June 2006 arXiv papers — page 39

Jose F. Gomez, Itziar de Gregorio-Monsalvo, Olga Suarez, Thomas B. H. Kuiper

We report the most sensitive water maser survey towards Bok globules to date, using NASA's 70m antenna in Robledo de Chavela (Spain). We observed 207 positions within the CB catalog with a higher probability of harboring a young star, using as selection criteria the presence of radio continuum emission (from submillimeter to centimeter wavelengths), geom

Toyohiro Tsurumaru

We study the security of quantum string commitment (QSC) protocols with group covariant encoding scheme. First we consider a class of QSC protocol, which is general enough to incorporate all the QSC protocols given in the preceding literatures. Then among those protocols, we consider group covariant protocols and show that the exact upperbound on the binding

V. N. Russkikh, Yu. B. Ivanov

Collective transverse flow in heavy-ion collisions at incident energies E_{lab} = (1 -160)A GeV is analyzed within the model of 3-fluid dynamics (3FD). Simulations are performed with purely hadronic equation of state (EoS). At the AGS energies the flow turns out to be sensitive to the stopping power of nuclear matter rather than only to the stiffness of the

Paolo Cea

Recent observations from the Swift gamma-ray burst mission indicate that a fraction of gamma ray bursts are characterized by a canonical behaviour of the X-ray afterglows. We present an effective theory which allows us to account for X-ray light curves of both (short - long) gamma ray bursts and X-ray rich flashes. We propose that gamma ray bursts originate

Akihiro Tsuji

We study the holographic principle of the two-point function in the case of a spinning string in the AdS/CFT correspondence. Following the general method proposed by Yoneya et al. for the bulk-boundary correspondence in the large $J$ limit, we study the spinning string solution which starts and ends at the boundary. We then show that the spinning string solu

Clement Sire, Satya N. Majumdar, David S. Dean

A simplified form of the time dependent evolutionary dynamics of a quasispecies model with a rugged fitness landscape is solved via a mapping onto a random flux model whose asymptotic behavior can be described in terms of a random walk. The statistics of the number of changes of the dominant genotype from a finite set of genotypes are exactly obtained confir

Shuo Jin, Bing-Hao Xie, Feng Pan, Joseph L. Birman

A cuprate superconductor model based on the analogy with atomic nuclei was shown by Iachello to have an $su(3)$ structure. The mean-field approximation Hamiltonian can be written as a linear function of the generators of $su(3)$ algebra. Using algebraic method, we derive the eigenvalues of the reduced Hamiltonian beyond the subalgebras $u(1)\bigotimes u(2)$

Masao Hirokawa

We are concerned with the stability of formation of large bipolaron in a 3-dimensional (3D) crystal. This problem is considered in the framework of nonrelativistic quantum field theory. Thus, the Hamiltonian formalism, as Froehlich introduced, is employed to describe the bipolaron. We approach the problem by characterizing some sufficient or necessary condit

Doyeol Ahn

It is shown that the internal stationary state of the Schwarzschild black hole can be represented by a maximally entangled two-mode squeezed state of collapsing matter and infalling Hawking radiation. The final boundary condition at the singularity is then described by the random unitary transformation acting on the collapsing matter field. The outgoing Hawk

Wen-Cong Chen, Xiang-Dong Li, Sheng-Bang Qian

It is generally thought that conservative mass transfer in Algol binaries causes their orbits to be wider, in which the less massive star overflows its Roche-lobe. The observed decrease in the orbital periods of some Algol binaries suggests orbital angular momentum loss during the binary evolution, and the magnetic braking mechanism is often invoked to expla

Yukinori Iwashita, Tsutomu Kobayashi, Tetsuya Shiromizu, Hirotaka Yoshino

We study the holographic representation of the entanglement entropy, recently proposed by Ryu and Takayanagi, in a braneworld context. The holographic entanglement entropy of a de Sitter brane embedded in an anti-de Sitter (AdS) spacetime is evaluated using geometric quantities, and it is compared with two kinds of de Sitter entropy: a quarter of the area of

Shohini Ghose, Barry C. Sanders

We investigate non-Gaussian states of light as ancillary inputs for generating nonlinear transformations required for quantum computing with continuous variables. We consider a recent proposal for preparing a cubic phase state, find the exact form of the prepared state and perform a detailed comparison to the ideal cubic phase state. We thereby identify the

Jean-Francois Grosjean, Paul-Andi Nagy

We investigate harmonic forms of geometrically formal metrics, which are defined as those having the exterior product of any two harmonic forms still harmonic. We prove that a formal Sasakian metric can exist only on a real cohomology sphere and that holomorphic forms of a formal Kähler metric are parallel w.r.t. the Levi-Civita connection. In the general Ri

Matthew Hedden

In this paper we study the knot Floer homology invariants of the twisted and untwisted Whitehead doubles of an arbitrary knot K. We present a formula for the filtered chain homotopy type of HFK(D(+,K,t)) in terms of the invariants for K, where D(+,K,t) denotes the t-twisted positive-clasped Whitehead double of K. In particular, the formula can be used iterat

N. Lundblad, R. J. Thompson, D. C. Aveline, L. Maleki

We demonstrate a novel dual-beam atom laser formed by outcoupling oppositely polarized components of an F=1 spinor Bose-Einstein condensate whose Zeeman sublevel populations have been coherently evolved through spin dynamics. The condensate is formed through all-optical means using a single-beam running-wave dipole trap. We create a condensate in the field-i

Andrew S. Fletcher, Peter W. Shor, Moe Z. Win

Quantum error correction (QEC) is an essential element of physical quantum information processing systems. Most QEC efforts focus on extending classical error correction schemes to the quantum regime. The input to a noisy system is embedded in a coded subspace, and error recovery is performed via an operation designed to perfectly correct for a set of errors

Fei Gao, Qiao-Yan Wen, Fu-Chen Zhu

The security of quantum exam [Phys. Lett. A 350 (2006) 174] is analyzed and it is found that this protocol is secure for any eavesdropper except for the "students" who take part in the exam. Specifically, any student can steal other examinees' solutions and then cheat in the exam. Furthermore, a possible improvement of this protocol is presented.

Michele Caponigro, Helen Lynn

The words: determinism, hidden variables, subjectivism, information, objectivism, informational-theoretic axioms,observers have some connection with physical reality? What we mean with "description" of physical reality? When we say that we understand this reality? Certain parameters:position, velocity are sufficient? We will focus only to conceptual

S. C. Tiwari

A critical review of the obscure nature of the contribution of spin energy to the energy of the electromagnetic field is presented. It is proposed that the total energy of photon hνcomprises of kinetic and spin parts each equal to hν/2. Classical magnetic field is reinterpreted as angular momentum flux of photon fluid. The black-body radiation law is revisit

A. D. Alhaidari, H. Bahlouli, M. S. Abdelmonem, F. S. Al-Ameen

In three dimensional scattering, the energy continuum wavefunction is obtained by utilizing two independent solutions of the reference wave equation. One of them is typically singular (usually, near the origin of configuration space). Both are asymptotically regular and sinusoidal with a phase difference (shift) that contains information about the scattering

M. Swisdak

A strong magnetic field can make it advantageous to work in a coordinate system aligned with dipolar field lines. This monograph collect the formulas for some of the most frequently used expressions and operations in dipole coordinates.

J. Antos, M. Babik, D. Benjamin, S. Cabrera

The data production for the CDF experiment is conducted on a large Linux PC farm designed to meet the needs of data collection at a maximum rate of 40 MByte/sec. We present two data production models that exploits advances in computing and communication technology. The first production farm is a centralized system that has achieved a stable data processing r

O. Mineev, A. Afanasjev, G. Bondarenko

The Tokai-to-Kamioka (T2K) experiment is a second generation long baseline neutrino oscillation experiment which aims at a sensitive search for the nu_e appearance. The main design features of the T2K near detectors located at 280 m from the target are presented. Scintillator counters developed for the T2K near detectors are described. Readout of the counter

M. F. Yagan

The Classical Coordinate System is geometrical by nature with time being an external variable. Constructing a classical coordinate system employs a point-like signal with infinite speed. In Special Relativity Theory the speed is limited but the signal is a point-like particle (photon). If the oscillatory nature of light is considered, an event in absolute sp

J. L. McCauley, G. H. Gunaratne, K. E. Bassler

First, classes of Markov processes that scale exactly with a Hurst exponent H are derived in closed form. A special case of one class is the Tsallis density, advertised elsewhere as nonlinear diffusion or diffusion with nonlinear feedback. But the Tsallis model is only one of a very large class of linear diffusion with a student-t like density. Second, we sh

D. V. Routgauzer

3-alpha cluster model with dynamic exclusion of forbidden by Pauli principle two-body states is studied. We implement this model by step-by-step inclusion of components of prescribed by the model Hamiltonian, carefully studying intermediate results, and behavior of obtained solutions. A few qualified modifications are introduced in order to significantly sim

Larry Zamick, Alberto Escuderos

We find a relationship between coefficients of fractional parentage (cfp) obtained on the one hand from the principal parent method and on the other hand from a seniority classification. We apply this to the Redmond recursion formula which relates $n \to n+1$ cfp's to $n-1 \to n$ cfp's where the principal parent classification is used. We transform t

Jaroslav Bielcik

In these proceedings, heavy flavor production as measured by STAR is disscussed. This can be done directly by reconstruction of the hadronic decays or indirectly by the measurement of electrons from semileptonic decays of heavy quark mesons. The extracted charm production total cross-section per nucleon-nucleon collision in d+Au and Au+Au collisions shows bi

Pedro J. Torres, Vladimir V. Konotop

A proof of existence of stationary dark soliton solutions of the cubic-quintic nonlinear Schrödinger equation with a periodic potential is given. It is based on the interpretation of the dark soliton as a heteroclinic on the Poincaré map.

Raphael Chetrite, Jean-Yves Delannoy, Krzysztof Gawedzki

The Kraichnan flow provides an example of a random dynamical system accessible to an exact analysis. We study the evolution of the infinitesimal separation between two Lagrangian trajectories of the flow. Its long-time asymptotics is reflected in the multiplicative large deviation regime of the statistics of stretching exponents. In the flow in a two-dimensi

Paul Ormerod, Rich Colbaugh

There is empirical evidence from a range of disciplines that as the connectivity of a network increases, we observe an increase in the average fitness of the system. But at the same time, there is an increase in the proportion of failure/extinction events which are extremely large. The probability of observing an extreme event remains very low, but it is mar

Jamie Mulholland, Dale Rolfsen

We determine which of the finite-type Artin groups are locally indicable, and compute presentations for their commutator subgroups.

Bin Lu, Jianyuan K. Zhong

The 2-bridge knots are a family of knots with bridge number 2. In this paper, we compute the Kauffman polynomials of 2-bridge knots using the Kauffman skein theory and linear algebra techniques. Our calculation can be easily carried out using Mathematica, Maple, Mathcad, etc.

J-L. Colliot-Thélène, V. Suresh

Let K be a global field, T a K-torus and S a finite set of places of K. Let K_v be the completion at a place v. Denote by T(O_v) the maximal compact subgroup of the group T(K_v) of K_v-points of T. We show that the diagonal map from T(K) to the product for v in S of the T(K_v)/T(O_v) need not be onto. As a corollary, for suitable v, the group T(O_v) does not

Takashi Taniguchi

We study the space of binary cubic and quadratic forms over the ring of integers $O$ of an algebraic number field $k$. By applying the theory of prehomogeneous vector spaces founded by M. Sato and T. Shintani, we can associate the zeta functions for these spaces. Applying these zeta functions, we derive some density theorems on the distributions of discrimin

Ali Tahzibi, Carlos Maquera

In this paper, we define $C^1$-robust transitivity for actions of $\RR^2$ on closed connected orientable manifolds. We prove that if the ambient manifold is three dimensional and the dense orbit of a robustly transitive action is not planar, then it is "degenerate" and the action is defined by an Anosov flow.

Samuel Boissiere, Alessandra Sarti

This paper deals with surfaces with many lines. It is well-known that a cubic contains 27 of them and that the maximal number for a quartic is 64. In higher degree the question remains open. Here we study classical and new constructions of surfaces with high number of lines. We obtain in particular a symmetric octic with 352 lines.

Evgeny Fominykh, Bruno Martelli

Following Matveev, a k-normal surface in a triangulated 3-manifold is a generalization of both normal and (octagonal) almost normal surfaces. Using spines, complexity, and Turaev-Viro invariants of 3-manifolds, we prove the following results: 1) a minimal triangulation of a closed irreducible or a bounded hyperbolic 3-manifold contains no non-trivial k-norma

Taekyun Kim

In [2], I constructed the p-adic q-integral on Zp. In this paper, we consider the properties of the p-adic invariant p-adic q-integral in the ring of p-adic integers at q=-1. Finally we give the some applications of p-adic q-integration at q=-1. These properties are useful and worthwhile to study Euler numbers and polynomials.

Masatoshi Suzuki

In this paper, we will give a certain formula for the Riemann zeta function that expresses the Riemann zeta function by an infinte series consisting of $K$-Bessel functions. Such an infinite series expression can be regarded as an analogue of the Chowla-Selberg formula. Roughly speaking, the Chowla-Selberg formula is the formula that expresses the Epstein ze

Feng Luo, Stephan Tillmann

Let M be the interior of a compact 3-manifold with non-empty boundary, and T be an ideal (topological) triangulation of M. This paper describes necessary and sufficient conditions for the existence of angle structures, semi-angle structures and generalised angle structures on (M; T) respectively in terms of a generalised Euler characteristic function on the

Omar Anza Hafsa, Jean-Philippe Mandallena

Acerbi, Buttazzo and Percivale gave a variational definition of the nonlinear string energy under the constraint "det$\nabla u>0$" (see [1]). In the same spirit, we obtain the nonlinear membrane energy under the simpler constraint "det$\nabla u\not=0$".

Edward Goldstein

Consider a 2-plane $P \subset \mathbb{C}^n$ and let $D$ be a bounded region in $P$ with a piecewise-smooth boundary. Let $I(D)$ be the infimum of areas of all piecewise-smooth isotropic surfaces in $\mathbb{C}^n$ with the same boundary as $D$. Then $I(D)= λ_P^n \cdot Area(D)$. If $P$ is not complex, $λ_P^n < \frac{3π}{2\sqrt{2}}$. For a complex plane $\mathb

J. P. Pridham

There has long been a philosophy that every deformation problem in characteristic zero should be governed by a differential graded Lie algebra (DGLA). In this paper, the theory of Simplicial Deformation Complexes (SDCs) is developed, as an alternative to DGLAs. These work in all characteristics, and for many problems can be constructed canonically. In partic

Dan Radu Grigore, Gunter Scharf

We consider the massless supersymmetric vector multiplet in a purely quantum framework and propose a power counting formula. Then we prove that the interaction Lagrangian for a massless supersymmetric non-Abelian gauge theory (SUSY-QCD) is uniquely determined by some natural assumptions, as in the case of Yang-Mills models, however we do have anomalies in th

Agnes Mocsy, Peter Petreczky

We discuss S-wave quarkonia correlators and spectral function using the Wong-potential, and show that these do not agree with the lattice results.

Gregory Mahlon, Stephen Parke

We investigate how to exploit the spin information imparted to the Z boson in associated Higgs production at a future linear collider as an aid in distinguishing between CP-even and CP-odd Higgs bosons. We apply a generalized spin-basis analysis which allowsus to study the possibilities offered by non-traditional choices of spin projection axis. In particula

C. Jarlskog

One of the central questions in theoretical particle physics, since already several decades, has been that of &#34;masses and mixings of the quarks. With the entry of neutrino oscillations into the field, the issue of lepton masses has added a new dimension to the problem. In the literature one finds many models of quark and lepton mass matrices. However, th

Gino Isidori

The impact of rare K decays and lepton-flavor violating processes in shedding light on physics beyond the Standard Model is reviewd. To this purpose, I first recall the formulation of the Minimal Flavor Violation hypothesis --both in the quark and in the lepton sector-- and then use it as guiding principle in comparing the new-physics sensitivity of differen

Christian Hagen, Dieter Hierl, Andreas Schäfer

We report on a study of the pentaquark Theta^+(1540), using a variety of different interpolating fields. We use Chirally Improved fermions in combination with Jacobi smeared quark sources to improve the signal and get reliable results even for small quark masses. The results of our quenched calculations, which have been done on a 12^3 x 24 lattice with a lat

M. D. Messier

Several experiments have sought evidence for neutrino mass and mixing via the phenomenon of neutrino flavor oscillations. In a three neutrino model, these oscillations are described by three angles, two mass splittings, and one CP violating phase. Experiments using neutrinos from the Sun, the atmosphere, nuclear reactors, and particle accelerators have gathe

Yaneer Bar-Yam

We describe a general approach to the correspondence of ZM theory with quantum electrodynamics. As a first step, we show the correspondence of helical clock-field states with plane wave states of the Dirac equation. Specifically, defining the direction of time as the gradient of the field in the combined field and space dimensions, for constant gradients, re

Matthias Bauer, Benjamin Fabian, Matthias Fischmann, Seda Gürses

RFID tags are held to become ubiquitous in logistics in the near future, and item-level tagging will pave the way for Ubiquitous Computing, for example in application fields like smart homes. Our paper addresses the value and the production cost of information that can be gathered by observing these tags over time and different locations. We argue that RFID

V. V. Kryssanov, K. Kakusho

Given that theoretical analysis and empirical validation is fundamental to any model, whether conceptual or formal, it is surprising that these two tools of scientific discovery are so often ignored in the contemporary studies of communication. In this paper, we pursued the ideas of a) correcting and expanding the modeling approaches of linguistics, which ar

Luca Dall&#39;Asta, Andrea Baronchelli

The models of statistical physics used to study collective phenomena in some interdisciplinary contexts, such as social dynamics and opinion spreading, do not consider the effects of the memory on individual decision processes. On the contrary, in the Naming Game, a recently proposed model of Language formation, each agent chooses a particular state, or opin

Rie Takagi, Mats Johnsson, Vladimir Gnezdilov, Reinhard K. Kremer

The crystal structure of the copper(II) tellurium(IV) oxochloride Cu$_{4}$Te$_{5}$O$_{12}$Cl$_{4}$ (Cu-45124) is composed of weakly coupled tetrahedral Cu clusters and shows crystallographic similarities with the intensively investigated compound Cu$_{2}$Te$_{2}$O$_{5}$X$_{2}$, with X~=~Cl, Br (Cu-2252). It differs from the latter by a larger separation of t

J. G. Restrepo, E. Ott, B. R. Hunt

The largest eigenvalue of the adjacency matrix of the networks is a key quantity determining several important dynamical processes on complex networks. Based on this fact, we present a quantitative, objective characterization of the dynamical importance of network nodes and links in terms of their effect on the largest eigenvalue. We show how our characteriz

Maikel C. Rheinstadter, Wolfgang Haussler, Tim Salditt

We have studied the mesoscopic shape fluctuations in aligned multilamellar stacks of DMPC bilayers using the neutron spin-echo technique. The corresponding in plane dispersion relation $τ^{-1}$(q$_{||}$) at different temperatures in the gel (ripple, P$_{β&#39;}$) and the fluid (L$_α$) phase of this model system has been determined. Two relaxation processes,

Takahiro Yamamoto, Kazuyuki Watanabe

We have developed a new theoretical formalism for phonon transport in nanostructures using the nonequilibrium phonon Green&#39;s function technique and have applied it to thermal conduction in defective carbon nanotubes. The universal quantization of low-temperature thermal conductance in carbon nanotubes can be observed even in the presence of local structu

E. A. Henriksen, S. Syed, Y. -J. Wang, H. L. Stormer

We perform a direct study of the magnitude of the anomalous splitting in the cyclotron resonance (CR) of a two-dimensional electron system (2DES) as a function of sample disorder. In a series of AlGaAs/GaAs quantum wells, identical except for a range of carbon doping in the well, we find the CR splitting to vanish at high sample mobilities but to increase dr

Teresa Lenkowska-Czerwinska

We investigate the superconducting states of the high-Tc superconductors which we argue to be commensurately locked by the tilted rigid octahedral distortion. The method is based on the analysis of the kinematics of the rigid-octahedra lattice model. The distortion modes cause the competing superconducting state of the &#34;s&#34; and &#34;d&#34; type symmet

Gilson Carneiro

The interaction between a straight vortex line in a superconducting film and a soft magnetic nanodisk in the magnetic vortex state in the presence of a magnetic field applied parallel to the film surfaces is studied theoretically. The superconductor is described by London theory and the nanodisk by the Landau-Lifshitz continuum theory of magnetism, using the

Kazue Kudo, Katsuhiro Nakamura

Spin-wave instability is studied analytically in the case of parallel pumping for thin films under external field perpendicular to the film plane. It is examined whether the instability threshold derived from only the Landau-Lifshitz (LL) equation can explain experimental instability threshold without using the microscopically-derived spin-wave line width, w

Zhiping Xu, Lifeng Wang, Quanshui Zheng

The ultra-low intershell shear strength in carbon nanotubes (CNTs) has been the primary obstacle to applications of CNTs as mechanical reinforcements. In this paper we propose a new CNT-system composed of comprising of coaxial cylindrical shells of sp2-bonded carbons with condensed intershell spacings. Our atomistic calculations show that such condensed mult

S. Gluzman, V. I. Yukalov

A method is suggested allowing for the improvement of accuracy of self-similar factor and root approximants, constructed from asymptotic series. The method is based on performing a power transform of the given asymptotic series, with the power of this transformation being a control function. The latter is defined by a fixed-point condition, which improves th

M. -H. Whangbo, D. Dai, R. K. Kremer

Non-stoichiometric NaxCoO2 (0.5 < x < 1) consists of CoO2 layers made up of edge-sharing CoO6 octahedra, and exhibits strongly anisotropic magnetic susceptibilities as well as metallic properties. A modified Curie-Weiss law was proposed for systems containing anisotropic magnetic ions to analyze the magnetic susceptibilities of NaxCoO2 (x ~~ 0.75), and impli

Yuh Tomio, Kotaro Honda, Tetsuo Ogawa

The BCS to Bose-Einstein condensation (BEC) crossover of electron-hole (e-h) pairs in optically excited semiconductors is studied using the two-band Hubbard model with both repulsive and attractive interactions. Applying the self-consistent t-matrix approximation combined with a local approximation, we examine the properties of a normal phase and an excitoni

S. Yi, H. Pu

We have mapped out a detailed phase diagram that shows the ground state structure of a spin-1 condensate with magnetic dipole-dipole interactions. We show that the interplay between the dipolar and the spin-exchange interactions induces a rich variety of quantum phases that exhibit spontaneous magnetic ordering in the form of intricate spin textures.

Bing-Hao Xie, Shuo Jin, Wei-Xian Yan

By using an algebraic diagonalization method, the XYZ Heisenberg antiferromagnetics under an external magnetic field is studied in the framework of spin-wave theory. The energy eigenstates are shown to be squeezed number states and the energy eigenvalues are obtained in some cases. Some quantum properties of the energy eigenstates, and the connection of the

Shuo Jin, Bing-Hao Xie, Hong-Biao Zhang, Jing-Min Hou

The $XYZ$ antiferromagnetic model in linear spin-wave frame is shown explicitly to have an $su(1,2)$ algebraic structure: the Hamiltonian can be written as a linear function of the $su(1,2)$ algebra generators. Based on it, the energy eigenvalues are obtained by making use of the similar transformations, and the algebraic diagonalization method is investigat

Y. S. Lee, S. Onoda, T. Arima, Y. Tokunaga

We report on the in-plane anisotropy of the electronic response in the spin/charge/orbital ordered phase of a half-doped layered-structure manganite. The optical conductivity spectra for a single domain of Eu$_{1/2}$% Ca$_{3/2}$MnO$_{4}$ unambiguously show the anisotropic charge dynamics which well corresponds to the theoretical calculation: the optical cond

Ginestra Bianconi, Matteo Marsili

In this paper we calculate the average number of cliques in random scale-free networks. We consider first the hidden variable ensemble and subsequently the Molloy Reed ensemble. In both cases we find that cliques, i.e. fully connected subgraphs, appear also when the average degree is finite. This is in contrast to what happens in Erdös and Renyi graphs in wh

Marcelo Arlego, Wolfram Brenig

Using series expansion based on the flow equation method we study the zero temperature properties of the spin-1/2 planar pyrochlore antiferromagnet in the limit of strong diagonal coupling. Starting from the limit of decoupled crossed dimers we analyze the evolution of the ground state energy and the elementary triplet excitations in terms of two coupling co

Martin Elvis

Feedback from quasars and AGNs is being invoked frequently in several cosmological settings. Currently, order of magnitude, or more, uncertainties in the structure of both the wind and the &#39;obscuring torus&#39; make predictions highly uncertain. To make testable models of this &#39;cosmological feedback&#39; it is essential to understand the detailed str

Nicolas Labrosse, Xing Li, Bo Li

We investigate the formation of the H I Lyman-alpha and Lyman-beta lines in an equatorial coronal streamer. Particular attention is paid to frequency redistribution for the scattering of the incident radiation. The properties of the spectral lines are studied. The coronal model is given by a global 2.5-D three fluid solar wind model with alpha particles. The

M. Schneider, L. Knox, H. Zhan, A. Connolly

We investigate how well the redshift distributions of galaxies sorted into photometric redshift bins can be determined from the galaxy angular two-point correlation functions. We find that the uncertainty in the reconstructed redshift distributions depends critically on the number of parameters used in each redshift bin and the range of angular scales used,

Yoel Rephaeli, Duane Gruber, Yinon Arieli

A2163 was observed by the RXTE satellite for 530 ks during a 6 month period starting in August 2004. The cluster primary emission is from very hot intracluster gas with kT~15 keV, but this component does not by itself provide the best fitting model. A secondary emission component is quite clearly needed, and while this could also be thermal at a temperature

L. Jeremy Richardson, Joseph Harrington, Sara Seager, Drake Deming

We have measured the infrared transit of the extrasolar planet HD209458b using the Spitzer Space Telescope. We observed two primary eclipse events (one partial and one complete transit) using the 24 micron array of the Multiband Imaging Photometer for Spitzer (MIPS). We analyzed a total of 2392 individual images (10-second integrations) of the planetary syst

Andrew I. Sheinis, Marsha J. Wolf, Matthew A. Bershady, David A. H. Buckley

The near infrared (NIR) upgrade to the Robert Stobie Spectrograph (RSS) on the Southern African Large Telescope (SALT), RSS/NIR, extends the spectral coverage of all modes of the visible arm. The RSS/NIR is a low to medium resolution spectrograph with broadband imaging, spectropolarimetric, and Fabry-Perot imaging capabilities. The visible and NIR arms can b

Kacper Kornet, Sebastian Wolf, Michal Rozyczka

We examine the predictions of the core accretion - gas capture model concerning the efficiency of planet formation around stars with various masses. First, we follow the evolution of gas and solids from the moment when all solids are in the form of small grains to the stage when most of them are in the form of planetesimals. We show that the surface density

Fridolin Weber, Matthew Meixner, Rodrigo P. Negreiros, Manuel Malheiro

With central densities way above the density of atomic nuclei, neutron stars contain matter in one of the densest forms found in the universe. Depending of the density reached in the cores of neutron stars, they may contain stable phases of exotic matter found nowhere else in space. This article gives a brief overview of the phases of ultra-dense matter pred

K. Kinemuchi, H. A. Smith, P. R. Wozniak, T. A. McKay

We use data from the Northern Sky Variability Survey (NSVS), obtained from the first generation Robotic Optical Transient Search Experiment (ROTSE-I), to identify and study RR Lyrae variable stars in the solar neighborhood. We initially identified 1197 RRab (RR0) candidate stars brighter than the ROTSE median magnitude V = 14. Periods, amplitudes, and mean V

N. J. Schurch, C. Done

The origin of the soft X-ray excess emission observed in many type-1 AGN has been an unresolved problem in X-ray astronomy for over two decades. We develop the model proposed Gierlinski & Done (2004), which models the soft excess with heavily smeared, ionized, absorption, by including the emission that must be associated with this absorption. We show that, r

Pedro P. Avelino, Andrew R. Liddle

We study the reionization history of the Universe in cosmological models with non-Gaussian density fluctuations, taking them to have a renormalized $χ^2$ probability distribution function parametrized by the number of degrees of freedom, $ν$. We compute the ionization history using a simple semi-analytical model, considering various possibilities for the ast

P. J. Käpylä, M. J. Korpi, I. Tuominen

(abridged) Results from kinematic solar dynamo models employing alpha-effect and turbulent pumping from local convection calculations are presented. We estimate the magnitude of these effects to be around 2-3 m/s. The rotation profile of the Sun as obtained from helioseismology is applied. We obtain an estimate of the ratio of the two induction effects, C_al

Didier Barret

With its ability to look at bright galactic X-ray sources with sub-millisecond time resolution, the Rossi X-ray Timing Explorer (RXTE) discovered that the X-ray emission from accreting compact stars shows quasi-periodic oscillations on the dynamical timescales of the strong field region. RXTE showed also that waveform fitting of the oscillations resulting fr

Joseph F. Hennawi, Jason X. Prochaska

With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar&#39;s environment in absorption. We used a sample of 17 Lyman limit systems with column density N_HI > 10^19 cm^-2 selected from 149 projected quasar pair sightlines, to investigate the clustering pattern of optically thick absorbers aro

Koushik Ghosh, Probhas Raychaudhuri

We have used Rayleigh power spectrum analysis of the monthly solar neutrino flux data from (1) SAGE detector during the period from 1st January 1990 to 31st December 2000; (2) SAGE detector during the period from April 1998 to December 2001; (3) GALLEX detector during the period from May 1991 to January 1997; (4) GNO detector during the period from May 1998

Koushik Ghosh, Probhas Raychaudhuri

We have used the Rayleigh Power Spectrum Analysis of the solar neutrino flux data from 1) 5-day-long samples from Super-Kamiokande-I detector during the period from June, 1996 to July, 2001; 2) 10 -day-long samples from the same detector during the same period and (3) 45-day long from the same detector during the same period. According to our analysis (1) gi

R. Soria, Z. Kuncic, J. W. Broderick, S. D. Ryder

We have studied the face-on, barred spiral NGC 7424 (site of the rare Type IIb SN 2001ig) with Chandra, Gemini and the Australia Telescope Compact Array. After giving revised X-ray colours and luminosity of the supernova, here we focus on some other interesting sources in the galaxy: in particular, our serendipitous discovery of two ultraluminous X-ray sourc

O. Petruk, R. Bandiera

Within a test-particle description of the acceleration process in parallel nonrelativistic shocks, we present an analytic treatment of the electron injection. We estimate the velocity distribution of the injected electrons as the product of the post-shock thermal distribution of electrons times the probability for electrons with a given velocity to be accele

A. Garson, H. Krawczynski, J. Grindlay, G. J. Fishman

The Energetic X-ray Imaging Survey Telescope (EXIST) is a mission design concept that uses coded masks seen by Cadmium Zinc Telluride (CZT) detectors to register hard X-rays in the energy region from 10 keV to 600 keV. A partially active or fully active anti-coincidence shield/collimator with a total area of between 15 and 35 square meters will be used to de

Alexandre Arbey

In this article, we examine a model which proposes a common explanation for the presence of additional attractive gravitational effects -- generally considered to be due to dark matter -- in galaxies and in clusters, and for the presence of a repulsive effect at cosmological scales -- generally taken as an indication of the presence of dark energy. We theref

Tomi Koivisto, David F. Mota

Cosmological consequences of a string-motivated dark energy scenario featuring a scalar field coupled to the Gauss-Bonnet invariant are investigated. We study the evolution of the universe in such a model, identifying its key properties. The evolution of the homogeneous background and cosmological perturbations, both at large and small scales, are calculated

Kieran Boyle

New results from polarized p-p collisions at sqrt(s)=200 GeV of double longitudinal spin asymmetry in pi0 production using the PHENIX detector in the 2005 RHIC run are presented. Both positive and negative maximal gluon polarization scenarios are inconsistent with the data. The data is consistent with small |\Delta g|, including \Delta g=0.

L. Platter

We calculate higher order corrections for the three-nucleon system up to next-to-next-to-leading within an effective field theory with contact interactions alone. We employ a subtraction formalism previously developed and for which it has been shown that no new three-body force counterterm is needed for complete renormalization up to this order. We give resu

Jeffrey E. McClintock, Rebecca Shafee, Ramesh Narayan, Ronald A. Remillard

Based on a spectral analysis of the X-ray continuum that employs a fully relativistic accretion-disk model, we conclude that the compact primary of the binary X-ray source GRS 1915+105 is a rapidly-rotating Kerr black hole. We find a lower limit on the dimensionless spin parameter of a* greater than 0.98. Our result is robust in the sense that it is independ

W. Bryc, W. Matysiak, R. Szwarc, J. Wesolowski

We prove a projection formula for the four-parameter family of orthogonal polynomials that are a reparameterization of the polynomials in the Askey-Wilson class. By carefully analyzing the recurrence relations we manage to avoid using the explicit expression for the orthogonality measure, which would be cumbersome due to the complexity of the reparameterizat

Shin&#39;ichi Nojiri, Sergei D. Odintsov

We suggest to generalize the dark energy equation of state (EoS) by introduction the relaxation equation for pressure which is equivalent to consideration of the inhomogeneous EoS cosmic fluid which often appears as the effective model from strings/brane-worlds. As another, more wide generalization we discuss the inhomogeneous EoS which contains derivatives

S. A. Stanford, A. K. Romer, K. Sabirli, M. Davidson

We report the discovery of XMMXCS J2215.9-1738, a massive galaxy cluster at z =1.45, which was found in the XMM Cluster Survey. The cluster candidate was initially identified as an extended X-ray source in archival XMM data. Optical spectroscopy shows that 6 galaxies within a 60 arcsec diameter region lie at z = 1.45 +/- 0.01. Model fits to the X-ray spectra