January 2006 arXiv papers — page 2

Abdenacer Makhlouf

The aim of this paper is to give an overview and to compare the different deformation theories of algebraic structures. We describe in each case the corresponding notions of degeneration and rigidity. We illustrate these notions with examples and give some general properties. The last part of this work shows how these notions help in the study of associative

K. Grove, B. Wilking, L. Verdiani, W. Ziller

In contrast to the homogeneous case, we show that there are compact cohomogeneity one manifolds, that do not support invariant metrics of non-negative sectional curvature. In fact we exhibit infinite families of such manifolds including the exotic Kervaire spheres. Such examples exist for any codimension of the singular orbits except for the case where both

Montserrat Manubens, Antonio Montes

In 1992, V. Weispfenning proved the existence of Comprehensive Groebner Bases (CGB) and gave an algorithm to compute one. That algorithm was not very efficient and not canonical. Using his suggestions, A. Montes obtained in 2002 a more efficient algorithm (DISPGB) for Discussing Parametric Groebner Bases. Inspired in its philosophy, V. Weispfenning defined,

Jason Lotay

This paper is dedicated to the study of deformations of coassociative 4-folds in a G_2 manifold which have conical singularities. We stratify the types of deformations allowed into three problems. The main result for each problem states that the moduli space is locally homeomorphic to the kernel of a smooth map between smooth manifolds. In each case, the map

Janusz Grabowski

Nijenhuis tensors $N$ on Courant algebroids compatible with the pairing are studied. This compatibility condition turns out to be of the form $N+N^*=aI$ for irreducible Courant algebroids, in particular for the extended tangent bundles $TM\oplus T^*M$. It is proved that compatible Nijenhuis tensors on irreducible Courant algebroids must satisfy quadratic rel

M. E. Kazarian, S. K. Lando

We present a new proof of Witten's conjecture. The proof is based on the analysis of the relationship between intersection indices on moduli spaces of complex curves and Hurwitz numbers enumerating ramified coverings of the 2-sphere.

Josep M. Brunat, Antonio Montes

Let $C(n,p)$ be the set of $p$-compositions of an integer $n$, i.e., the set of $p$-tuples $\bmα=(α_1,...,α_p)$ of nonnegative integers such that $α_1+...+α_p=n$, and $\mathbf{x}=(x_1,...,x_p)$ a vector of indeterminates. For $\bmα$ and ${\bmβ}$ two $p$-compositions of $n$, define $(\mathbf{x}+\bmα)^{\bmβ} = (x_1+α_1)^{β_1}... x_p+α_p)^{β_p}$. In this paper

Wieslaw Bajguz

Knopfmacher et all [1] was introduced the graph compositions` notion. In this note we add to these a new construction of tree-like graphs where nodes are graphs themselves. The first examples of these tree-like compositions, a corresponding theorem and resulting conclusions are provided.

Alan Weinstein

A complex Lie algebroid is a complex vector bundle over a smooth (real) manifold M with a bracket on sections and an anchor to the complexified tangent bundle of M which satisfy the usual Lie algebroid axioms. A proposal is made here to integrate analytic complex Lie algebroids by using analytic continuation to a complexification of M and integration to a ho

A. Rod Gover, Josef Silhan

We construct a conformally invariant vector bundle connection such that its equation of parallel transport is a first order system that gives a prolongation of the conformal Killing equation on differential forms. Parallel sections of this connection are related bijectively to solutions of the conformal Killing equation. We construct other conformally invari

Yuuki Abe

The purpose of this paper is to prove that we can construct all finite dimensional irreducible nilpotent modules of type 1 inductively by using Schnizer homomorphisms for quantum algebra at roots of unity of type A, B, C, D or G.

Josep M. Brunat, Antonio Montes

Let $Φ(x,y)$ be a bivariate polynomial with complex coefficients. The zeroes of $Φ(x,y)$ are given a combinatorial structure by considering them as arcs of a directed graph $G(Φ)$. This paper studies some relationship between the polynomial $Φ(x,y)$ and the structure of $G(Φ)$.

Cornelia Drutu, Mark Sapir

Tree-graded spaces are generalizations of R-trees. They appear as asymptotic cones of groups (when the cones have cut points). Since many questions about endomorphisms and automorphisms of groups, solving equations over groups, studying embeddings of a group into another group, etc. lead to actions of groups on the asymptotic cones, it is natural to consider

Klaus Hulek, Remke Kloosterman, Matthias Schuett

In this paper we discuss recent progress on the modularity of Calabi-Yau varieties. We focus mostly on the case of surfaces and threefolds. We will also discuss some progress on the structure of the L-function in connection with mirror symmetry. Finally, we address some questions and open problems.

Nicolas Perrin

In this paper, we describe on the one hand, all relative minimal models Y of a minuscule Schubert variety X using some combinatorics on quivers and we prove that the morphism from Y to X is small (in the sense of intersection cohomology). On the other hand, thanks to a result of B. Totaro, any small resolution Z of a minuscule Schubert variety X has to be a

Michael Kunzinger, Hermann Schichl, Roland Steinbauer, James A. Vickers

We prove Gronwall-type estimates for the distance of integral curves of smooth vector fields on a Riemannian manifold. Such estimates are of central importance for all methods of solving ODEs in a verified way, i.e., with full control of roundoff errors. Our results may therefore be seen as a prerequisite for the generalization of such methods to the setting

Peter Imkeller, Ilya Pavlyukevich

We study the exit problem of solutions of the stochastic differential equation dX(t)=-U'(X(t))dt+epsilon dL(t) from bounded or unbounded intervals which contain the unique asymptotically stable critical point of the deterministic dynamical system dY=-U'(Y) dt. The process L is composed of a standard Brownian motion and a symmetric alpha-stable Levy p

Carlos Gutierrez, Benito Pires

Let M be a non-orientable compact 2-manifold of genus 4. Then there exists a family of quasi-minimal, Kupka-Smale smooth vector fields X_r in M, depending smoothly on 0<=r<e, such that, for some flow box V in M of X_0, and for all 0<=r,v<e, (1) X_r restricted to V is a flow box; (2) If r is not equal to v, X_r is a C^\infty--twist perturbation of X_v localiz

Bindusar Sahoo, Ashoke Sen

The entropy of a BTZ black hole in the presence of gravitational Chern-Simons terms has previously been analyzed using Euclidean action formalism. In this paper we treat the BTZ solution as a two dimensional black hole by regarding the angular coordinate as a compact direction, and use Wald&#39;s Noether charge method to calculate the entropy of this black h

V. A. Smirnov

Some recent results on evaluating Feynman integrals are reviewed. The status of the method based on Mellin-Barnes representation as a powerful tool to evaluate individual Feynman integrals is characterized. A new method based on Groebner bases to solve integration by parts relations in an automatic way is described.

P. Huber, J. Kopp, M. Lindner, M. Rolinec

We discuss the potential of the proposed Double Chooz reactor experiment to measure the neutrino mixing angle $\sin^2 2\theta_{13}$. We especially consider systematical uncertainties and their partial cancellation in a near and far detector operation, and we discuss implications of a delayed near detector startup. Furthermore, we introduce Triple Chooz, whic

O. Leitner, Xin-Heng Guo, A. W. Thomas

We calculate the direct CP violating asymmetry parameter, $a_{CP}$, for $B \to \pi^{+} \pi^{-} \pi$ and $B \to \pi^{+} \pi^{-} K$ decays, in the case where $\rho^0-\omega$ mixing effects are taken into account. We find that the direct CP asymmetry for $B^{-} \to \pi^{+} \pi^{-} \pi^{-}$, $\bar{B}^{0} \to \pi^{+} \pi^{-}\pi^{0}$, $B^{-} \to \pi^{+} \pi^{-} K^

Youichi Yamada

We calculate the pole mass of the gluino as a function of the running parameters in the lagrangian, to O(alpha_s^2) in SUSY QCD. The correction shifts the pole mass from the running mass by typically 1-2 %. This shift can be larger than the expected accuracy of the mass determination at future colliders, and should be taken into account for precision studies

Hirotaka Shimizu, George Sterman, Werner Vogelsang, Hiroshi Yokoya

We present a recent study of the QCD corrections to dilepton production near partonic threshold in transversely polarized \bar{p}p scattering. We analyze the role of the higher-order perturbative QCD corrections in terms of the available fixed-order contributions as well as of all-order soft-gluon resummations for the kinematical regime of proposed experimen

Yoshitaka Okumura

The generalized covariant derivative on 5-dimen-sional space including 1-dimensional extra compact space is defined, and, by use of it, the Weinberg-Salam model is reconstructed. The spontaneous breakdown of symmetry takes place owing to the extra dimension under the settings that the Higgs field exists in the extra dimensional space depending on the argumen

M. Strikman, C. Weiss

We review a recently proposed framework for studying the approach to the unitarity limit in small-x processes in ep and pp scattering within the DGLAP approximation. Our formulation is based on the correspondence between the standard QCD factorization theorems for hard processes and the dipole picture of small-x scattering in the leading logarithmic approxim

S. Alekhin, G. Altarelli, N. Amapane, J. Andersen

The HERA electron--proton collider has collected 100 pb$^{-1}$ of data since its start-up in 1992, and recently moved into a high-luminosity operation mode, with upgraded detectors, aiming to increase the total integrated luminosity per experiment to more than 500 pb$^{-1}$. HERA has been a machine of excellence for the study of QCD and the structure of the

The OPAL Collaboration, G. Abbiendi

Data from e+e- annihilation into hadrons at centre-of-mass energies between 91 GeV and 209 GeV collected with the OPAL detector at LEP, are used to study the four-jet rate as a function of the Durham algorithm resolution parameter ycut. The four-jet rate is compared to next-to-leading order calculations that include the resummation of large logarithms. The s

D0 Collaboration, V. Abazov

We report on a search for the pair production of second generation scalar leptoquarks (LQ_2) in ppbar collisions at the center-of-mass energy sqrt(s) = 1.96 TeV, using data corresponding to an integrated luminosity of 294 +- 19 pb^-1 recorded with the D0 detector. No evidence for a leptoquark signal in the LQ_2 LQ_2 -> muq muq channel has been observed, and

Lode Wylleman

In a paper by Maartens, Lesame and Ellis (Class. Quant. Grav. 15, 1005) it was shown that irrotational dust solutions with vanishing electric part of the Weyl tensor are subject to severe integrability conditions and it was conjectured that the only such solutions are FLRW spacetimes. In their analysis the possibility of a cosmological constant Lambda was om

Aldo A. Martinez-Merino, Merced Montesinos

A proposal for the Hamilton-Jacobi theory in the context of the covariant formulation of Hamiltonian systems is done. The current approach consists in applying Dirac&#39;s method to the corresponding action which implies the inclusion of second-class constraints in the formalism which are handled using the procedure of Rothe and Scholtz recently reported. Th

Gregor Leiler, Luciano Rezzolla

The iterated Crank-Nicolson is a predictor-corrector algorithm commonly used in numerical relativity for the solution of both hyperbolic and parabolic partial differential equations. We here extend the recent work on the stability of this scheme for hyperbolic equations by investigating the properties when the average between the predicted and corrected valu

Juan Antonio Morales Lladosa

Lorentzian frames may belong to one of the 199 causal classes. Of these numerous causal classes, people are essentially aware only of two of them. Nevertheless, other causal classes are present in some well-known solutions, or present a strong interest in the physical construction of coordinate systems. Here we show the unusual causal classes to which belong

Marko A. Rodriguez, Johan Bollen

A particle-swarm is a set of indivisible processing elements that traverse a network in order to perform a distributed function. This paper will describe a particular implementation of a particle-swarm that can simulate the behavior of the popular PageRank algorithm in both its {\it global-rank} and {\it relative-rank} incarnations. PageRank is compared agai

Lane A. Hemaspaandra, Mayur Thakur

We study reductions that limit the extreme adaptivity of Turing reductions. In particular, we study reductions that make a rapid, structured progression through the set to which they are reducing: Each query is strictly longer (shorter) than the previous one. We call these reductions query-increasing (query-decreasing) Turing reductions. We also study query-

Robert Brijder, Hendrik Jan Hoogeboom, Michael Muskulus

Gene assembly in ciliates is an extremely involved DNA transformation process, which transforms a nucleus, the micronucleus, to another functionally different nucleus, the macronucleus. In this paper we characterize which loop recombination operations (one of the three types of molecular operations that accomplish gene assembly) can possibly be applied in th

A. G. Dimakis, D. Petrovic, K. Ramchandran

The vision of wireless sensor networks is one of a smart collection of tiny, dumb devices. These motes may be individually cheap, unintelligent, imprecise, and unreliable. Yet they are able to derive strength from numbers, rendering the whole to be strong, reliable and robust. Our approach is to adopt a distributed and randomized mindset and rely on in netwo

Francois Leonard

At reduced dimensionality, Coulomb interactions play a crucial role in determining device properties. While such interactions within the same carbon nanotube have been shown to have unexpected properties, device integration and multi-nanotube devices require the consideration of inter-nanotube interactions. We present calculations of the characteristics of p

Francois Leonard, A. Alec Talin

Metal-semiconductor contacts play a key role in electronics. Here we show that for quasi-one-dimensional structures such as nanotubes and nanowires, side contact with the metal only leads to weak band re-alignement, in contrast to bulk metal-semiconductor contacts. Schottky barriers are much reduced compared with the bulk limit, and should facilitate the for

Enrico Rossi, Dirk K. Morr

We study the Kondo screening of a single magnetic impurity inside a non-magnetic quantum corral located on the surface of a metallic host system. We show that the spatial structure of the corral&#39;s eigenmodes lead to a spatially dependent Kondo effect whose signatures are spatial variations of the Kondo temperature, $T_K$. Moreover, we predict that the Ko

Thierry Lahaye, David Guéry-Odelin

We compare two distincts models of evaporative cooling of a magnetically guided atomic beam: a continuous one, consisting in approximating the atomic distribution function by a truncated equilibrium distribution, and a discrete-step one, in which the evaporation process is described in terms of successive steps consisting in a truncation of the distribution

David ford

The role of the algebraic method has long been understood in shedding light on the topological structure of sets. However, when the set is a simplicial complex and host to a dynamical process, in particular the trajectory of a canonically distributed system in thermal equilibrium with a heat bath, the algebra re-enters. Via a theorem of Levy and Dynkin, ther

K. C. Rule, J. P. C. Ruff, B. D. Gaulin, S. R. Dunsiger

High resolution time-of-flight neutron scattering measurements on Tb2Ti2O7 reveal a rich low temperature phase diagram in the presence of a magnetic field applied along [110]. In zero field at T=0.4 K, terbium titanate is a highly correlated cooperative paramagnet with disordered spins residing on a pyrochlore lattice of corner-sharing tetrahedra. Applicatio

O. Zobay, Georgios M. Nikolopoulos

We present a detailed theoretical analysis of superradiant Rayleigh scattering from atomic Bose-Einstein condensates. A thorough investigation of the spatially resolved time-evolution of optical and matter-wave fields is performed in the framework of the semiclassical Maxwell-Schroedinger equations. Our theory is not only able to explain many of the known ex

Paolo Amore

We have devised a variational sinc collocation method (VSCM) which can be used to obtain accurate numerical solutions to many strong-coupling problems. Sinc functions with an optimal grid spacing are used to solve the linear and non-linear Schrödinger equations and a lattice $ϕ^4$ model in $(1+1)$. Our results indicate that errors decrease exponentially with

M. Eddrief, M. Marangolo, V. H. Etgens, S. Ustaze

We have probed the interface of a ferromagnetic/semiconductor (FM/SC) heterojunction by a combined high resolution photoemission spectroscopy and x-ray photoelectron diffraction study. Fe/ZnSe(001) is considered as an example of a very low reactivity interface system and it expected to constitute large Tunnel Magnetoresistance devices. We focus on the interf

Vanessa Preisler, Robson Ferreira, Sophie Hameau, Louis-Anne De Vaulchier

We investigate the valence intraband transitions in p-doped self-assembled InAs quantum dots using far-infrared magneto-optical technique with polarized radiation. We show that a purely electronic model is unable to account for the experimental data. We calculate the coupling between the mixed hole LO-phonon states using the Fröhlich Hamiltonian, from which

S. Lerouge, M. Argentina, J. P. Decruppe

We report on the spatio-temporal dynamics of the interface in shear-banding flow of a wormlike micellar system (cetyltrimethylammonium bromide and sodium nitrate in water) during a start-up experiment. Using the scattering properties of the induced structures, we demonstrate the existence of an instability of the interface between bands along the vorticity d

B. A. van Tiggelen, D. Anache, A. Ghysels

We study the spatial correlation function of the phase and its derivative, and related, fluctuations of topological charge, in two and three dimensional random media described by Gaussian statistics. We investigate their dependence on the scattering mean free path.

D. Graf, M. Frommenwiler, P. Studerus, T. Ihn

Nanolithography based on local oxidation with a scanning force microscope has been performed on an undoped GaAs wafer and a Ga[Al]As heterostructure with an undoped GaAs cap layer and a shallow two-dimensional electron gas. The oxide growth and the resulting electronic properties of the patterned structures are compared for constant and modulated voltage app

John Ardelius, Erik Aurell

We study the behavior of ASAT, a heuristic for solving satisfiability problems by stochastic local search near the SAT/UNSAT transition. The heuristic is focused, i.e. only variables in unsatisfied clauses are updated in each step, and is significantly simpler, while similar to, walksat or Focused Metropolis Search. We show that ASAT solves instances as larg

L. Mihály, B. Dóra, A. Ványolos, H. Berger

The field dependence of the electron spin resonance in a helimagnet, LiCu_2O_2, was investigated for the first time. In the paramagnetic state a broad resonance line was observed corresponding to a g-factor of 2.3. In the critical regime around the paramagnetic to helimagnetic phase transition the resonance broadens and shifts to higher frequencies. A narrow

L. C. Pardo, P. Lunkenheimer, A. Loidl

We present a thorough dielectric investigation of the relaxation dynamics of plastic crystalline Freon112, which exhibits freezing of the orientational degrees of freedom into a glassy crystal below 90 K. Among other plastic crystals, Freon112 stands out by being relatively fragile within Angell&#39;s classification scheme and by showing an unusually strong

E. K. Nazarova, K. Nenkov, G. Fuchs, K. -H. Muller

The influence of Ca substitution on the superconducting properties of polycrystalline R1-xCaxBa2Cu3Oz (R = Eu, Gd, Er; x=0; 0.2; 0.25 and 0.3) samples has been studied by X-ray powder diffraction, ac susceptibility and dc magnetization measurements. The superconducting parameters such as critical temperature, inter- and intra-granular critical current and fl

D. I. Khomskii

Multiferroics - materials which are simultaneously (ferro)magnetic and ferroelectric, and often also ferroelastic, attract now considerable attention, both because of the interesting physics involved and as they promise important practical applications. In this paper I give a survey of microscopic factors determining the coexistence of these properties, and

Michiel Snoek, H. T. C. Stoof

We investigate quantum fluctuations of a vortex lattice in a one-dimensional optical lattice. Our method gives full access to all the modes of the vortex lattice and we discuss in particular the Bloch bands of the Tkachenko modes. Because of the small number of particles in the pancake Bose-Einstein condensates at every site of the optical lattice, finite-si

M. D. Croitoru, V. N. Gladilin, V. M. Fomin, J. T. Devreese

We analyze the influence of the characteristics of the STM-tip (applied voltage, tip radius) on the electroluminescence spectra from an STM-tip-induced quantum dot taking into account the many-body effects. We find that positions of electroluminescence peaks, attributed to the electron-hole recombination in the quantum dot, are very sensitive to the shape an

L. Samaj

This paper is a continuation of a previous one [L. {Š}amaj, {\it J. Stat. Phys.} {\bf 120}:125 (2005)] dealing with the renormalization of a guest charge immersed in a two-dimensional logarithmic Coulomb gas of pointlike $\pm$ unit charges, the latter system being in the stability-against-collapse regime of reduced inverse temperatures $0\le β<2$. In the pre

O. Vainio, C. J. Vale, M. J. Davis, N. R. Heckenberg

We experimentally investigate the outcoupling of atoms from Bose-Einstein condensates using two radio-frequency (rf) fields in the presence of gravity. We show that the fringe separation in the resulting interference pattern derives entirely from the energy difference between the two rf fields and not the gravitational potential difference. We subsequently d

Sher Alam, T. Nagai, Y. Matsui

Heat Capacity of needle-like [length=5mm, diameter=1 mm] $β$-FeSi$_{2}$ single crystal, grown by chemical vapor transport has been measured. Two anomalies are found, a broad deviation centered around 160 K and a clear deviation at a temperature of 255 K approximately. We have attempted to relate these to the anomalies previously reported in the case of the r

Trieu Mai

Simulations show that sliding bilayers of colloidal particles can exhibit a new phase, the ``melt-freeze&#39;&#39; phase, where the layers stochastically alternate between solidlike and liquidlike states. We introduce a mean field phenomenological model with two order parameters to understand the interplay of two adjacent layers while the system is in this r

F. Jiang, Y. X. Zhou, H. Chen. R. Note, H. Mizuseki

We use a self-consistent method to study the distinct current-switch of $2^{&#39;}$-amino-4-ethynylphenyl-4&#39;-ethynylphenyl-5&#39;-nitro-1-benzenethiol, from the first-principles calculations. The numerical results are in accord with the early experiment [Reed et al., Sci. Am. \textbf{282}, 86 (2000)]. To further investigate the transport mechanism, we ca

Manabu Kiguchi, Tatsuya Konishi, Kei Murakoshi

Quantized conductance behavior of gold nano wires was studied under electrochemical potential control. We fabricated 1 nm long mono atomic wires in solution at room temperature. Electrochemical potential significantly affected the stability of the mono atomic wire and fractional conductance peak occurrence in the conductance histogram. We revealed that the h

E. Martinez, C. Perez-Penichet, O. Sotolongo-Costa, O. Ramos

We have experimentally observed a new phenomenon in the surface flow of a granular material. A heap is constructed by injecting sand between two vertical glass plates separated by a distance much larger than the average grain size, with an open boundary. As the heap reaches the open boundary, &#34;soliton-like&#34; fluctuations appear on the flowing layer, a

K. Ueda, S. Saito, K. Semba, T. Makimoto

Sandwich-type MgB2 Josephson tunnel junctions (MgB2/AlOx/MgB2) have been fabricated using as-grown MgB2 films formed by molecular beam epitaxy. The junctions exhibited substantial supercurrent and a well-defined superconducting gap (D=2.2~2.3mV). The superconducting gap voltage (D) agrees well with those of the smaller gap in the multi-gap scenario. The IcRN

Victor Barzykin

It has been recently shown by Nakatsuji, Pines, and Fisk [S. Nakatsuji, D. Pines, and Z. Fisk, Phys. Rev. Lett. 92, 016401 (2004)] from the phenomenological analysis of experiments in Ce1-xLaxCoIn5 and CeIrIn5 that thermodynamic and transport properties of Kondo lattices below coherence temperature can be very successfully described in terms of a two-fluid m

J. Catani, P. Maioli, L. De Sarlo, F. Minardi

We report on an experimental realization of a two-dimensional magneto-optical trap (2D-MOT) that allows the generation of cold atomic beams of 39K and 41K bosonic potassium isotopes. The high measured fluxes up to 1.0x10^11 atoms/s and low atomic velocities around 33 m/s are well suited for a fast and reliable 3D-MOT loading, a basilar feature for new genera

Yuhong Wang, Kapilanjan Krishan, Michael Dennin

Under conditions of sufficiently slow flow, foams, colloids, granular matter, and various pastes have been observed to exhibit shear localization, i.e. regions of flow coexisting with regions of solid-like behavior. The details of such shear localization can vary depending on the system being studied. A number of the systems of interest are confined so as to

R. Mélin

In connection with a recent experiment [Russo {\it et al.}, Phys. Rev. Lett. {\bf 95}, 027002 (2005)], we investigate the effect of weak localization on non local transport in normal metal / insulator / superconductor / insulator / normal metal (NISIN) trilayers, with extended interfaces. The negative weak localization contribution to the crossed resistance

J. Loos, M. Hohenadler, H. Fehske

An analytical approach to the one-dimensional spinless Holstein model is proposed, which is valid at finite charge-carrier concentrations. Spectral functions of charge carriers are computed on the basis of self-energy calculations. A generalization of the Lang-Firsov canonical transformation method is shown to provide an interpolation scheme between the extr

P. Gegenwart, F. Weickert, M. Garst, R. S. Perry

We report low-temperature thermal expansion measurements on the bilayer ruthenate Sr$_3$Ru$_2$O$_7$ as a function of magnetic field applied perpendicular to the Ruthenium-oxide planes. The field-dependence of the c-axis expansion coefficient indicates the accumulation of entropy close to 8 Tesla, related to an underlying quantum critical point. The latter is

Byeong-Gon Park, Young-Beom Jeon, Chung-Uk Lee, Cheongho Han

Microlensing is one of the most powerful methods that can detect extrasolar planets and a future space-based survey with a high monitoring frequency is proposed to detect a large sample of Earth-mass planets. In this paper, we examine the sensitivity of the future microlensing survey to Earth-mass planets located in the habitable zone. For this, we estimate

E. D&#39;Onghia, A. Burkert, G. Murante, S. Khochfar

The processes are investigated by which gas loses its angular momentum during the protogalactic collapse phase, leading to disk galaxies that are too compact with respect to the observations. High-resolution N-body/SPH simulations in a cosmological context are presented including cold gas and dark matter. A halo with quiet merging activity since z~3.8 and wi

E. Berger

Despite a rich diversity in observational properties, gamma-ray bursts (GRBs) can be divided into two broad categories based on their duration and spectral hardness -- the long-soft and the short-hard GRBs. The discovery of afterglows from long GRBs in 1997, and their localization to arcsecond accuracy, was a watershed event. The ensuing decade of intense st

Kambiz Fathi, Thaisa Storchi-Bergmann, Rogemar A. Riffel, Claudia Winge

We have used GMOS-IFU and high resolution HST-ACS observations to map, in unprecedented detail, the gas velocity field and structure within the 0.7 kpc circumnuclear ring of the SBb LINER/Seyfert 1 galaxy NGC 1097. We find clear evidence of radial streaming motions associated with spiral structures leading to the unresolved (<3.5 parsecs) nucleus, which we i

B. D. Lehmer, W. N. Brandt, A. E. Hornschemeier, D. M. Alexander

We analyze a population of intermediate-redshift (z ~ 0.05-0.3), off-nuclear X-ray sources located within optically-bright galaxies in the Great Observatories Origins Deep Survey (GOODS) and Galaxy Evolution from Morphology and SEDs (GEMS) fields. A total of 24 off-nuclear source candidates are classified using deep Chandra exposures from the Chandra Deep Fi

J. S. Urquhart, M. A. Thompson, L. K. Morgan, Glenn J. White

We present the results of radio continuum and molecular line observations conducted using the Mopra millimetre-wave telescope and Australia Telescope Compact Array. These observations reveal the presence of a dense core embedded within each cloud, and the presence of a layer of hot ionised gas coincided with their bright-rims. The ionised gas has electron de

Jocelyn Tomkin, Francis C. Fekel

Radial velocities from the 2.1 m telescope at McDonald Observatory supplemented with radial velocities from the coude&#39; feed telescope at KPNO provide new precise orbits for the double-lined spectroscopic binaries RR Lyn (A3/A8/A6), 12 Boo (F8IV), and HR 6169 (A2V). We derive orbital dimensions and minimum masses with accuracies of 0.06 to 0.9 %. The thre

R. Teyssier, S. Fromang, E. Dormy

We propose to extend the well-known MUSCL-Hancock scheme for Euler equations to the induction equation modeling the magnetic field evolution in kinematic dynamo problems. The scheme is based on an integral form of the underlying conservation law which, in our formulation, results in a ``finite-surface&#39;&#39; scheme for the induction equation. This natural

Solen Balman, Alon Retter, Marc Bos

We present CCD photometry, light curve and time series analysis of the classical nova V382 Vel (N Vel 1999). The source was observed for 2 nights in 2000, 21 nights in 2001 and 7 nights in 2002 using clear filters. We report the detection of a distinct period in the light curve of the nova P=0.146126(18) d (3.5 h). The period is evident in all data sets, and

David Boyd, Arto Oksanen, Arne Henden

The orbital period of the eclipsing cataclysmic variable SDSS J170213.26+322954.1 has been measured as 0.10008215+/-0.00000001d using observations of eclipses during the first recorded superoutburst in October 2005 together with eclipses observed in quiescence in July 2003. This period puts the system in the centre of the period gap. Observation of superhump

Remo Ruffini, Maria Grazia Bernardini, Carlo Luciano Bianco, Pascal Chardonnet

We present an analysis of the late time X-ray emission (URCA-3) connected with GRB 031203 and SN 2003lw.

Anthony J. Remijan, D. N. Friedel, Imke de Pater, M. R. Hogerheijde

We present an interferometric search for large molecules, including methanol, methyl cyanide, ethyl cyanide, ethanol, and methyl formate in comets LINEAR (C/2002 T7) and NEAT (C/2001 Q4) with the Berkeley-Illinois-Maryland Association (BIMA) array. In addition, we also searched for transitions of the simpler molecules CS, SiO, HNC, HN13C and 13CO . We detect

Remo Ruffini, Maria Grazia Bernardini, Carlo Luciano Bianco, Pascal Chardonnet

Using the Swift data of GRB 050315, we progress in proving the uniqueness of our theoretically predicted Gamma-Ray Burst (GRB) structure as composed by a proper-GRB, emitted at the transparency of an electron-positron plasma with suitable baryon loading, and an afterglow comprising the &#34;prompt radiation&#34; as due to external shocks. Detailed light curv

Ding-Xiong Wang, Wei-Hua Lei, Yong-Chun Ye

A toy model for gamma-ray burst supernovae (GRB-SNe) is discussed by considering the effects of screw instability of magnetic field in black hole (BH) magnetosphere. The screw instability in the Blandford-Znajek (BZ) process (henceforth SIBZ) can coexist with the screw instability in the magnetic coupling (MC) process (henceforth SIMC). It turns out that bot

Erik Rosolowsky, Adam Leroy

(abridged) We review methods for measuring the sizes, line widths, and luminosities of giant molecular clouds (GMCs) in molecular-line data cubes with low resolution and sensitivity. We find that moment methods are robust and sensitive -- making full use of both position and intensity information -- and we recommend a standard method to measure the position

F. Haardt, A. Sesana, P. Madau

We study the long-term evolution of massive black hole binaries (MBHBs) at the centers of galaxies using detailed full three-body scattering experiments. Stars, drawn from a distribution unbound to the binary, are ejected by the gravitational slingshot. We quantify the effect of secondary slingshots -- stars returning on small impact parameter orbits to have

H. Reboul, J. -P. Cordoni

We propose a (physical)-geometrical method to measure the present rates of the density cosmological parameters for a Friedmann-Lemaitre universe. The distribution of linear separations between two interacting galaxies,when both of them undergo a first massive starburst, is used as a standard of length. Statistical properties of the linear separations of such

R. Cassano, G. Brunetti, G. Setti

There are several possibilities to constrain the value of the magnetic field in the ICM, the most direct ones being the combination of inverse Compton and synchrotron observations, and the Faraday rotation measures. Here we discuss on the possibility to provide constraints on the magnetic field in the ICM from the analysis of the statistical properties of th

Norihito Matsunaga, Kazuhiro Yamamoto

We investigate the finite source size effect in the context of the wave optics in the gravitational lensing. The magnification of an extended source is presented in an analytic manner for the singular isothermal sphere lens model as well as the point mass lens model with the use of the thin lens approximation. The condition that the finite source size effect

Emma V. Ryan-Weber

The HI Parkes All Sky Survey (HIPASS) galaxy catalogue is cross-correlated with known low redshift, low column density (N_HI <10^15 cm^-2) Lyman-alpha absorbers from the literature. The redshift-space correlation is found to be similar in strength to HIPASS galaxy self-clustering (correlation length s_0,ag=6+/-4 and s_0,gg=3.1+/-0.5 h^-1 Mpc respectively). I

Sarah Smith, Anthony Challinor, Graca Rocha

The effect of weak gravitational lensing on the cosmic microwave background (CMB) temperature anisotropies and polarization will provide access to cosmological information that cannot be obtained from the primary anisotropies alone. We compare the information content of the lensed B-mode polarization power spectrum, properly accounting for the non-Gaussian c

Leonard A. Harris, Paulette Clancy

We present a novel multiscale simulation approach for modeling stochasticity in chemical reaction networks. The approach seamlessly integrates exact-stochastic and &#34;leaping&#34; methodologies into a single &#34;partitioned leaping&#34; algorithmic framework. The technique correctly accounts for stochastic noise at significantly reduced computational cost

Katsuki Hiraide, Hisakazu Minakata, Tsuyoshi Nakaya, Hiroshi Nunokawa

If the lepton mixing angle theta_{23} is not maximal, there arises a problem of ambiguity in determining theta_{23} due to the existence of two degenerate solutions, one in the first and the other in the second octant. We discuss an experimental strategy for resolving the theta_{23} octant degeneracy by combining reactor measurement of theta_{13} with accele

Abdou M. Abdel-Rehim, Randy Lewis, R. M. Woloshyn, Jackson M. S. Wu

Two twisted doublets, one containing the up and down quarks and the other containing the strange quark with an SU(2)-flavor partner, are used for studies in the meson sector. The relevant chiral perturbation theory is presented, and quenched QCD simulations (where the partner of the strange quark is not active) are performed. Pseudoscalar meson masses and de

F. Bonetto, G. Gallavotti, A. Giuliani, F. Zamponi

In this note we discuss a paradigmatic example of interacting particles subject to non conservative external forces and to the action of thermostats consisting of external (finite) reservoirs of particles. We then consider a model of granular materials of interest for experimental tests that had recently attracted lot of attentions. This model can be reduced

Daniel Kikola, Wiktor Peryt, Yuri M. Sinyukov, Marcin Slodkowski

An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use

Travis Norsen

It is demonstrated that hidden variables of a certain type follow logically from a certain local causality requirement (``Bell Locality&#39;&#39;) and the empirically well-supported predictions of quantum theory for the standard EPR-Bell setup. The demonstrated hidden variables are precisely those needed for the derivation of the Bell Inequalities. We thus r

V. G. Rousseau, D. P. Arovas, M. Rigol, F. Hébert

We use Quantum Monte Carlo simulations and exact diagonalization to explore the phase diagram of the Bose-Hubbard model with an additional superlattice potential. We first analyze the properties of superfluid and insulating phases present in the hard-core limit where an exact analytic treatment is possible via the Jordan-Wigner transformation. The extension

Abraham Loeb, Eli Waxman

We show that starburst galaxies convert efficiently cosmic-rays into pions, which in turn decay into high-energy neutrinos and photons. The cumulative background of GeV neutrinos is 10^{-7}GeV/cm^2/s/sr. Its extrapolation to higher neutrino energies depends on the energy spectrum of the injected cosmic-rays and is proportional to E^{-0.15+-0.1} up to E~0.3Pe