August 2004 arXiv papers — page 14

Omar Benhar

I review the main features of the nuclear response extracted from electron scattering data. The emerging picture clearly shows that the shell model does not provide a fully quantitative description of nuclear dynamics. On the other hand, many body approaches in which correlation effetcs are explicitely taken into account lead to a satisfactory account of ele

Denes Molnar

We show that either mass ordering or quark number scaling of anisotropic flow can result from quark coalescence, depending on the nature of phase space correlations at hadronization. Quark number scaling signals nonequilibrium dynamics because it can only appear when hydrodynamic correlations break down. However, the scaling does not hold for all nonthermal

V. Tyng

Classical tools of nonlinear dynamics are used to study the highly excited vibrations of small molecules. For effective Hamiltonians with one polyad number (approximate constant of motion), previously developed methods locate new anharmonic modes using the critical points in the reduced classical phase space. Theoretical arguments are given for generalizing

S. Vijayalakshmi, M. Lakshmanan

Ishimori equation is a $(2+1)$ dimensional generalization of the $(1+1)$ dimensional integrable classical continuous Heisenberg ferromagnetic spin equation. The richness of the coherent structures admitted by Ishimori equation I such as dromion, lump and rationally- exponentially localized solutions, have been demonstrated in the literature through $\bar \pa

D. V. Senthilkumar, M. Lakshmanan

We reinvestigate the dynamical behavior of a first order scalar nonlinear delay differential equation with piecewise linearity and identify several interesting features in the nature of bifurcations and chaos associated with it as a function of the delay time and external forcing parameters. In particular, we point out that the fixed point solution exhibits

Ramaswamy Jaganathan, Sudeshna Sinha

A scheme of q-deformation of nonlinear maps is introduced. As a specific example, a q-deformation procedure related to the Tsallis q-exponential function is applied to the logistic map. Compared to the canonical logistic map, the resulting family of q-logistic maps is shown to have a wider spectrum of interesting behaviours, including the co-existence of att

Y. Hassouni, E. M. F. Curado, M. A. Rego-Monteiro

We construct a general state which is an eigenvector of the annihilation operator of the Generalized Heisenberg Algebra. We show for several systems, which are characterized by different energy spectra, that this general state satisfies the minimal set of conditions required to obtain Klauder's minimal coherent states.

A. B. Mehmood, U. A. Shah, G. Shabbir

In this paper, an approach is developed to solve the three body problem involving masses which posses spherical symmetry. The problem dates back to the times of Poincare, and is undoubtedly one of the oldest of unsolved problems of classical mechanics. The Poincares Dictum comprehensively proves that the problem is truly insolvable as a result of the nature

Bjorn Poonen, Alexandra Shlapentokh

We prove that infinite p-adically discrete sets have Diophantine definitions in large subrings of some number fields. First, if K is a totally real number field or a totally complex degree-2 extension of a totally real number field, then there exists a prime p of K and a set of K-primes S of density arbitrarily close to 1 such that there is an infinite p-adi

Stephen Semmes

These informal notes concern some basic themes of harmonic analysis related to representations of groups.

Herbert S. Wilf

R. Redheffer described an $n\times n$ matrix of 0's and 1's the size of whose determinant is connected to the Riemann Hypothesis. We describe the permutations that contribute to its determinant and evaluate its permanent in terms of integer factorizations. We generalize the Redheffer matrix to finite posets that have a 0 element and find the analogou

Yusuf Civan, Nigel Ray

We describe Bott towers as sequences of toric manifolds M^k, and identify the omniorientations which correspond to their original construction as toric varieties. We show that the suspension of M^k is homotopy equivalent to a wedge of Thom complexes, and display its complex K-theory as an algebra over the coefficient ring. We extend the results to KO-theory

Catarina Carvalho

We give a proof of the cobordism invariance of the index of elliptic pseudodifferential operators on sigma-compact manifolds, where, in the non-compact case, the operators are assumed to be multiplication outside a compact set. We show that, if the principal symbol class of such an elliptic operator on the boundary of a manifold X has a suitable extension to

A. Volberg, P. Yuditskii

We consider the Jacobi matrix generated by a balanced measure of hyperbolic polynomial map. The conjecture of Bellissard says that this matrix should have an extremely strong periodicity property. We show how this conjecture is related to a certain noncommutative version of Bowen--Ruelle theory, and how the two weight Hilbert transform naturally appears in t

Vladimir Turaev

We introduce two constructions of a coassociative comultiplication in the algebra of phrases in a given alphabet. As a preliminary step we give two constructions of a pre-Lie comultiplication in the module generated by words.

F. Peherstorfer, A. Volberg, P. Yuditskii

In this work we build a certain machine that allows to construct almost periodic Jacobi matrices with singularly continuous spectrum a prescribed p-adic hull.

Marek Golasinski, Juno Mukai

This paper takes up the systematic study of the Gottlieb groups $G_{n+k}(§^n)$ of spheres for $k\le 13$ by means of the classical homotopy theory methods. The groups $G_{n+k}(§^n)$ for $k\le 7$ and $k=10,12,13$ are fully determined. Partial results on $G_{n+k}(§^n)$ for $k=8,9,11$ are presented as well. We also show that $[ι_n,η^2_nσ_{n+2}]=0$ if $n=2^i-7$ f

Vassily Olegovich Manturov

We prove that there is an algorithm to decide whehter two virtual links are equivalent or not

S. Berceanu, A. Gheorghe

Representations of coherent state Lie algebras on coherent state manifolds as first order differential operators are presented. The explicit expressions of the differential action of the generators of semisimple Lie groups determine for linear Hamiltonians in the generators of the groups first order differential equations of motion with holomorphic polynomia

Thomas Robinson, Sujith Vijay

Dreidel is a popular game played during the festival of Chanukah. Players start with an equal number of tokens, donate one token each to a common pot, and take turns spinning a four-sided top, called the dreidel. Depending on the side showing up, the spinner takes all the tokens in the pot, takes half the tokens in the pot, gives a token to the pot, or does

S. Deser, A. Waldron

We show that there exist conformally invariant theories for all spins in d=4 de Sitter space, namely the partially massless models with higher derivative gauge invariance under a scalar gauge parameter. This extends the catalog from the two known gauge models -- Maxwell and partially massless spin 2 -- to all spins.

V. Elias, D. G. C. McKeon, T. N. Sherry

The renormalization group (RG) is known to provide information about radiative corrections beyond the order in perturbation theory to which one has calculated explicitly. We first demonstrate the effect of the renormalization scheme used on these higher order effects determined by the RG. Particular attention is payed to the relationship between bare and ren

Marcelo Botta Cantcheff

Our purpose here is to introduce the idea of viewing the spacetime as a macroscopic complex system which, consequently, cannot be directly quantized. It should be thought of as a collection of more fundamental "microscopical" entities (atoms of geometry), much like a solid system, in which an atomic (classical) structure must be first recognized in o

Gerard 't Hooft

A simple model is discussed in which baryons are represented as pieces of open string connected at one common point. There are two surprises: one is that, in the conformal gauge, the relative lengths of the three arms cannot be kept constant, but are dynamical variables of the theory. The second surprise (as reported earlier by Sharov) is that, in the classi

R. Blumenhagen, T. Weigand

We summarize recent progress in constructing orientifolds of Gepner models, a phenomenologically interesting class of exactly solvable string compactifications with viable gauge groups and chiral matter.

Justin F. Vazquez-Poritz

We construct various non-singular p-branes on higher-dimensional generalizations of Taub-NUT and Taub-BOLT instantons. Among other solutions, these include S^1-wrapped D3-branes and M5-branes, as well as deformed M2-branes. The resulting geometries smoothly interpolate between product spaces which include Minkowski elements of different dimensionality. The n

Marcelo Botta Cantcheff

We propose a symmetry law for a doublet of different form fields, which resembles gauge transformations for matter fields. This may be done for general Lie groups, resulting in an extension of Lie algebras and group manifolds. It is also shown that non-associative algebras naturally appear in this formalism, which are briefly discussed. Afterwards, a general

Halina Abramowicz, Aharon Levy

The ALLM parameterization of sigma_{tot}(gamma* p) has been updated by using all published F_2 data to determine its parameters. The fit yields a chi^2/ndf of 0.97 for the 1356 data points. The updated ALLM parameterization, ALLM97, gives a good description of all the available data in the whole x and Q^2 range studied so far (3\times10^{-6} < x < 0.85, 0 \l

Dmitri Diakonov

There is a prejudice that the chiral soliton model of baryons is something orthogonal to the good old constituent quark models. In fact, it is the opposite: the spontaneous chiral symmetry breaking in strong interactions explains the appearance of massive constituent quarks of small size thus justifying the constituent quark models, in the first place. Chira

Thorsten Renk

Using a model for the evolution of the fireball created in Au-Au collisions at full RHIC energy which reproduces the hadronic single particle spectra and two-particle correlations we calculate thermal photon emission from the hot partonic and hadronic matter. We present predictions for both the emitted photon transverse momentum spectrum and Hanbury-Brown Tw

Edmond L. Berger

Parton distribution functions for protons are devised in which a light gluino is included along with standard model quark, antiquark, and gluon constituents. A global analysis of a large set of hadronic scattering data provides empirical constraints on the allowed range of the gluino mass as a function of the value of the strong coupling strength alpha_s(M_Z

De-Min Li, Bing Ma, Yu-Xiao Li, Qian-Kai Yao

Under the assumption that both light and heavy quarkonia populate approximately linear Regge trajectories with the requirements of additivity of intercepts and inverse slopes, the masses of different meson multiplets are estimated. The predictions derived from the quasi-linear Regge trajectories are in reasonable agreement with those given by many other refe

Celine Boehm, Yago Ascasibar

In a previous work, it was found that the Light Dark Matter (LDM) scenario could be a possible explanation to the 511 keV emission line detected at the centre of our galaxy. Here, we show that hints of this scenario may also have been discovered in particle physics experiments. This could explain the discrepancy between the measurement of the fine structure

S. Groote, J. G. Körner, A. A. Pivovarov

We show that configuration space techniques can be used to efficiently calculate the complete Laurent series \eps-expansion of sunrise-type diagrams to any loop order in D-dimensional space-time for any external momentum and for arbitrary mass configurations. For negative powers of \eps the results are obtained in analytical form. For positive powers of \eps

B. Ananthanarayan, Saurabh D. Rindani

We show how transverse beam polarization at $e^+e^-$ colliders can provide a novel means to search for CP violation by observing the distribution of a single final-state particle without measuring its spin. We suggest an azimuthal asymmetry which singles out interference terms between standard model contribution and new-physics scalar or tensor effective int

Jon-Ivar Skullerud, Patrick O. Bowman, Ayse Kizilersu, Derek B. Leinweber

We compute the quark-gluon vertex in quenched lattice QCD, in the Landau gauge using an off-shell mean-field O(a)-improved fermion action. The complete vertex is computed in two specific kinematical limits, while the Dirac-vector part is computed for arbitrary kinematics. We find a nontrivial and rich tensor structure, including a substantial infrared enhanc

The OPAL collaboration, G. Abbiendi

Upper limits on the cross-section of the pair-production process e+e- -> h0A0 assuming 100% decays into hadrons, are derived from a new search for the h0A0 -> hadrons topology, independent of the hadronic flavour of the decay products. Searches for the neutral Higgs bosons h0 and A0, are used to obtain constraints on the Type II Two Higgs Doublet Model (2HDM

The BABAR Collaboration, B. Aubert

We present a search for the decays B0->e+e-, B0->mu+mu-, and B0->e+- mu-+ in data collected at the Y(4S) resonance with the Babar detector at the SLAC B Factory. Using a data set of 111 fb^-1, we find no evidence for a signal in any of the three channels investigated and set the following branching fraction upper limits at the 90% confidence level: B(B0->e+e

The BABAR Collaboration, B. Aubert

We have performed a search for the $D^*_{sJ}(2632)^+$ state recently reported by the SELEX Collaboration at FNAL. This preliminary analysis makes use of an integrated luminosity of 125 ${\rm fb}^{-1}$ collected by the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ collider. The resulting $D_s η$ and $D^0 K^+$ mass spectra show no evidence for the $D

Z. Metreveli, CLEO Collaboration

We report on an exclusive search for the X(3872) state in the decay pi+ pi- J/psi, J/psi to l+ l- (l = e, mu) from untagged gamma-gamma fusion and initial state radiation production using a 15.1 fb-1 data sample with the CLEO III detector. By taking advantage of the unique pi+ pi- J/psi decay kinematics, separate measurements for each production process are

A. E. Dominguez, D. E. Barraco

Recently D. Vollick [Phys. Rev. D68, 063510 (2003)] has shown that the inclusion of the 1/R curvature terms in the gravitational action and the use of the Palatini formalism offer an alternative explanation for cosmological acceleration. In this work we show not only that this model of Vollick does not have a good Newtonian limit, but also that any f(R) theo

Keye Martin

We prove that the space of causal curves between compact subsets of a separable globally hyperbolic poset is itself compact in the Vietoris topology. Although this result implies the usual result in general relativity, its proof does not require the use of geometry or differentiable structure.

Viktor Kuncak, K. Rustan M. Leino

This paper presents a method for computing a least fixpoint of a system of equations over booleans. The resulting computation can be significantly shorter than the result of iteratively evaluating the entire system until a fixpoint is reached.

Michael Thielscher

FLUX is a programming method for the design of agents that reason logically about their actions and sensor information in the presence of incomplete knowledge. The core of FLUX is a system of Constraint Handling Rules, which enables agents to maintain an internal model of their environment by which they control their own behavior. The general action represen

H. Pardo, R. Faccio, A. W. Mombru, F. M. Araujo-Moreira

The search for macroscopic magnetic ordering phenomena in organic materials, in particular in pure graphite, has been one of the more exciting scientific activities working in the frontiers of physics, chemistry, and materials science. In this Letter we report on a novel chemical route leading to undoubtedly obtain macroscopic quantities of magnetic graphite

T. Tomita, S. Deemyad, J. J. Hamlin, J. S. Schilling

The ability of single grain boundaries in YBa2Cu3Ox bicrystalline rings to carry electrical current is found to be significantly enhanced under hydrostatic pressure. Nearly hydrostatic pressures are applied to the alkali metals Li, Na, and K. in a search for superconductivity. Whereas Li becomes superconducting above 20 GPa at temperatures as high as 15 K, n

D. M. Gangardt, P. Pedri, L. Santos, G. V. Shlyapnikov

We discuss the 2D Mott insulator (MI) state of a 2D array of coupled finite size 1D Bose gases. It is shown that the momentum distribution in the lattice plane is very sensitive to the interaction regime in the 1D tubes. In particular, we find that the disappearance of the interference pattern in time of flight experiments will not be a signature of the MI p

M. Machon, S. Reich, H. Telg, J. Maultzsch

We show by ab initio calculations that the electron-phonon coupling matrix element M of the radial breathing mode in single-walled carbon nanotubes depends strongly on tube chirality. For nanotubes of the same diameter the coupling strength |M|^2 is up to one order of magnitude stronger for zig-zag than for armchair tubes. For (n,m) tubes M depends on the va

Jens Hjorleifur Bardarson, Ingibjorg Magnusdottir, Gudny Gudmundsdottir, Chi-Shung Tang

Coherent electron transport through a quantum channel in the presence of a general extended scattering potential is investigated using a T-matrix Lippmann-Schwinger approach. The formalism is applied to a quantum wire with Gaussian type scattering potentials, which can be used to model a single impurity, a quantum dot or more complicated structures in the wi

Afif Siddiki, Rolf R. Gerhardts

We study the current and charge distribution of a two dimensional electron gas under strong perpendicular magnetic fields within the linear response regime. We show within a self-consistent screening theory that incompressible strips with integer values of local Landau-level filling factor exist for finite intervals of the magnetic field strength $B$. Within

Sergei F. Lyuksyutov, Ruslan A. Sharipov

We report a method for describing plasticity in a broad class of amorphous materials. The method is based on nonlinear (geometric) deformation theory allowing the separation of the plastic deformation from the general deformation tensor. This separation allows an adequate pattern of thermodynamical phenomena for plastic deformations in polymers to be constru

M. N. Iliev, V. N. Popov, A. P. Litvinchuk, M. V. Abrashev

The polarized Raman spectra of layered ruthenates of the Srn+1RunO3n+1 (n=1,2,3) Ruddlesden-Popper series were measured between 10 and 300 K. The phonon spectra of Sr3Ru2O7 and Sr4Ru3O10 confirmed earlier reports for correlated rotations of neighboring RuO6 octahedra within double or triple perovskite blocks. The observed Raman lines of Ag or B1g symmetry we

J. K. Viljas

We calculate the current-pressure characteristics of a ballistic pinhole aperture between two volumes of B-phase superfluid 3He. The most important mechanism contributing to dissipative currents in weak links of this type is the process of multiple Andreev reflections. At low biases this process is significantly affected by relaxation due to inelastic quasip

Krzysztof Urbanowicz, Holger Kantz, Janusz A. Holyst

We present a new type of deterministic dynamical behaviour that is less predictable than white noise. We call it anti-deterministic (AD) because time series corresponding to the dynamics of such systems do not generate deterministic lines in Recurrence Plots for small thresholds. We show that although the dynamics is chaotic in the sense of exponential diver

H. Sakurai, K. Takada, T. Sasaki, F. Izumi

We synthesized the five batches of the samples of the novel P3 type superconductor, Na$_{x}$(H$_{3}$O)$_{y&#39;}$CoO$_{2}\cdot y&#39;&#39;$H$_{2}$O, by the soft chemical process starting from $α$-NaCoO$_{2}$. The chemical and structural properties varied rather widely from batch to batch, with a result that $T_{c}$ varied from 4.6 K to 3.2 K. The magnetic su

S. D. Tiwari, K. P. Rajeev

Nickel oxide nanoparticles of different sizes are prepared and characterized by x-ray diffraction and transmission electron microscopy. A.C. susceptibility measurements as a function of temperature are carried out for various particle sizes and frequencies. We find that the behavior of the system is spin glass like.

H. Sakurai, K. Takada, T. Sasaki, E. Takayama-Muromachi

We synthesized powder samples of Na$_{x}$CoO$_{2}\cdot y$H$_{2}$O changing the volume of the water in the hydration process, then investigated their superconducting properties,. It was proved that the volume of water is one of key parameters to obtain a single phase of Na$_{x}$CoO$_{2}\cdot y$H$_{2}$O with good superconducting properties. The transition temp

W. B. Payne, J. K. Olson, A. Allen, V. F. Kozhevnikov

The speed of longitudinal sound waves at 7 and 22 MHz has been measured in liquid, supecooled, and amorphous selenium, including the region around the glass transition temperature, Tg, near 35 C. In amorphous selenium the speed of shear waves at 7 MHz was also measured. The experiments were performed with high purity Se (99.9999%) hermetically sealed in an e

M. Uhlarz, C. Pfleiderer, S. M. Hayden

We report a study of the ferromagnetism of ZrZn$_{2}$, the most promising material to exhibit ferromagnetic quantum criticality, at low temperatures $T$ as function of pressure $p$. We find that the ordered ferromagnetic moment disappears discontinuously at $p_c$=16.5 kbar. Thus a tricritical point separates a line of first order ferromagnetic transitions fr

K. Waku, T. Katsufuji, Y. Kohsaka, T. Sasagawa

We report the reflectivity and the resistivity measurement of Ca_{2-x}Na_{x}CuO_{2}Cl_{2} (CNCOC), which has a single-CuO2-plane lattice with no orthorhombic distortion. The doping dependence of the in-plane optical conductivity spectra for CNCOC is qualitatively the same to those of other cuprates, but a slight difference between CNCOC and LSCO, i.e., the a

C. T. Shih, Y. C. Chen, C. P. Chou, T. K. Lee

The possibility of coexistence of superconductivity (SC) and antiferromagnetic long range order (AFLRO) of the two-dimensional extended $t-J$ model in the very underdoped region is studied by the variational Monte-Carlo (VMC) method. In addition to using previously studied wave functions, a recently proposed new wave function generated from the half-filled M

Pengfei Qi, Ali Javey, Marco Rolandi, Qian Wang

As the dimensions of electronic devices approach those of molecules, the size, geometry and chemical composition of the contact electrodes play increasingly dominant roles in device functions. It is shown here that single-walled carbon nanotubes (SWNT) can be used as quasi one-dimensional (1D) electrodes to construct organic field effect transistors (FET) wi

J. N. Kriel, A. Y. Morozov, F. G. Scholtz

We use a novel parameterization of the flowing Hamiltonian to show that the flow equations based on continuous unitary transformations, as proposed by Wegner, can be implemented through a nonlinear partial differential equation involving one flow parameter and two system specific auxiliary variables. The implementation is non-perturbative as the partial diff

Zhigang Jiang, Venkat Chandrasekhar

We study the thermopower of diffusive Andreev interferometers, which are hybrid loops with one normal-metal arm and one superconducting arm. The thermopower oscillates as a function of the magnetic flux through the loop with a fundamental period corresponding to one flux quantum $Φ_0=h/2e$. Unlike the electrical resistance oscillations and the thermal resist

Peter J. Burke, Shengdong Li, Zhen Yu

We present quantitative predictions of the performance of nanotubes and nanowires as antennas, including the radiation resistance, the input reactance and resistance, and antenna efficiency, as a function of frequency and nanotube length. Particular attention is paid to the quantum capacitance and kinetic inductance. In so doing, we also develop a circuit mo

M. M. Mola, R. Haddad, S. Hill

Angle dependent torque measurements have been carried out on the organic superconductor, kappa-(ET)2Cu(NCS)2 at extremely low temperatures (25 - 300 mK). Magneto-thermal instabilities are observed in the form of abrupt magnetization (flux) jumps for magnetic field sweeps of 0 - 20 tesla. A fractal analysis of the flux jumps indicates that the instabilities d

D. Beckmann, H. B. Weber, H. v. Löhneysen

We report on non-equilibrium electronic transport through normal-metal (Cu) nanobridges coupled to large reservoirs at low temperatures. We observe a logarithmic temperature dependence of the zero-bias conductance, as well as a universal scaling behavior of the differential conductance. Our results are explained by electron-electron interactions in diffusive

Patrick J. McCarthy, Damien Le Borgne, David Crampton, Hsiao-Wen Chen

We present spectroscopic evidence from the Gemini Deep Deep Survey (GDDS) for a significant population of color-selected red galaxies at 1.3 < z < 2.2 whose integrated light is dominated by evolved stars. Unlike radio-selected objects, the z > 1.5 old galaxies have a sky density > 0.1 per sq. arcmin. Conservative age estimates for 20 galaxies with z > 1.3; <

Sergei M. Kopeikin, Vladimir A. Potapov

This paper discusses spectral sensitivity of solitary and binary pulsars to a low-frequency (colored) noise. It is a third paper in a series of papers devoted to analysis of the low-frequency noise in pulsar timing observations and its impact on observable fitting parameters of timing model.

A. D. Falcone, the VERITAS collaboration

Blazars have traditionally been separated into two broad categories based upon their optical emission characteristics; BL Lacs, with faint or no emission lines, and flat spectrum radio quasars (FSRQs) with prominent, broad emission lines. The spectral energy distribution of FSRQs has generally been thought of as being more akin to the low-peaked BL Lacs, whi

T. S. Metcalfe, M. H. Montgomery, A. Kanaan

More than 40 years have passed since Ed Salpeter and others predicted that the carbon/oxygen cores of the coolest white dwarf stars in our Galaxy will theoretically crystallize. This effect has a dramatic impact on the calculated ages of cool white dwarfs, but until recently we have had no way of testing the theory. In 1992, pulsations were discovered in the

You-Hua Chu, Robert A. Gruendl, Rosa M. Williams, Theodore R. Gull

We have detected an ionized nebula around the hot DO white dwarf KPD 0005+5106, and used the [OIII]/H-alpha ratios and nebular velocities to separate this nebula from the background HII region of AO Cas. The angular size of the [OIII] nebula of KPD 0005+5106 is ~3 deg. The velocity of this nebula is similar to those of the local interstellar HI gas and the i

J. S. Arabadjis, M. W. Bautz

We present a spectroscopic deprojection analysis of a sample of ten relaxed galaxy clusters. We use an empirical F-test derived from a set of Markov Chain Monte Carlo simulations to determine if the core plasma in each cluster could contain multiple phases. We derive non-parametric baryon density and temperature profiles, and use these to construct total gra

J. Maíz-Apellániz

We have developed a CHi-square cOde for parameteRized modelIng and characteriZation of phOtometry and Spectrophotometry (CHORIZOS). CHORIZOS can use up to two intrinsic free parameters (e.g. temperature and gravity for stars; type and redshift for galaxies; or age and metallicity for stellar clusters) and two extrinsic ones (amount and type of extinction). T

R. Manso Sainz, E. Landi Degl&#39;Innocenti, J. Trujillo Bueno

We report on the a5F-y5F* multiplet of Ti I and its interest for the study of &#39;turbulent&#39; magnetic fields in the quiet solar photosphere. In particular, we argue that the sizable scattering polarization signal of the 4536 Åline (whose lower and upper levels have Landé factors equal to zero), relative to the rest of the lines in the multiplet, gives d

Joel R. Primack

The good agreement between large-scale observations and the predictions of the now-standard $Λ$CDM theory gives us hope that this will become a lasting foundation for cosmology. After briefly reviewing the current status of the key cosmological parameters, I summarize several of the main areas of possible disagreement between theory and observation: big bang

M. Tristram

We present a refined angular power spectrum of the Cosmic Microwave Background (CMB) anisotropies using the Archeops last flight data. The estimation of the Cl described here is performed using Xspect, a method which uses the cross-power spectra of the maps of 6 different detectors. It covers multipole range from l=10 to l=700 in 25 bins and confirms a stron

C. Tappert, T. Augusteijn, J. Maza

In a search for cataclysmic variables in the Calan-Tololo Survey we have detected 21 systems, 16 of them previously unknown. In this paper we present detailed time-series photometry for those six confirmed cataclysmic variables that show periodic variability in their light curves. Four of them turned out to be eclipsing systems, while the remaining two show

C. Motch, K. Sekiguchi, F. Haberl, V. E. Zavlin

We obtained deep optical imaging of the thermally emitting X-ray bright and radio-quiet isolated neutron star RX J1605.3+3249 with the Subaru telescope in 1999 and 2003. Together with archival HST images acquired in 2001 these data reveal a proper motion of mu = 144.5 +/- 13.2 mas/yr. This implies a relatively high spatial velocity and indicates that the sta

Yang Chen, Yang Su, Patrick O. Slane, Q. Daniel Wang

We present a 60 ks Chandra ACIS-S observation of the thermal composite supernova remnant 3C391. The southeast-northwest elongated morphology is similar to that previously found in radio and X-ray studies. This observation unveils a highly clumpy structure of the remnant. Detailed spatially resolved spectral analysis for the small-scale features reveals that

V. Majernik

In this Letter we point out to the possibility that the cloud of the vacuum energy excitations in gravitation fields surrounding galaxies forms a component of dark matter. These clouds of the vacuum energy excitations interact gravitationally with the baryonic matter of galaxies changing their dynamical and kinematical properties. In four model galaxies we s

T. Nagel, S. Dreizler, T. Rauch, K. Werner

We present a recently developed code for detailed NLTE calculations of accretion disc spectra of cataclysmic variables and compact X-ray binaries. Assuming a radial structure of a standard alpha-disc, the disc is divided into concentric rings. For each disc ring the solution of the radiation transfer equation and the structure equations, comprising the hydro

Sudhanshu Barway, S. K. Pandey

In this paper we report the multi-band BVRI photometry of HD 52452. The comparison of our data with previous observations reported by Messina et al. (2001) shows that there is a variation in amplitude, but the phases of the two minima, thus the positions of the spot, are quite stable during our observations.

G. Ghirlanda, G. Ghisellini, D. Lazzati, C. Firmani

The best measure of the Universe should be done using a standard &#34;ruler&#34; at any redshift. Type Ia Supernovae (SN Ia) probe the universe up to z$\sim$1.5, while the Cosmic Microwave Background (CMB) primary anisotropies concern basically $z\sim$1000. Apparently, Gamma--Ray Bursts (GRBs) are all but standard candles. However, their emission is collimat

Takahiko Matsubara

Recent development of galaxy surveys enables us to investigate the deep universe of high redshift. We quantitatively present the physical information extractable from the observable correlation function in deep redshift space in a framework of the linear theory. The correlation function depends on the underlying power spectrum, velocity distortions, and the

Abhas Mitra

We present here a very simple, short and new proof which shows that no trapped surface is ever formed in spherical gravitational collapse of isolated bodies. Although this derivation is of purely mathematical nature and without any assumption, it is shown, in the Appendix, that, physically, trapped surfaces do not form in order that the 3 speed of the fluid

W. de Boer, M. Herold, C. Sander, V. Zhukov

The diffuse galactic EGRET gamma ray data show a clear excess for energies above 1 GeV in comparison with the expectations from conventional galactic models. The excess is seen with the same spectrum in all sky directions, as expected for Dark Matter (DM) annihilation. This hypothesis is investigated in detail. The energy spectrum of the excess is used to li

Antony Lewis

Primordial inhomogeneous magnetic fields of the right strength can leave a signature on the CMB temperature anisotropy and polarization. Potentially observable contributions to polarization B-modes are generated by vorticity and gravitational waves sourced by the magnetic anisotropic stress. We compute the corresponding CMB transfer functions in detail inclu

Marc Audard, Alessandra Telleschi, Manuel Guedel, Stephen L. Skinner

(Abridged abstract) We present an analysis of the X-ray emission of the rapidly rotating giant star YY Mensae observed by Chandra HETGS and XMM-Newton. Although no obvious flare was detected, the X-ray luminosity changed by a factor of two between the XMM-Newton and Chandra observations taken 4 months apart. The coronal abundances and the emission measure di

Ingve Simonsen, Damien Vandembroucq, Stephane Roux

We derive an analytical expression for the scattering of a scalar wave from a perfectly conducting self-affine one dimensional surface in the framework of the Kirchhoff approximation. We show that most of the results can be recovered via a scaling analysis. We identify the typical slope taken over one wavelength as the relevant parameter controlling the scat

Ben Freivogel, Leonard Susskind

It seems likely that string theory has a landscape of vacua that includes very many metastable de Sitter spaces. However, as emphasized by Banks, Dine and Gorbatov, no current framework exists for examining these metastable vacua in string theory. In this paper we attempt to correct this situation by introducing an eternally inflating background in which the

Aleksey Cherman, Thomas D. Cohen, Abhinav Nellore

The distinction between the rigid rotor and Callan-Klebanov approaches to the quantization of SU(3) solitons is considered in the context of exotic baryons. A numerically tractable quantum mechanical analog system is introduced to test the reliability of the two quantization schemes. We find that in the equivalent of the large N_c limit of QCD, the Callan-Kl

David R. Alves

This paper has been withdrawn.

Zoltan Eisler, Janos Kertesz, Soon-Hyung Yook, Albert-Laszlo Barabasi

For many externally driven complex systems neither the noisy driving force, nor the internal dynamics are a priori known. Here we focus on systems for which the time dependent activity of a large number of components can be monitored, allowing us to separate each signal into a component attributed to the external driving force and one to the internal dynamic

Troels Harmark

We study stationary and axisymmetric solutions of General Relativity, i.e. pure gravity, in four or higher dimensions. D-dimensional stationary and axisymmetric solutions are defined as having D-2 commuting Killing vector fields. We derive a canonical form of the metric for such solutions that effectively reduces the Einstein equations to a differential equa

Giacomo Mauro D&#39;Ariano, Paoloplacido Lo Presti, Paolo Perinotti

Similarly to quantum states, also quantum measurements can be &#34;mixed&#34;, corresponding to a random choice within an ensemble of measuring apparatuses. Such mixing is equivalent to a sort of hidden variable, which produces a noise of purely classical nature. It is then natural to ask which apparatuses are &#34;indecomposable&#34;, i. e. do not correspon

M. Sami, N. Savchenko, A. Toporensky

The Einstein-Gauss-Bonnet equations projected from the bulk to brane lead to a complicated Friedmann equation which simplifies to $H^2 \sim ρ^q$ in the asymptotic regimes. The Randall-Sundrum (RS) scenario corresponds to $q=2$ whereas $q=2/3$ $&$ $q=1$ give rise to high energy Gauss-Bonnet (GB) regime and the standard GR respectively. Amazingly, while evolvi

Filipe Paccetti Correia, Michael G. Schmidt, Zurab Tavartkiladze

We propose that the radion chiral supermultiplet of five dimensional compactified supergravity is obtained by reduction of the graviphoton gauge multiplet to N=1 superfields in the off shell 5D superconformal gravity formalism of Fujita, Kugo and Ohashi. We present a superfield Lagrangian of Chern-Simons type (similar to global SUSY), which reproduces all co

Sung Yong Park, D. Stroud

We calculate the effective dielectric function for a suspension of small metallic particles immersed in a nematic liquid crystal (NLC) host. For a random suspension of such particles in the dilute limit, we calculate the effective dielectric tensor exactly and show that the surface plasmon (SP)resonance of such particles splits into two resonances, polarized

Joel H. Kastner, Noam Soker

We present the results of XMM-Newton X-ray observations of the Mira AB binary system, which consists of a pulsating, asymptotic giant branch primary and nearby (~0.6&#39;&#39; separation) secondary of uncertain nature. The EPIC CCD (MOS and pn) X-ray spectra of Mira AB are relatively soft, peaking at ~1 keV, with only very weak emission at energies > 3 keV;