January 2006 arXiv papers — page 23

I. Matute, F. La Franca, F. Pozzi, C. Gruppioni

We study the evolution of the luminosity function (LF) of type-1 and type-2 AGN in the mid-infrared, and derive their contribution to the Cosmic InfraRed Background (CIRB) and the expected deep source counts to be observed by Spitzer at 24 micron. The sample of type-1 and type-2 AGN was selected at 15 micron (ISO) and 12 micron (IRAS), and classified on the

T. Murphy, P. Lamb, C. Owen, M. Marquarding

We present three Virtual Observatory tools developed at the ATNF for the storage, processing and visualisation of ATCA data. These are the Australia Telescope Online Archive, a prototype data reduction pipeline, and the Remote Visualisation System. These tools were developed in the context of the Virtual Observatory and were intended to be both useful for as

D. J. Bombardieri, M. L. Duldig, K. J. Michael, J. E. Humble

Protons accelerated to relativistic energies by transient solar and interplanetary phenomena caused a ground-level cosmic ray enhancement on 14 July 2000, Bastille Day. Near-Earth spacecraft measured the proton flux directly and ground-based observatories measured the secondary responses to higher energy protons. We have modelled the arrival of these relativ

C. Allende Prieto

The determination of chemical abundances from stellar spectra is considered a mature field of astrophysics. Digital spectra of stars are recorded and processed with standard techniques, much like samples in the biological sciences. Nevertheless, uncertainties typically exceed 20%, and are dominated by systematic errors. The first part of this paper addresses

B. Rutily, L. Chevallier, J. Bergeat

We come back to the Cauchy integral equations occurring in radiative transfer problems posed in finite, plane-parallel media with light scattering taken as monochromatic and isotropic. Their solution is calculated following the classical scheme where a Cauchy integral equation is reduced to a couple of Fredholm integral equations. It is expressed in terms of

E. S. Rykoff, V. Mangano, S. A. Yost, R. Sari

The ROTSE-IIIc telescope at the H.E.S.S. site, Namibia, obtained the earliest detection of optical emission from a Gamma-Ray Burst (GRB), beginning only 21.8 s from the onset of Swift GRB 050801. The optical lightcurve does not fade or brighten significantly over the first ~250 s, after which there is an achromatic break and the lightcurve declines in typica

B. Rutily, J. Bergeat, L. Chevallier

In the central part of this paper, we revisit the classical study of the H-function defined as the unique solution, regular in the right complex half-plane, of a Cauchy integral equation. We take advantage of our work on the N-function published in the first article of this series. The H-function is then used to solve a class of Cauchy integral equations occ

Casey Meakin, David Arnett

We have simulated 2.5$\times10^3$ s of the late evolution of a $23 \rm M_\odot$ star with full hydrodynamic behavior. We present the first simulations of a multiple-shell burning epoch, including the concurrent evolution and interaction of an oxygen and carbon burning shell. In addition, we have evolved a 3D model of the oxygen burning shell to sufficiently

Ignacio Negueruela

There are obvious and direct ways in which the presence of binary companions may affect activity in OB stars through tidal interactions. In this review, however, I consider a more fundamental role for multiplicity and explore claims that the Be phenomenon may be intimately linked to binarity. I describe the binary channel for the formation of Be stars and th

G. A. Mamon, E. Lokas, A. Dekel, F. Stoehr

Elements of kinematical and dynamical modeling of elliptical galaxies (Es) are presented. In projection, NFW models resemble Sersic models, but with a very narrow range of shapes (m=3+/-1). The total density profile of Es cannot be NFW-like because the predicted local M/L and aperture velocity dispersion within an effective radius (Re) are much lower than ob

Felix Stoehr, Gary A. Mamon, Avishai Dekel, Thomas J. Cox

The kinematical properties of elliptical galaxies formed during the mergers of equal mass, stars+gas+dark matter spiral galaxies are compared to the observed low velocity dispersions found for planetary nebulae on the outskirts of ellipticals, which have been interpreted as pointing to a lack of dark matter in ellipticals (which poses a problem for the stand

B. Rutily, L. Chevallier

We solve a weakly singular integral equation by Laplace transformation over a finite interval of R. The equation is transformed into a Cauchy integral equation, whose resolution amounts to solving two Fredholm integral equations of the second kind with regular kernels. This classical scheme is used to clarify the emergence of the auxiliary functions expressi

B. Rutily, L. Chevallier, J. Bergeat

We come back to a non linear integral equation satisfied by the function H, which is distinct from the classical H-equation. Established for the first time by Busbridge (1955), it appeared occasionally in the literature since then. First of all, this equation is generalized over the whole complex plane using the method of residues. Then its counterpart in a

L. Chevallier, F. Paletou, B. Rutily

We solve the integral equation describing the propagation of light in an isothermal plane-parallel atmosphere of optical thickness $τ^*$, adopting a uniform thermalization parameter $ε$. The solution given by the ALI method, widely used in the field of stellar atmospheres modelling, is compared to the exact solution. Graphs are given that illustrate the accu

bernard rutily, loic chevallier, joachim pelkowski

We solve exactly the problem of a finite slab receiving an isotropic radiation on one side and no radiation on the other side. This problem - to be more precise the calculation of the source function within the slab - was first formulated by K. Schwarzschild in 1914. We first solve it for unspecified albedos and optical thicknesses of the atmosphere, in part

Georges Meynet, Sylvia Ekström, André Maeder, Fabio Barblan

The aim of this paper is to determine the initial rotational velocities required on the ZAMS for single stars to reach the critical velocity, sometimes called the break-up velocity, during the Main-Sequence (MS) phase. Some useful relations between $Ω/Ω_{\rm crit}$, $\upsilon/\upsilon_{\rm crit}$ ($\upsilon$ is the velocity at the equator), the moments of in

M. Pannella, U. Hopp, R. P. Saglia, R. Bender

We study the evolution of the stellar mass density for the separate families of bulge-dominated and disk-dominated galaxies over the redshift range 0.25 < z < 1.15. We derive quantitative morphology for a statistically significant galaxy sample of 1645 objects selected from the FORS Deep and the GOODS-S Fields. We find that the morphological mix evolves mono

Jason W. T. Hessels, Scott M. Ransom, Ingrid H. Stairs, Paulo C. C. Freire

We have discovered a 716-Hz eclipsing binary radio pulsar in the globular cluster Terzan 5 using the Green Bank Telescope. It is the fastest-spinning neutron star ever found, breaking the 23-year-old record held by the 642-Hz pulsar B1937+21. The difficulty in detecting this pulsar, due to its very low flux density and high eclipse fraction (~40% of the orbi

J. Cernicharo, J. R. Goicoechea, J. R. Pardo, A. Asensio Ramos

We have conducted a study combining H2O lines in two spectral regions. First, Infrared Space Observatory observations of several H2O thermal lines seen in absorption toward Sgr B2(M) at a spectral resolution of 35 kms^-1 have been analyzed. Second, an IRAM-30m telescope map of the para-H2O 3_13-2_20 line at 183.31 GHz, seen in emission, has also been obtaine

M. J. Jee, R. L. White, H. C. Ford, G. D. Illingworth

(Abridged) We present a HST/ACS weak-lensing study of RX J0849+4452 and RX J0848+4453, the two most distant (at z=1.26 and z=1.27, respectively) clusters yet measured with weak-lensing. The two clusters are separated by ~4&#39; from each other and appear to form a supercluster in the Lynx field. Using our deep ACS F775W and F850LP imaging, we detected weak-l

Seokcheon Lee, Guo-Chin Liu, Kin-Wang Ng

We discuss the evolution of linear perturbations in a quintessence model in which the scalar field is non-minimally coupled to cold dark matter. We consider the effects of this coupling on both cosmic microwave background temperature anisotropies and matter perturbations. Due to the modification of the scale of cold dark matter as $ρ_{c} = ρ_{c}^{(0)} a^{-3

Andrew J. Levan, Graham A. Wynn, Robert Chapman, Melvyn B. Davies

Recent progress on the nature of short duration gamma-ray bursts has shown that a fraction of them originate in the local universe. These systems may well be the result of giant flares from soft gamma-repeaters (highly magnetized neutron stars commonly known as magnetars). However, if these neutron stars are formed via the core collapse of massive stars then

T. Manos, E. Athanassoula

The chaotic or ordered character of orbits in galactic models is an important issue, since it can influence dynamical evolution. This distinction can be achieved with the help of the Smaller Alingment Index - (SALI). We describe here briefly this method and its advantages. Then we apply it to that case of 2D and 3D barred galaxy potentials. In particular, we

M. Fellhauer, P. Kroupa

A recent study of ultra-compact dwarf galaxies (UCDs) in the Virgo cluster revealed that some of them show faint envelopes and have measured mass-to-light ratios of 5 and larger, which can not be explained by simple population synthesis models. It is believed that this proves that some of the UCDs must possess a dark matter halo and may therefore be stripped

Arnon Dar

There is mounting evidence from observations of long duration gamma ray bursts (GRBs), supernova remnants (SNR) and the supernova (SN) explosion 1987A, that SN explosions eject highly relativistic bipolar jets of plasmoids (cannonballs) of ordinary matter. Here we use the remarkably successful cannonball (CB) model of GRBs to show that bipolar jets from Gala

R. A. Laing, J. R. Canvin, A. H. Bridle

The question of the degree of order in the magnetic fields of relativistic jets is important to any understanding of their production. Both vector-ordered (e.g. helical) and disordered, but anisotropic fields can produce the high observed degrees of polarization. We outline our models of jets in FR I radio galaxies as decelerating relativistic flows. We then

S. Mei, J. P. Blakeslee, S. A. Stanford, B. P. Holden

The color-magnitude relation has been determined for the RDCS J0910+5422 cluster of galaxies at redshift z = 1.106. Cluster members were selected from HST ACS images, combined with ground--based near--IR imaging and optical spectroscopy. The observed early--type color--magnitude relation (CMR) in (i_775 -z_850) versus z_850 shows intrinsic scatters in color

Marta Gavilan, Mercedes Molla, James F. Buell

We analyze the impact on the Galactic nitrogen abundances of using a new set of low and intermediate mass star yields. These yields have a significant yield of primary nitrogen from intermediate mass stars. We use these yields as an input to a Galactic Chemical Evolution model and study the nitrogen abundances in the halo and in the disc, and compare them wi

V. K. Agrawal, R. Misra

The results of a spectral analysis, using {\it XMM-Newton} and {\it Chandra} data of the brightest ultra luminous X-ray source in the nearby galaxy M82, are presented. The spectrum of M82 X-1, was found to be unusually hard (photon spectral index $Γ\approx 1$) with a sharp cutoff at $\approx 6$ keV. Disk black body emission model requires a nonphysically hig

Takuji Tsujimoto, Toshikazu Shigeyama

Renewed interest in the first stars that were formed in the universe has led to the discovery of extremely iron-poor stars. Since several competing scenarios exist, our understanding of the mass range that determines the observed elemental abundances remains unclear. In this study, we consider three well-studied metal-poor stars in terms of the theoretical s

Gai I. Boger, Amiel Sternberg

We present an analysis of &#34;bistability&#34; in gas-phase chemical models of dark interstellar clouds. We identify the chemical mechanisms that allow high- and low-ionization solutions to the chemical rate-equations to coexist. We derive simple analytic scaling relations for the gas densities and ionization rates for which the chemistry becomes bistable.

Mikhail V. Medvedev

We demonstrate that the rapid spectral variability of prompt GRBs is an inherent property of radiation emitted from shock-generated, highly anisotropic small-scale magnetic fields. We interpret the hard-to-soft evolution and the correlation of the soft index $α$ with the photon flux observed in GRBs as a combined effect of temporal variation of the shock vie

Bradley E. Warren, Helmut Jerjen, Baerbel S. Koribalski

We present a multi-wavelength study (BVRI band photometry and HI line interferometry) of nine late-type galaxies selected from the HIPASS Bright Galaxy Catalog on the basis of apparently high HI mass-to-light ratios (3 M_sun/L_sun < M_HI/L_B < 27 M_sun/L_sun). We found that most of the original estimates for M_HI/L_B based on available photographic magnitude

Adam G Riess, Mario Livio

Future measurements of the nature of dark energy using Type Ia supernovae will require a precise characterization of systematic sources of error. Evolutionary effects remain the most uncertain contributor to the overall systematic error budget. Present plans to probe evolution with cosmology-independent explosion parameters could yield absence of evidence fo

C. M. Zhang, H. X. Yin, Y. H. Zhao, F. Zhang

We analyzed the recently published kHz QPO data in the neutron star low-mass X-ray binaries (LMXBs), in order to investigate the different correlations of the twin peak kilohertz quasi-eriodic oscillations (kHz QPOs) in bright Z sources and in the less luminous Atoll sources. We find that a power-law relation $\no\sim\nt^{b}$ between the upper and the lower

L. Perivolaropoulos

This is a pedagogical review of the recent observational data obtained from type Ia supernova surveys that support the accelerating expansion of the universe. The methods for the analysis of the data are reviewed and some of the theoretical implications obtained from their analysis are discussed.

Shiri Artstein-Avidan, Omer Friedland, Vitali Milman, Sasha Sodin

We prove a quantitative version of the bound on the smallest singular value of a Bernoulli covariance matrix (due to Bai and Yin). Then we use this bound, together with several recent developments, to show that the distance from a random (1-delta) n - dimensional section of ell_1^n, realised as an image of a sign matrix, to an Euclidean ball is polynomial in

Marc Kesseböhmer, Manuel Stadlbauer, Bernd O. Stratmann

We study relations between $(H,β)$--KMS states on Cuntz--Krieger algebras and the dual of the Perron--Frobenius operator $\mathcal{L}_{-βH}^{*}$. Generalising the well--studied purely hyperbolic situation, we obtain under mild conditions that for an expansive dynamical system there is a one--one correspondence between $(H,β)$--KMS states and eigenmeasures of

E. D. Skvortsov, M. A. Vasiliev

The manifestly gauge invariant formulation for free symmetric partially massless fields in $(A)dS_d$ is given in terms of gauge connections and linearized curvatures that take values in the irreducible representations of $(o(d-1,2)) o(d,1)$ described by two-row Young tableaux, in which the lengths of the first and second row are, respectively, associated wit

Kenichi Fuki, Masaki Yasue

The requirement of the mu-tau symmetry in the neutrino sector that yields the maximal atmospheric neutrino mixing is shown to yield either sin(θ_{13})=0 (referred to as C1)) or sin(θ_{12})=0 (referred to as C2)), where θ_{12(13)} stands for the solar (reactor) neutrino mixing angle. We study general properties possessed by approximately mu-tau symmetric text

Kourosh Nozari, S. H. Mehdipour

Several alternative approaches to quantum gravity problem suggest the modification of the {\it fundamental volume $ω_{0}$} of the accessible phase space for representative points. This modified fundamental volume has a novel momentum dependence. In this paper, we study the effects of this modification on the thermodynamics of an ideal gas within the microcan

Bin Liu, Ying Liang, Shiping Feng, Wei Yeu Chen

Within the t-J model, the heat transport of electron-doped cobaltates is studied based on the fermion-spin theory. It is shown that the temperature dependent thermal conductivity is characterized by the low temperature peak located at a finite temperature. The thermal conductivity increases monotonously with increasing temperature at low temperatures T $<$ 0

Nikolai Nikolov, Peter Pflug, Wlodzimierz Zwonek

We prove that the Lempert function of the symmetrized polydisc in dimension greater than two is not a distance.

X. X. Yi, H. Wang, W. Wang

We establish a relation between Hahn spin-echo of a spin-$\frac 1 2 $ particle and quantum phase transition in a spin-chain, which couples to the particle. The Hahn echo is calculated and discussed at zero as well as at finite temperatures. On the example of XY model, we show that the critical points of the chain are marked by the extremal values in the Hahn

Roderick Sutherland

A version of Bohm's model incorporating retrocausality is presented, the aim being to explain the nonlocality of Bell's theorem while maintaining Lorentz invariance in the underlying ontology. The strengths and weaknesses of this alternative model are compared with those of the standard Bohm model.

Christof Zalka

In this note we consider optimised circuits for implementing Shor&#39;s quantum factoring algorithm. First I give a circuit for which none of the about 2n qubits need to be initialised (though we still have to make the usual 2n measurements later on). Then I show how the modular additions in the algorithm can be carried out with a superposition of an arithme

G. W. Ford, R. F. O&#39;Connell

The free energy of a quantum oscillator in an arbitrary heat bath at a temperature T is given by a &#34;remarkable formula&#34; which involves only a single integral. This leads to a corresponding simple result for the entropy. The low temperature limit is examined in detail and we obtain explicit results both for the case of an Ohmic heat bath and a radiati

Maximilian Schlosshauer

We analyze three important experimental domains (SQUIDs, molecular interferometry, and Bose-Einstein condensation) as well as quantum-biophysical studies of the neuronal apparatus to argue that (i) the universal validity of unitary dynamics and the superposition principle has been confirmed far into the mesoscopic and macroscopic realm in all experiments con

Huijie Yang, Fangcui Zhao, Jianzhong Gu, Binghong Wang

By means of the nonlinear modeling technique (NM technique), we find the nonlinear deterministic structures in the promoter regions (PPRs) of DNA sequences, called deterministic valleys (DVs) in this paper. These DVs prefer to occur much more outside of a special region around TSS. The number, positions and shapes of the DVs are basically different for diffe

R. Appleby, L. Keller, T. Markiewicz, A. Seryi

The ILC beam dumps are a key part of the accelerator design. At Snowmass 2005, the current status of the beam dump designs were reviewed, and the options for the overall dump layout considered. This paper describes the available dump options for the baseline and the alternatives and considers issues for the dumps that require resolution.

M. Rysavy

Measurements of the endpoint region of the tritium beta-decay spectrum provides good possibility to determine neutrino mass. This, however, needs a perfect monitoring of the spectrometer energy scale. A parallel measurement of electron line of known energy - in particular the 83mKr conversion K-line - may serve well to this purpose. The 83Rb decaying to 83mK

G. M. Chechin, G. S. Dzhelauhova, E. A. Mehonoshina

For the James breathers in the K2-K3-K4 chain and for breathers in the K4-chain, we prove numerically that these dynamical objects are not strictly time-periodic. Indeed, for the both cases, there exist certain deviations in the vibrational frequencies of the individual particles, which certainly exceed the possible numerical errors. We refer to the dynamica

O. Costin, G. Gallavotti, G. Gentile, A. Giuliani

Resonant motions of integrable systems subject to perturbations may continue to exist and to cover surfaces with parametric equations admitting a formal power expansion in the strength of the perturbation. Such series may be, sometimes, summed via suitable sum rules defining $C^\infty$ functions of the perturbation strength: here we find sufficient condition

Shamgar Gurevich

This is my Ph.D. thesis written under the direction of Prof. Joseph Bernstein at Tel-Aviv University. Submitted: March 2005.

Raphael Ponge

In this paper we give a survey of the constructions in math.DG/0510061 of several new invariants for CR and contact manifolds. The latter extend previous constructions of Hirachi and Boutet de Monvel. In addition, we give simple algebro-geometric arguments proving that Hirachi&#39;s invariant vanishes on strictly pseudoconvex CR manifolds of dimension 4m+1.

Massimo Giovannini

The dynamical effects of the tensor modes of the geometry are investigated in the context of curvature bounces. Since the bouncing behaviour implies sharp deviations from a radiation-dominated evolution, significant back-reaction effects of relic gravitons may be expected at short wavelengths. After developing a general iterative framework for the calculatio

Bo Hu, Yi Ling

The interacting and holographic dark energy models involve two important quantities. One is the characteristic size of the holographic bound and the other is the coupling term of the interaction between dark energy and dark matter. Rather than fixing either of them, we present a detailed study of theoretical relationships among these quantities and cosmologi

J. Linder

In this paper, analytical formulas for elastic neutrino-fermion scattering cross sections are presented. These are evaluated in the limit where the neutrino mass is neglible compared to the incoming momentum. The fermion mass is taken into account, however, yielding a good approximation to realistic scattering reactions. The intended level of readership is f

J. Linder

An instructive method of deriving the matter potentials felt by neutrinos propagating through matter on Earth is presented. This paper thoroughly guides the reader through the calculations involving the effective weak Hamiltonian for lepton and quark scattering. The matter potentials are well-known results since the late 70&#39;s, but a detailed and pedagogi

Sean A. Hayward

Black holes can be practically located (e.g. in numerical simulations) by trapping horizons, hypersurfaces foliated by marginal surfaces, and one desires physically sound measures of their mass and angular momentum. A generically unique angular momentum can be obtained from the Komar integral by demanding that it satisfy a simple conservation law. With the i

Kourosh Nozari, S. Hamid Mehdipour

Bekenstein-Hawking Black hole thermodynamics should be corrected to incorporate quantum gravitational effects. Generalized Uncertainty Principle(GUP) provides a perturbational framework to perform such modifications. In this paper we consider the most general form of GUP to find black holes thermodynamics in microcanonical ensemble. Our calculation shows tha

Boris Ryabko

The problem of ranking can be described as follows. We have a set of combinatorial objects $S$, such as, say, the k-subsets of n things, and we can imagine that they have been arranged in some list, say lexicographically, and we want to have a fast method for obtaining the rank of a given object in the list. This problem is widely known in Combinatorial Anal

Ivan Lanese, Ugo Montanari

In this paper we compare three different formalisms that can be used in the area of models for distributed, concurrent and mobile systems. In particular we analyze the relationships between a process calculus, the Fusion Calculus, graph transformations in the Synchronized Hyperedge Replacement with Hoare synchronization (HSHR) approach and logic programming.

V. Barsegov, D. Klimov, D. Thirumalai

In the current AFM experiments the distribution of unfolding times, P(t), is measured by applying a constant stretching force f_s from which the apparent unfolding rate is obtained. To describe the complexity of the underlying energy landscape requires additional probes that can incorporate the dynamics of tension propagation and relaxation of the polypeptid

Wonkee Kim, L. Covaci, F. Marsiglio

Correlated, or extended, impurities play an important role in the transport properties of dirty metals. Here, we examine, in the framework of a tight-binding lattice, the transmission of a single electron through an array of correlated impurities. In particular we show that particles transmit through an impurity array in identical fashion, regardless of the

Masudul Haque, H. T. C. Stoof

We consider the phase separation of a trapped atomic mixture of fermions with unequal spin populations near a Feshbach resonance. In particular, we determine the density profile of the two spin states and compare with the recent experiments of Partridge et al. (cond-mat/0511752). Overall we find quite good agreement. We identify the remaining discrepancies a

E. O. Kamenetskii

The interaction of electromagnetic radiation with temporally dispersive magnetic solids of small dimensions may show very special resonant behaviors. The internal fields of such samples are characterized by magnetostatic-potential scalar wave functions. The oscillating modes have the energy orthogonality properties and unusual pseudo-electric (gauge) fields.

Mamoru Yogi, Hidekazu Mukuda, Yoshio Kitaoka, Shin Hashimoto

We report the measurements of the $^{29}$Si Knight shift $^{29}K$ on the noncentrosymmetric heavy-fermion compound CePt$_{3}$Si in which antiferromagnetism (AFM) with $T_{\rm N}=2.2$ K coexists with superconductivity (SC) with $T_{c}=0.75$ K. Its spin part $^{29}K_{\rm s}$, which is deduced to be $K_{\rm s}^{c}\ge 0.11$ and 0.16% at respective magnetic field

Lafe Spietz, John Teufel, R. J. Schoelkopf

In low temperature transport measurements, there is frequently a need to protect a device at cryogenic temperatures from thermal noise originating in warmer parts of the experiment. There are also a wide range of experiments, such as high precision transport measurements on low impedance devices, in which a twisted-pair wiring configuration is useful to elim

Mathieu Bouville

Germanosilicide thin films are quite different from silicides and germanides. The germanium composition is not homogeneous, grains have a different shape, and the substrate is generally strained. This affects grain boundary grooving and favors agglomeration of germanosilicide films. Our thermodynamics model shows that the equilibrium Ge composition of german

Phil Arras, Lars Bildsten

We consider the thermal structure and radii of strongly irradiated gas giant planets over a range in mass and irradiating flux. The cooling rate of the planet is sensitive to the surface boundary condition, which depends on the detailed manner in which starlight is absorbed and energy redistributed by fluid motion. We parametrize these effects by imposing an

Minjin Kim, Luis C. Ho, Myungshin Im

The [O II] 3727 emission line is often used as an indicator of star formation rate in extragalactic surveys, and it can be an equally effective tracer of star formation in systems containing luminous active galactic nuclei (AGNs). In order to investigate the ongoing star formation rate of the host galaxies of AGNs, we measured the strength of [O II] and othe

Hiroaki Yamamoto, Akiko Kawamura, Kengo Tachihara, Norikazu Mizuno

We have carried out large scale 12CO and 13CO observations with a mm/sub-mm telescope NANTEN toward a loop-like structure in far infrared whose angular extent is about 20x20 degrees around (l, b) ~ (109, -45) in Pegasus. The 12CO distribution is found to consist of 78 small clumpy clouds whose masses range from 0.04 Mo to 11 Mo. About 83% of the 12CO clouds

Karl D. Gordon, J. Bailin, C. W. Engelbracht, G. H. Rieke

New images of M31 at 24, 70, and 160 micron taken with the Multiband Imaging Photometer for Spitzer (MIPS) reveal the morphology of the dust in this galaxy. This morphology is well represented by a composite of two logarithmic spiral arms and a circular ring (radius ~10 kpc) of star formation offset from the nucleus. The two spiral arms appear to start at th

A. Rodriguez-Ardila, X. Mazzalay

We report 0.8-4.5 micron SpeX spectroscopy of the narrow-line Seyfert 1 galaxy Mrk1239. The spectrum is outstanding because the nuclear continuum emission in the near-infrared is dominated by a strong bump of emission peaking at 2.2 micron, with a strength not reported before in an AGN. A comparison of the Mrk1239 spectrum to that of Ark564 allowed us to con

G. Weidenspointner

Since its launch in October 2002, ESA&#39;s INTEGRAL observatory has enabled significant advances to be made in the study of Galactic nucleosynthesis. In particular, the imaging Ge spectrometer SPI combines for the first time the diagnostic powers of high resolution gamma-ray line spectroscopy and moderate spatial resolution. This review summarizes the major

G. Brodin M. Marklund, L. Stenflo, P. K. Shukla

A dispersion relation for electromagnetic wave propagation in a strongly magnetized cold plasma is deduced, taking photon-photon scattering into account. It is shown that the combined plasma and quantum electrodynamic effect is important for understanding the mode-structures in magnetar and pulsar atmospheres. The implications of our results are discussed.

Michael K. Kinyon, J. D. Phillips, Petr Vojtěchovský

A left Bol loop is a loop satisfying $x(y(xz)) = (x(yx))z$. The commutant of a loop is the set of elements which commute with all elements of the loop. In a finite Bol loop of odd order or of order $2k$, $k$ odd, the commutant is a subloop. We investigate conditions under which the commutant of a Bol loop is not a subloop. In a finite Bol loop of order relat

M. Zarea, Sergio E. Ulloa

We calculate the spin Hall conductivity driven by Rashba spin-orbit interaction in $p$-type two-dimensional semiconductors in the presence of a perpendicular magnetic field. For a highly confined quantum well, the system is described by a $k$-cubic Rashba term for two-dimensional heavy holes. The eigenstates of the system can be described by Landau spinor st

J. Garai, A. Laugier

It is well established that the product of the volume coefficient of thermal expansion and the bulk modulus is nearly constant at temperatures higher than the Debye temperature. Using this approximation allows predicting the values of the bulk modulus. The derived analytical solution for the temperature dependence of the isothermal bulk modulus has been appl

Debasish Chaudhuri, Abhishek Dhar

We study heat conduction in a system of hard disks confined to a narrow two dimensional channel. The system is initially in a high density solid-like phase. We study, through nonequilibrium molecular dynamics simulations, the dependence of the heat current on an externally applied elongational strain. The strain leads to deformation and failure of the solid

Giovanni D'Arrigo, Giuseppe Briganti, Marco Maccarini

We present measurements of the steady shear viscosity, the longitudinal elastic modulus and the ultrasonic absorption in the one-phase isotropic liquid region of the nonionic surfactant C12E8 aqueous solutions. The overall results support the presence of two separated intervals of concentration corresponding to different structural properties. In the surfact

Wenjuan Zou, Zhenjun Xiao

By choosing two typical input parameter points in the minimal supergravity (mSUGRA) model and using the QCD factorization (QCDF) approach, we studied the supersymmetric effects to the CP violation of the two-body charmless hadronic $B$ meson decays. We found that though the SUSY contributions can give large corrections to the CP asymmetries for some decay ch

Yukiko Konishi, Satoshi Minabe

We prove transformation formulae for generating functions of Gromov-Witten invariants on general toric Calabi-Yau threefolds under flops. Our proof is based on a combinatorial identity on the topological vertex and analysis of fans of toric Calabi-Yau threefolds.

Paul-Olivier Dehaye

A classical question for a Toeplitz matrix with given symbol is to compute asymptotics for the determinants of its reductions to finite rank. One can also consider how those asymptotics are affected when shifting an initial set of rows and columns (or, equivalently, asymptotics of their minors). Bump and Diaconis (Toeplitz minors, J. Combin. Theory Ser. A, 9

Stephanie Wehner

Quantum theory imposes a strict limit on the strength of non-local correlations. It only allows for a violation of the CHSH inequality up to the value 2 sqrt(2), known as Tsirelson&#39;s bound. In this note, we consider generalized CHSH inequalities based on many measurement settings with two possible measurement outcomes each. We demonstrate how to prove Ts

Stephanie Wehner

If two classical provers share an entangled state, the resulting interactive proof system is significantly weakened [quant-ph/0404076]. We show that for the case where the verifier computes the XOR of two binary answers, the resulting proof system is in fact no more powerful than a system based on a single quantum prover: +MIP*[2] is contained in QIP(2). Thi

Thomas S. Deisboeck, Caterina Guiot, Pier Paolo Delsanto, Nicola Pugno

We argue that volumetric growth dynamics of a solid cancer depend on the tumor system&#39;s overall surface extension. While this at first may seem evident, to our knowledge, so far no theoretical argument has been presented explaining this relationship explicitly. In here, we therefore develop a conceptual framework based on the universal scaling law and th

Jie Liang

This chapter discusses geometric models of biomolecules and geometric constructs, including the union of ball model, the weigthed Voronoi diagram, the weighted Delaunay triangulation, and the alpha shapes. These geometric constructs enable fast and analytical computaton of shapes of biomoleculres (including features such as voids and pockets) and metric prop

Michael Courtney, Brian Edwards

This article describes a simple method for using a PC soundcard to accurately measure bullet velocity. The method involves placing the microphone within a foot of the muzzle and firing at a steel target between 50 and 100 yards away. The time of flight for the bullet is simply the recorded time between muzzle blast and sound of the bullet hitting the target

Marek Borowiec, Grzegorz Litak, Arkadiusz Syta

We have applied the Melnikov criterion to examine a global homoclinic bifurcation and transition to chaos in a case of the Duffing system with nonlinear fractional damping and external excitation. Using perturbation methods we have found a critical forcing amplitude above which the system may behave chaotically. The results have been verified by numerical si

Grzegorz Litak, Marek Borowiec, Arkadiusz Syta, Kazimierz Szabelski

We examine the Melnikov criterion for a global homoclinic bifurcation and a possible transition to chaos in case of a single degree of freedom nonlinear oscillator with a symmetric double well nonlinear potential. The system was subjected simultaneously to parametric periodic forcing and self excitation via negative damping term. Detailed numerical studies c

G. Litak, M. Ali, L. M. Saha

We examine a strange chaotic attractor and its unstable periodic orbits in case of one degree of freedom nonlinear oscillator with non symmetric potential. We propose an efficient method of chaos control stabilizing these orbits by a pulsive feedback technique. Discrete set of pulses enable us to transfer the system from one periodic state to another.

Grzegorz Litak, Marek Borowiec, Michael I. Friswell, Kazimierz Szabelski

The Melnikov criterion is used to examine a global homoclinic bifurcation and transition to chaos in the case of a quarter car model excited kinematically by the road surface profile. By analyzing the potential an analytic expression is found for the homoclinic orbit. By introducing an harmonic excitation term and damping as perturbations, the critical Melni

Yoel Feler

Let X denote either CP^m or C^m. We study certain analytic properties of the space E^n of ordered geometrically generic n-point configurations in X. This space consists of all q=(q_1,...,q_n) in X^n such that no m+1 of the points q_1,...,q_n belong to a hyperplane in X. In particular, we show that for X=CP^m and n big enough any holomorphic map f:E^n-->E^n c

Melody Chan

The distinguishing number of a graph G, denoted D(G), is the minimum number of colors such that there exists a coloring of the vertices of G where no nontrivial graph automorphism is color-preserving. In this paper, we show that the distinguishing number of p-th graph power of the n-dimensional hypercube is 2 whenever 2 < p < n-1. This completes the study of

Dragos Ghioca

We determine the structure of the intersection of a finitely generated subgroup of a semiabelian variety $G$ defined over a finite field with a closed subvariety $X\subset G$.

Melody Chan

Let G be a group acting faithfully on a set X. The distinguishing number of the action of G on X is the smallest number of colors such that there exists a coloring of X where no nontrivial group element induces a color-preserving permutation of X. In this paper, we show that if G is nilpotent of class c or supersolvable of length c then G always acts with di

Weronika Buczynska, Jaroslaw A. Wisniewski

We investigate projective varieties which are geometric models of binary symmetric phylogenetic 3-valent trees. We prove that these varieties have Gorenstein terminal singularities (with small resolution) and they are Fano varieties of index 4. Moreover any two such varieties associated to trees with the same number of leaves are deformation equivalent, that

Jelena Grbic

There exist spaces BSol(q) which are the classifying spaces of a family of 2-local finite groups based on certain fusion system over the Sylow 2-subgroups of Spin_7(q). In this paper we calculate the cohomology of BSol(q) as an algebra over the Steenrod algebra A_2. We also provide the calculation of the cohomology algebra over A_2 of the finite group of Lie