September 2009 arXiv papers — page 53

Alfred Hucht

A driven Ising model with friction due to magnetic correlations has recently been proposed by Kadau et al. (Phys. Rev. Lett. 101, 137205 (2008)). The non-equilibrium phase transition present in this system is investigated in detail using analytical methods as well as Monte Carlo simulations. In the limit of high driving velocities $v$ the model shows mean fi

J Ovalle

In the context of the Randall-Sundrum braneworld, an exhaustive and detailed description of the approach based in the minimal anisotropic consequence onto the brane, which has been successfully used to generate exact interior solutions to Einstein's field equations for static and non-uniform braneworld stars with local and non-local bulk terms, is carefu

Walter Van Herck, Thomas Wyder

The enumeration of BPS bound states in string theory needs refinement. Studying partition functions of particles made from D-branes wrapped on algebraic Calabi-Yau 3-folds, and classifying states using split attractor flow trees, we extend the method for computing a refined BPS index, arXiv:0810.4301. For certain D-particles, a finite number of microstates,

Joel Berge, Adam Amara, Alexandre Refregier

We compare the efficiency of weak lensing-selected galaxy clusters counts and of the weak lensing bispectrum at capturing non-Gaussian features in the dark matter distribution. We use the halo model to compute the weak lensing power spectrum, the bispectrum and the expected number of detected clusters, and derive constraints on cosmological parameters for a

Yongquan Hu

Let p>3 be a prime, f a positive integer and Q_{p^f} the unramified extension of Q_p of degree f. After Breuil and Paskunas, to a generic semi-simple continue modulo p representation of the absolute Galois group of Q_{p^f}, we can associate a parameterized family of smooth admissible modulo p representations of GL_2(Q_{p^f}). In this article, we prove that t

Hubert L. Bray, Jeffrey L. Jauregui

The Schwarzschild spacetime metric of negative mass is well-known to contain a naked singularity. In a spacelike slice, this singularity of the metric is characterized by the property that nearby surfaces have arbitrarily small area. We develop a theory of such "zero area singularities" in Riemannian manifolds, generalizing far beyond the Schwarzschi

Neil Barnaby, J. Richard Bond, Zhiqi Huang, Lev Kofman

We study (p)reheating in modular (closed string) inflationary scenarios, with a special emphasis on Kahler moduli/Roulette models. It is usually assumed that reheating in such models occurs through perturbative decays. However, we find that there are very strong non-perturbative preheating decay channels related to the particular shape of the inflaton potent

Brant E. Robertson, Andrey V. Kravtsov, Nickolay Y. Gnedin, Tom Abel

Eulerian hydrodynamical simulations are a powerful and popular tool for modeling fluids in astrophysical systems. In this work, we critically examine recent claims that these methods violate Galilean invariance of the Euler equations. We demonstrate that Eulerian hydrodynamics methods do converge to a Galilean-invariant solution, provided a well-defined conv

Matthew D. Kistler, Jennifer M. Siegal-Gaskins

Due to their higher concentrations and small internal velocities, Milky Way subhalos can be at least as important as the smooth halo in accounting for the GeV positron excess via dark matter annihilation. After showing how this can be achieved in various scenarios, including in Sommerfeld models, we demonstrate that, in this case, the diffuse inverse-Compton

Valerio Faraoni

Clifton's exact solution of f(R)=R^(1+δ) gravity describing a dynamical spherical metric which is asymptotically Friedmann-Lemaitre-Robertson-Walker is studied. It is shown that it harbours a strong spacetime singularity and that this singularity is naked at late times.

Louise Dolan, Peter Goddard

We show how the link variables of Arkani-Hamed, Cachazo, Cheung and Kaplan (ACCK), can be used to compute general gluon tree amplitudes in the twistor string. They arise from instanton sectors labelled by d, with d=n-1, where n is the number of negative helicities. Read backwards, this shows how the various forms for the tree amplitudes studied by ACCK can b

Xingang Chen, Yi Wang

We study the slow-roll inflation models, where the inflaton slow-rolls along a trajectory whose orthogonal directions are lifted by potentials with masses of order the Hubble parameter. In these models large non-Gaussianities can be generated through the transformation from the isocurvature modes to the curvature mode, once the inflaton trajectory turns. We

Steven Lalley, Gregory Lawler, Hariharan Narayanan

Let A be a bounded, relatively closed subset of the upper half plane H whose complement C is simply connected. If B_t is a standard complex Brownian motion starting at iy and t_A = inf {t > 0: B_t not in C}, the half-plane capacity of A, hcap(A) is defined to be the limit as y goes to infinity of y E[Im(B_{t_A}]. This quantity arises naturally in the study o

Zoltán Keresztes, László Á. Gergely

We develop a 3+1+1 covariant formalism with cosmological and astrophysical applications. First we give the evolution and constraint equations both on the brane and off-brane in terms of 3-space covariant kinematical, gravito-electro-magnetic (Weyl) and matter variables. We discuss the junction conditions across the brane in terms of the new variables. Then w

Rami Mehrem

This paper shows that the plane wave expansion can be a useful tool in obtaining analytical solutions to infinite integrals over spherical Bessel functions and the derivation of identites for these functions. The integrals are often used in nuclear scattering calculations, where an analytical result can provide an insight into the reaction mechanism. A techn

Mariska Kriek, Pieter G. van Dokkum, Marijn Franx, Garth D. Illingworth

We present Hubble Space Telescope NIC2 morphologies of a spectroscopic sample of massive galaxies at z~2.3, by extending our sample of 9 compact quiescent galaxies (r_e~0.9 kpc) with 10 massive emission-line galaxies. The emission-line galaxies are classified by the nature of their ionized emission; there are six star-forming galaxies and four galaxies hosti

Satoshi Tojo, Taro Hayashi, Tatsuyoshi Tanabe, Takuya Hirano

We studied spin-dependent two-body inelastic collisions in F=2 87Rb Bose-Einstein condensates both experimentally and theoretically. The 87Rb condensates were confined in an optical trap and selectively prepared in various spin states in the F=2 manifold at a magnetic field of 3.0 G. Measured atom loss rates are found to depend on spin states of colliding at

László Á. Gergely, Peter L. Biermann, Balázs Mikóczi, Zoltán Keresztes

We analyze galactic black hole mergers and their emitted gravitational waves. Such mergers have typically unequal masses with mass ratio of the order 1/10. The emitted gravitational waves carry the inprint of spins and mass quadrupoles of the binary components. Among these contributions, we consider here the quasi-precessional evolution of the spins. A metho

H. Sana, E. Gosset, C. J. Evans

Based on a set of over 100 medium- to high-resolution optical spectra collected from 2003 to 2009, we investigate the properties of the O-type star population in NGC6611 in the core of the Eagle Nebula (M16). Using a much more extended data set than previously available, we revise the spectral classification and multiplicity status of the nine O-type stars i

Srikanta Sinha

The modulation of high-energy transients' (or steadily emitting sources') light curves due to the imperfect alignment of the detector's view axis with the spin axis in a spin-stabilized satellite is derived. It is shown how the orientation of the detector's view axis with respect to the satellite's spin axis may be estimated using observe

L. Benfatto, C. Castellani, T. Giamarchi

We discuss the crucial role played by finite-size effects and inhomogeneity on the Beresinkii-Kosterlitz-Thouless (BKT) transition in two-dimensional superconductors. In particular, we focus on the temperature dependence of the resistivity, that is dominated by superconducting fluctuations above the BKT transition temperature $T_{BKT}$ and by inhomogeneity b

Stefan Haesen, Leopold Verstraelen

A proposal is made for what could well be the most natural symmetrical Riemannian spaces which are homogeneous but not isotropic, i.e. of what could well be the most natural class of symmetrical spaces beyond the spaces of constant Riemannian curvature, that is, beyond the spaces which are homogeneous and isotropic, or, still, the spaces which satisfy the ax

Brandy Guntel Doleshal

Berge introduced knots that are primitive/primitive with respect to the genus 2 Heegaard surface, $F$, in $S^3$; surgery on such knots at the surface slope yields a lens space. Later Dean described a similar class of knots that are primitive/Seifert with respect to $F$; surgery on these knots at the surface slope yields a Seifert fibered space. Here we const

Dmitry Yearchuck, Yauhen Yerchak, Alla Dovlatova

Transition operator method is proposed for description of the dynamics of spectroscopic transitions. Quantum-mechanical analogue of Landau-Lifshitz equation has been derived for the system representing itself the periodical ferroelectrically (ferromagnetically) ordered chain of $N$ equivalent elements, interacting with external oscillating electromagnetic fi

Ricardo Amorim, Everton M. C. Abreu

In this work we analyze complex scalar fields using a new framework where the object of noncommutativity $θ^{μν}$ represents independent degrees of freedom. In a first quantized formalism, $θ^{μν}$ and its canonical momentum $π_{μν}$ are seen as operators living in some Hilbert space. This structure is compatible with the minimal canonical extension of the D

Devang A. Joshi, Neeraj Kumar, A. Thamizhavel, S. K. Dhar

We report on the magnetic behavior of RRhB (R = La, Ce, Pr, Nd, Gd, Tb and Tm) and RRhC (R = La, Ce, Pr and Gd) compounds crystallizing in the cubic perovskite type structure with space group Pm3m. The heat capacity data on Pauli-paramagnetic LaRhB and LaRhC indicate a high frequency vibrating motion of boron and carbon atoms in the unit cell. Ce is in -like

Rodolfo Gambini, Jorge Pullin, Saeed Rastgoo

We show that the canonical formulation of a generic action for 1+1-dimensional models of gravity coupled to matter admits a description in terms of Ashtekar-type variables. This includes the CGHS model and spherically symmetric reductions of 3+1 gravity as particular cases. This opens the possibility of discussing models of black hole evaporation using loop

V. V. Gvaramadze, A. Y. Kniazev, S. Fabrika

Massive evolved stars loss a large fraction of their mass via copious stellar wind or instant outbursts and during certain evolutionary phases they can be identified via the presence of their circumstellar nebulae. In this paper, we present the results of search for compact nebulae (reminiscent of circumstellar nebulae around evolved massive stars) using arc

M R Setare

In the usual Hořava-Lifshitz cosmological models, the scalar field is responsible for dark matter. Using an additional scalar field, Saridakis \cite{sari} has formulated Hořava-Lifshitz cosmology with an effective dark energy sector. In the paper \cite{sari} the scalar fields do not interact with each other, here we extend this work to the interacting case,

Huan Dong, T. T. S. Kuo, R. Machleidt

Neutron star properties, such as its mass, radius, and moment of inertia, are calculated by solving the Tolman-Oppenheimer-Volkov (TOV) equations using the ring-diagram equation of state (EOS) obtained from realistic low-momentum NN interactions $V_{low-k}$. Several NN potentials (CDBonn, Nijmegen, Argonne V18 and BonnA) have been employed to calculate the r

D. Jones, M. Lloyd, D. L. Mitchell, D. L. Pollacco

We present the first detailed spatio-kinematical analysis and modelling of the Southern planetary nebula SuWt 2. This object presents a problem for current theories of planetary nebula formation and evolution, as it is not known to contain a central post-main sequence star. Deep narrowband [NII]6584 images reveal the presence of faint bipolar lobes emanating

S. Giacintucci, T. Venturi, R. Cassano, D. Dallacasa

We report on the detection of diffuse radio emission in the X-ray luminous and massive galaxy cluster A1351 (z=0.322) using archival Very Large Array data at 1.4 GHz. Given its central location, morphology, and Mpc-scale extent, we classify the diffuse source as a giant radio halo. X-ray and weak lensing studies show A1351 to be a system undergoing a major m

Eduardo Cuervo-Reyes, Elizabeth Diane Stalder, Christian Mensing, Serhiy Budnyk

Alkaline earth mono-silicides (ÆSi, Æ $=$ Ca, Sr, Ba) are poor metals and their transport properties are not solely determined by the Zintl anion, in contrast to their Zintl-type composition. Their conducting network is formed by the depopulated ${}^{1}_{\infty}$[Si$^{2-}$] $π$-system and Æ-$d$ states. This justifies the special local coordination of the met

David M. Evans, Elisabetta Pastori

For D an infinite set, k>1 and W the set of k-sets from D, there is a natural closed permutation group G_k which is a non-split extension of \mathbb{Z}_2^W by \Sym(D). We classify the closed subgroups of G_k which project onto \Sym(D)$. The question arises in model theory as a problem about finite covers, but here we formulate and solve it in algebraic terms

Jian-Wen Xu, Ya-Peng Hu

Our statistics on Galactic supernova remnants (SNRs) shows that the electrons temperature ($T$) of hard X-ray and the shock waves traveling velocity ($\upsilon$) decreases with ages ($t$) for all-sort remnants. However, the shock waves swept-up mass ($M_{su}$) of ISM increases with the age. Second, the remnant radio fluxes ($S$) at 1 GHz increase slightly wi

T. Lappi, L. McLerran

We analyze long range rapidity correlations observed in the STAR experiment at RHIC. Our goal is to extract properties of the two particle correlation matrix, accounting for the analysis method of the STAR experiment. We find a surprisingly large correlation strength for central collisions of gold nuclei at highest RHIC energies. We argue that such correlati

Kentaro Tanabe, Norihiro Tanahashi, Tetsuya Shiromizu

We discuss the asymptotic structure of null infinity in five dimensional space-time. Since it is known that the conformal infinity is not useful for odd higher dimensions, we shall employ the coordinate based method like the Bondi coordinate firstly introduced in four dimensions. Then we define the null infinity and identify the asymptotic symmetry. We also

S. Adhikari, A. S. Majumdar, Dipankar Home, Alok Kumar pan

Based on a scheme that produces an entanglement between the spin and the path variables of a single spin-1/2 particle (qubit) using a beam-splitter and a spin-flipper, we formulate a procedure for transferring this intraparticle hybrid entanglement to an interparticle entanglement between the spin variables of two other spatially separated spin-1/2 particles

M. O. Katanaev

A new simple proof of the adiabatic theorem is given in the finite dimensional case for nondegenerate as well as degenerate states. The explicitly integrable two level system is considered as an example. It is demonstrated that the error estimate given by the adiabatic theorem can not be improved.

A. Dannenberg, M. E. Gruner, A. Hucht, P. Entel

We have calculated surface energies and surface magnetic order of various low-indexed surfaces of monoatomic Fe, Co, and Pt, and binary, ordered FePt, CoPt, and MnPt using density functional theory. Our results for the binary systems indicate that elemental, Pt-covered surfaces are preferred over Fe- and Co-covered and mixed surfaces of the same orientation.

Stanislaw Drozdz, Pawel Oswiecimka

Based on our "finance-prediction-oriented" methodology which involves such elements as log-periodic self-similarity, the universal preferred scaling factor lambda=2, and allows a phenomenon of the "super-bubble" we analyze the 2009 world stock market (here represented by the SP500, Hang Seng and WIG) development. We identify elements that ind

Dinah R. Parker, Matthew J. P. Smith, Tom Lancaster, Andrew J. Steele

Using a combination of neutron, muon and synchrotron techniques we show how the magnetic state in NaFeAs can be tuned into superconductivity by replacing Fe by either Co or Ni. Electron count is the dominant factor, since Ni-doping has double the effect of Co-doping for the same doping level. We follow the structural, magnetic and superconducting properties

E. Rasanen, S. Pittalis, C. R. Proetto, K. Capelle

We study the properties of the lower bound on the exchange-correlation energy in two dimensions. First we review the derivation of the bound and show how it can be written in a simple density-functional form. This form allows an explicit determination of the prefactor of the bound and testing its tightness. Next we focus on finite two-dimensional systems and

Tohru Eguchi, Kazuhiro Hikami

We study the elliptic genera of hyperKahler manifolds using the representation theory of N=4 superconformal algebra. We consider the decomposition of the elliptic genera in terms of N=4 irreducible characters, and derive the rate of increase of the multiplicities of half-BPS representations making use of Rademacher expansion. Exponential increase of the mult

Yu. A. Sitenko, N. D. Vlasii

Vacuum polarization effects in the cosmic string background are considered. We find that a current is induced in the vacuum of the quantized massive scalar field and that the current circulates around the string which is generalized to a $(d-2)$-brane in locally flat $(d+1)$-dimensional space-time. As a consequence of the Maxwell equation, a magnetic field s

Sebastien Clesse, Christophe Ringeval, Jonathan Rocher

We show that the initial field values required to produce inflation in the two fields original hybrid model, and its supergravity F-term extension, do not suffer from any fine-tuning problem, even when the fields are restricted to be sub-planckian and for almost all potential parameter values. This is due to the existence of an initial slow-roll violating ev

P. S. Lykawka, J. Horner, B. W. Jones, T. Mukai

We present the results of detailed dynamical simulations of the effect of the migration of the four giant planets on both the transport of pre-formed Neptune Trojans, and the capture of new Trojans from a trans-Neptunian disk. We find that scenarios involving the slow migration of Neptune over a large distance (50Myr to migrate from 18.1AU to its current loc

Andreas Ziehl, Jochen Bammert, Lukas Holzer, Christian Wagner

Shear-induced cross-correlations of particle fluctuations perpendicular and along stream-lines are investigated experimentally and theoretically. Direct measurements of the Brownian motion of micron-sized beads, held by optical tweezers in a shear-flow cell, show a strong time-asymmetry in the cross-correlation, which is caused by the non-normal amplificatio

T. Venumadhav, Masudul Haque, R. Moessner

For a Bose-Hubbard dimer, we study quenches of the site energy imbalance, taking a highly asymmetric Hamiltonian to a fully symmetric one. The ramp is carried out over a finite time that interpolates between the instantaneous and adiabatic limits. We provide results for the excess energy of the final state compared to the ground state energy of the final Ham

Nicolas F. Martin, Alan W. McConnachie, Mike Irwin, Lawrence M. Widrow

We present the discovery of two new dwarf galaxies, Andromeda XXI and Andromeda XXII, located in the surroundings of the Andromeda and Triangulum galaxies (M31 and M33). These discoveries stem from the first year data of the Pan-Andromeda Archaeological Survey (PAndAS), a photometric survey of the M31/M33 group conducted with the Megaprime/MegaCam wide-field

L. Birzan, D. A. Rafferty, B. R. McNamara, P. E. J. Nulsen

Chandra X-ray Observatory has revealed X-ray cavities in many nearby cooling flow clusters. The cavities trace feedback from the central active galactic nulceus (AGN) on the intracluster medium (ICM), an important ingredient in stabilizing cooling flows and in the process of galaxy formation and evolution. But, the prevalence and duty cycle of such AGN outbu

Hiroyuki Nakaoka

This paper has been withdrawn by the author, since the result was already known.

A. K. Chaudhuri

In the Israel-Stewart's theory of dissipative hydrodynamics, we have analysed the STAR data on $ϕ$ meson production in Au+Au collisions at $\sqrt{s}$=200 GeV. From a simultaneous fit to $ϕ$ mesons multiplicity, mean $p_T$ and integrated $v_2$, we obtain a phenomenological estimate of QGP viscosity, $η/s =0.07 \pm 0.03 \pm 0.14$, the first error is due to

A. Arbey, F. Mahmoudi

Relic density calculations are often used to constrain particle physics models, and in particular supersymmetry. We will show that the presence of additional energy or entropy before the Big-Bang nucleosynthesis can however completely change the relic density constraints on the SUSY parameter space. Therefore one should be extremely careful when using the re

Rudolf Umla, Matthias Augustin, Bjoern Huke, Manfred Luecke

We investigate theoretically the nonlinear state of ideal straight rolls in the Rayleigh-Bénard system of a fluid layer heated from below with a porous medium using a Galerkin method. Applying the Oberbeck-Boussinesq approximation, binary mixtures with positive separation ratio are studied and compared to one-component fluids. Our results for the structural

Yubing Dong, Amand Faessler, Thomas Gutsche, Valery E. Lyubovitskij

The X(3872) with quantum numbers J(PC) = 1(++) is considered as a composite state containing both molecular hadronic and a c bar(c) component. Based on this structure assumption we first constrain model parameters in order to reproduce the predictions for the radiative decay widths of X(3872) to J/psi gamma and X(3872) to psi(2S) gamma as obtained in c bar(c

Yuri A. Markov, Margaret A. Markova

We discuss two ways of deriving the fluctuation-dissipation theorem (FDT) for soft fermion excitations in a hot non-Abelian plasma being in a thermal equilibrium. The first of them is based on the extended (pseudo)classical model in describing a quark-gluon plasma suggested in [Yu.A. Markov, M.A. Markova, Nucl. Phys. A {\bf 784} (2007) 443], while the second

A. K. Chaudhuri

In the Israel-Stewart's theory of dissipative hydrodynamics, we study the scaling properties elliptic flow in Au+Au collisions. Initial energy density of the fluid was fixed to reproduce STAR data on $ϕ$ meson multiplicity in 0-5% Au+Au collisions, such that irrespective of fluid viscosity, entropy at the freeze-out is similar in ideal or in viscous evol

Keiji Yada, Seiichiro Onari, Yukio Tanaka, Jun-ichiro Inoue

We study the symmetry of Cooper pair in a two-dimensional Hubbard model with the Rashba-type spin-orbit interaction as a minimal model of electron gas generated at a heterointerface of SrTiO$_3$/LaAlO$_3$. Solving the Eliashberg equation based on the third-order perturbation theory, we find that the gap function consists of the mixing of the spin-singlet $d_

Jean-Marc Huré, Arnaud Pierens

In 2D-simulations of self-gravitating gaseous discs, the potential is often computed in the framework of "softened gravity" initially designed for N-body codes. In this special context, the role of the softening length LAMBDA is twofold: i) to avoid numerical singularities in the integral representation of the potential (i.e., arising when the relati

S. Pittalis, E. Rasanen, C. R. Proetto

We extend the Becke-Johnson approximation [J. Chem. Phys. 124, 221101 (2006)] of the exchange potential to two dimensions. We prove and demonstrate that a direct extension of the underlying formalism may lead to divergent behavior of the potential. We derive a cure to the approach by enforcing the gauge invariance and correct asymptotic behavior of the excha

Michael Gekhtman, Michael Shapiro, Alexander Stolin, Alek Vainshtein

We describe all Poisson brackets compatible with the natural cluster algebra structure in the open Schubert cell of the Grassmannian $G_k(n)$ and show that any such bracket endows $G_k(n)$ with a structure of a Poisson homogeneous space with respect to the natural action of $SL_n$ equipped with an R-matrix Poisson-Lie structure. The corresponding R-matrices

Jian-Wen Xu, Hui-Rong Zhang

There are several different methods to determine the individual supernovae (SNe) initial explosion energy, here we derive the average or typical explosion energy of shell-type supernova remnants (SNRs) in a particular way. By solving a group of equations pertaining to shell-type SNRs at the same stage we obtained some physical parameters, e.g. the distance (

Magdalena Malek

In this paper, we summarize the perspectives on quarkonia detection in the ALICE experiment at the CERN LHC, both in the dielectron and dimuon decay channels.

Loïc Foissy

We consider systems of combinatorial Dyson-Schwinger equations (briefly, SDSE) X_1=B^+_1(F_1(X_1,...,X_N))...X_N=B^+_N(F_N(X_1,...,X_N)) in the Connes-Kreimer Hopf algebra H_I of rooted trees decorated by I={1,...,N},where B^+_i is the operator of grafting on a root decorated by i, and F_1...,F_N are non-constant formal series.The unique solution X=(X_1,...,

Michael Yuan Sun

We give a semi-direct product decomposition of the point stabilisers for the enhanced and exotic nilpotent cones. In particular, we arrive at formulas for the number of points in each orbit over a finite field. This is in accordance with a recent conjecture of Achar and Henderson.

B. Baibussinov, E. Calligarich, S. Centro, D. Gibin

The LSND experiment has observed a 3.8 sigma excess of anti-nu_e events from an anti-nu_mu beam coming from pions at rest. If confirmed, the LSND anomaly would imply new physics beyond the standard model, presumably in the form of some additional sterile neutrinos. The MiniBooNE experiment at FNAL-Booster has further searched for the LSND anomaly. Above 475

Andras Nemethi, Agnes Szilard

Let f be a hypersurface surface local singularity whose zero set has 1-dimensional singular locus. We develop an explicit procedure that provides the boundary of the Milnor fibre of f as an oriented plumbed 3-manifold. The method provides the characteristic polynomial of the algebraic monodromy as well. Moreover, for any analytic germ g such that the pair (f

Kourosh Nozari, Tahereh Azizi

We investigate possible realization of the phantom-like behavior in the framework of $f(R)$-gravity models where there are no phantom fields in the matter sector of the theory. By adopting some observationally reliable ansatz for $f(R)$, we show that it is possible to realize phantom-like behavior in $f(R)$-gravity without introduction of phantom fields that

J. J. Honrubia, J. C. Fernandez, M. Temporal, B. M. Hegelich

Two-dimensional simulations of ion beam driven fast ignition are presented. Ignition energies of protons with Maxwellian spectrum and carbon ions with quasimonoenergetic and Maxwellian energy distributions are evaluated. The effect of the coronal plasma surrounding the compressed deuterium-tritium is studied for three different fuel density distributions. It

Andrew Niedermaier, Douglas Rizzolo, Francis Edward Su

In this paper we prove a combinatorial theorem for finite labellings of trees, and show that it is equivalent to a theorem for finite covers of metric trees and a fixed point theorem on metric trees. We trace how these connections mimic the equivalence of the Brouwer fixed point theorem with the classical KKM lemma and Sperner's lemma. We also draw conne

The HARP Collaboration, M. Apollonio, A. Artamonov, A. Bagulya

The HARP collaboration has presented measurements of the double-differential pi+/pi- production cross-section in the range of momentum 100 MeV/c <= p 800 MeV/c and angle 0.35 rad <= theta <= 2.15 rad with proton beams hitting thin nuclear targets. In many applications the extrapolation to long targets is necessary. In this paper the analysis of data taken wi

C. Barbieri

Preliminary ab-initio applications of many-body Green&#39;s functions theory to the ground state of He-4 suggest that high accuracy can be achieved in the so-called Faddeev-random-phase-approximation method. We stress the potentialities of this approach for microscopic studies of medium-large nuclei and report applications to 1s0d and 1p0f-shell nuclei. In p

Masahiro Shimano, Tomohiro Harada

In loop quantum cosmology there may be a super-inflation phase in the very early universe, in which a single scalar field with a negative power-law potential $V= -M^4(ϕ/M)^β$ plays important roles. Since the effective horizon $\sqrt{SD}/H$ controls the behavior of quantum fluctuation instead of the usual Hubble horizon, we assume the following inflation scen

G. Puddu

A simple and general prescription for evaluating unambiguously the sign of the grand-canonical trace of quasi-particle statistical density operators (the so-called sign ambiguity in taking the square root of determinants) is given. Sign ambiguities of this kind appear in the evaluation of the grand-canonical partition function projected to good quantum numbe

Matthieu Petelet, Bertrand Iooss, Olivier Asserin, Alexandre Loredo

In some studies requiring predictive and CPU-time consuming numerical models, the sampling design of the model input variables has to be chosen with caution. For this purpose, Latin hypercube sampling has a long history and has shown its robustness capabilities. In this paper we propose and discuss a new algorithm to build a Latin hypercube sample (LHS) taki

Luke Shulenburger, Sergey Y. Savrasov, R E Cohen

The crystal field splitting and d bandwidth of the 3d transition metal monoxides MnO, FeO, CoO and NiO are analyzed as a function of pressure within density functional theory. In all four cases the 3d bandwidth is significantly larger than the crystal field splitting over a wide range of compressions. The bandwidth actually increases more as pressure is incr

T. Nakano, N. Fujiwara, K. Tatsumi, H. Okada

Nuclear magnetic resonance (NMR) measurements of an iron (Fe)-based superconductor LaFeAsO_{1-x}F_x (x = 0.08 and 0.14) were performed at ambient pressure and under pressure. The relaxation rate 1/T_1 for the overdoped samples (x = 0.14) shows T-linear behavior just above T_c, and pressure application enhances 1/T_1T similar to the behavior of T_c. This impl

A. S. Rodin, M. M. Fogler

Hopping transport in a one-dimensional system is studied numerically. A fast algorithm is devised to find the lowest-resistance path at arbitrary electric field. Probability distribution functions of individual resistances on the path and the net resistance are calculated and fitted to compact analytic formulas. Qualitative differences between statistics of

Zhuo Chen, Mathieu Stienon, Ping Xu

For any regular Courant algebroid, we construct a characteristic class a la Chern-Weil. This intrinsic invariant of the Courant algebroid is a degree-3 class in its naive cohomology. When the Courant algebroid is exact, it reduces to the Severa class (in H^3_{DR}(M)). On the other hand, when the Courant algebroid is a quadratic Lie algebra g, it coincides wi

N. Bostani, N. Farhangkhah

We present the asymptotically AdS solutions of the Einstein gravity with hyperbolic horizons in the presence of $So(n(n-1)/2-1, 1)$ Yang-Mills fields governed by the non-Abelian Born-Infeld lagrangian. We investigate the properties of these solutions as well as their asymptotic behavior in varies dimensions. The properties of these kind of solutions are like

Victor J. W. Guo, Jiang Zeng

By using the Newton interpolation formula, we generalize the recent identities on the Catalan triangle obtained by Miana and Romero as well as those of Chen and Chu. We further study divisibility properties of sums of products of binomial coefficients and an odd power of a natural number. For example, we prove that for all positive integers $n_1, ..., n_m$,

Stephen Parrott

Precise definitions of &#34;weak [quantum] measurements&#34; and &#34;weak value&#34; [of a quantum observable] are offered, which seem to capture the meaning of the often vague ways that these terms are used in the literature. Simple finite dimensional examples are given showing that weak values of an observable are not unique, and in fact arbitrary weak va

Katsuaki Asano, Sylvain Guiriec, Peter Mészáros

A short gamma-ray burst GRB 090510 detected by {\it Fermi} shows an extra spectral component between 10 MeV and 30 GeV, an addition to a more usual low-energy ($<10$ MeV) Band component. In general, such an extra component could originate from accelerated protons. In particular, inverse Compton emission from secondary electron-positron pairs and proton synch

Kai-Uwe Bux, Mikhail Ershov, Andrei Rapinchuk

The goal of this paper is to give a group-theoretic proof of the congruence subgroup property for $Aut(F_2)$, the group of automorphisms of a free group on two generators. This result was first proved by Asada using techniques from anabelian geometry, and our proof is, to a large extent, a translation of Asada&#39;s proof into group-theoretic language. This

A. Sheykhi, A. Bagheri, M. M. Yazdanpanah

We suggest a correspondence between interacting agegraphic dark energy models and the quintessence scalar field in a non-flat universe. We demonstrate that the agegraphic evolution of the universe can be described completely by a single quintessence scalar field. Then, we reconstruct the potential of the interacting agegraphic quintessence dark energy as wel

Qing Lin, Bing He

We present a simple architecture for deterministic quantum circuits operating on single photon qubits. Few resources are necessary to implement two elementary gates and can be recycled for computing with large numbers of qubits. The deterministic realization of some key multi-qubit gates, such as the Fredkin and Toffoli gate, is greatly simplified in this ap

Manuel J. Freire, Lukas Jelinek, Ricardo Marques

In this work some possible applications of negative permeability magnetic metamaterial lenses for magnetic resonance imaging (MRI) are analyzed. Metamaterials are artificial composites designed to have a given permittivity and/or permeability, including negative values for these constants. It is shown that using magnetic metamaterials lenses it is possible t

Artur Ishkhanyan, Hiroki Nakamura

The strong-coupling limit of molecule formation in an atomic Bose-Einstein condensate via two-mode one-color photoassociation or sweep across a Feshbach resonance is examined using a basic nonlinear time-dependent two-state model. For the general class of term-crossing models with constant coupling, a common strategy for attacking the problem is developed ba

A. Ishkhanyan, R. Sokhoyan, B. Joulakian, K. -A. Suominen

The Rosen-Zener model for association of atoms in a Bose-Einstein condensate is studied. Using a nonlinear Volterra integral equation, we obtain an analytic formula for final probability of the transition to the molecular state for weak interaction limit. Considering the strong coupling limit of high field intensities, we show that the system reveals two dif

S. Riikonen, A. S. Foster, A. V. Krasheninnikov, R. M. Nieminen

In an attempt to understand why catalytic methods for the growth of boron nitride nanotubes work much worse than for their carbon counterparts, we use first-principles calculations to study the energetics of elemental reactions forming N2, B2 and BN molecules on an iron catalyst. We observe that in the case of these small molecules, the catalytic activity is

N. Nakasato

The kd-tree is a fundamental tool in computer science. Among others, an application of the kd-tree search (oct-tree method) to fast evaluation of particle interactions and neighbor search is highly important since computational complexity of these problems are reduced from O(N^2) with a brute force method to O(N log N) with the tree method where N is a numbe

A. M. Ishkhanyan, B. Joulakian, K. -A. Suominen

Two distinct strongly non-linear scenarios of molecule formation in an atomic Bose-Einstein condensate (either by photoassociation or Feshbach resonance) corresponding to large and small field detuning are revealed. By examining arbitrary external field configurations, we show that the association process in the first case is almost non-oscillatory in time w

A. K. McMahan, R. T. Scalettar, M. Jarrell

Spin and charge susceptibilities and the 4f^n, 4f^{n-1}, and 4f^{n+1} configuration weights are calculated for compressed Ce (n=1), Pr (n=2), and Nd (n=3) metals using dynamical mean field theory combined with the local-density approximation. At ambient and larger volumes these trivalent rare earths are pinned at sharp 4f^n configurations, their 4f moments a

C. R. O&#39;Dell, W. M. Goss

We have combined 327.5 MHz radio observations and optical spectroscopy to study conditions in the Extended Orion Nebula. We see a steady progression of characteristics with increasing distance from the dominant photoionizing star Theta1OriC. This progression includes a decrease in the F(Halpha)/F(Hbeta) ratio, an increase in the relative strength of scattere

Chandra Chekuri, Kenneth L. Clarkson, Sariel Har-Peled

We consider the set multi-cover problem in geometric settings. Given a set of points P and a collection of geometric shapes (or sets) F, we wish to find a minimum cardinality subset of F such that each point p in P is covered by (contained in) at least d(p) sets. Here d(p) is an integer demand (requirement) for p. When the demands d(p)=1 for all p, this is t

P. L. Overfelt, Klaus Halterman, Simin Feng, D. R. Bowling

In this paper the complex dispersion curves of the four lowest-order transverse magnetic modes of a dielectric Goubau line ($ε>0, μ>0$) are compared with those of a dispersive metamaterial Goubau line. The vastly different dispersion curve structure for the metamaterial Goubau line is characterized by unusual features such as mode bifurcation, complex fold p

N. Lugaz, A. Vourlidas, I. I. Roussev

We present general considerations regarding the derivation of the radial distances of coronal mass ejections (CMEs) from elongation angle measurements such as those provided by SECCHI and SMEI, focusing on measurements in the Heliospheric Imager 2 (HI-2) field of view (i.e. past 0.3 AU). This study is based on a three-dimensional (3-D) magneto-hydrodynamics

Scott F. Daniel

Cosmological departures from general relativity offer a possible explanation for the cosmic acceleration. To linear order, these departures (quantified by the model-independent parameter $\varpi$, referred to as a `gravitational slip&#39;) amplify or suppress the growth of structure in the universe relative to what we would expect to see from a general relat

TM Schneider, D Marinc, Bruno Eckhardt

We study the turbulence transition of plane Couette flow in large domains where localised perturbations are observed to generate growing turbulent spots. Extending previous studies on the boundary between laminar and turbulent dynamics we determine invariant structures intermediate between laminar and turbulent flow. In wide but short domains we find states