproduce the infrared properties of the corresponding Yang-Mills theories on the basis of a simple vortex world-surface curvature action, new dynamical characteristics become important. In the SU(4) case, an
Ivan Horvath
We discuss a proposal for the construction of lattice QCD with gauge action, fermionic action, theta-term, and the operators all based on the lattice Dirac operator D with exact chiral symmetry. The simplest regularization of this type uses the proposition that the classical limit of scalar gauge density associated with trace of D is (up to an additive const
Falk Bruckmann, Mark de Kok
The noncommutativity approach to SUSY on the lattice is shown to be inconsistent and a similar inconsistency is displayed for the link approach.
C. Allton, D. J. Antonio, P. A. Boyle, C. Dawson
We present results for the light meson masses, the bare strange quark mass and preliminary non-perturbative renormalisation of B_K in 2+1 flavour domain wall QCD. The ensembles used were generated with the Iwasaki gauge action and have a volume of 16^3 x 32 with a fifth dimension size of 16 and an inverse lattice spacing of 1.6 GeV. These ensembles have u an
Bernd Bruegmann, Jose A. Gonzalez, Mark Hannam, Sascha Husa
We present single and binary black hole simulations that follow the moving puncture paradigm of simulating black-hole spacetimes without excision, and use moving boxes mesh refinement. Focussing on binary black hole configurations where the simulations cover roughly two orbits, we address five major issues determining the quality of our results: numerical di
Johan Bollen, Herbert Van de Sompel
There exist ample demonstrations that indicators of scholarly impact analogous to the citation-based ISI Impact Factor can be derived from usage data. However, contrary to the ISI IF which is based on citation data generated by the global community of scholarly authors, so far usage can only be practically recorded at a local level leading to community-speci
Anytime coding on the infinite bandwidth AWGN channel: A sequential semi-orthogonal optimal code
cs.ITAnant Sahai
It is well known that orthogonal coding can be used to approach the Shannon capacity of the power-constrained AWGN channel without a bandwidth constraint. This correspondence describes a semi-orthogonal variation of pulse position modulation that is sequential in nature -- bits can be ``streamed across'' without having to buffer up blocks of bits at
Evgueni A. Haroutunian, Parandzem M. Hakobyan
The problem of many hypotheses logarithmically asymptotically optimal (LAO) testing for a model consisting of three or more independent objects is solved. It is supposed that $M$ probability distributions are known and each object independently of others follows to one of them. The matrix of asymptotic interdependencies (reliability--reliability functions) o
Maximilien Gadouleau, Zhiyuan Yan
In this paper, we first introduce the concept of elementary linear subspace, which has similar properties to those of a set of coordinates. Using this new concept, we derive properties of maximum rank distance (MRD) codes that parallel those of maximum distance separable (MDS) codes. Using these properties, we show that the decoder error probability of MRD c
Kun-hong Liu, Yong Xu, De-shuang Huang, Min Cheng
The advances in WDM technology lead to the great interest in traffic grooming problems. As traffic often changes from time to time, the problem of grooming dynamic traffic is of great practical value. In this paper, we discuss dynamic grooming of traffic in star and tree networks. A genetic algorithm (GA) based approach is proposed to support arbitrary dynam
Joost Vennekens, David Gilis, Marc Denecker
It is well known that, under certain conditions, it is possible to split logic programs under stable model semantics, i.e. to divide such a program into a number of different "levels", such that the models of the entire program can be constructed by incrementally constructing models for each level. Similar results exist for other non-monotonic formal
P. Ao
Two years ago the reasons for resistance to the fundamental vortex dynamics in super media emerged in 1990's were analyzed (cond-mat/0407007). Five "mistakes" were identified to explain this resistance. Given the current tremendous interest in vortex dynamics, it would be desirable to provide a progress report: A survey of literature reveals that
Tomas Novotny, Jonas Nyvold Pedersen, Tobias Ambjornsson, Mikael Sonne Hansen
We investigate the coalescence of two DNA-bubbles initially located at weak segments and separated by a more stable barrier region in a designed construct of double-stranded DNA. The characteristic time for bubble coalescence and the corresponding distribution are derived, as well as the distribution of coalescence positions along the barrier. Below the melt
F. E. Camino, Wei Zhou, V. J. Goldman
We report experimental realization of a quasiparticle interferometer where the entire system is in 1/3 primary fractional quantum Hall state. The interferometer consists of chiral edge channels coupled by quantum-coherent tunneling in two constrictions, thus enclosing an Aharonov-Bohm area. We observe magnetic flux and charge periods h/e and e/3, equivalent
Sadhan K. Adhikari
We use a time-dependent dynamical hydrodynamic model to study a collapse in a degenerate fermion-fermion mixture (DFFM) of different atoms. Due to a strong Pauli-blocking repulsion among identical spin-polarized fermions at short distances there cannot be a collapse for repulsive interspecies fermion-fermion interaction. However, there can be a collapse for
D. P. Wang, D. E. Feldman, B. R. Perkins, A. J. Yin
We report electrical transport measurements on individual disordered carbon nanotubes, grown catalytically in a nanoporous anodic aluminum oxide template. In both as-grown and annealed types of nanotubes, the low-field conductance shows as exp[-(T_{0}/T)^{1/2}] dependence on temperature T, suggesting that hopping conduction is the dominant transport mechanis
Jens Koch, Eran Sela, Yuval Oreg, Felix von Oppen
Low-temperature transport through molecules with effectively negative charging energy U exhibits a charge-Kondo effect. We explore this regime analytically by establishing an exact mapping between the negative-U and the positive-U Anderson models, which is suitable for the description of nonequilibrium transport. We employ this mapping to demonstrate the int
Vladimir Belostotsky
This paper presents a new defect model for the mixed mobile ion effect. The essential physical concept involved is that simultaneous migration of two unlike mobile ions in mixed ionic glass is accompanied by expansion or contraction of the guest-occupied sites with distortion of surrounding glass matrix; in many cases, an intensity of the local stresses in g
Anderson transition: numerical vs analytical results (comment on the review article by P.Markos cond-mat/0609580)
cond-mat.dis-nnI. M. Suslov
In the recent review article, P.Markos admits that practically all numerical results on the critical behavior near the Anderson transition are in conflict with analytical expectations, but no serious discussion of this fact is given. The aim of the present comment is to give an analysis of the arising situation.
Density functional theory and DFT+U study of transition metal porphines adsorbed on Au(111) surfaces and effects of applied electric fields
cond-mat.mtrl-sciKevin Leung, Susan B. Rempe, Peter A. Schultz, Eduardo M. Sproviero
We apply Density Functional Theory (DFT) and the DFT+U technique to study the adsorption of transition metal porphine molecules on atomistically flat Au(111) surfaces. DFT calculations using the Perdew-Burke-Ernzerhof (PBE) exchange correlation functional correctly predict the palladium porphine (PdP) low-spin ground state. PdP is found to adsorb preferentia
Michael Grinfeld
The purpose of the study is to further investigate the classical Gibbs analysis of the heterogeneous system "stressed crystal - melt." It is demonstrated that each equilibrium configuration is stable with respect to a special class of variations introduced by Gibbs. This basic result is compared with the opposite result on the universal morphological
Fangwei Ye, Yaroslav V. Kartashov, Lluis Torner
We predict the existence and study the basic properties of strongly asymmetric matter wave solitons that form at the interface produced by regions with different inter-atomic interaction strengths in pancake Bose-Einstein condensates. We address several types of surface solitons featuring topologically complex structures, including vortex and dipole-mode sol
H. C. Walker, K. A. McEwen, D. F. McMorrow, S. B. Wilkins
By combining accurate heat capacity and X-ray resonant scattering results we have resolved the long standing question regarding the nature of the quadrupolar ordered phases in UPd_3. The order parameter of the highest temperature quadrupolar phase has been uniquely determined to be antiphase Q_{zx} in contrast to the previous conjecture of Q_{x^2-y^2} . The
Exact ground state for a class of matrix Hamiltonian models: quantum phase transition and universality in the thermodynamic limit
cond-mat.dis-nnMassimo Ostilli, Carlo Presilla
By using a recently proposed probabilistic approach, we determine the exact ground state of a class of matrix Hamiltonian models characterized by the fact that in the thermodynamic limit the multiplicities of the potential values assumed by the system during its evolution are distributed according to a multinomial probability density. The class includes i) t
Quantitative Evaluation of the Effects of Positional versus Orientational Disorder on the Scattering of Acoustic Phonons in Disordered Matter
cond-mat.dis-nnF. J. Bermejo, R. Fernandez-Perea, C. Cabrillo, A. I. Krivchikov
The phonon scattering processes on the three solid phases of ethanol are investigated by means of thermal conductivity, light and neutron scattering measurements as well as molecular dynamics simulations on single-crystalline models for the two crystalline modifications (fully ordered monooclinic and orientationally disordered bcc phases). The orientationall
Pure spin currents induced by spin-dependent scattering processes in SiGe quantum well structures
cond-mat.mes-hallS. D. Ganichev, S. N. Danilov, V. V. Bel'kov, S. Giglberger
We show that spin-dependent electron-phonon interaction in the energy relaxation of a two-dimensional electron gas results in equal and oppositely directed currents in the spin-up and spin-down subbands yielding a pure spin current. In our experiments on SiGe heterostructures the pure spin current is converted into an electric current applying a magnetic fie
Markus Rauscher, S. Dietrich, Joel Koplik
We propose to drive open microfluidic systems by shear in a covering fluid layer, e.g., oil covering water-filled chemical channels. The advantages as compared to other means of pumping are simpler forcing and prevention of evaporation of volatile components. We calculate the expected throughput for straight channels and show that devices can be built with o
Geometric treatment of electromagnetic phenomena in conducting materials: variational principles
cond-mat.supr-conA Badia-Majos, J F Cariñena, C Lopez
The dynamical equations of an electromagnetic field coupled with a conducting material are studied. The properties of the interaction are described by a classical field theory with tensorial material laws in space-time geometry. We show that the main features of superconducting response emerge in a natural way within the covariance, gauge invariance and vari
L. Tornberg, G. Johansson
We analyze the dispersive readout of superconducting charge and flux qubits as a quantum measurement process. The measurement oscillator frequency is considered much lower than the qubit frequency. This regime is interesting because large detuning allows for strong coupling between the measurement oscillator and the signal transmission line, thus allowing fo
Gabor J Kalman, Peter Hartmann, Zoltan Donko, Kenneth I Golden
We report a combined analytic and Molecular Dynamics analysis of the collective mode spectrum of an electron-hole (bipolar) bilayer in the strong coupling quasi-classical limit. A robust, isotropic energy gap is identified in the out-of-phase spectra, generated by the combined effect of correlations and of the excitation of the bound dipoles; the in-phase sp
Potential super-hard Osmium di-nitride with fluorite structure: First-principles calculations
cond-mat.mtrl-sciChang-Zeng Fan, Song-Yan Zeng, Li-Xin Li, Ri-Ping Liu
We have performed systematic first-principles calculations on di-carbide, -nitride, -oxide and -boride of platinum and osmium with the fluorite structure. It is found that only PtN$_{2}$, OsN$_{2}$ and OsO$_{2}$ are mechanically stable. In particular OsN$_{2}$ has the highest bulk modulus of 360.7 GPa. Both the band structure and density of states show that
Low compressible noble metal carbides with rock-salt structure: ab initio total energy calculations of the elastic stability
cond-mat.mtrl-sciChang-Zeng Fan, Song-Yan Zeng, Zai-Ji Zhan, Ri-Ping Liu
We have systematically studied the mechanical stability of all noble metal carbides with the rock-salt structure by calculating their elastic constants within the density function theory scheme. It was found that only four carbides (RuC, PdC, AgC and PtC) are mechanically stable. In particular, we have shown that RuC, PdC, and PtC have very high bulk modulus
Tomoyuki Maruyama, Takushi Nishimura
We investigate collective excitations coupled with monopole and quadrupole oscillations in two-component fermion condensates in deformed traps. The frequencies of monopole and dipole modes are calculated using Thomas-Fermi theory and the scaling approximation. When the trap is largely deformed, these collective motions are decoupled to the transverse and lon
Alex Arenas, Albert Diaz-Guilera
We investigate the connection between the dynamics of synchronization and the modularity on complex networks. Simulating the Kuramoto's model in complex networks we determine patterns of meta-stability and calculate the modularity of the partition these patterns provide. The results indicate that the more stable the patterns are, the larger tends to be t
Masahiko Higuchi, Katsuhiko Higuchi
We present a density functional scheme for calculating the pair density (PD) by means of the correlated wave function. This scheme is free from both of problems related to PD functional theory, i.e., (a) the need to constrain the variational principle to $N$-representable PDs and (b) the development of a kinetic energy functional. By using the correlated wav
Disentangling single-particle gap by electronic Raman absorption in electron-doped cuprates
cond-mat.supr-conHong-Yan Lu, Qiang-Hua Wang
In the under- to optimal-doping regimes of electron-doped cuprates, it was theoretically suspected that there is a coexistence of superconducting (SC) and antiferromagnetic (AFM) orders. The quasi-particle excitations could be gapped by both orders, and the effective gap is non-monotonic d-wave-like in the momentum space. Alternatively the gap was also specu
Supplementary Information for cond-mat/0610721: Potok et al. "Observation of the two-channel Kondo effect"
cond-mat.mes-hallR. M. Potok, I. G. Rau, Hadas Shtrikman, Yuval Oreg
This document provides detailed descriptions of data acquisition and data analysis in support of the accompanying Article, cond-mat/0610721: Observation of the two-channel Kondo effect. Some of the most intriguing problems in solid state physics arise when the motion of one electron dramatically affects the motion of surrounding electrons. Traditionally, suc
Yu. N. Gartstein, T. D. Bustamante, S. Ortega Castillo
Electrons and holes on semiconducting nanotubes immersed in sluggish polar media can undergo self-localization into polaronic states. We evaluate the binding energy $\bpol$ of adiabatic Fröhlich-Pekar polarons confined to a cylindrical surface and compare it to the corresponding exciton binding energy $\bexc$. The ratio $\bpol/\bexc$ is found to be a non-mon
R. M. Potok, I. G. Rau, Hadas Shtrikman, Yuval Oreg
Some of the most intriguing problems in solid state physics arise when the motion of one electron dramatically affects the motion of surrounding electrons. Traditionally, such highly-correlated electron systems have been studied mainly in materials with complex transition metal chemistry. Over the past decade, researchers have learned to confine one or a few
Jörn Davidsen, Sergei Stanchits, Georg Dresen
We present a detailed statistical analysis of acoustic emission time series from laboratory rock fracture obtained from different experiments on different materials including acoustic emission controlled triaxial fracture and punch-through tests. In all considered cases, the waiting time distribution can be described by a unique scaling function indicating i
Manipulation of collective spin correlations in semiconductors with polarization squeezed vacuum
cond-mat.mes-hallE. Ginossar, Y. Levinson, S. Levit
We calculate the transfer rate of correlations from polarization entangled photons to the collective spin of a many-electron state in a two-band system. It is shown that when a semiconductor absorbs pairs of photons from a two-mode squeezed vacuum, certain fourth order electron-photon processes correlate the spins of the excited electron pairs of different q
Temperature and Magnetic Field Dependencies of Condon Domain Phase in Lifschitz-Kosevich-Shoenberg Approximation
cond-mat.str-elN. Logoboy, W. Joss
The temperature and magnetic field behavior of non-uniform diamagnetic phase of strongly correlated electron gas at the conditions of dHvA effect is analyzed. It is shown, that in the framework of Lifschitz-Kosevich-Shoenberg approximation the magnetic induction splitting, as well as the range of existence of Condon domains, are characterized by strong depen
Temperature and Magnetic Field Dependencies in a Model of Diamagnetic Hysteresis in Beryllium
cond-mat.str-elN. Logoboy, W. Joss
The model of diamagnetic hysteresis loop of strongly correlated electron gas at the conditions of dHvA effect is developed. It is shown, that in the framework of Rayleigh theory for magnetization loop, the coercive force and remnant magnetization in every period of dHvA oscillations are characterized by strong dependencies on temperature, magnetic field and
The HgMn Binary Star Phi Herculis: Detection and Properties of the Secondary and Revision of the Elemental Abundances of the Primary
astro-phR. T. Zavala, S. J. Adelman, C. A. Hummel, A. F. Gulliver
Observations of the Mercury-Manganese star Phi Herculis with the Navy Prototype Optical Interferometer (NPOI) conclusively reveal the previously unseen companion in this single-lined binary system. The NPOI data were used to predict a spectral type of A8V for the secondary star Phi Her B. This prediction was subsequently confirmed by spectroscopic observatio
A. A. Schekochihin, S. C. Cowley, W. Dorland
Theoretical approaches to low-frequency magnetized turbulence in collisionless and weakly collisional astrophysical plasmas are reviewed. The proper starting point for an analytical description of these plasmas is kinetic theory, not fluid equations. The anisotropy of the turbulence is used to systematically derive a series of reduced analytical models. Abov
XMM-Newton survey of the central region of M31. Spectral properties and variability of bright X-ray sources and source classification
astro-phSergey Trudolyubov, William Priedhorsky, France Cordova
(Abridged) We present the results of the systematic survey of X-ray sources in the central region of M31 using the data from XMM-Newton observations performed in the years 2000-2004. The spectral properties and variability of 123 bright X-ray sources with apparent luminosities between ~10^{36} and \~5x10^{38} ergs/s were studied in detail. The spectral distr
Benjamin D. Oppenheimer, Romeel Davé, Kristian Finlator
We use cosmological hydrodynamic simulations including galactic feedback based on observations of local starbursts to find a self-consistent evolutionary model capable of fitting the observations of the intergalactic metallicity history as traced by C IV between z=6.0->1.5. Our main finding is that despite the relative invariance in the measurement of Omega(
Zeeman tomography of magnetic white dwarfs IV. The complex field structure of the polars EF Eri, BL Hyi, and CP Tuc
astro-phK. Beuermann, F. Euchner, K. Reinsch, S. Jordan
The magnetic fields of the accreting white dwarfs (WDs) in magnetic cataclysmic variables (mCVs) determine the accretion geometries, the emission properties, and the secular evolution of these objects. We determine the structure of the surface magnetic fields of the WDs primaries in magnetic CVs using Zeeman tomography. Our study is based on orbital-phase re
RXTE observations of the first transient Z source XTE J1701-462: shedding new light on mass accretion in luminous neutron star LMXBs
astro-phJeroen Homan, Michiel van der Klis, Rudy Wijnands, Tomaso Belloni
(Abridged) We report on ten weeks of RXTE observations of the X-ray transient XTE J1701-462. Comparisons with other sources suggest it had all the characteristics of the neutron star Z sources (the brightest persistent neutron star LMXBs). These include Z tracks in X-ray color diagrams and typical variability components detected in the power spectra. XTE J17
K. Katarzynski, G. Ghisellini
We investigate the dissipation of the bulk kinetic energy of a relativistic jet at different distances from the central power--house and analyse in detail how the dissipated energy is radiated away. We assume that the location of the dissipation region is a function of the bulk Lorentz factor Gamma of the jet, being closer to the center for smaller Gamma. Th
Galaxy groups and low mass clusters at z<0.6: A perspective from the XMM Large Scale Structure survey
astro-phJ. P. Willis, F. Pacaud, M. Pierre
Galaxy groups and low-mass clusters provide important laboratories in which to study X-ray gas physics and the interplay between galaxy evolution and environmental effects. The X-ray Multi-Mirror (XMM) Large Scale Structure (LSS) survey has currently imaged 5 deg2 to a nominal extended source flux limit of order 10e-14 ergs/s/cm2 and is dominated numerically
Anne Pellerin, Martin Meyer, Jason Harris, Daniela Calzetti
Traditional studies of stellar clusters in external galaxies use surface photometry and therefore focus on systems that are still bright and compact enough to be separated from the stellar background. Consequently, the latter stages of unbound cluster evolution are still poorly understood. This dramatically constrains our knowledge of the dissolution process
Timothy Y. Brooke, Tracy L. Huard, Tyler L. Bourke, A. C. Adwin Boogert
Infrared images of the dark cloud core B59 were obtained with the Spitzer Space Telescope as part of the "Cores to Disks" Legacy Science project. Photometry from 3.6-70 microns indicates at least 20 candidate low-mass young stars near the core, more than doubling the previously known population. Out of this group, 13 are located within about 0.1 pc i
Hubble diagram of gamma-ray bursts: Robust evidence for a Chaplygin gas expansion-driven universe with phase transition at $z \simeq 3$
astro-phHerman J. Mosquera Cuesta, Habib Dumet M., Rodrigo Turcati, Carlos A. Bonilla Quintero
The Hubble diagram (HD) of Gamma-Ray Bursts (GRBs) having properly estimated redshifts is compared with the predicted one for the Chaplygin gas (CG), a dark energy candidate. The CG cosmology and that of Friedmann and $Λ$-CDM models are studied and confronted to the GRBs observations. The model-to-sample $χ^2$ statistical analysis indicates the CG model as t
Melike Afşar, Howard E. Bond
The unusual variable star V838 Monocerotis underwent an eruption in 2002. It continues to illuminate a spectacular series of light echoes, as the outburst light is scattered from circumstellar dust. V838 Mon has an unresolved B3 V companion star. We serendipitously discovered that a neighboring 16th-mag star is also of type B. We then carried out a survey of
M. B. N. Kouwenhoven
Observations over the last decade have indicated that a large fraction of the stars are part of a binary or multiple system. For our understanding of star formation it is therefore of crucial importance to characterise the outcome of the star forming process in terms of binary parameters. This thesis describes the recovery of the primordial binary population
Andreas Mueller
We study and quantify gravitational redshift by means of relativistic ray tracing simulations of emission lines. The emitter model is based on thin, Keplerian rotating rings in the equatorial plane of a rotating black hole. Emission lines are characterised by a generalized fully relativistic Doppler factor or redshift associated with the line core. Two modes
Instability strips of SPB and beta Cephei stars: the effect of the updated OP opacities and of the metal mixture
astro-phA. Miglio, J. Montalban, M. -A. Dupret
The discovery of $β$ Cephei stars in low metallicity environments, as well as the difficulty in theoretically explaining the excitation of the pulsation modes observed in some $β$ Cephei and hybrid SPB-$β$ Cephei pulsators, suggest that the ``iron opacity bump'' provided by stellar models could be underestimated. We analyze the effect of uncertaintie
Sergey Ostapchenko
The status of present theoretical description of very high energy hadronic interactions is reviewed. The impact of new results of accelerator and cosmic ray experiments on hadronic interaction model constructions is discussed in detail. Special attention is payed to remaining uncertainties in model extrapolations into the ultra-high energy domain, in particu
A. I. Diaz, E. Terlevich, M. Castellanos, G. F. Hagele
We present a spectrophotometric study of circumnuclear star forming regions (CNSFR) in the early type spiral galaxies: NGC 2903, NGC 3351 and NGC 3504, all of them of over solar metallicity according to standard empirical calibrations. A detailed determination of their abundances is made after careful subtraction of the very prominent underlying stellar abso
Sascha P. Quanz, Daniel Apai, Thomas Henning
We characterize the small and large scale environment of the young star V1331 Cygni with high resolution HST/WFPC2 and Digitized Sky Survey images. In addition to a previously known outer dust ring (~30'' in diameter), the HST/WFPC2 scattered light image reveals an inner dust ring for the first time. This ring has a maximum radius of 6.5'' an
F. Royer, J. Zorec, A. E. Gomez
Aim - In this work, a sample of vsini of B9 to F2-type main sequence single stars has been built from highly homogeneous vsini parameters determined for a large sample cleansed from objects presenting the Am and Ap phenomenon as well as from all known binaries. The aim is to study the distributions of rotational velocities in the mass range of A-type stars f
U. Lisenfeld, L. Verdes-Montenegro, J. Sulentic, S. Leon
We describe the mid- (MIR) and far- (FIR) infrared properties of a large ($\sim$1000) sample of the most isolated galaxies in the local Universe. This sample is intended as a ``nurture-free'' zero point against which more environmentally influenced samples can be compared. We reprocess IRAS MIR/FIR survey data using the ADDSCAN/SCANPI utility for 103
G. Cresci, F. Mannucci, M. Della Valle, R. Maiolino
The detection of obscured supernovae (SNe) in near-infrared monitoring campaigns of starburst galaxies has shown that a significant fraction of SNe is missed by optical surveys. However, the number of SNe detected in ground-based near-IR observations is still significantly lower than the number of SNe extrapolated from the FIR luminosity of the hosts. A poss
E. V. Filippova, S. S. Tsygankov, A. A. Lutovinov, R. A. Sunyaev
We studied spectra for 34 accretion-powered X-ray and one millisecond pulsars that were within the field of view of the INTEGRAL observatory over two years (December 2002 - January 2005) of its in-orbit operation and that were detected by its instruments at a statistically significant level (>8 sigma in the energy range 18-60 keV). There are seven recently d
W. Brinkmann, G. W. Pratt, S. Rohr, N. Kawai
The radio supernova remnant W50 hosts at its center the peculiar galactic X-ray binary SS 433. It shows a central spherical structure with two `ears' which are supposed to be formed by the interaction of the precessing jets of SS 433 with the supernova shell. In two pointings in September/October 2004 for 30 ks each the eastern jet of SS 433 was observed
Dimitri A. Gadotti, Ronaldo E. de Souza
In an effort to obtain further observational evidences for secular evolution processes in galaxies, as well as observational constraints to current theoretical models of secular evolution, we have used BVRI and Ks images of a sample of 18 barred galaxies to measure the lengths and colours of bars, create colour maps and estimate global colour gradients. In a
N. Biver, D. Bockelée-Morvan, J. Crovisier, A. Lecacheux
The Odin satellite, launched in Feb. 2001, is equipped with a 1.1-m submillimetre telescope. Odin was used to observe the 557 GHz line of water with high spectral resolution in 12 comets between 2001 and 2005. Line shapes and spatial mapping provide information on the anisotropy of the outgassing and constraints on water excitation, enabling accurate measure
J. Robrade, J. H. M. M. Schmitt
Methods. The northern-eastern fringe of the Chameleon I dark cloud was observed with XMM-Newton, revisiting a region observed with ROSAT 15 years ago. Centered on the extended X-ray source CHXR49 we are able to resolve it into three major contributing components and to analyse their spectral properties. Furthermore, the deep exposure allows not only the dete
Effects of the tilted and wavy current sheet on the solar modulation of galactic cosmic rays
astro-phShoko Miyake, Shohei Yanagita
Transport equation of the galactic cosmic ray (GCR) is numerically solved for qA>0 and qA<0 based on the stochastic differential equation (SDE) method. We have developed a fully time-dependent and three-dimensional code adapted for the wavy heliospheric current sheet (HCS). Results anticipated by the drift pattern are obtained for sample trajectories and dis
Shoko Miyake, Shohei Yanagita, Tatsuo Yoshida
The structure of the cosmic ray electron halo of a starburst galaxy depends strongly on the nature of galactic wind and the configuration of the magnetic field. We have investigated these dependencies by solving numerically the propagation of electrons originating in starburst galaxies, most likely in supernova remnants. The calculations are made for several
Markus Ahlers
In R-parity conserving supersymmetric (SUSY) models the lightest SUSY particle (LSP) is stable and a candidate for dark matter. Depending on the coupling and mass of this particle the life time of the next-to-lightest SUSY particle (NLSP) may be large compared to experimental time scales. In particular, if the NLSP is a charged particle and its decay length
A. Brunthaler, M. J. Reid, H. Falcke, C. Henkel
We have measured the proper motion of the Local Group galaxy IC 10 with the Very Long Baseline Array by measuring the position of an H2O maser relative to two background quasars over 4.3 years. After correction for the rotation of the Milky Way and IC 10, we obtain a motion of -39 +/- 9 microas/yr toward the East and 31 +/- 8 microas/yr toward the North. Thi
Halton Arp
New observations suggest that high redshift quasars can be turned into Gamma Ray Bursters and BL Lacertids by interaction with absorbing clouds in their vicinity.
E. Sturm, D. Rupke, A. Contursi, D. -C. Kim
We report results from the first mid-infrared spectroscopic study of a comprehensive sample of 33 LINERs, observed with the Spitzer Space Telescope. We compare the properties of two different LINER populations: infrared-faint LINERs, with LINER emission arising mostly in compact nuclear regions, and infrared-luminous LINERs, which often show spatially extend
Search for polarization from the prompt gamma-ray emission of GRB 041219a with SPI on INTEGRAL
astro-phE. Kalemci, S. E. Boggs, C. Kouveliotou, M. Finger
Measuring the polarization of the prompt gamma-ray emission from GRBs can significantly improve our understanding of both the GRB emission mechanisms, as well as the underlying engine driving the explosion. We searched for polarization in the prompt gamma-ray emission of GRB 041219a with the SPI instrument on INTEGRAL. Using multiple-detector coincidence eve
Three-Dimensional Distribution of the ISM in the Milky Way Galaxy: II. The Molecular Gas Disk
astro-phHiroyuki Nakanishi, Yoshiaki Sofue
We created a three-dimensional distribution map of molecular gas throughout the Milky Way Galaxy using the latest $^{12}$CO($J=$1--0) survey data cube and rotation curve based on the kinematic distance. The radial distribution of the molecular gas shows a central peak and a second peak around 0.5 $R_0$. The thickness of the molecular disk slightly increases
S. K. Patel, J. Zurita, M. Del Santo, M. Finger
We present detailed spectral and timing analysis of the hard x-ray transient IGR J16358-4726 using multi-satellite archival observations. A study of the source flux time history over 6 years, suggests that lower luminosity transient outbursts can be occuring in intervals of at most 1 year. Joint spectral fits of the higher luminosity outburst using simultane
Li-Chin Yeh, Ing-Guey Jiang
Motivated by Papadakis (2005a, 2005b), we study a Chermnykh-like problem, in which an additional gravitational potential from the belt is included. In addition to the usual five equilibrium points (three collinear and two triangular points), there are some new equilibrium points for this system. We studied the conditions for the existence of these new equili
A. Beresnyak, A. Lazarian
It is most natural to assume that mysterious Small Ionized and Neutral Structures (SINS) indiffuse ISM arise from turbulence. There are two obvious problem with such an explanation, however. First of all, it is generally believed that at the small scales turbulence should be damped. Second, turbulence with Kolmogorov spectrum cannot be the responsible for th
A. Lazarian
Turbulence is a key element of the dynamics of astrophysical fluids, including those of interstellar medium, clusters of galaxies and circumstellar regions. Turbulent motions induce Doppler shifts of observable emission and absorption lines. In the review we discuss new techniques that relate the spectra of underlying velocity turbulence and spectra of Doppl
Marc Bellon
A general method for the determination of the harmonics of quotients of the 3-sphere is given. They can all be deduced from three objects already known from Klein. We further show explicitly how these harmonics can be organized in irreducible representations of the holonomy group: this allows for the determination of the full correlation matrix of the Cosmic
Shintaro Sawayama
In this paper we can solve a Wheeler-DeWitt equation of the some inhomogeneous spacetime models as a local solution. From the previous study of up-to-down method we derived the static restriction relating the problem of the time. Although static restriction does not commute with the general Hamiltonian constraint, the Hamiltonian constraint of some mini-supe
The necessity and sufficiency of anytime capacity for stabilization of a linear system over a noisy communication link, Part II: vector systems
cs.ITAnant Sahai, Sanjoy Mitter
In part I, we reviewed how Shannon's classical notion of capacity is not sufficient to characterize a noisy communication channel if the channel is intended to be used as part of a feedback loop to stabilize an unstable scalar linear system. While classical capacity is not enough, a sense of capacity (parametrized by reliability) called "anytime capa
Nicola Pinamonti
Some years ago it was shown that, in some cases, a notion of locality can arise from the group of symmetry enjoyed by the theory, thus in an intrinsic way. In particular, when Moebius covariance is present, it is possible to associate some particular transformations to the Tomita Takesaki modular operator and conjugation of a specific interval of an abstract
Existence and Uniqueness of constant mean curvature foliation of asymptotically hyperbolic 3-manifolds
math.DGAndré Neves, Gang Tian
We prove existence and uniqueness of foliations by stable spheres with constant mean curvature for 3-manifolds which are asymptotic to Anti-de Sitter-Schwarzschild metrics with positive mass. These metrics arise naturally as spacelike timeslices for solutions of the Einstein equation with a negative cosmological constant.