August 2003 arXiv papers — page 28

Zaira Nazario, David I. Santiago

The phase diagram of a single component Bose system in a lattice at zero temperature is obtained. We calculate the variational energies for the Mott insulating and superfluid phases. Below a certain critical density, which depends monotonically on the well depth of the lattice, the Mott insulating phase is stable over the superfluid phase for low enough tune

T. Appl, D. H. Schiller

We introduce a large class of holomorphic quantum states by choosing their normalization functions to be given by generalized hypergeometric functions. We call them generalized hypergeometric states in general, and generalized hypergeometric coherent states in particular, if they allow a resolution of unity. Depending on the domain of convergence of the gene

Pawel Wocjan, Dominik Janzing, Thomas Decker, Thomas Beth

We consider a hypothetical apparatus that implements measurements for arbitrary 4-local quantum observables A on n qubits. The apparatus implements the ``measurement algorithm'' after receiving a classical description of A. We show that a few precise measurements, applied to a basis state would provide a probabilistic solution of PSPACE problems. The

Chirag Dekate

Quantum teleportation schemes in which operations are performed before establishing the quantum channel are not constrained by resource limits set in H.K.Lo and Bennett et al. We compare the standard teleportation protocol to the one proposed by Kak on the basis of the classical communication cost. Due to its unique architecture we study the problems in impl

S. Albeverio, S. M. Fei, W. L. Yang

Teleportation for pure states, mixed states with standard and optimal protocols are introduced and investigated systematically. An explicit equation governing the teleportation of finite dimensional quantum pure states by a generally given non-local entangled state is presented. For the teleportation of a mixed state with an arbitrary mixed state resource, a

Osamu Hirota, Kentaro Kato, Masaki Shoma, Tsuyoshi Sasaki Usuda

In this paper, we present an efficient implementation method of physical layer of Y-00 which can support a secure communication and a quantum key distribution (more generally key expansion) by IMDD(intensity modulation/direct detection) or FSK(frequency shift keying)optical fiber communication network. Although the general proof of the security is not yet gi

Raoul Nakhmanson

Analogies between quantum mechanics and sociology lead to the hypothesis that quantum objects are complex products of evolution. Like biological objects they are able to receive, to work on, and to spread semantic information. In general meaning we can name it "consciousness". The important ability of consciousness is ability to predict future. Key w

Kun Hu, Plamen Ch. Ivanov, Zhi Chen, Michael F. Hilton

We investigate if known extrinsic and intrinsic factors fully account for the complex features observed in recordings of human activity as measured from forearm motion in subjects undergoing their regular daily routine. We demonstrate that the apparently random forearm motion possesses previously unrecognized dynamic patterns characterized by fractal and non

A. Buzulutskov, A. Bondar, L. Shekhtman, R. Snopkov

We study the performance of gaseous and two-phase (liquid-gas) cryogenic detectors of ionizing radiation, based on gas electron multipliers (GEMs). For the first time, high gas gains, exceeding 10^4, were obtained in pure He, Ar and Kr at low temperatures and the stable avalanche mode of operation was observed in the two-phase cryogenic detector in Kr. The e

J. Pardo, F. Gomez, A. Iglesias, R. Lobato

We have analyzed data on the free ion yield observed in liquid isooctane irradiated by Co60 gamma rays within the framework of the Onsager theory about initial recombination. Several distribution functions describing the electron thermalization distance have been used and compared with the experimental results: a delta function, a Gaussian type function and

E. V. Makeev, S. E. Skipetrov

We study the second harmonic generation (SHG) in a suspension of small spherical particles confined within a slab, assuming undepleted pump and applying (i) single scattering approximation and (ii) diffusion approximation. In the case (i), the angular diagram, the differential and total crossections of the SHG process, as well as the average cosine of SH sca

Hanno Essen

The effect of the electrodynamic forces on a charged particle in a propagating plane electromagnetic wave is investigated. First it is pointed out that for constant fields fulfilling the radiation condition there will be an acceleration in the direction of the Poynting vector. When oscillating fields are considered the Lorentz force on the particle only caus

M. Grendar,, M. Grendar

Traditionally, the Method of (Shannon-Kullback's) Relative Entropy Maximization (REM) is considered with linear moment constraints. In this work, the method is studied under frequency moment constraints which are non-linear in probabilities. The constraints challenge some justifications of REM since a) axiomatic systems are developed for classical linear

V. O. Nesterenko, W. Kleinig, P. -G. Reinhard, D. S. Dolci

Properties of low-energy (infra-red) quadrupole modes (LEQM) of multipolarity $+AFw-lambda+AFw-mu =$20, 21 and 22 in deformed sodium clusters are studied within the Kohn-Sham LDA RPA approach. Possible manifestations of LEQM in stimulated Raman adiabatic passage (STIRAP) reaction are discussed. It is shown that, in free light clusters, where the low-energy s

Supurna Sinha

In recent years molecular elasticity has emerged as an active area of research: there are experiments that probe mechanical properties of single biomolecules such as DNA and Actin, with a view to understanding the role of elasticity of these polymers in biological processes such as transcription and protein-induced DNA bending. Single molecule elasticity has

Jozsef Garai

The observed higher uplift rates before the end of deglaciation requires the existence of a low viscosity channel or layer. The uplifts observed after the end of deglaciation does not show any contribution from this low viscosity channel and a homogeneous viscosity model fits very well to the observed uplift. Most of the researchers therefore prefer the homo

J. C. Hardy, I. S. Towner

The most precise value of V_{ud}, which is obtained from superallowed nuclear beta decay, leads to a violation of CKM unitarity by 2.2 sigma. Experiments are underway on two continents to test and improve this result through decay studies of odd-odd N = Z nuclei with A >or= 62. We show, in a series of illustrative shell-model calculations, that numerous weak

H. V. von Geramb, B. Davaadorj, St. Wirsching

The formalism of two coupled Dirac equations within constraint instant form dynamics is used to study the nucleon-nucleon interaction. The salient features and the final Schroedinger type equation is given. Explicitly energy dependent coupled channel potentials, for use in partial wave Schroedinger like equations, with nonlinear and complicated derivative te

Kazuyuki Ogata, M. Yahiro, Y. Iseri, T. Matsumoto

Systematic analysis of 8B Coulomb dissociation with the Asymptotic Normalization Coefficient (ANC) method is proposed to determine the astrophysical factor S17 accurately. An important advantage of the analysis is that uncertainties of the extracted S17 coming from the use of the ANC method can quantitatively be evaluated, in contrast to previous analyses us

D. Hennig, E. B. Starikov, J. F. R. Archilla, F. Palmero

We investigate the charge transport in synthetic DNA polymers built up from single types of base pairs. In the context of a polaron-like model, for which an electronic tight-binding system and bond vibrations of the double helix are coupled, we present estimates for the electron-vibration coupling strengths utilizing a quantum-chemical procedure. Subsequent

Jun Shibata, Y-h. Taguchi

We have investigated the relationship between height and spacing of Barchan dunes which the coupled map lattice model numerically generates. There is a scaling relation between them and the values of the scaling exponents agree well with real dunes' values. The values of these scaling exponents are same for both steady states and transient states.

Yuri Latushkin, Yuri Tomilov

We prove that a first order linear differential operator G with unbounded operator coefficients is Fredholm on spaces of functions on the real line with values in a reflexive Banach space if and only if the corresponding strongly continuous evolution family has exponential dichotomies on both semiaxises and a pair of the ranges of the dichotomy projections i

V. Aldaya, J. Guerrero

The expression for $\hatκ$ in J. Math. Phys. 36, 3191 (1995) was miswritten. The correct expression is given.

Cilanne E. Boulet

We present a new partition identity and give a combinatorial proof of our result. This generalizes a result of Andrew's in which he considers the generation function for partitions with respect to size, number of odd parts, and number of odd parts of the conjugate.

Martin Scharlemann, Abigail Thompson

Understanding non-Haken 3-manifolds is central to many current endeavors in 3-manifold topology. We describe some results for closed orientable surfaces in non-Haken manifolds, and extend Fox's theorem for submanifolds of the 3-sphere to submanifolds of general non-Haken manifolds. In the case where the submanifold has connected boundary, we show also th

Andrew Granville, Kannan Soundararajan

Typically, one expects that there are around x\prod_{p\not\in P, p <= x} (1-1/p) integers up to x, all of whose prime factors come from the set P. Of course for some choices of P one may get rather more integers, and for some choices of P one may get rather less. Hall [4] showed that one never gets more than e^γ+o(1) times the expected amount (where γis the

Victor Guillemin, Tara S. Holm

Let $M^{2d}$ be a compact symplectic manifold and $T$ a compact $n$-dimensional torus. A Hamiltonian action, $τ$, of $T$ on $M$ is a GKM action if, for every $p \in M^T$, the isotropy representation of $T$ on $T_pM$ has pair-wise linearly independent weights. For such an action the projection of the set of zero and one-dimensional orbits onto $M/T$ is a regu

Vassil Kanev

We prove that the moduli space A_3(1,1,4) of polarized abelian threefolds with polarization of type (1,1,4) is unirational. By a result of Birkenhake and Lange this implies the unirationality of the isomorphic moduli space A_3(1,4,4). The result is based on the study the Hurwitz space H_{4,n}(Y) of quadruple coverings of an elliptic curve Y simply branched i

A. M. Bigatti, A. Conca, L. Robbiano

The generic initial ideals of a given ideal are rather recent invariants. Not much is known about these objects, and it turns out to be very difficult to compute them. The main purpose of this paper is to study the behaviour of generic initial ideals with respect to the operation of taking distractions. Our main result states that the revlex generic initial

Dionyssios Lappas, Panayotis Spyrou

In this paper, we propose that &#39;embodied mathematics&#39; should be studied not only by reduction to the present individual bodily experience but in an historical context as well, as far as the origins of mathematics are concerned. Some early mathematical results are the Theorems of Geometry and arose as attempts to objectively render the main perceptual

Hitoshi Murakami

We will study the asymptotic behaviors of the colored Jones polynomials of the figure-eight knot. In particular we will show that for certain limits we obtain the volumes of the cone manifolds with singularities along the knot.

P. I. Katsylo

We consider natural differential operations acting on sections of tensor vector bundles. Arrising problems can be reformulated as invariant theoretical problems (the IT-reduction). We give examples of usage of the IT-reduction. In particular, on a manifold with a connection and a Poisson structure we construct the canonical quantization.

M. Deza, M. Dutour

A zigzag in a plane graph is a circuit of edges, such that any two, but no three, consecutive edges belong to the same face. A railroad in a plane graph is a circuit of hexagonal faces, such that any hexagon is adjacent to its neighbors on opposite edges. A graph without a railroad is called tight. We consider the zigzag and railroad structures of general 3-

M. Deza, M. Dutour, M. Shtogrin

Call {\em i-hedrite} any 4-valent n-vertex plane graph, whose faces are 2-, 3- and 4-gons only and $p_2+p_3=i$. The edges of an i-hedrite, as of any Eulerian plane graph, are partitioned by its {\em central circuits}, i.e. those, which are obtained by starting with an edge and continuing at each vertex by the edge opposite the entering one. So, any i-hedrite

Iosif Bena, Radu Roiban

One of the powerful techniques to analyze the 5 dimensional Super Yang Mills theory with a massive hypermultiplet (N=1*) is provided by the AdS/CFT correspondence. It predicts that, for certain special values of the hypermultiplet mass, this theory develops nonperturbative branches of the moduli space as well as new light degrees of freedom. We use the highe

P. Sundberg, R. L. Jaffe

We study the Casimir problem for a fermion coupled to a static background field in one space dimension. We examine the relationship between interactions and boundary conditions for the Dirac field. In the limit that the background becomes concentrated at a point (a ``Dirac spike&#39;&#39;) and couples strongly, it implements a confining boundary condition. W

M. Trzetrzelewski, J. Wosiek

Standard quantum mechanics is viewed as a limit of a cut system with artificially restricted dimension of a Hilbert space. Exact spectrum of cut momentum and coordinate operators is derived and the limiting transition to the infinite dimensional Hilbert space is studied in detail. The difference between systems with discrete and continuous energy spectra is

M. Ait Ben Haddou, A. Belhaj, E. H. Saidi

Using geometric engineering method of 4D $\mathcal{N}=2$ quiver gauge theories and results on the classification of Kac-Moody (KM) algebras, we show on explicit examples that there exist three sectors of $\mathcal{N}=2$ infrared CFT$_{4}$s. Since the geometric engineering of these CFT$_{4}$s involve type II strings on K3 fibered CY3 singularities, we conject

Ji Young Han, Won Tae Kim, Hee Ju Yee

We present an exactly soluble charged wormhole model in two dimensions by adding infalling chiral fermions on the static wormhole. The infalling energy due to the infalling charged matter requires the classical back reaction of the geometry, which is solved by taking into account of the nontrivial nonchiral exotic energy. Finally, we obtain the exact express

Edward Witten

On the space of three-dimensional conformal field theories with U(1) symmetry and a chosen coupling to a background gauge field, there is a natural action of the group $SL(2,{\bf Z})$. The generator $S$ of $SL(2,{\bf Z})$ acts by letting the background gauge field become dynamical, an operation considered recently by Kapustin and Strassler in explaining thre

Ahmad Idilbi, Xiangdong Ji, Jian-Ping Ma

We present a leading-order pQCD calculation of the helicity-flip $Δ\to Nγ^*$ matrix element $G_0$ (Coulomb quadrupole amplitude $C2$), taking into account the transverse momenta of the quarks and the contribution from the gluons. In the large $Q^2$ limit, its scaling behavior acquires a double-logarithmic correction $\log^2{(Q^2/Λ^2)}$ compared with the stan

Efrain J. Ferrer, Vivian de la Incera

In this talk we review the results on neutrino propagation under external magnetic fields. We concentrate on the effects of strong magnetic fields $M_{W}^{2}\gg B\gg m_{e}^{2}$ in neutral media. It is shown that the neutrino energy density get a magnetic contribution in the strong-field, one-loop approximation, which is linear in the Fermi coupling constant

Konstantinos Dimopoulos, George Lazarides, David Lyth, Roberto Ruiz de Austri

In contrast to the inflaton&#39;s case, the curvature perturbations due to the curvaton field depend strongly on the evolution of the curvaton before its decay. We study in detail the dynamics of the curvaton evolution during and after inflation. We consider that the flatness of the curvaton potential may be affected by supergravity corrections, which introd

M. Ciuchini, E. Franco, A. Masiero, L. Silvestrini

We discuss the twofold role of flavor and CP violation as a constraint in model building and as a signal of SUSY. Considering as an example b to s transitions, we analyze present bounds on SUSY parameters, discuss possible deviations from SM predictions in Bd and Bs physics and present strategies to reveal SUSY signals in present and future experiments in th

Xiao-Hong Wu, Chong Sheng Li, Jian Jun Liu

The electroweak corrections of order ${\cal O}(α_{\rm em} m^2_{t,b}/m^2_w)$ and ${\cal O}(α_{\rm em} m^3_{t,b}/m^3_w)$ to Higgs boson associated production with top quark pair are calculated at $e^+e^-$ colliders in the standard model (SM), the two-Higgs-doublet model (2HDM) and the minimal supersymmetric standard model (MSSM). These corrections are a few pe

J. Dias de Deus, A. Rodrigues

Transverse momentum fluctuations can be understood as resulting from clustering of strings or partons. Data allows to distinguish clustering without percolation, from clustering with percolation. Percolation is clearly favored by data.

I. Schienbein, J. -Y. Yu

Single pion leptoproduction in the region of the (3,3) resonance is currently of high interest for at least two reasons: (i) These reactions constitute an important part of the total cross section in low energy reactions and are utilized to detect neutrino oscillations in current and future long baseline experiments. (ii) Intranuclear rescattering of the pio

M. Blasone, P. Jizba, G. Vitiello

We report about recent results on the Quantum Field Theory of neutrino mixing and oscillations. A discussion of the relevant observables for flavor fields is given, leading to oscillation formulas which exhibit corrections with respect to the usual ones.

Daijiro Suematsu

We study the $μ$ problem and the radiative electroweak symmetry breaking in an extended gauge mediation supersymmetry breaking (GMSB) model, in which the messenger fields are assumed to couple to the different singlet fields due to the discrete symmetry. Since the spectrum of superpartners is modified, the constraint from the $μ$ problem can be relaxed in co

T. Fuchs, M. R. Schindler, J. Gegelia, S. Scherer

It is demonstrated that using a suitable renormalization condition one obtains a consistent power counting in manifestly Lorentz-invariant baryon chiral perturbation theory including vector mesons as explicit degrees of freedom.

Anatoly Kopylov, Valery Petukhov

A lithium-based radiochemical detector is aimed primarily to detect neutrinos from CNO cycle what will provide a direct proof of its existence and will be a stringent test of the theory of stellar evolution. Another task which can be solved by this experiment is to measure a mixing angle $θ_{12}$. The sensitivity of a lithium experiment to $θ_{12}$ was calcu

C. Barrabes, P. A. Hogan

We present a general formalism for describing singular hypersurfaces in the Einstein theory of gravitation with a Gauss--Bonnet term. The junction conditions are given in a form which is valid for the most general embedding and matter content and for coordinates chosen independently on each side of the hypersurface. The theory is applied to both a time--like

Pavel Krtous, Jiri Podolsky, Jiri Bicak

We present a characterization of general gravitational and electromagnetic fields near de Sitter-like conformal infinity which supplements the standard peeling behavior. This is based on an explicit evaluation of the dependence of the radiative component of the fields on the null direction from which infinity is approached. It is shown that the directional p

Lior M. Burko

We consider the evolution of the orbit of a spinning compact object in a quasi-circular, planar orbit around a Schwarzschild black hole in the extreme mass ratio limit. We compare the contributions to the orbital evolution of both spin-orbit coupling and the local self force. Making assumptions on the behavior of the forces, we suggest that the decay of the

K. A. Bronnikov, G. N. Shikin, E. N. Sibileva

We consider static, cylindrically symmetric configurations in general relativity coupled to nonlinear electrodynamics (NED) with an arbitrary gauge-invariant Lagrangian of the form $L_{em}= Φ(F)$, $F =F_{mn}F^{mn}$. We study electric and magnetic fields with three possible orientations: radial (R), longitudinal (L) and azimuthal (A), and try to find solitoni

Floris Geerts, Lieven Smits, Jan Van den Bussche

This paper addresses the question whether one can determine the connectivity of a semi-algebraic set in three dimensions by testing the connectivity of a finite number of two-dimensional ``samples&#39;&#39; of the set, where these samples are defined by first-order queries. The question is answered negatively for two classes of first-order queries: cartesian

Daniel I. Goldman, J. B. Swift, Harry L. Swinney

We study fluctuations in a vertically oscillated layer of grains below the critical acceleration for the onset of ordered standing waves. As onset is approached, transient disordered waves with a characteristic length scale emerge and increase in power and coherence. The scaling behavior and the shift in the onset of order agrees with the Swift-Hohenberg the

Chia-Ren Hu

It is shown that in a heterostructure where screening is eliminated, the Ampére-Maxwell law of electrodynamics implies that a dc or ac spinomotive force can be inudced with a time rate of change of a transverse electric field, and the magnetic analog of Ampére law implies that a dc or ac spin current can generate a transverse electric field at the same frequ

Denis A. Gorokhov, Rava A. da Silveira

The decay of metastable states is dominated by quantum tunneling at low temperatures and by thermal activation at high temperatures. The escape rate of a particle out of a square well is calculated within a semi-classical approximation and exhibits an `ultrasharp&#39; crossover: a kink in the decay rate separates a purely quantum regime at low temperatures f

Raul Perez-Enriquez

An index for the characterisation of the Perovskite type Superconductors is introduced. The index, denominated as Structural Parameter of High Tc Superconductivity (PESATc from its name in Spanish), is calculated using a Moebius Orbital defined as the length of an Octahedral Moebius Strip overlaying the octahedra created by the CuO planes and the apical Oxyg

J. Cubizolles, T. Bourdel, S. J. J. M. F. Kokkelmans, G. V. Shlyapnikov

We create weakly-bound Li2 molecules from a degenerate two component Fermi gas by sweeping a magnetic field across a Feshbach resonance. The atom-molecule transfer efficiency can reach 85% and is studied as a function of magnetic field and initial temperature. The bosonic molecules remain trapped for 0.5 s and their temperature is within a factor of 2 from t

S. Chakravarty, D. G. Georgiev, P. Boolchand, M. Micoulaut

Non-reversing relaxation enthalpies (DHnr) at glass transitions Tg(x) in the PxGexSe1-2x ternary display a wide, sharp and deep global minimum (~0) in the 0.09 < x < 0.145 range, within which Tg becomes thermally reversing. In the reversibility window these glasses are found not to age, in contrast to aging observed for fragile glass compositions outside the

Gabriel Tellez, Emmanuel Trizac

We investigate the possibility of electrostatic potential saturation, which may lead to the phenomenon of effective charge saturation. The system under study is a uniformly charged infinite plane immersed in an arbitrary electrolyte made up of several micro-species. To describe the electric double layer, we use a generic density functional theory in which th

Kaushik Matia, Mukul Pal, H. Eugene Stanley, H. Salunkay

Classic studies of the probability density of price fluctuations $g$ for stocks and foreign exchanges of several highly developed economies have been interpreted using a {\it power-law} probability density function $P(g) \sim g^{-(α+1)}$ with exponent values $α> 2$, which are outside the Lévy-stable regime $0 < α< 2$. To test the universality of this relatio

Kaushik Matia, Yosef Ashkenazy, H. Eugene Stanley

We analyze daily prices of 29 commodities and 2449 stocks, each over a period of $\approx 15$ years. We find that the price fluctuations for commodities have a significantly broader multifractal spectrum than for stocks. We also propose that multifractal properties of both stocks and commodities can be attributed mainly to the broad probability distribution

S. E. Skipetrov

Linear stability analysis of speckle pattern resulting from multiple, diffuse scattering of coherent light waves in random media with intensity-dependent refractive index (noninstantaneous Kerr nonlinearity) is performed. The speckle pattern is shown to become unstable with respect to dynamic perturbations within a certain frequency band, provided that nonli

M. Kozlowski, J. Marciak-Kozlowska

The LASETRON project (Phys. Rev. Lett, 88, (2002), p. 074801-1) offers the possibility of the investigation of electron-positron structure of the space-time. Following our results (From Quarks to Bulk Matter, Hadronic Press, 2001) we analyze theoretically possibility of the penetration of zeptosecond laser pulses through space-time. Key words: Zeptosecond la

Andrei N. Yakunin

An technique is extended to estimate some critical exponents without using the expansion over the coupling constant. The data obtained is in a agreement with those found by help of the 2D Onsager method or with recent 3D results. In the second case the exponent of the correlation radius can be expressed in terms of the fine structure constant. The polymer pl

Ali Rana Atilgan, Pelin Akan, Canan Baysal

It is not merely the position of residues that are of utmost importance in protein function and stability, but the interactions between them. We illustrate, by using a network construction on a set of 595 non-homologous proteins, that regular packing is preserved in short-range interactions, but short average path lengths are achieved through some long-range

Xuan P. A. Gao, A. P. Mills, A. P. Ramirez, L. N. Pfeiffer

The resistivity $ρ$ of high mobility dilute 2D holes in GaAs exhibits a peak at a certain temperature $T^*$ in zero magnetic field($B$=0). In the $T>T^*$ regime where d$ρ$/d$T<$0, we observe for the first time both the $ν=1$ quantum Hall(QH) effect and a low field insulator-QH transition which is consistent with the 2D hole system being a Fermi liquid(FL). T

C. C. Homes, S. V. Dordevic, D. A. Bonn, Ruixing Liang

The Ferrell-Glover-Tinkham (FGT) sum rule has been applied to the temperature dependence of the in-plane optical conductivity of optimally-doped YBa_2Cu_3O_{6.95} and underdoped YBa_2Cu_3O_{6.60}. Within the accuracy of the experiment, the sum rule is obeyed in both materials. However, the energy scale ω_c required to recover the full strength of the superfl

D. R. Ballantyne, Joseph C. Weingartner, N. Murray

Hubble Space Telescope images of MCG-6-30-15 show a dust lane crossing the galaxy just below the nucleus. In this paper, we argue that this dust lane is responsible for the observed reddening of the nuclear emission and the Fe I edge hinted at in the Chandra spectrum of MCG-6-30-15. We further suggest that the gas within the dust lane can comprise much of th

L. Costamante

Multi-wavelength observations with TeV photons are an essential diagnostic tool to study the physics of TeV sources. The complex variability of blazars, however (timescales from years down to minutes, with different patterns and SED behaviours), requires a great effort on simultaneous campaigns, which should be performed possibly over several days. Spectral

L. Costamante, F. Aharonian, D. Horns, G. Ghisellini

The intrinsic BL Lac spectra above few hundreds GeV can be very different from the observed ones due to the absorption effects by the diffuse Extragalactic Background Light (EBL), at present poorly known. With the recent results, there are now 4 sources with good spectral information: Mkn 421 (z=0.031), Mkn 501 (z=0.034), 1ES 1426+428 (z=0.129) and 1ES 1959+

Megan Donahue, Jessica A. Gaskin, Sandeep K. Patel, Marshall Joy

We present new Chandra X-ray observations of the luminous X-ray cluster, MS0451.6-0305, at z=0.5386. Spectral imaging data for the cluster are consistent with an isothermal cluster of 10.0 - 10.6 +/-1.6 keV and an Fe abundance of 0.32-0.40 +/-0.13 solar. The systematic uncertainties, arising from calibration and model uncertainties, of the temperature determ

Edward A. Baltz, James Stone

In the nuclear and particle astrophysics session of CIPANP 2003 we heard talks on a number of topics, focused for the most part into four broad areas. Here we outline the discussions of the standard cosmological model, dark matter searches, cosmic rays, and neutrino astrophysics. The robustness of theoretical and experimental programs in all of these areas i

F. Combes

CO emission, tracing the molecular content and distribution in galaxies, is a privileged tool to trace gas towards the nucleus, since the HI tracer is in general depleted there. A review is done of recent CO line observations, with sufficient spatial resolution to indicate the morphology and kinematics of the gas near the nucleus. The puzzling result that nu

S. Yesilyurt, A. Del Popolo, N. Ercan

In the current paper, we further improved the model for the migration of planets introduced in Del Popolo et al. (2001) and extended to time-dependent planetesimal accretion disks in Del Popolo and Eksi (2002). In the current study, the assumption of Del Popolo and Eksi (2002), that the surface density in planetesimals is proportional to that of gas, is rele

C. Alcock, D. R. Alves, A. Becker, D. Bennett

We have frequency analyzed 6391 variables classified earlier as fundamental mode RR Lyrae (RR0) stars in the MACHO database on the Large Magellanic Cloud (LMC). The overwhelming majority of these variables have been proved to be indeed RR0 stars, whereas the remaining ones have fallen in one of the following categories: single- and double-mode Cepheids, bina

Mario Livio, Adam Riess

The recent detection of H-alpha emission in the supernova Type Ia SN 2002ic could be taken to mean that the elusive progenitor systems of Type Ia supernovae have finally been identified. At first glance, the observation appears to support a single-degenerate scenario, in which the white dwarf accretes from a normal companion. In this Letter we show that the

J. -U. Ness, S. Starrfield, V. Burwitz, P. Hauschildt

V4743 Sgr (Nova Sgr 2002 No. 3) was discovered on 20 September 2002. We obtained a 5ks ACIS-S spectrum in November 2002 and found that the nova was faint in X-rays. We then obtained a 25ks CHANDRA LETGS observation on 19 March 2003. By this time, it had evolved into the Super Soft X-ray phase exhibiting a continuous spectrum with deep absorption features. Th

Norbert Christlieb

I review the status of the search for extremely metal-poor halo stars with the Hamburg/ESO objective-prism survey (HES). 2194 candidate metal-poor turn-off stars and 6133 giants in the magnitude range 14 < B < 17.5 have been selected from 329 (out of 380) HES fields, covering an effective area of 6400 square degrees in the southern extragalactic sky. Moderat

L. F. Olsen, L. Hansen, H. E. Joergensen, C. Benoist

We present the results of carrying out multi-object spectroscopy in 10 EIS cluster fields. Based on the list of 345 galaxy redshifts we identify significant 3D-density enhancements. For 9 of the EIS clusters we identify significant 3D-concentrations corresponding to the originally detected cluster candidate. We find redshifts in the range 0.097<=z<=0.257 whi

Charles B. Leffert

A new vision of the beginning and expansion of our universe has produced a solution to the vacuum energy problem (also known as &#34;cosmological constant problem&#34;). A new dynamic of cellular spaces and a discrete time has space being produced by a process called spatial condensation (SC). With generic energy defined as Planck&#39;s constant times the ra

G. Malaguti, A. Bazzano, A. J. Bird, G. Di Cocco

PICsIT (Pixellated Imaging CaeSium Iodide Telescope) is the high energy detector of the IBIS telescope on-board the INTEGRAL satellite. It consists of 4096 independent detection units, ~0.7 cm^2 in cross-section, operating in the energy range between 175 keV and 10 MeV. The intrinsically low signal to noise ratio in the gamma-ray astronomy domain implies ver

Swadesh M. Mahajan, Riszard Miklaszewski, Komunela I. Nikol&#39;skaya, Nana L. Shatashvili

It is shown that the connection of sufficiently fast flows with dynamical channels for particle escape in the Solar Corona is rather direct: it depends on their ability to deform (in specific cases to distort) the ambient magnetic field lines to temporarily stretch (shrink, destroy) the closed field lines so that the flow can escape the local region. Using a

Daniel Harbeck, Graeme H. Smith, Eva K. Grebel

Rotationally induced mixing with subsequent dredge-up of nucleosynthesized material is discussed as a second parameter of the horizontal branch morphology in globular clusters. CNO abundances have been proposed as tracers of the dredge up of processed material. \ngc is a prominent example of a second parameter GC: Its HB morphology is too red for its metalli

T. Kiang

An attempt to answer the question &#39;Can we observe galaxies that recede faster than light ?&#39; led to a re-examination of the notions of time, distance, velocity and redshift as they occur in newtonian physics, special relativity, general relativity and cosmology. A number of misconceptions were uncovered. It was found that, once freed of special relati

D. Martinez-Delgado, M. A. Gomez-Flechoso, A. Aparicio, R. Carrera

The main aim of this paper is to report two new detections of tidal debris in the northern stream of the Sagittarius dwarf galaxy located at 45 arcdeg and 55 arcdeg from the center of galaxy. Our observational approach is based on deep color-magnitude diagrams, that provides accurate distances, surface brightness and the properties of stellar population of t

F. Yusef-Zadeh

The unusual class of magnetized nonthermal radio filaments (NTF), threads and streaks with their unique physical characteristics are found only within the inner couple of degrees of the Galactic center. Also, a number of young, mass-losing and rare stellar clusters are recognized to lie in the Galactic center region. The latter characteristic of the Galactic