March 2007 arXiv papers — page 8

Firas Rassoul-Agha, Timo Seppäläinen

We consider a ballistic random walk in an i.i.d. random environment that does not allow retreating in a certain fixed direction. We prove an invariance principle (functional central limit theorem) under almost every fixed environment. The assumptions are nonnestling, at least two spatial dimensions, and a $2+ε$ moment for the step of the walk uniformly in th

Sebastian Baader

The Gordian distance between two knots measures how many crossing changes are needed to transform one knot into the other. It is known that there are always infinitely many non-equivalent knots `between' a pair of knots of Gordian distance two. In this paper we prove an extreme generalisation of this fact: there are knots with arbitrarily prescribed Vass

Yuri A. Kordyukov, Andrey A. Yakovlev

We present some recent results on the behavior of the spectrum of the differential form Laplacian on a Riemannian foliated manifold when the metric on the ambient manifold is blown up in directions normal to the leaves (in the adiabatic limit).

Alberto Elduque

Some simple Lie superalgebras, specific of characteristic 3, defined by S. Bouarroudj and D. Leites, are shown to be related to the simple alternative and commutative superalgebras discovered by I.P. Shestakov.

Hassan Ibrahim

We study a mathematical model describing the dynamics of dislocation densities in crystals. This model is expressed as a one-dimensional system of a parabolic equation and a first order Hamilton-Jacobi equation that are coupled together. We show the existence and uniqueness of a viscosity solution among those assuming a lower-bound on their gradient for all

Li Guo, William Keigher

A Rota-Baxter operator of weight $λ$ is an abstraction of both the integral operator (when $λ=0$) and the summation operator (when $λ=1$). We similarly define a differential operator of weight $λ$ that includes both the differential operator (when $λ=0$) and the difference operator (when $λ=1$). We further consider an algebraic structure with both a differen

Fengbo Hang

We prove all the maximizers of the sharp Hardy-Littlewood-Sobolev inequality are smooth. More generally, we show all the nonnegative critical functions are smooth, radial with respect to some points and strictly decreasing in the radial direction. In particular, this resolves all the cases left open by previous works of Chen, Li and Ou on the corresponding i

Shijong Ryang

We construct the integral equations by taking the thermodynamic limit of both the all-loop gauge Bethe ansatz equation and the string Bethe ansatz equation for the highest states in the su(1|1) and su(2) sectors of the N=4 super Yang-Mills theory. Using the Fourier transformation we solve the integral equations iteratively to obtain the anomalous dimensions

Yongming Fu, Zheng-Mao Sheng

The cross section for process $e^+e^-\toμ^+μ^-γ$ in the framework of noncommutative quantum electrodynamics(NC QED) is studied. It is shown that the NC correction of scattering sections is not monotonous enhancement with total energy of colliding electrons, but there is an optimal collision energy to get the greatest NC correction. Moreover, there is a linea

S. Pruvot, M. H. Schune, V. Sordini, A. Stocchi

We present a feasibility study for a new analysis for extracting the angle gamma of the Unitarity Triangle from the study of the neutral B meson decays. We reconstruct the decay channel B0 ->D0 K*0 with the K*0->K+pi- and the D0 -> KSpipi using a Dalitz analysis technique. The sensitivity to the angle gamma comes from the interference of the Vcb and Vub proc

R. S. Decca, D. López, E. Fischbach, G. L. Klimchitskaya

A micromechanical torsion oscillator has been used to strengthen the limits on new Yukawa forces by determining the Casimir pressure between two gold-coated plates. By significantly reducing the random errors and obtaining the electronic parameters of the gold coatings, we were able to conclusively exclude the predictions of large thermal effects below 1 $μ$

Howard Baer, Vernon Barger, Gabe Shaughnessy, Heaya Summy

One way to ameliorate the SUSY flavor and CP problems is to postulate that scalar masses lie in the TeV or beyond regime. For example, the focus point (FP) region of the minimal supergravity (mSUGRA) model is especially compelling in that heavy scalar masses can co-exist with low fine-tuning while yielding the required relic abundance of cold dark matter (vi

A. Afanasev, M. Anselmino, H. Avakian, G. Cates

The JLab 12 GeV upgrade with a proposed solenoid detector and the CLAS12 detector can provide the granularity and three-dimensional kinematic coverage in longitudinal and transverse momentum, $0.1\le x \le 0.5$, $0.3 \le z \le 0.7$ with $P_T \le 1.5 {\rm GeV}$ to precisely measure the leading twist chiral-odd and $T$-odd quark distribution and fragmentation

Eef van Beveren, George Rupp

We study S- and P-wave pion-pion and kaon-pion distributions for the three-body production processes $J/ψ\toωπ^{+}π^{-}$, $D^{+}\to K^{-}π^{+}π^{+}$, $D^{+}\to K^{+}π^{+}π^{-}$, and $D^{+}_{s}\to K^{+}π^{+}π^{-}$, by applying the Resonance-Spectrum Expansion to the two-body subamplitudes. The results are compared to the corresponding signals reported by the

Isabella Bierenbaum, Johannes Blümlein, Sebastian Klein

We calculate the $O(α_s^2)$ massive operator matrix elements for the twist--2 operators, which contribute to the heavy flavor Wilson coefficients in unpolarized deeply inelastic scattering in the region $Q^2 \gg m^2$. The calculation has been performed using light--cone expansion techniques. We confirm an earlier result obtained in \cite{Buza:1995ie}. The ca

Johann H. Kuhn, A. Kulesza, S. Pozzorini, M. Schulze

To match the precision of present and future measurements of W-boson production at hadron colliders, electroweak radiative corrections must be included in the theory predictions. In this paper we consider their effect on the transverse momentum (p_T) distribution of W bosons, with emphasis on large p_T. We evaluate the full electroweak O(α) corrections to th

V. A. Bednyakov, N. D. Giokaris, A. V. Bednyakov

The mass-generation mechanism is the most urgent problem of the modern particle physics. The discovery and study of the Higgs boson with the Large Hadron Collider at CERN are the highest priority steps to solve the problem. In this paper, the Standard Model Higgs mechanism of the elementary particle mass generation is reviewed with pedagogical details. The d

Thomas Schwetz

We point out a synergy between T-conjugated oscillation channels in the determination of the neutrino mass hierarchy with oscillation experiments with relatively short baselines (L < 700 km), where the matter effect is small. If information from all four oscillation channels $ν_μ\toν_e$, $\barν_μ\to\barν_e$, $ν_e\toν_μ$ and $\barν_e\to\barν_μ$ is available,

De-Min Li, Bing Ma, Yun-Hu Liu

In the framework of Regge phenomenology, masses of the charmed states $c\bar{q} (q=u,d,s)$ lying on the $1^3S_1$-like trajectories are estimated. The overall agreement between our estimated masses and the recent predictions given by modified quark models[hep-ph/0605019, hep-ph/0608011, hep-ph/0608139] is good. Masses of the observed charmed states $D_{s0}(23

H. Ishino, M. Hazumi, M. Nakao, T. Yoshikawa

We propose two novel methods for testing the standard model using external photon conversion at a high-luminosity e^+e^- B factory proposed recently. The first method is to measure the mixing-induced CP-violation parameter S_{pi^0pi^0} in B^0 --> pi^0 pi^0 decays. The precision of S_{pi^0pi^0} is estimated to be 0.23 from a Monte Carlo study for a data sampl

Yu-Huei Wu

From the &#39;quasi-local&#39; definition of horizons, e.g. isolated horizon and dynamical horizon, the consequence quasi-local energy-momentum near horizons can be observed by using the idea of frame alignment. In particular, we find the horizon news function from the asymptotic expansion near horizons and use this to describe the gravitational flux and cha

Michael P. Reisenberger

It is well known that free (unconstrained) initial data for the gravitational field in general relativity can be identified on an initial hypersurface consisting of two intersecting null hypersurfaces. Here the phase space of vacuum general relativity associated with such an initial data hypersurface is defined; a Poisson bracket is defined, via Peierls&#39;

Mikhail Z. Iofa

We study some aspects of cosmology in a five-dimensional model with matter, radiation and cosmological constant on the four-dimensional brane(s) and without matter in the bulk. The action of the model does not contain explicit curvature terms on the the brane(s). We obtain solution of the generalized Friedman equation as a function of dimensionless ratio of

Gregory J. Galloway, Didier A. Solis

All inextendible null geodesics in four dimensional de Sitter space dS^4 are complete and globally achronal. This achronality is related to the fact that all observer horizons in dS^4 are eternal, i.e. extend from future infinity scri^+ all the way back to past infinity scri^-. We show that the property of having a null line (inextendible achronal null geode

Rajesh Sudarsan, Calvin J. Ribbens

Applications in science and engineering often require huge computational resources for solving problems within a reasonable time frame. Parallel supercomputers provide the computational infrastructure for solving such problems. A traditional application scheduler running on a parallel cluster only supports static scheduling where the number of processors all

Virginia Savova, Leonid Peshkin

Exact parsing with finite state automata is deemed inappropriate because of the unbounded non-locality languages overwhelmingly exhibit. We propose a way to structure the parsing task in order to make it amenable to local classification methods. This allows us to build a Dynamic Bayesian Network which uncovers the syntactic dependency structure of English se

Edith Elkind, Leslie Ann Goldberg, Paul W. Goldberg

This paper addresses the problem of fair equilibrium selection in graphical games. Our approach is based on the data structure called the {\em best response policy}, which was proposed by Kearns et al. \cite{kls} as a way to represent all Nash equilibria of a graphical game. In \cite{egg}, it was shown that the best response policy has polynomial size as lon

Leonid Peshkin

This work is motivated by the necessity to automate the discovery of structure in vast and evergrowing collection of relational data commonly represented as graphs, for example genomic networks. A novel algorithm, dubbed Graphitour, for structure induction by lossless graph compression is presented and illustrated by a clear and broadly known case of nested

Dragos-Victor Anghel

A first order phase transition is found in a model which was introduced originally by Murthy and Shankar [Phys. Rev. B 60, 6517 (1999)] to describe systems of generalised exclusion statistics. I characterise the phase transition in the canonical and grandcanonical ensebles for the case when the statistical exclusion parameter is 1, which corresponds to the F

S. S. Kancharla, S. Okamoto

The ground state phase diagram of the half-filled repulsive Hubbard model in a bilayer is investigated using cluster dynamical mean field theory. For weak to intermediate values of Coulomb repulsion $U$, the system undergoes a transition from a Mott insulating phase to a metallic phase and then onto a band insulating phase as the interlayer hopping is increa

Yoshitaka Maeda, Chisa Hotta, Masaki Oshikawa

Temperature dependence of the magnetization of the Haldane spin chain at finite magnetic field is analyzed systematically. Quantum Monte Carlo data indicates a clear minimum of magnetization as a function of temperature in the gapless regime. On the basis of the Tomonaga-Luttinger liquid theory, we argue that this minimum is rather universal and can be obser

V. Mlinar, F. M. Peeters

A full three-dimensional model for the calculation of the electronic structure of semiconductor quantum dots (QD) and molecules (QDM) grown on high index surfaces and/or in the presence of an external magnetic field is presented. The strain distribution of the dots is calculated using continuum elasticity and singe-particle states are extracted from the nons

R. Khasanov, N. D. Zhigadlo, J. Karpinski, H. Keller

A study of the in-plane magnetic penetration depth λ_ab in a series of the cuprate superconductors Ca_2-xNa_xCuO_2Cl_2 (Na-CCOC) with Na content x=0.11, 0.12, 0.15, 0.18, and 0.19 is reported. The zero temperature values of λ_ab(0) were obtained by means of the muon-spin rotation technique, as well as from measurements of the intrinsic susceptibility χ^int(0

Sergio Gaudio, Jason Jackiewicz, Kevin S. Bedell

Based on the results obtained in a previous paper (S. Gaudio et al., cond-mat/0505309}, we derive the thermodynamic properties of a Fermi gas, deep into the quantum degenerate regime. We show that, if Luttinger&#39;s theorem holds, a first order phase transition occurs in the normal phase as a function of the interaction strength, U. We also show that a volu

Guillaume Weick, Gert-Ludwig Ingold, Dietmar Weinmann, Rodolfo A. Jalabert

The dynamics of the surface plasmon in laser-driven metallic nanoparticles is described by means of a master-equation formalism. Within the Markov approximation, the dynamics is studied for different regimes ranging from weak excitation in photoabsorption experiments to strong excitation in pump-probe spectroscopy. It is shown that two collective levels are

Cesar Seoanez, Guillaume Weick, Rodolfo A. Jalabert, D. Weinmann

We show that the dynamics of the surface plasmon in metallic nanoparticles damped by its interaction with particle-hole excitations can be modelled by a single degree of freedom coupled to an environment. In this approach, the fast decrease of the dipole matrix elements that couple the plasmon to particle-hole pairs with the energy of the excitation allows a

R. L. Willett, M. J. Manfra, L. N. Pfeiffer, K. W. West

Two fundamental extensions to the function of previously described fully field effect two-dimensional (2D) electron heterostructures are presented: First, using the same basic heterostructure design of lithographically defined contacts overlain by both an insulating layer and top-gate employed for electron systems, appropriate contact material allows a high

R. L. Willett, L. N. Pfeiffer, K. W. West

We present a two-dimensional electron heterostructure field effect device of simplistic design and ease of fabrication that displays high mobility electron transport. This is accomplished using a high efficacy contacting scheme and simple metallic overlapping gate, obviating dopant layers. The resultant devices demonstrate adjustable electron densities and m

Paolo Ranzieri, Matteo Masino, Alberto Girlando, Marie-Helene Lemee-Cailleau

We report a detailed spectroscopic investigation of temperature-induced valence and structural instability of the mixed-stack organic charge-transfer (CT) crystal 4,4&#39;-dimethyltetrathiafulvalene-chloranil (DMTTF-CA). DMTTF-CA is a derivative of tetrathiafulvalene-chloranil (TTF-CA), the first CT crystal exhibiting the neutral-ionic transition by lowering

G. Roati, M. Zaccanti, C. D&#39;Errico, J. Catani

We produce a Bose-Einstein condensate of 39-K atoms. Condensation of this species with naturally small and negative scattering length is achieved by a combination of sympathetic cooling with 87-Rb and direct evaporation, exploiting the magnetic tuning of both inter- and intra-species interactions at Feshbach resonances. We explore tunability of the self-inte

R. Friedrich, S. Eule, F. Jenko

In recent years, several fractional generalizations of the usual Kramers-Fokker-Planck equation have been presented. Using an idea of Fogedby [H.C. Fogedby, Phys. Rev. E {\bf 50}, 041103 (1994), we show how these equations are related to Langevin equations via the procedure of subordination.

Tao Tu, Yong-Jie Zhao, Guo-Ping Guo, Xiao-Jie Hao

We have measured the temperature dependence of the longitudinal resistivity $% ρ_{xx}$ of a two-dimensional electron system in the regime of the quantum Hall plateau transition. We extracted the quantitative form of scaling function for $ρ_{xx}$ and compared it with the results of ordinary scaling theory and variable range hopping based theory. We find that

A. S. Rybalko, S. P. Rubets, E. Ya. Rudavskii, V. A. Tikhiy

Microwave (MW) absorption in liquid 4He is investigated in the frequency range of 40-200 GHz at T = 1.4 - 2.5 K. Whispering gallery of waves was generated by a dielectric disc resonator immersed into the liquid. Resonance absorption of MWs was detected at 180.3 GHz, which corresponds to the roton minimum of the liquid helium excitation spectrum. The creation

H. H. Wensink

We study the stability of inhomogeneous liquid crystalline states in systems of monodisperse, stiff, charged rods. By means of a bifurcation analysis applied to the Onsager free energy for charged rods in strongly nematic states, we investigate nematic-smectic and nematic-columnar instabilities as a function of the Debye screening length. While the nematic-s

Illes J. Farkas, Daniel Abel, Gergely Palla, Tamas Vicsek

The inclusion of link weights into the analysis of network properties allows a deeper insight into the (often overlapping) modular structure of real-world webs. We introduce a clustering algorithm (CPMw, Clique Percolation Method with weights) for weighted networks based on the concept of percolating k-cliques with high enough intensity. The algorithm allows

Hiroshi Kohno, Junya Shibata

Previous calculation of spin torques for small-amplitude magnetization dynamics around a uniformly magnetized state [J. Phys. Soc. Jpn. {\bf 75} (2006) 113706] is extended here to the case of finite-amplitude dynamics. This is achieved by introducing an `` adiabatic&#39;&#39; spin frame for conduction electrons, and the associated SU(2) gauge field. In parti

M. Nicklas, O. Stockert, Tuson Park, K. Habicht

The heavy fermion superconductor CeCoIn5 is believed to be close to a magnetic instability, but no static magnetic order has been found. Cadmium doping on the In-site shifts the balance between superconductivity and antiferromagnetism to the latter with an extended concentration range where both types of order coexist at low temperatures. We investigated the

Michel Alba, Stephanie Pouget, Peter Fouquet, Bela Farago

High resolution Neutron Spin Echo (NSE) spectroscopy was used to investigate the dynamics of an 3D Heisenberg ferromagnet in the exchange-controlled regime over a broad range of temperatures and momentum transfer. These results allow for the first time an extensive comparison between the experimental dynamical critical behavior and the predictions of the Ren

P. S. Burada, G. Schmid, D. Reguera, J. M. Rubi

We study biased, diffusive transport of Brownian particles through narrow, spatially periodic structures in which the motion is constrained in lateral directions. The problem is analyzed under the perspective of the Fick-Jacobs equation which accounts for the effect of the lateral confinement by introducing an entropic barrier in a one dimensional diffusion.

L. Ravagnan, P. Piseri, M. Bruzzi, S. Miglio

We report the production and characterization of a form of amorphous carbon films with sp/sp2 hybridization (atomic fraction of sp hybridized species > 20%) where the predominant sp bonding appears to be (=C=C=)n cumulene. Vibrational and electronic properties have been studied by in situ Raman spectroscopy and electrical conductivity measurements. Cumulenic

F. Neumann, Y. A. Genenko, C. Melzer, S. V. Yampolskii

We present a closed description of the charge carrier injection process from a conductor into an insulator. Common injection models are based on single electron descriptions, being problematic especially once the amount of charge-carriers injected is large. Accordingly, we developed a model, which incorporates space charge effects in the description of the i

Sylvain Joubaud, Nicolas Garnier, Frédéric Douarche, Artem Petrosyan

The work fluctuations of a harmonic oscillator in contact with a thermostat and driven out of equilibrium by an external force are studied experimentally. For the work both the transient and stationary state fluctuation theorems hold. The finite time corrections are very different from those of a first order Langevin equation. The heat and work fluctuations

M. -A. Measson, D. Braithwaite, G. Lapertot, J. -P. Brison

A thorough characterization of many samples of the filled skutterudite compound PrOs4Sb12 is provided. We find that the double superconducting transition in the specific heat Tc1~1.89K and Tc2~1.72K tends to appear in samples with a large residual resistivity ratio, large specific heat jump at the superconducting transition and with the highest absolute valu

E. N. Myasnikov, A. E. Myasnikova, Z. P. Mastropas

Quantum-field theory methods are applied to consider the state of the polarization field in a strongly-coupled large polaron (SCLP) and after its photodissociation. It is demonstrated that in the adiabatic approximation the polarization field in such a polaron coincides with the classical polarization field considered in Landau-Pekar theory up to small quant

Chuanfu Luo, Wei Fa, Jinming Dong

We report that ice nanotubes with odd number of side faces inside carbon nanotubes exhibit spontaneous electric polarization along its axes direction by using molecular dynamics simulations. The mechanism of this nanoscale quasi-one-dimensional ferroelectricity is due to low dimensional confinement and the orientational order of hydrogen bonds. These ferroel

Ren-Bao Liu, Wang Yao, L. J. Sham

Control of electron spin decoherence in contact with a mesoscopic bath of many interacting nuclear spins in an InAs quantum dot is studied by solving the coupled quantum dynamics. The nuclear spin bath, because of its bifurcated evolution predicated on the electron spin up or down state, measures the which-state information of the electron spin and hence dim

Yositake Takane

We consider quasiparticle charge and energy imbalances in a thin superconductor weakly coupled with two normal-metal electrodes via tunnel junctions at low temperatures. Charge and energy imbalances, which can be created by injecting quasiparticles at one junction, induce excess tunneling current $I_{\rm ex}$ at the other junction. We numerically obtain $I_{

B. Pilecki, D. Fabrycky, R. Poleski

We present 31 bright eclipsing contact and semi-detached binaries that showed high period change rates in a 5 year interval in observations by the All-Sky Automated Survey (ASAS). The time-scales of these changes range from only 50 up to 400 kyr. The orbital periods of 10 binaries are increasing and of 21 are decreasing, and even a larger excess is seen in c

Cristina M Oliveira, Pierre Chayer, H. Warren Moos, Jeffrey W. Kruk

We present FUSE observations of the line of sight to WD0439+466 (LS V +46 21), the central star of the old planetary nebula Sh2-216. The FUSE data shows absorption by many interstellar and stellar lines, in particular D I, H2 (J = 0 - 9), HD (J = 0 - 1), and CO. Many other stellar and ISM lines are detected in the STIS E140M HST spectra of this sightline, wh

A. de la Macorra

We study the cosmological evolution of two coupled scalar fields with an arbitrary interaction term V_T(ϕ,\vp) in the presence of a barotropic fluid, which can be matter or radiation. The force between the barotropic fluid and the scalar fields is only gravitational. We show that the dynamics is completely determine by only three parameters L_i i=1,2,3. We d

Jason X. Prochaska, Hsiao-Wen Chen, Arthur M. Wolfe, Miroslava Dessauges-Zavadsky

We analyze the gas kinematics of damped Lya systems (DLAs) hosting high z gamma-ray bursts (GRBs) and those toward quasars (QSO-DLAs) focusing on threestatistics: (1) dv, the velocity interval encompassing 90% of the totaloptical depth, (2,3) Wsi and Wciv, the rest equivalent widths of the SiII1526 and CIV1548 transitions. The dv distributions of the GRB-DLA

Shlomo Dado, Arnon Dar, A. De Rujula

We show that the mean values and distributions of the time ending the shallow decay of the light curve of the X-ray afterglow of long gamma ray bursts (GRBs), the equivalent isotropic energy in the X-ray afterglow up to that time and the equivalent isotropic GRB energy, as well as the correlations between them, are precisely those predicted by the cannonball

Gerardo A. Vazquez, Claus Leitherer, Daniel Schaerer, Georges Meynet

We present and discuss evolutionary synthesis models for massive stellar populations generated with the Starburst99 code in combination with a new set of stellar evolution models accounting for rotation. The new stellar evolution models were compiled from several data releases of the Geneva group and cover heavy-element abundances ranging from twice solar to

Jifeng Liu, Joel Bregman, Jon Miller, Philip Kaaret

NGC1313 X-2 was among the first ultraluminous X-ray sources discovered, and has been a frequent target of X-ray and optical observations. Using the HST/ACS multi-band observations, this source is identified with a unique counterpart within an error circle of $0\farcs2$. The counterpart is a blue star on the edge of a young cluster of $\le10^7$ years amid a d

Z. Abraham, D. Falceta-Goncalves

We modeled the HeII 4686 line profiles observed in the eta Carinae binary system close to the 2003.5 spectroscopic event, assuming that they were formed in the shocked gas that flows at both sides of the contact surface formed by wind-wind collision. We used a constant flow velocity and added turbulence in the form of a gaussian velocity distribution. We all

P. Petit

In recent years, the development of spectropolarimetric techniques deeply modified our knowledge of stellar magnetism. In the case of solar-type stars, the challenge is to measure a geometrically complex field and determine its evolution over very different time frames. In this article, I summarize some important observational results obtained in this field

L. Leger, L. Chevallier, F. Paletou

New high-resolution spectropolarimetric observations of solar prominences require improved radiative modelling capabilities in order to take into account both multi-dimensional - at least 2D - geometry and complex atomic models. This makes necessary the use of very fast numerical schemes for the resolution of 2D non-LTE radiative transfer problems considerin

B. Cameron Reed

Cross-identifications for 14,574 intrinsically luminous galactic stars (mostly OB stars) to objects in the 2MASS survey have been determined using a search box of +/-0.0015 degrees (+/- 5.4 arcsec) in both RA and Dec. Instructions on obtaining the relevant files can be obtained at othello.alma.edu/~reed/OB-2MASS.doc.

A. Odrzywolek, M. Kutschera

Effects of the neutrino trapping and symmetry energy behavior are investigated in the framework of the chiral Kaplan-Nelson model with kaon condensation. Decrease in the condensation threshold during deleptonization if found to be generic regardless uncertainties in the nucleon-kaon interactions and symmetry energy. Quantitatively however, differences are sh

H. B. Lau, R. J. Stancliffe, C. A. Tout

We use the Cambridge stellar evolution code STARS to model the evolution and nucleosynthesis of zero-metallicity intermediate-mass stars. We investigate the effect of duplicity on the nucleosynthesis output of these systems and the potential abundances of the secondaries. The surfaces of zero-metallicity stars are enriched in CNO elements after second dredge

G. L. Israel, S. Campana, S. Dall&#39;Osso, M. P. Muno

On September 21, 2006, an intense (~10^39 erg/s) and short (20 ms) burst was detected by Swift BAT at a position consistent with that of the candidate Anomalous X-ray Pulsar, CXOU J164710.2-455216, discovered by Chandra in 2005. Swift follow-up observations began about 13 hours after the event and found the source at a 1-10keV flux level of about 4.5 x 10^-1

Gary Steigman, Donatella Romano, Monica Tosi

The deuterium abundances inferred from observations of the interstellar medium within 1-2 kpc of the Sun range over a factor of three and the corresponding oxygen abundances show an even larger dispersion. While the lower D (and O) abundances likely result from depletion onto dust, the higher D abundances are consistent with the BBN-predicted primordial D ab

A. G. Tlatov

Duration of the extended solar cycles is taken into the consideration. The beginning of cycles is counted from the moment of polarity reversal of large-scale magnetic field in high latitudes, occurring in the sunspot cycle n till the minimum of the cycle n+2. The connection between cycle duration and its amplitude is established. Duration of the &#34;latent&

L. Angeretti G. Fiorentino, L. Greggio

In this proceeding we present the procedure that we have adopted to obtain a dataset of Padova94 tracks interpolated in metallicity. The procedure requires special care to avoid spurious features in the resulting grid, thus we have subdivided tracks in evolutionary phases, we have chosen the suitable interpolation method and the transition masses. Finally, w

G. Fiorentino, M. Marconi, G. Clementini, I. Musella

In the framework of an ongoing ACS@HST project (HST program #10586, PI: Aloisi) we have obtained deep multi-color imaging of the very metal-poor Blue Compact Dwarf galaxy IZw18. The data were acquired in time-series fashion to allow the identification of Classical Cepheids (CCs). The main aim of this project is to constrain both the distance and the Star For

D. Watson, J. P. U. Fynbo, C. C. Thöne, J. Sollerman

There is strong evidence that long duration gamma-ray bursts (GRBs) are produced during the collapse of a massive star. In the standard version of the Collapsar model, a broad-lined and luminous Type Ic core-collapse supernova (SN) accompanies the GRB. This association has been confirmed in observations of several nearby GRBs. Recent observations show that s

A. Feoli, D. Mele

We support, with new fitting instruments and the analysis of more recent experimental data, the proposal of a relationship between the mass of a Supermassive Black Hole (SMBH) and the kinetic energy of random motions in the host elliptical galaxy. The first results obtained in a previous paper with 13 elliptical galaxies are now confirmed by the new data and

J. A. Combi, L. Bronfman, I. F. Mirabel

Aims. Motivated by the new determination of the distance to the microquasar GRO J1655-40 by Foellmi et al. (2006), we conduct a detailed study of the distribution of the atomic and molecular gas, and dust around the open cluster NGC 6242, the possible birth place of the microquasar. The proximity and relative height of the cluster on the galactic disk provid

Mikhail Shaposhnikov

An extension of the Standard Model by three right-handed neutrinos with masses smaller than the electroweak scale (the $ν$MSM) can explain simultaneously dark matter and baryon asymmetry of the Universe, being consistent with the data on neutrino oscillations. A dark matter candidate in this theory is the sterile neutrino with the mass in keV range. We discu

M. P. Doellinger, A. P. Hatzes, L. Pasquini, E. W. Guenther

Context: For the past 3 years we have been monitoring a sample of 62 K giant stars using precise stellar radial velocity measurements taken at the Thueringer Landessternwarte Tautenburg. Aims: To search for sub-stellar companions to giant stars and to understand the nature of the diverse radial velocity variations exhibited by K giant stars. Methods: We pres

V. S. Titov

The study of magnetic connectivity in the solar corona reveals a need to generalize the field line mapping technique to arbitrary geometry of the boundaries and systems of coordinates. Indeed, the global description of the connectivity in the corona requires the use of the photospheric and solar wind boundaries. Both are closed surfaces and therefore do not

Attila Popping, Robert Braun

In the last few years the realization has emerged that the universal baryons are almost equally distributed by mass in three components: (1) galactic concentrations, (2) a warm-hot intergalactic medium (WHIM) and (3) a diffuse intergalactic medium. These three components are predicted by hydrodynamical simulations and are probed by QSO absorption lines. To o

Georgij M. Rudnitskij, Jessica M. Chapman

We hereby report on a sensitive search for radio continuum observations from a sample of 34 Mira and semi-regular variable stars. The main aim of this survey was to search for thermal free-free emission from post-shock ionised gas. Thirty-four stars were observed at 3- and 6-cm using the Australia Telescope Compact Array. Radio continuum emission was detecte

Luisa T. Buchman, Olivier C. A. Sarbach

In a recent article, we constructed a hierarchy B_L of outer boundary conditions for Einstein&#39;s field equations with the property that, for a spherical outer boundary, it is perfectly absorbing for linearized gravitational radiation up to a given angular momentum number L. In this article, we generalize B_2 so that it can be applied to fairly general fol

Jason Bell, John Farina, Cayley Pendergrass-Rice

We study just infinite algebras which remain so upon extension of scalars by arbitrary field extensions. Such rings are called stably just infinite. We show that just infinite rings over algebraically closed fields are stably just infinite provided that the ring is either right noetherian or countably generated over a large field. We give examples to show th

E. Minguzzi

Hawking&#39;s stable causality implies Sorkin and Woolgar&#39;s K-causality. The work investigates the possible equivalence between the two causality requirements, an issue which was first considered by H. Seifert and then raised again by R. Low after the introduction of K-causality. First, a new proof is given that a spacetime is stably causal iff the Seife

Hirotaka Yoshino, Andrei Zelnikov, Valeri P. Frolov

The gyraton model describes a gravitational field of an object moving with the velocity of light which has finite energy and spin distributed during some finite time interval $L$. A gyraton may be considered as a classical toy model for a quantum wave packet of high-energy particles with spin. In this paper we study a head-on collision of two gyratons and bl

Daisuke Nagai, Andrey V. Kravtsov, Alexey Vikhlinin

We present detailed comparisons of the intracluster medium (ICM) in cosmological Eulerian cluster simulations with deep Chandra observations of nearby relaxed clusters. To assess the impact of galaxy formation, we compare two sets of simulations, one performed in the non-radiative regime and another with radiative cooling and several physical processes criti

Carlos G. Bornancini, Carlos De Breuck, Wim de Vries, Steve Croft

We present a sample of 40 Ultra Steep Spectrum (USS, $α\leq -1.3$, $S_ν\propto ν^α$) radio sources selected from the Westerbork in the Southern Hemisphere (WISH) catalog. The USS sources have been imaged in K--band at the Cerro Tololo Inter-American Observatory (CTIO) and with the Very Large Telescope at Cerro Paranal. We also present VLT, Keck and Willian H

Riccardo Argurio, Matteo Bertolini, Sebastian Franco, Shamit Kachru

We consider quiver gauge theories arising on D-branes at simple Calabi-Yau singularities (quotients of the conifold). These theories have metastable supersymmetry breaking vacua. The field theoretic mechanism is basically the one exhibited by the examples of Intriligator, Seiberg and Shih in SUSY QCD. In a dual description, the SUSY breaking is captured by t

Silvia Lüscher, Lindsay S. Moore, Tomaz Rejec, Yigal Meir

Compressibility measurements, sensitive to charge rearrangements, are performed on a quantum point contact (QPC). Screening due to mobile charges in the QPC is quantitatively measured, using a second point contact to detect the screened electrical potential. These measurements are performed from pinch-off through the opening of the first few modes in the QPC

David Uminsky, Karen Yeats

We study the properties of a logconcavity operator on a symmetric, unimodal subset of finite sequences. In doing so we are able to prove that there is a large unbounded region in this subset that is $\infty$-logconcave. This problem was motivated by the conjecture of Moll and Boros in that the binomial coefficients are $\infty$-logconcave.

Timothy Clifton

We find the general behaviour of homogeneous and isotropic cosmological models in some fourth-order theories of gravity. Explicit, exact, general solutions are given for both empty universes and those filled with a perfect fluid. For the vacuum case, solutions are found with closed, open and flat geometries, whilst the perfect fluid solutions are all spatial

Alexander Fel&#39;shtyn

It is proved for Abelian groups that the Reidemeister coincidence number of two endomorphisms $ϕ$ and $ψ$ is equal to the number of coincidence points of $\whϕ$ and $\whψ$ on the unitary dual, if the Reidemeister number is finite. An affirmative answer to the bitwisted Dehn conjugacy problem for almost polycyclic groups is obtained. Finally we explain why th

Robert E. Smith, Roman Scoccimarro, Ravi K. Sheth

The baryonic acoustic signature in the large-scale clustering pattern of galaxies has been detected in the two-point correlation function. Its precise spatial scale has been forwarded as a rigid-rod ruler test for the space-time geometry, and hence as a probe for tracking the evolution of Dark Energy. Percent-level shifts in the measured position can bias su

Joy Christian

This is a collection of my responses to the criticisms of my argument against the impossibility proof of John Bell, which aims to undermine any conceivable local realistic completion of quantum mechanics. I plan to periodically update this preprint instead of creating a new one for each response.

Y. Matsuoka, S. Oyabu, Y. Tsuzuki, K. Kawara

We present results of the near-infrared (IR) spectroscopy of six quasars whose redshifts range from 0.158 to 1.084. Combined with the satellite ultraviolet data, the relative line strengths of OI 1304, OI 8446, OI 11287, and the near-IR CaII triplet are given. In addition, the corresponding OI line strengths measured in normal Seyfert 1s and narrow-line Seyf

Robert Spalek

We present a new variant of the quantum adversary method. All adversary methods give lower bounds on the quantum query complexity of a function by bounding the change of a progress function caused by one query. All previous variants upper-bound the_difference_ of the progress function, whereas our new variant upper-bounds the_ratio_ and that is why we coin i

Julien Lesgourgues, Wessel Valkenburg

We derive some new constraints on single-field inflation from the Wilkinson Microwave Anisotropy Probe 3-year data combined with the Sloan Luminous Red Galaxy survey. Our work differs from previous analyses by focusing only on the observable part of the inflaton potential, or in other words, by making absolutely no assumption about extrapolation of the poten

Jianyang He, Moshe Rozali

We discuss non-perturbative instabilities, mediated by bubbles of nothing, in the context of the AdS/CFT correspondence. By exploring the phase diagram of such decays we give an interpretation of the process in terms of an effective potential in a quantum mechanics of a single variable, a winding mode condensate. The decay corresponds to a conventional first