October 2010 arXiv papers — page 44

Luchezar L. Avramov, Inês B. Henriques, Liana M. Şega

Extending a notion defined for surjective maps by Blanco, Majadas, and Rodicio, we introduce and study a class of homomorphisms of commutative noetherian rings, which strictly contains the class of locally complete intersection homomorphisms, while sharing many of its remarkable properties.

Tore Opsahl, Bernie Hogan

Building on existing stochastic actor-oriented models for panel data, we employ a conditional logistic framework to explore growth mechanisms for tie creation in continuously-observed networks. This framework models the likelihood of tie formation distinguishing it from hazard models that consider time to tie formation. It enables multiple growth mechanisms

Alexander Braverman, Michael Finkelberg

Let G be a reductive group; in this note we give an interpretation of the dynamical Weyl group of of the Langlands dual group $\check{G}$ defined by Etingof and Varchenko in terms of the geometry of the affine Grassmannian Gr of G. In this interpretation the dynamical parameters of Etingof and Varchenko correspond to equivariant parameters with respect to ce

Leonardo Leitao, Ariel Megevand

The cosmological remnants of a first-order phase transition generally depend on the perturbations that the walls of expanding bubbles originate in the plasma. Several of the formation mechanisms occur when bubbles collide and lose their spherical symmetry. However, spherical bubbles are often considered in the literature, in particular for the calculation of

Marcis Auzinsh, Ruvin Ferber, Florian Gahbauer, Andrey Jarmola

We present and experimental and theoretical study of nonlinear magneto-optical resonances observed in the fluorescence to the ground state from the 7P_{3/2} state of cesium, which was populated directly by laser radiation at 455 nm, and from the 6P_{1/2} and 6P_{3/2} states, which were populated via cascade transitions that started from the 7P_{3/2} state an

Thomas Reichelt, Christian Sevenheck

We describe mirror symmetry for weak toric Fano manifolds as an equivalence of D-modules equipped with certain filtrations. We discuss in particular the logarithmic degeneration behavior at the large radius limit point, and express the mirror correspondence as an isomorphism of Frobenius manifolds with logarithmic poles. The main tool is an identification of

Thorsten Feldmann

We build on a recent paper by Grinstein, Redi and Villadoro, where a see-saw like mechanism for quark masses was derived in the context of spontaneously broken gauged flavour symmetries. The see-saw mechanism is induced by heavy Dirac fermions which are added to the Standard Model spectrum in order to render the flavour symmetries anomaly-free. In this lette

Marcus V. S. Bonança

We provide a path integral treatment of the decoherence process induced by a heat bath on a single particle whose dynamics is classically chaotic and show that the decoherence rate is given by the Lyapunov exponent. The loss of coherence is charaterized by the purity, which is calculated semiclassically within diagonal approximation, when the particle initia

Matteo Luca Ruggiero

We study spherically symmetric perturbations determined by alternative theories of gravity to the gravitational field of a central mass in General Relativity. In particular, we focus on perturbations in the form of power laws and calculate their effect on the secular variations of the orbital elements of a Keplerian orbit. We show that, to lowest approximati

Seyoung Kim, Insun Jo, Junghyo Nah, Z. Yao

Using a novel structure, consisting of two, independently contacted graphene single layers separated by an ultra-thin dielectric, we experimentally measure the Coulomb drag of massless fermions in graphene. At temperatures higher than 50 K, the Coulomb drag follows a temperature and carrier density dependence consistent with the Fermi liquid regime. As the t

S. Bittolo Bon, L. Valentini

We report a chemical free method for the reduction of graphene oxide (GO) thin films. It was observed how for GO films annealed in air the oxygen species desorb from the GO surface upon exposure to UV light and how the surface resistivity of such deoxygenated GO films decreases with increasing the exposure to the UV light. The obtained results open a clean a

M. Ahsan Zeb

It is argued that Trauzettel et al. [Phys. Rev. B 75, 035305 (2007)] made some mistakes in their calculations regarding the photon-assisted transport in graphene that lead to uncoupled sidebands and emergence of step-like features in dG/dV (G is differential conductance and V is the bias voltage). We discuss the relevant corrections and explain in detail how

L. E. Oxman, A. Z. Khoury

We investigate the topological structure of entangled qudits under unitary local operations. Different sectors are identified in the evolution, and their geometrical and topological aspects are analyzed. The geometric phase is explicitly calculated in terms of the concurrence. As a main result, we predict a fractional topological phase for cyclic evolutions

Stefan Hunn, Moritz Hiller, Andreas Buchleitner, Doron Cohen

We devise a microscopic scattering approach to probe the excitation spectrum of a Bose-Einstein condensate. We show that the experimentally accessible scattering cross section exhibits universal Ericson fluctuations, with characteristic properties rooted in the underlying classical field equations.

R. B. Neufeld

Recent experimental advances at the Relativistic Heavy Ion Collider (RHIC) and the large center-of-mass energies available to the heavy-ion program at the Large Hadron Collider (LHC) will enable strongly interacting matter at high temperatures and densities, that is, the quark-gluon plasma (QGP), to be probed in unprecedented ways. Among these exciting new p

Christian Corda

The potential realization of a gravitational wave (GW) astronomy in next years is a great challenge for the scientific community. By giving a significant amount of new information, GWs will be a cornerstone for a better understanding of the universe and of the gravitational physics. In this paper the author shows that the GW astronomy will permit to solve a

Martin Reinecke

Libpsht (or "library for Performant Spherical Harmonic Transforms") is a collection of algorithms for efficient conversion between spatial-domain and spectral-domain representations of data defined on the sphere. The package supports transforms of scalars as well as spin-1 and spin-2 quantities, and can be used for a wide range of pixelisations (incl

F. Darabi

We study the classical Euclidean wormhole solutions for the gravitational systems with minimally coupled pure Phantom field and minimally coupled Phantom field accompanied by perfect fluid. It is shown that such solutions do exist and then the general forms of the Phantom field potential are obtained for which there are classical Euclidean wormhole solutions

Xiaofei Qi, Jinchuan Hou

For any bipartite systems, a universal entanglement witness of rank-4 for pure states is obtained and a class of finite rank entanglement witnesses is constructed. In addition, a method of detecting entanglement of a state only by entries of its density matrix with respect to some product basis is obtained.

J. X. Lu, Shibaji Roy, Zhiguang Xiao

We study the thermodynamics and phase structure of asymptotically flat non-dilatonic as well as dilatonic black branes in a cavity in arbitrary dimensions ($D$). We consider the canonical ensemble and so the charge inside the cavity and the temperature at the wall are fixed. We analyze the stability of the black brane equilibrium states and derive the phase

John C. Baez, Mike Stay

Algorithmic entropy can be seen as a special case of entropy as studied in statistical mechanics. This viewpoint allows us to apply many techniques developed for use in thermodynamics to the subject of algorithmic information theory. In particular, suppose we fix a universal prefix-free Turing machine and let X be the set of programs that halt for this machi

R. Tsekov

Financial market dynamics is rigorously studied via the exact generalized Langevin equation. Assuming market Brownian self-similarity, the market return rate memory and autocorrelation functions are derived, which exhibit an oscillatory-decaying behavior with a long-time tail, similar to empirical observations. Individual stocks are also described via the ge

Qasem Exirifard

We introduce the the Triangular Ring (TR) resonator. We show that the difference between the clockwise and anti-clockwise resonant frequencies of a vacuum TR resonator is sensitive to the birefringence parity-odd parameters of the photon's sector of the minimal Standard Model Extension (mSME): the Standard Model plus all the perturbative parameters encod

Qasem Exirifard

We calculate the birefringent in the vacuum for light at the leading and sub-leading orders for the CPT-even part of the SME. We report that all the LIV coefficients absent in the leading order, but the isotropic one, contributes to the sub-leading order birefringent. We consider models free of the first order birefringent. We then show that infrared, optica

Geoffrey L. Sewell

We employ a novel thermodynamical argument to show that, at the macroscopic level,there is no intrinsic law of temperature transformation under Lorentz boosts. This result extends the corresponding microstatistical one of earlier works to the purely macroscopic regime and signifies that the concept of temperature as an objective entity is restricted to the d

Ying Xu, Gemma De las Cuevas, Wolfgang Dür, Hans J. Briegel

We show that the partition function of many classical models with continuous degrees of freedom, e.g. abelian lattice gauge theories and statistical mechanical models, can be written as the partition function of an (enlarged) four-dimensional lattice gauge theory (LGT) with gauge group U(1). This result is very general that it includes models in different di

Jean Schneider

Reply to A Comment on The Far Future of Exoplanet Direct Characterization - the Case for Interstellar Space Probess by Ian Crawford. The paper The Far Future of Exoplanet Direct Characterization resulted from the collective work of TE-SAT, a team appointed by ESA in 2003 to assess a strategy to find and characterize Terrestrial Exoplanets. The interstellar f

Manuel Bello-Hernández, Manuel Benito, Emilio Fernández

We find a polynomial in three variables whose values at nonnegative integers satisfy the Erdős-Straus Conjecture. Although the perfect squares are not covered by these values, it allows us to prove that there are arbitrarily long sequence of consecutive numbers satisfying the Erdős-Straus Conjecture. We conjecture that the values of this polynomial include a

Sander Wolters

The aim of this paper is to compare the two topos-theoretic approaches to quantum mechanics that may be found in the literature to date. The first approach, which we will call the contravariant approach, was originally proposed by Isham and Butterfield, and was later extended by Doering and Isham. The second approach, which we will call the covariant approac

Shengtian Yang, Thomas Honold, Yan Chen, Zhaoyang Zhang

The average weight distribution of a regular low-density parity-check (LDPC) code ensemble over a finite field is thoroughly analyzed. In particular, a precise asymptotic approximation of the average weight distribution is derived for the small-weight case, and a series of fundamental qualitative properties of the asymptotic growth rate of the average weight

Chih-Hao Hsia, Sun Kwok, Yong Zhang, Nico Koning

High-resolution HST imaging of the compact planetary nebula NGC 6644 has revealed two pairs of bipolar lobes and a central ring lying close to the plane of the sky. From mid-infrared imaging obtained with the Gemini Telescope, we have found a dust torus which is oriented nearly perpendicular to one pair of the lobes. We suggest that NGC 6644 is a multipolar

Timo Karg

The South Pole Acoustic Test Setup (SPATS) has been deployed to study the feasibility of acoustic neutrino detection in Antarctic ice around the South Pole. An array of four strings equipped with acoustic receivers and transmitters, permanently installed in the upper 500 m of boreholes drilled for the IceCube neutrino observatory, and a retrievable transmitt

Kenji Fukukawa, Yoshikazu Fujiwara

The S-wave effective range parameters of the neutron-deuteron (nd) scattering are derived in the Faddeev formalism, using a nonlocal Gaussian potential based on the quark-model baryon-baryon interaction fss2. The spin-doublet low-energy eigenphase shift is sufficiently attractive to reproduce predictions by the AV18 plus Urbana three-nucleon force, yielding

Gianfranco Bertone, Kyoungchul Kong, Roberto Ruiz de Austri, Roberto Trotta

In theories with Universal Extra-Dimensions (UED), the gamma_1 particle, first excited state of the hypercharge gauge boson, provides an excellent Dark Matter (DM) candidate. Here we use a modified version of the SuperBayeS code to perform a Bayesian analysis of the minimal UED scenario, in order to assess its detectability at accelerators and with DM experi

Jixiang Fu, Zhizhang Wang, Damin Wu

In this paper we prove the existence and uniqueness of the form-type Calabi-Yau equation on Kähler manifolds of nonnegative orthogonal bisectional curvature.

Xin Li, Zhe Chang

Within the framework of projective geometry, we investigate kinematics and symmetry in $(α,β)$ spacetime-one special types of Finsler spacetime. The projectively flat $(α,β)$ spacetime with constant flag curvature is divided into four types. The symmetry in type A-Riemann spacetime with constant sectional curvature is just the one in de Sitter special relati

Salah Menouar, Mustapha Maamache, Jeong Ryeol Choi

A general treatment of the quantal time-dependent coupled oscillators in presence of the variable magnetic field is presented. The treatment is based on the use of an alternative canonical transformations, time-dependent unitary transformations and the invariant methods. Exact wave functions for Schrödinger equations of this system are constructed.We applied

A. E. Blinov, A. S. Rudenko

The total cross-sections of the reaction e+e- --> W+W-, as measured at LEP-II at centre-of-mass energies between 183 and 207 GeV are used to derive the upper limits on the parameters of CP-violating (P-odd and C-even) triple gauge-boson couplings WWγand WWZ. The 95% CL limits |\widetildeκ_Z|<0.13 and |\widetildeλ_Z|<0.31 are obtained assuming local SU(2)_L x

Takemi Yamada, Yoshiaki Ōno

We investigate the metamagnetism in the periodic Anderson model with the $\bm{k}$-dependent $c-f$ mixing by using the dynamical mean-field theory combined with the exact diagonalization method. It is found that both effects of the $\bm{k}$-dependent $c-f$ mixing and strong correlation due to the Coulomb interaction between $f$ electrons are significant for d

Jixiang Fu, Zhizhang Wang, Damin Wu

In this paper, we generalize the Gauduchon metrics on a compact complex manifold and define the $γ_k$ functions on the space of its hermitian metrics.

P. Kurzynski, T. Paterek, R. Ramanathan, W. Laskowski

We present a method to derive Bell monogamy relations by connecting the complementarity principle with quantum non-locality. The resulting monogamy relations are stronger than those obtained from the no-signaling principle alone. In many cases, they yield tight quantum bounds on violation of single and multiple qubit correlation Bell inequalities. In contras

Claudio Coriano, Marco Guzzi, Antonio Mariano

We compute the dark matter relic densities of neutralinos and axions in a supersymmetric model with a gauged anomalous U(1) symmetry, kinetically mixed with $U(1)_Y$ of hypercharge. The model is a variant of the USSM (the U(1) extended NMSSM), containing an extra U(1) symmetry and an extra singlet in the superpotential respect to the MSSM, where gauge invari

Mickael Loire, Virginie Simonet, Sylvain Petit, Karol Marty

The spin wave excitations emerging from the chiral helically modulated 120$^{\circ}$ magnetic order in a langasite Ba$_3$NbFe$_3$Si$_2$O$_{14}$ enantiopure crystal were investigated by unpolarized and polarized inelastic neutron scattering. A dynamical fingerprint of the chiral ground state is obtained, singularized by (i) spectral weight asymmetries answera

Elias Tsigaridas

We consider the problem of isolating the real roots of a square-free polynomial with integer coefficients using (variants of) the continued fraction algorithm (CF). We introduce a novel way to compute a lower bound on the positive real roots of univariate polynomials. This allows us to derive a worst case bound of $\sOB(d^6 + d^4τ^2 + d^3τ^2)$ for isolating

Kiwamu Watanabe

In this paper, we investigate the minimal length of chains of minimal rational curves needed to join two general points on a Fano manifold of Picard number 1. In particular, we give a sharp bound of the length by a fundamental argument. As an application, we compute the length for Fano manifolds of dimension < 8.

Tom Braden, Anthony Licata, Nicholas Proudfoot, Ben Webster

We study the representation theory of the invariant subalgebra of the Weyl algebra under a torus action, which we call a "hypertoric enveloping algebra." We define an analogue of BGG category O for this algebra, and identify it with a certain category of sheaves on a hypertoric variety. We prove that a regular block of this category is highest weight and Kos

J. D. Bray, R. D. Ekers, P. Roberts, J. E. Reynolds

LUNASKA (Lunar UHE Neutrino Astrophysics with the Square Kilometre Array) is an ongoing project conducting lunar Cherenkov observations in order to develop techniques for detecting neutrinos with the next generation of radio telescopes. Our current observing campaign is with the 64-metre Parkes radio telescope, using a multibeam receiver with 300 MHz of band

Zoran Sunic, Enric Ventura

(Free-abelian)-by-free, self-similar groups generated by finite self-similar sets of tree automorphisms and having unsolvable conjugacy problem are constructed. Along the way, orbit undecidable, free subgroups of GL_d(Z), for d > 5, and Aut(F_d), for d > 4, are constructed as well.

Xiao-Ye Xu, Jin-Shi Xu, Chuan-Feng Li, Guang-Can Guo

By using photon pairs created in parametric down conversion, we report on an experiment, which demonstrates that measurement can recover the quantum entanglement of two qubit system in a pure dephasing environment. The concurrence of the final state with and without measurement are compared and analyzed. Furthermore, we verify that recovered states can still

Li Guo, Fang Li

This article studies the Lie algebra $Diff(KΓ)$ of derivations on the path algebra $KΓ$ of a quiver $Γ$ and the Lie algebra on the first Hochschild cohomology group $H^1(KΓ)$. We relate these Lie algebras to the algebraic and combinatorial properties of the path algebra. Characterizations of derivations on a path algebra are obtained, leading to a canonical

Valeri P. Frolov, Pavel Krtous

We study charged particle motion in weakly charged higher dimensional black holes. To describe the electromagnetic field we use a test field approximation and use the higher dimensional Kerr-NUT-(A)dS metric as a background geometry. It is shown that for a special configuration of the electromagnetic field the equations of motion of charged particles are com

R. Lavín, J. C. Denardin, J. Escrig, D. Altbir

The angular dependence of the remanence and coercivity of Ni nanowire arrays produced inside the pores of anodic alumina membranes has been studied. By comparing our analytical calculations with our measurements, we conclude that the magnetization reversal in this array is driven by means of the nucleation and propagation of a transverse wall. A simple model

Joseph A. Muñoz, Abraham Loeb

We model the latest HST WFPC3/IR observations of > 100 galaxies at redshifts z=7-8 in terms of a hierarchical galaxy formation model with starburst activity. Our model provides a distribution of UV luminosities per dark matter halo of a given mass and a natural explanation for the fraction of halos hosting galaxies. The observed luminosity function is best f

Barbara T. Ferreira

This thesis investigates phenomena occurring in black-hole accretion discs which are likely to induce high-frequency quasi-periodic variability. Two classes of pseudo-relativistic theoretical models are studied. The first is based on the stability of transonic accretion flows and its connection to a disc instability that takes the form of propagating waves (

B. Leighton, O. J. Suarez, P. Landeros, J. Escrig

The magnetic configurations of barcode-type magnetic nanostructures consisting of alternate ferromagnetic and nonmagnetic layers arranged within a multilayer nanotube structure are investigated as a function of their geometry. Based on a continuum approach we have obtained analytical expressions for the energy which lead us to obtain phase diagrams giving th

John M. Neuberger, Nandor Sieben, James W. Swift

We seek solutions $u\in\R^n$ to the semilinear elliptic partial difference equation $-Lu + f_s(u) = 0$, where $L$ is the matrix corresponding to the Laplacian operator on a graph $G$ and $f_s$ is a one-parameter family of nonlinear functions. This article combines the ideas introduced by the authors in two papers: a) {\it Nonlinear Elliptic Partial Differenc

Hauyu Baobab Liu, Paul T. P. Ho, Qizhou Zhang, Eric Keto

This is the first paper of our series of high resolution (1&#34;) studies of the massive star forming region G10.6--0.4. We present the emission line observations of the hot core type tracers (O$^{13}$CS, OCS, SO$_{2}$) with $\sim$0$&#34;$.5 resolution. By comparing the results to the high--resolution NH$_{3}$ absorption line observation, we confirm for the

Jonathan Browder

We show that if a $d$-dimensional Cohen-Macaulay complex is, in a certain sense, sufficiently &#34;close&#34; to being balanced, then there is a $d$-dimensional balanced Cohen-Macaulay complex having the same $f$-vector. This in turn provides some partial evidence for a conjecture of Kalai on the $f$-vectors of Cohen-Macaulay flag complexes.

Florian Elste, David R. Reichman, Andrew J. Millis

We study the effect of a dot-lead interaction on transport through a quantum dot hybridized to two semi-infinite Luttinger-liquid leads. A bosonization approach is applied to treat the interaction between charge fluctuations on the dot and the dynamically generated image charge in the leads. The nonequilibrium distribution function of the dot and the tunneli

Richard J. Mathar

The Clebsch--Gordan coefficients of the Kronecker products of the irreducible representations of the Quaternion Group Q8, of the Generalized Quaternion Groups Q16 and Q32, and of the factor group (Q32 X Q32)/{(1,1),(-1,-1)} are computed as eigenvectors of a well-known matrix of triple-products of the irreducible representations.

V. Petit

The presence of magnetic fields at the surfaces of many massive stars has been suspected for decades, to explain the observed properties and activity of OB stars. However, very few genuine high-mass stars had been identified as magnetic before the advent of a new generation of powerful spectropolarimeters that has resulted in a rapid burst of precise informa

Ian R. Manchester, Mark M. Tobenkin, Michael Levashov, Russ Tedrake

This paper illustrates the application of recent research in region-of-attraction analysis for nonlinear hybrid limit cycles. Three example systems are analyzed in detail: the van der Pol oscillator, the &#34;rimless wheel&#34;, and the &#34;compass gait&#34;, the latter two being simplified models of underactuated walking robots. The method used involves de

Panagiotis Stinis

We present numerical results for the solution of the 1D critical nonlinear Schrodinger with periodic boundary conditions and initial data that give rise to a finite time singularity. We construct, through the Mori-Zwanzig formalism, a reduced model which allows us to follow the solution after the formation of the singularity. The computed post-singularity so

V. Petit, D. L. Massa, W. L. F. Marcolino, G. A. Wade

The B0.2 V magnetic star tau Sco stands out from the larger population of massive magnetic OB stars due to its remarkable, superionized wind, apparently related to its peculiar magnetic field - a field which is far more complex than the mostly-dipolar fields usually observed in magnetic OB stars. tau Sco is therefore a puzzling outlier in the larger picture

V. Petit, G. A. Wade, E. Alecian, L. Drissen

In some massive stars, magnetic fields are thought to confine the outflowing radiatively-driven wind. Although theoretical models and MHD simulations are able to illustrate the dynamics of such a magnetized wind, the impact of this wind-field interaction on the observable properties of a magnetic star - X-ray emission, photometric and spectral variability -

Isaac Goldbring

Let H be an infinite-dimensional (real or complex) Hilbert space, viewed as a metric structure in its natural signature. We characterize the definable linear operators on H as exactly the &#34;scalar plus compact&#34; operators.

P. M. Ricker, K. -C. Pan, R. E. Taam

We present adaptive mesh refinement (AMR) hydrodynamical simulations of the interaction between Type Ia supernovae and their companion stars within the context of the single-degenerate model. Results for 3D red-giant companions without binary evolution agree with previous 2D results by Marietta et al. We also consider evolved helium-star companions in 2D. Fo

Ian R. Manchester

This paper presents an algorithm for computing inner estimates of the regions of attraction of limit cycles of a nonlinear hybrid system. The basic procedure is: (1) compute the dynamics of the system transverse to the limit cycle; (2) from the linearization of the transverse dynamics construct a quadratic candidate Lyapunov function; (3) search for a new Ly

Agnieszka Ryś, Jesús Falcón-Barroso, Mina Koleva

Dwarf elliptical galaxies are the most common galaxy type in nearby galaxy clusters, yet they remain relatively poorly studied objects and many of their basic properties have yet to be quantified. In this contribution we present the preliminary results of a study of 4 Virgo and 1 field galaxy obtained with the SAURON integral field unit on the William Hersch

Eric F. Bell, Xiang Xiang Xue, Hans-Walter Rix, Christine Ruhland

If the stellar halos of disk galaxies are built up from the disruption of dwarf galaxies, models predict highly structured variations in the stellar populations within these halos. We test this prediction by studying the ratio of blue horizontal branch stars (BHB stars; more abundant in old, metal-poor populations) to main-sequence turn-off stars (MSTO stars

P. Daniel Meerburg

There exist several models of inflation that produce primordial bispectra that contain a large number of oscillations. In this paper we discuss these models, and aim at finding a method of detecting such bispectra in the data. We explain how the recently proposed method of mode expansion of bispectra might be able to reconstruct these spectra from separable

Damir D. Dzhafarov

The stable Ramsey&#39;s theorem for pairs has been the subject of numerous investigations in mathematical logic. We introduce a weaker form of it by restricting from the class of all stable colorings to subclasses of it that are non-null in a certain effective measure-theoretic sense. We show that the sets that can compute infinite homogeneous sets for non-n

The BABAR Collaboration, P. del Amo Sanchez et al

We report the result of a search for the rare decay B^0 -> gamma gamma in 426 fb-1 of data, corresponding to 226 million B^0 \bar{B}^0 pairs, collected on the Upsilon(4S) resonance at the PEP-II asymmetric-energy e+e- collider using the BABAR detector. We use a maximum likelihood fit to extract the signal yield and observe 21^{+13}_{-12} signal events with s

Carl P. Dettmann, Edson D. Leonel

We consider time-dependence of dynamical transport, following a recent study of the stadium billiard in which classical transmission and reflection probabilities were shown to exhibit exponential or algebraic decay depending on the choice of the lead or &#34;hole&#34;. The system considered here is much more general, having a generic mixed phase space struct

R. Tripathi, A. Bonasera, S. Wuenschel, L. W. May

The critical phenomena of the liquid-gas phase transition has been investigated in the reactions 78,86Kr+58,64Ni at beam energy of 35 MeV/nucleon using the Landau free energy approach with isospin asymmetry as an order parameter. Fits to the free energy of fragments showed three minima suggesting the system to be in the regime of a first order phase transiti

P. A. Sturrock, J. B. Buncher, E. Fischbach, J. T. Gruenwald

Evidence for an anomalous annual periodicity in certain nuclear decay data has led to speculation concerning a possible solar influence on nuclear processes. We have recently analyzed data concerning the decay rates of Cl-36 and Si-32, acquired at the Brookhaven National Laboratory (BNL), to search for evidence that might be indicative of a process involving

A. W. Fullerton, V. Petit, S. Bagnulo, G. A. Wade

Spectropolarimetric observations of HD 155806 - the hottest Galactic Oe star - were obtained with CFHT/ESPaDOnS to test the hypothesis that disk signatures in its spectrum are due to magnetic channeling and confinement of its stellar wind. We did not detect a dipole field of sufficient strength to confine the wind, and could not confirm previous reports of a

Lavi Karp

We study a moving boundary problem modeling an injected fluid into another viscous fluid. The viscous fluid is withdrawn at infinity and governed by Darcy&#39;s law. We present solutions to the free boundary problem in terms of time-derivative of a generalized Newtonian potentials of the characteristic function of the bubble. This enables us to show that the

Michael Hochman, Artur Siemaszko

We show that if (X,T) is a topological dynamical system with is deterministic in the sense of Kamiski, Siemaszko and Szymaski then T^{-1} and the product system need not be determinstic in this sense. However if the product system is deterministic then T^n is deterministic for all integers n>0.

Damir D. Dzhafarov

We generalize the notion of saturated order to infinite partial orders and give both a set-theoretic and an algebraic characterization of such orders. We then study the proof theoretic strength of the equivalence of these characterizations in the context of reverse mathematics, showing that depending on one&#39;s choice of definitions it is either provable i

Andreas Fring, Monique Smith

We provide a construction procedure for complex root spaces invariant under antilinear transformations, which may be applied to any Coxeter group. The procedure is based on the factorisation of a chosen element of the Coxeter group into two factors. Each of the factors constitutes an involution and may therefore be deformed in an antilinear fashion. Having t

J. Fritz, B. M. Poggianti, A. Cava, T. Valentinuzzi

The WIde-field Nearby Galaxy clusters Survey (WINGS) is a project whose primary goal is to study the galaxy populations in clusters in the local universe (z<0.07) and of the influence of environment on their stellar populations. This survey has provided the astronomical community with a high quality set of photometric and spectroscopic data for 77 and 48 nea

Akram Hasani Zonoozi, Andreas H. W. Kuepper, Holger Baumgardt, Hosein Haghi

We present the first ever direct $N$-body computations of an old Milky Way globular cluster over its entire life time on a star-by-star basis. Using recent GPU hardware at Bonn University, we have performed a comprehensive set of $N$-body calculations to model the distant outer halo globular cluster Palomar 14 (Pal 14). By varying the initial conditions we a

Chee Sheng Fong, M. C. Gonzalez-Garcia, J. Racker

We present an explicit computation of the CP asymmetry in scattering processes involving the heavy right-handed neutrinos of the type I seesaw framework and the Standard Model gauge bosons. Compared to CP violation in two--body decays and in scatterings with top quarks there are new contributions at one loop in the form of new type of vertex corrections as w

Carsten Weidner, Jorick Vink

Context. The &#34;mass discrepancy&#34; in massive O stars represents a long-standing problem in stellar astrophysics with far-reaching implications for the chemical and dynamical feedback in galaxies. Aims. Our goal is to investigate this mass discrepancy by comparing state-of-the-art model masses with model-independent masses determined from eclipsing bina

M. Boquien, P. -A. Duc, F. Galliano, J. Braine

During galaxy-galaxy interactions, massive gas clouds can be injected into the intergalactic medium which in turn become gravitationally bound, collapse and form stars, star clusters or even dwarf galaxies. The objects resulting from this process are both &#34;pristine&#34;, as they are forming their first generation of stars, and chemically evolved because

S. E. de Mink, N. Langer, R. G. Izzard

Stellar models of massive single stars are still plagued by major uncertainties. Testing and calibrating against observations is essential for their reliability. For this purpose one preferably uses observed stars that have never experienced strong binary interaction, i.e. &#34;true single stars&#34;. However, the binary fraction among massive stars is high

David S. Spiegel

Although our solar system features predominantly circular orbits, the exoplanets discovered so far indicate that this is the exception rather than the rule. This could have crucial consequences for exoplanet climates, both because eccentric terrestrial exoplanets could have extreme seasonal variation, and because giant planets on eccentric orbits could excit

Hai-Jun Zhang, Stanislav Chadov, Lukas Müchler, Binghai Yan

One of the most exciting subjects in solid state physics is a single layer of graphite which exhibits a variety of unconventional novel properties. The key feature of its electronic structure are linear dispersive bands which cross in a single point at the Fermi energy. This so-called Dirac cone is closely related to the surface states of the recently discov

Kordian Lärz

A parallel lightlike vector field on a Lorentzian manifold $X$ naturally defines a foliation $\mathcal{F}$ of codimension one. If either all leaves of $\mathcal{F}$ are compact or $X$ itself is compact admitting a compact leaf and the (transverse) Ricci curvature is non-negative then a Bochner type argument implies that the first Betti number of $X$ is bound

Igor Rivin

We give a very short proof of the Golden-Thompson inequality

Germain Rousseaux, Philippe Maïssa

We study the propagation of surface waves on a current in the presence of an electromagnetic field. A horizontal (vertical) field strengthens (weakens) the counter-current which blocks the waves. We compute the phase space diagrams (blocking velocities versus period of the waves) with and without surface tension. Three new dimensionless numbers are introduce

L. Spadafora, G. P. Berman, F. Borgonovi

In the Black-Scholes context we consider the probability distribution function (PDF) of financial returns implied by volatility smile and we study the relation between the decay of its tails and the fitting parameters of the smile. We show that, considering a scaling law derived from data, it is possible to get a new fitting procedure of the volatility smile

S. Post, A. M. Grundland

In this paper, we study rank-1 projector solutions to the completely integrable Euclidean $CP^{N-1}$ sigma model in two dimension and their associated surfaces immersed in the $su(N)$ Lie algebra. We reinterpret and generalize the proof of A.M. Din and W.J. Zakzrewski [1980] that any solution for the $CP^{N-1}$$ sigma model defined on the Riemann sphere with

Miriam Garcia, Artemio Herrero, Norberto Castro, Luis Corral

The important role of metallicity on massive star evolution and the combination of multi-object spectrographs and 10m class telescopes, have lead to numerous systematic studies of massive stars in Local Group galaxies. While color based quests of blue massive stars are relatively successful, they must be confirmed with spectroscopy and usually lead to lists

Jacob Tsimerman

We prove the existence of an Abelian variety $A$ of dimension $g$ over $\Qa$ which is not isogenous to any Jacobian, subject to the necessary condition $g>3$. Recently, C.Chai and F.Oort gave such a proof assuming the André-Oort conjecture. We modify their proof by constructing a special sequence of CM points for which we can avoid any unproven hypotheses. W

M. Döring

The recently discovered enhancement of eta photoproduction on the quasi-free neutron at energies around s^1/2 ~ 1.67 GeV is addressed within an SU(3) coupled channels model. The K Sigma threshold plays a significant role and the quasi-free cross sections on proton and neutron, sigma_n and sigma_p, can be quantitatively explained. For the reaction gamma p -->

Wanxiang Feng, Di Xiao, Ying Zhang, Yugui Yao

We systematically investigate the topological band structures of half-Heusler compounds using first-principles calculations. The modified Becke-Johnson exchange potential together with local density approximation for the correlation potential (MBJLDA) has been used here to obtain accurate band inversion strength and band order. Our results show that a large

Miriam Garcia, Francisco Najarro, Artemio Herrero

The theory of radiatively driven winds successfully explains the key points of the stellar winds of hot massive stars. However, there is an apparent break-down of this paradigm at L/Lsun<5.2: the stellar wind momentum is smaller than predicted for low luminosity early-type stars from metal poor environments, and there are also some Galactic examples. In this

S. E. de Mink, M. Cantiello, N. Langer, O. R. Pols

Rotation can have severe consequences for the evolution of massive stars. It is now considered as one of the main parameters, alongside mass and metallicity that determine the final fate of single stars. In massive, fast rotating stars mixing processes induced by rotation may be so efficient that helium produced in the center is mixed throughout the envelope