February 2009 arXiv papers — page 4

Claus-Peter Wirth, Joerg Siekmann, Christoph Benzmueller, Serge Autexier

We give some lectures on the work on formal logic of Jacques Herbrand, and sketch his life and his influence on automated theorem proving. The intended audience ranges from students interested in logic over historians to logicians. Besides the well-known correction of Herbrand's False Lemma by Goedel and Dreben, we also present the hardly known unpublish

C. Stoica

In the present article we intend to accomplish a rigorous analysis which allows to elaborate useful symbolic and numerical codes leading to an accurate evaluation of the thermal radiation. We will consider the case of the electromagnetic field in axially symmetric systems, a case of real interest in cryogenics.

L. M. Dieng

In this work, we expand the idea of Samuelson[3] and Shepp[2,5,6] for stock optimization using the Bachelier model [4] as our models for the stock price at the money (X[stock price]= K[strike price]) for the American call and put options [1]. At the money (X= K) for American options, the expected payoff of both the call and put options is zero. Shepp investi

G. Gentili, C. Stoppato

We study power series and analyticity in the quaternionic setting. We first consider a function f defined as the sum of a quaternionic power series centered at 0 in its domain of convergence (which is a ball B(0,R) centered at 0). At each point p of this ball, f admits expansions in terms of appropriately defined 'regular power series centered at p'.

Fabio Riccioni, Peter West

We give a method of deriving the field-strengths of all massless and massive maximal supergravity theories in any dimension starting from the Kac-Moody algebra $E_{11}$. Considering the subalgebra of $E_{11}$ that acts on the fields in the non-linear realisation as a global symmetry, we show how this is promoted to a gauge symmetry enlarging the algebra by t

Graham G Ross, Gabriel German

A spontaneously broken global discrete symmetry may have pseudo Goldstone modes associated with the spontaneous breaking of the approximate continuous symmetry of the low dimension terms in the Lagrangian. These provide natural candidates for an inflaton that can generate slow roll inflation. We show that, in the case of a non Abelian discrete symmetry, the

Nicolas Yunes, Frans Pretorius

The low-energy limit of string theory contains an anomaly-canceling correction to the Einstein-Hilbert action, which defines an effective theory: Chern-Simons (CS) modified gravity. The CS correction consists of the product of a scalar field with the Pontryagin density, where the former can be treated as a background field (non-dynamical formulation) or as a

Victor Przyjalkowski

The paper is joined with arXiv:0911.5428 and improved. We prove that Landau-Ginzburg models for all 17 smooth Fano threefolds with Picard rank 1 can be represented as Laurent polynomials in 3 variables exhibiting them case by case. We check that these Landau-Ginzburg models can be compactified to open Calabi-Yau varieties. In the spirit of L. Katzarkov's pro

Gaetan Bisson, Andrew V. Sutherland

We present two algorithms to compute the endomorphism ring of an ordinary elliptic curve E defined over a finite field F_q. Under suitable heuristic assumptions, both have subexponential complexity. We bound the complexity of the first algorithm in terms of log q, while our bound for the second algorithm depends primarily on log |D_E|, where D_E is the discr

L. Feher, P. A. Horvathy

The Kepler-type dynamical symmetries of the Kaluza-Klein monopole are reviewed. At the classical level, the conservation of the angular momentum and of a Runge-Lenz vector imply that the trajectories are conic sections. The o(4) algebra allows us to calculate the bound-state spectrum, and the o(3,1) algebra yields the scattering matrix. The symmetry algebra

Darryl Leiter

In order to describe the quantum electrodynamic measurement process in a relativistic observer-participant manner, an operator symmetry of "microscopic observer-participation" called Measurement Color (MC) is incorporated into the field theoretic structure of Quantum Electrodynamics (QED) in the Heisenberg Picture. It is found that the resultant Meas

Xiang-Bin Wang, Lin Yang, Cheng-Zhi Peng, Jian-Wei Pan

We show how to calculate the fraction of single photon counts of the 3-intensity decoy-state quantum cryptography faithfully with both statistical fluctuations and source errors. Our results only rely on the bound values of a few parameters of the states of pulses.

Vernon Barger, Lisa Everett, Jing Jiang, Paul Langacker

We present a correlated analysis for the $ΔB =1, 2$ processes which occur via $b\to s$ transitions within models with a family non-universal $U(1)^\prime$. We take a model-independent approach, and only require family universal charges for the first and second generations and small fermion mixing angles. The results of our analysis show that within this clas

Emmerich Tempfli, Sascha Zöllner, Peter Schmelcher

We investigate the ground state of one-dimensional few-atom Bose-Bose mixtures under harmonic confinement throughout the crossover from weak to strong inter-species attraction. The calculations are based on the numerically exact multi-configurational time-dependent Hartree method. For repulsive components we detail the condition for the formation of a molecu

Piero Nicolini, Euro Spallucci

We provide a new exact solution of the Einstein equations which generalizes the noncommutative geometry inspired Schwarzschild metric, we previously obtained. We consider here more general relations between the energy density and the radial pressure and find new a geometry describing a regular ``dirty black hole''. We discuss strong and weak energy condition

Thilo Kopp, Jochen Mannhart

The equation describing the capacitance of capacitors is determined. It is shown that by optimizing the material of the conducting electrodes, the capacitance of capacitors reaching the quantum regime can be substantially enhanced or reduced. Dielectric capacitors with negative total capacitances are suggested and their properties analyzed. Resulting perspec

B. Georgeot, F. Mila

We show that the chirality of triangular antiferromagnetic clusters can be used as a qubit even if it is entirely decoupled from the total spin of the cluster. In particular, we estimate the orbital moment associated to the chirality, and we show that it can be large enough to allow a direct measurement of the chirality with a field perpendicular to the clus

Paola Gava, Michele Lazzeri, A. Marco Saitta, Francesco Mauri

The electronic properties of doped bilayer graphene in presence of bottom and top gates have been studied and characterized by means of Density Functional Theory calculations. Varying independently the bottom and top gates it is possible to control separately the total doping charge on the sample, and the average external electric field acting on the bilayer

Jörn Dunkel, Peter Hänggi, Stefan Hilbert

The unification of relativity and thermodynamics has been a subject of considerable debate over the last 100 years. The reasons for this are twofold: (i) Thermodynamic variables are nonlocal quantities and, thus, single out a preferred class of hyperplanes in spacetime. (ii) There exist different, seemingly equally plausible ways of defining heat and work in

J. H. Bardarson, M. Titov, P. W. Brouwer

We compare the conductance of an undoped graphene sheet with a small region subject to an electrostatic gate potential for the cases that the dynamics in the gated region is regular (disc-shaped region) and classically chaotic (stadium). For the disc, we find sharp resonances that narrow upon reducing the area fraction of the gated region. We relate this obs

Andrew Parrish

We show that for each Orlicz space properly contained in L^1 there is a sequence along which the ergodic averages converge for functions in the Orlicz space, but diverge for all f in L^1. This extends the work of K. Reinhold, who, building on the work of A. Bellow,constructed a sequence for which the averages converge a.e. for every f in L^p, p>q, but diverg

P. Anders, H. Baumgardt, N. Bissantz, S. Portegies Zwart

N-body simulations are widely used to simulate the dynamical evolution of a variety of systems, among them star clusters. Much of our understanding of their evolution rests on the results of such direct N-body simulations. They provide insight in the structural evolution of star clusters, as well as into the occurrence of stellar exotica. Although the major

G. Braeunlich, G. M. Graf, G. Ortelli

The Schroedinger equation with a potential periodically varying in time is used to model adiabatic quantum pumps. The systems considered may be either infinitely extended and gapped or finite and connected to gapless leads. Correspondingly, two descriptions of the transported charge, one relating to a Chern number and the other to a scattering matrix, have b

Jeff Achter, Rachel Pries

We prove results about the intersection of the p-rank strata and the boundary of the moduli space of hyperelliptic curves in characteristic p > 2. Using this, we prove that the Z/\ell-monodromy of every irreducible component of the stratum H_g^f of hyperelliptic curves of genus g and p-rank f is the symplectic group Sp_{2g}(Z/\ell) if g > 2, f > 0 and \ell i

Gerard Clement

We investigate stationary, rotationally symmetric solutions of a recently proposed three-dimensional theory of massive gravity. Along with BTZ black holes, we also obtain warped AdS_3 black holes, and (for a critical value of the cosmological constant) AdS_2 x S^1 as solutions. The entropy, mass and angular momentum of these black holes are computed.

Dario Benedetti, Pedro F. Machado, Frank Saueressig

We use functional renormalization group methods to study gravity minimally coupled to a free scalar field. This setup provides the prototype of a gravitational theory which is perturbatively non-renormalizable at one-loop level, but may possess a non-trivial renormalization group fixed point controlling its UV behavior. We show that such a fixed point indeed

A. L. Barabanov

It is suggested that superfluid helium (condensate of 4-He atoms) may stimulate nuclear alpha-decay in a situation when an alpha-emitter moves through superfluid helium with fine-tuned velocity, so that the backward-emitted alpha-particle is at rest in the laboratory frame. It is shown that the probability of stimulated alpha-decay in this case may be sizabl

S. I. Denisov, T. V. Lyutyy, E. S. Denisova, P. Hänggi

We study directed transport of overdamped particles in a periodically rocked random sawtooth potential. Two transport regimes can be identified which are characterized by a nonzero value of the average velocity of particles and a zero value, respectively. The properties of directed transport in these regimes are investigated both analytically and numerically

Shi-Jian Gu

In this work, we examine the validity of quantum adiabatic theorem in thermodynamic systems. For a $d$-dimensional quantum many-body system, we show that the duration time $τ_0$ required by its ground-state adiabatic process does not depend on the microscopic details, but the scaling dimension of the fidelity susceptibility $d_a$. Our result, therefore, prov

E. Garcia-Melendo, P. R. McCullough

We report a times series of B-band photometric observations initiated on the eve of Valentine's day, February 14, 2009, at the anticipated time of a transit of the extrasolar planet HD 80606b. The same transit has been observed independently (Fossey et al. 2009; Moutou et al. 2009). For one transit model favored by the data, minimum light equals 0.990 ti

Yehonatan Knoll

It is argued that, contrary to conventional wisdom, no trustworthy universal self-force/radiative corrections to the Lorentz force equation, can be derived from the basic tenets of classical electrodynamics. This concords with the apparent randomness observed in quantum mechanical scattering experiments and with the absence of any experimental support for su

Esteban F. E. Morales, Diego Mardones, Guido Garay, Kate J. Brooks

We present mid-infrared (MIR) observations, made with the TIMMI2 camera on the ESO 3.6 m telescope, toward 14 young massive star-forming regions. All regions were imaged in the N band, and nine in the Q band, with an angular resolution of ~ 1 arcsec. Typically, the regions exhibit a single or two compact sources (with sizes in the range 0.008-0.18 pc) plus e

Wilfried Buchmuller, Riccardo Catena, Kai Schmidt-Hoberg

We study a supersymmetric field theory in six dimensions compactified on the orbifold T^2/Z_2 with two Wilson lines. After supersymmetry breaking, the Casimir energy fixes the shape moduli at fixed points in field space where the symmetry of the torus lattice is enhanced. Localized Fayet-Iliopoulos terms stabilize the volume modulus at a size much smaller th

Stephen J. Fossey, Ingo P. Waldman, David M. Kipping

We report the detection of a transit egress by the ~ 3.9-Jupiter-mass planet HD 80606b, an object in a highly-eccentric orbit (e ~ 0.93) about its parent star of approximately solar type. The astrophysical reality of the signal of variability in HD 80606 is confirmed by observation with two independent telescope systems, and checks against several reference

Fabian Schmidt

The Pierre Auger Observatory, recently completed, has been operational since 2004. As a hybrid experiment, it allows for a wide range of measurements of UHECR-induced extensive air showers (EAS), including measurements of the EAS particle content on ground which is sensitive to high-energy hadronic interactions. We present the results of several independent

Mauro Rovezzi, Francesco D'Acapito, Andrea Navarro-Quezada, Bogdan Faina

X-ray absorption fine-structure (XAFS) measurements supported by {\em ab initio} computations within the density functional theory (DFT) are employed to systematically characterize Fe-doped as well as Fe and Si-co-doped films grown by metalorganic vapour phase epitaxy. The analysis of extended-XAFS data shows that depending on the growth conditions, Fe atoms

Janak Ramakrishnan

We give necessary and sufficient conditions on a non-oscillatory curve in an o-minimal field such that, for any bounded definable function, the germ of the function on an initial segment of the curve can be continuously extended to a closed definable set. This situation is translated into a question about types: What are the conditions on an $n$-type such th

Thomas Trenner, P. M. H. Wilson

Motivated by the classical statements of Mirror Symmetry, we study certain Kahler metrics on the complexified Kahler cone of a Calabi-Yau threefold, conjecturally corresponding to approximations to the Weil-Petersson metric near large complex structure limit for the mirror. In particular, the naturally defined Riemannian metric (defined via cup-product) on a

K. Nagatomo, A. Tsuchiya

We prove the abelian category of the modules over triplet VOA W(p) is category equivalent to the abelian category of the modules over quantum algebra of type sl_2 at root of unity.

Utpal Chattopadhyay, Debottam Das, D. P. Roy

We have considered nonuniversal gaugino mass models of supergravity, arising from a mixture of two superfield contributions to the gauge kinetic term, belonging to a singlet and a nonsinglet representation of the GUT group. In particular we analyse two models, where the contributing superfields belong to the singlet and the 75-dimensional, and the singlet an

Stefan Antusch, Martin Spinrath

Group theoretical factors from GUT symmetry breaking can lead to predictions for the ratios of quark and lepton masses (or Yukawa couplings) at the unification scale. Due to supersymmetric (SUSY) threshold corrections the viability of such predictions can depend strongly on the SUSY parameters. For three common minimal SUSY breaking scenarios with anomaly, g

Josip Milanovic, Mikael Lassen, Ulrik L. Andersen, Gerd Leuchs

Photonic Crystal Fibers can be tailored to increase the effective Kerr nonlinearity, while producing smaller amounts of excess noise compared to standard silicon fibers. Using these features of Photonic Crystal Fibers we create polarization squeezed states with increased purity compared to standard fiber squeezing experiments. Explicit we produce squeezed st

Jan Christian Rohde

Assume that the local universal deformation of a Calabi-Yau 3-manifold X has an automorphism which does not act by 1 or -1 on the third cohomology. We show that the $F^2$ bundle in the Variation of Hodge structures of each maximal family containing $X$ is constant in this case. Thus X cannot be a fiber of a maximal family with maximally unipotent monodromy,

Laurent Lellouch

I critically review recent lattice QCD results relevant for kaon phenomenology, as well as the methods that are used to obtain them. The focus is on calculations with N_f=2 and N_f=2+1 flavors of sea quarks. Concerning methodology, the subjects covered include a discussion of how best to extrapolate and/or interpolate results to the physical quark-mass point

Thomas Baird

We use Morse theory of the Yang-Mills functional to compute the Betti numbers of the moduli stack of flat U(3)-bundles over a compact nonorientable surface. Our result establishes the antiperfection conjecture of Ho-Liu, and provides evidence for the equivariant formality conjecture of the author.

Robert C. Dalang, Marta Sanz-Solé

We develop several results on hitting probabilities of random fields which highlight the role of the dimension of the parameter space. This yields upper and lower bounds in terms of Hausdorff measure and Bessel--Riesz capacity, respectively. We apply these results to a system of stochastic wave equations in spatial dimension $k\ge1$ driven by a $d$-dimension

Zhenhai Jing, Baoming Bai, Xiao Ma

Determining how to approach the rate boundary of the Gaussian interference channel in practical system is a big concern. In this paper, a distributed rate-splitting (DRS) scheme is proposed to approach the rate region boundary of the Gaussian interference channel. It is shown that the DRS scheme can be formulated as a non-cooperative game. We introduce the S

Shi-Chun Su, M. -C. Chu

Models of a rotating universe have been studied widely since G{ö}del \cite{1}, who showed an example that is consistent with General Relativity (GR). By now, the possibility of a rotating universe has been discussed comprehensively in the framework of some types of Bianchi's models, such as Type V, VII and IX \cite{2,3}, and different approaches have bee

Atreyee Biswas, Barnana Roy

We construct coherent state of the effective mass harmonic oscillator and examine some of its properties. In particular closed form expressions of coherent states for different choices of the mass function are obtained and it is shown that such states are not in general x-p uncertainty states. We also compute the associated Wigner functions.

Abouzeid M. Shalaby

In this work, we study the vacuum stability of the classical unstable $\left( -ϕ^{4}\right) $ scalar field potential. Regarding this, we obtained the effective potential, up to second order in the coupling, for the theory in $1+1$ and $2+1$ space-time dimensions. We found that the obtained effective potential is bounded from below, which proves the vacuum st

Piotr S. Żuchowski, Jeremy M. Hutson

We carry out quantum inelastic scattering calculations of collisions of Rb atoms with inverting NH3 and ND3 molecules in the energy range between 0 and 100 cm-1, which are important for experiments using velocity-controlled molecular beams to probe scattering resonances. We focus on molecules initially in the upper level of the ammonia inversion doublet, whi

K. Anguige

We consider a family of multi-phase Stefan problems for a certain 1-d model of cell-to-cell adhesion and diffusion, which takes the form of a nonlinear forward-backward parabolic equation. In each material phase the cell density stays either high or low, and phases are connected by jumps across an `unstable' interval. We develop an existence theory for s

B. Nayak, A. S. Majumdar, L. P. Singh

We consider the effect of accretion of radiation in the early universe on primordial black holes in Brans-Dicke theory. The rate of growth of a primordial black hole due to accretion of radiation in Brans-Dicke theory is considerably smaller than the rate of growth of the cosmological horizon, thus making available sufficient radiation density for the black

Leonardo L. Gollo, Osame Kinouchi, Mauro Copelli

Since the first experimental evidences of active conductances in dendrites, most neurons have been shown to exhibit dendritic excitability through the expression of a variety of voltage-gated ion channels. However, despite experimental and theoretical efforts undertaken in the last decades, the role of this excitability for some kind of dendritic computation

Suratna Das, Subhendra Mohanty

Glashow and Cohen make the interesting observation that certain proper subgroups of the Lorentz group like HOM(2) or SIM(2) can explain many results of special relativity like time dilation, relativistic velocity addition and a maximal isotropic speed of light. We show here that such SIM(2) and HOM(2) based VSR theories predict an incorrect value for the Tho

T. V. Shchedrina, P. I. Zarubin

Progress in the study of the peripheral nuclear interactions in $^{14}N$ dissociation at $2.1A GeV$ in nuclear emulsion is outlined. The leading role of the multiple fragmentations in the most peripheral nucleus interactions is discussed. The production of unusual states, for which a regrouping of nucleons beyond the $α$-particle clustering is needed, is ide

D. Allard, R. J. Protheroe

In this paper, we study the diffusive shock acceleration of cosmic-ray protons and nuclei, taking into account all the relevant interaction processes with photon backgrounds. We investigate how the competition between protons and nuclei is modified by the acceleration parameters such as the acceleration rate, its rigidity dependence, the photon density and t

Naoki Yamamoto, Takuya Kanazawa

We study the properties of QCD at high baryon density in a finite volume where color superconductivity occurs. We derive exact sum rules for complex eigenvalues of the Dirac operator at finite chemical potential, and show that the Dirac spectrum is directly related to the color superconducting gap $Δ$. Also, we find a characteristic signature of color superc

A. A. Zdziarski, R. Kawabata, S. Mineshige

We study mass flow rate through a disc resulting from a varying mass supply rate. Variable mass supply rate occurs, e.g., during disc state transitions, and in interacting eccentric binaries. It is, however, damped by the viscosity of the disc. Here, we calculate this damping in detail. We derive an analytical description of the propagation of the flow rate

Clement de Seguins Pazzis

We give a new and elementary proof that simultaneous similarity and simultaneous equivalence of families of matrices are invariant under extension of the ground field, a result which is non-trivial for finite fields and first appeared in a paper of Klinger and Levy.

J. Binney, C. Nipoti, F. Fraternali

We examine the proposal that the HI "high-velocity" clouds (HVCs) surrounding the Milky Way and other disc galaxies form by condensation of the hot galactic corona via thermal instability. Under the assumption that the galactic corona is well represented by a non-rotating, stratified atmosphere, we find that for this formation mechanism to work the c

Satyabrata Adhikari

We present a mathematical formulation of old teleportation protocol (original teleportation protocol introduced by Bennett et.al.) for mixed states and study in detail the role of mixedness of the two qubit quantum channel in a teleportation protocol. We show that maximally entangled mixed state described by the density matrix of rank-4 will be useful as a t

Robert Löw, Hendrik Weimer, Ulrich Krohn, Rolf Heidemann

We study a gas of ultracold atoms resonantly driven into a strongly interacting Rydberg state. The long distance behavior of the spatially frozen effective pseudospin system is determined by a set of dimensionless parameters, and we find that the experimental data exhibits algebraic scaling laws for the excitation dynamics and the saturation of Rydberg excit

Gregory Eskin, James Ralston

We consider wave equations in domains with time-dependent boundaries (moving obstacles) contained in a fixed cylinder for all time. We give sufficient conditions for the determination of the moving boundary from the Cauchy data on part of the boundary of the cylinder. We also study the related problem of accessibility of the moving boundary by time-like curv

Andrei K. Svinin

We show a broad class of constraints compatible with Itoh-Narita-Bogoyavlenskii lattice hierarchy. All these constraints can be written in the form of discrete conservation law $I_{i+1}=I_i$ with appropriate homogeneous polynomial discrete function $I=I[a]$.

I. L. Zhogin

Supernova Ia redshifts are fitted with a simple $5D$ model: the galaxies are assumed to be enclosed in a giant $S^3$-spherical shell of significant thickness, which expands (ultra)relativisticaly in Minkowski (1+4)$D$-space. This model, as compared with the kinematic (1+3)$D$ Milne cosmological model (which was reinvented by Prof Farley), goes in line with t

Piljin Yi

We review baryons in the D4-D8 holographic model of low energy QCD, with the large $N_c$ and the large 't Hooft coupling limit. The baryon is identified with a bulk soliton of a unit Pontryagin number, which from the four-dimensional viewpoint translates to a heavily modified Skyrmion dressed by condensates of spin one mesons. We explore classical proper

Joel Yuen-Zhou, David G. Tempel, César Rodríguez-Rosario, Alán Aspuru-Guzik

We extend the Runge-Gross theorem for a very general class of Markovian and non-Markovian open quantum systems under weak assumptions about the nature of the bath and its coupling to the system. We show that for Kohn-Sham (KS) Time-Dependent Density Functional Theory, it is possible to rigorously include the effects of the environment within a bath functiona

Zachary W. E. Evans, Ashley M. Stephens

We present a method of concatenated quantum error correction in which improved classical processing is used with existing quantum codes and fault-tolerant circuits to more reliably correct errors. Rather than correcting each level of a concatenated code independently, our method uses information about the likelihood of errors having occurred at lower levels

Yoshio Koide

In the so-called yukawaon model, where the effective Yukawa coupling constants Y_f^{eff} (f=e,ν,u,d) are given by vacuum expectation values (VEVs) of gauge singlet scalars (yukawaons) Y_f with 3\times 3 components, i.e. Y_f^{eff}= y_f < Y_f>/Λ, massless (and light) scalars appear because a global flavor symmetry is assumed. In order to demonstrate whether su

Farrukh Mukhamedov, Hasan Akin, Seyit Temir, Abduaziz Abduganiev

In the present paper we study nonlinear dynamics of quantum quadratic operators (q.q.o) acting on the algebra of $2\times 2$ matrices $\bm_2(\bc)$. First, we describe q.q.o. with Haar state as well as quadratic operators with the Kadison-Schwarz property. By means of such a description we provide an example of q.q.o. which is not the Kadision-Schwarz operato

N. Berry, C. Capan, G. Seyfarth, A. D. Bianchi

Heat capacity, resistivity, and magnetic susceptibility measurements confirm bulk superconductivity in single crystals of BaIr$_2$P$_2$ (T$_c$=2.1K) and BaRh$_2$P$_2$ (T$_c$ = 1.0 K). These compounds form in the ThCr$_2$Si$_2$ (122) structure so they are isostructural to both the Ni and Fe pnictides but not isoelectronic to either of them. This illustrates t

Jonathan C. Mattingly, Scott A. McKinley, Natesh S. Pillai

We consider a simple model for the fluctuating hydrodynamics of a flexible polymer in dilute solution, demonstrating geometric ergodicity for a pair of particles that interact with each other through a nonlinear spring potential while being advected by a stochastic Stokes fluid velocity field. This is a generalization of previous models which have used linea

Martin Hairer, Jonathan C. Mattingly, Michael Scheutzow

There are many Markov chains on infinite dimensional spaces whose one-step transition kernels are mutually singular when starting from different initial conditions. We give results which prove unique ergodicity under minimal assumptions on one hand and the existence of a spectral gap under conditions reminiscent of Harris&#39; theorem. The first uses the exi

Mark T. Lusk, David T. Wu, L. D. Carr

We analyze a new fundamental building block for monolithic nanoengineering on graphene: the Inverse-Stone-Thrower-Wales (ISTW) defect. The ISTW is formed from a pair of joined pentagonal carbon rings placed between a pair of heptagonal rings; the well-known Stone-Thrower-Wales (STW) defect is the same arrangement, but with the heptagonal rather than pentagon

J. L. Díaz-Cruz, J. Hernández--Sánchez, S. Moretti, R. Noriega-Papaqui

We discuss the implications of assuming a four-zero Yukawa texture for the properties of the charged Higgs boson within the context of the general 2-Higgs Doublet Model of Type III. We begin by presenting a detailed analysis of the charged Higgs boson couplings with heavy quarks and the resulting pattern for its decays. The production of charged Higgs bosons

Paul S. Cally

Phase perturbations due to inclined surface magnetic field of active region strength are calculated numerically in quiet Sun and simple sunspot models in order to estimate and compare the direct and indirect (thermal) effects of the fields on helioseismic waves. It is found that the largest direct effects occur in highly inclined field characteristic of penu

Joerg Endrullis, Herman Geuvers, Hans Zantema

Undecidability of various properties of first order term rewriting systems is well-known. An undecidable property can be classified by the complexity of the formula defining it. This gives rise to a hierarchy of distinct levels of undecidability, starting from the arithmetical hierarchy classifying properties using first order arithmetical formulas and conti

R. J. Wilman, A. C. Edge, A. M. Swinbank

We present VLT-SINFONI K-band IFU spectroscopy of the central galaxies in the cool core clusters A1664, A2204 and PKS 0745-191, to probe the Pa-alpha and ro-vibrational H2 line emission. In A1664 the two emission-line velocity systems seen in our previous H-alpha data appear in both Pa-alpha and H2 emission, with notable morphological differences. The recess

Sidney van den Bergh

The data collected in the Shapley-Ames catalog of bright galaxies show that lenticular (S0) galaxies are typically about a magnitude fainter than both elliptical (E) and early spiral (Sa) galaxies. Hubble (1936) was therefore wrong to regard S0 galaxies as being intermediate between morphological types E and Sa. The observation that E5-E7 galaxies are signif

M. E. Putman, P. Henning, A. Bolatto, D. Keres

Great strides have been made in the last two decades in determining how galaxies evolve from their initial dark matter seeds to the complex structures we observe at z=0. The role of mergers has been documented through both observations and simulations, numerous satellites that may represent these initial dark matter seeds have been discovered in the Local Gr

Ronald G. Douglas, Jaydeb Sarkar

A classical problem in operator theory has been to determine the spectrum of Toeplitz-like operators on Hilbert spaces of vector-valued holomorphic functions on the open unit ball in C^m. In this note we obtain necessary conditions for k-tuples of such operators to be Fredholm in the sense of Taylor and show they are sufficient in the case of the unit disk.

S. Muller, M. Mudrich, F. Stienkemeier

We systematically investigate the formation and stability of snowballs formed by femtosecond photo-ionization of small alkali clusters bound to helium nanodroplets. For all studied alkali species Ak=(Na, K, Rb, Cs) we observe the formation of snowballs (AkHe_N)^+ when multiply doping the droplets. Fragmentation of clusters Ak_N upon ionization appears to enh

John E. Norris, Gerard Gilmore, Rosemary F. G. Wyse, Mark I. Wilkinson

We present medium-resolution spectra of 16 radial velocity red-giant members of the low-luminosity Bootes I dwarf spheroidal (dSph) galaxy, that have sufficient S/N for abundance determination, based on the strength of the Ca II K line. Assuming [Ca/Fe] ~ +0.3, the abundance range in the sample is Delta [Fe/H] ~ 1.7 dex, with one star having [Fe/H] = -3.4. T

Andrés Navas

According to Thurston&#39;s stability theorem, every group of C^1 diffeomorphisms of the closed interval is locally indicable (.e., every finitely generated subgroup factors through Z). We show that, even for finitely generated groups, the converse of this statement is not true. More precisely, we show that the semi-direct product between F_2 an Z^2, althoug

Kaden R. A. Hazzard, Erich J. Mueller

We extend the standard Bose-Hubbard model to capture arbitrarily strong on-site correlations. In addition to being important for quantitatively modeling experiments, for example, with Rubidium atoms, these correlations must be included to describe more exotic situations. Two such examples are when the interactions are made large via a Feshbach resonance, or

S. Y. Choi, M. Drees, J. Kalinowski, J. M. Kim

Elements of the phenomenology of color-octet scalars (sgluons), as predicted in the hybrid N=1/N=2 supersymmetric model, are discussed in the light of forthcoming experiments at the CERN Large Hadron Collider.

J. J. Lunazzi, D. S. F. Magalhaes, N. I. R. Rivera, R. L. Serra

We show a system capable of projecting a video scene on a white-light holographic screen to obtain a kind of image that results in a plane in front of the screen. This holographic screen is mainly a diffractive lens and it is constructed by holography. The image plane can be located at any azimuth angle and seen with continuous parallax and without the use o

Mark Dijkstra, Abraham Loeb

Active Galactic Nuclei (AGN) produce a dominant fraction (~80%) of the Soft X-ray background (SXB) at photon energies 0.5<E<2 keV. If dust pervaded throughout the intergalactic medium, its scattering opacity would have produced diffuse X-ray halos around AGN. Taking account of known galaxies and galaxy clusters, only a fraction F_halo <10% of the SXB can be

G. Cresci, E. K. S. Hicks, R. Genzel, N. M. Foerster Schreiber

We present the modeling of SINFONI integral field dynamics of 18 star forming galaxies at z ~ 2 from Halpha line emission. The galaxies are selected from the larger sample of the SINS survey, based on the prominence of ordered rotational motions with respect to more complex merger induced dynamics. The quality of the data allows us to carefully select system

B. C. Allanach, C. H. Kom, H. Päs

In the minimal supersymmetric extension to the Standard Model, a non-zero lepton number violating coupling lambda&#39;_111 predicts both neutrinoless double beta decay and resonant single slepton production at the LHC. We show that, in this case, if neutrinoless double beta decay is discovered in the next generation of experiments, there exist good prospects

E. Zackrisson, G. Micheva, N. Bergvall, G. Ostlin

Red halos are faint, extended and extremely red structures that have been reported around various types of galaxies since the mid-1990s. The colours of these halos are too red to be reconciled with any hitherto known type of stellar population, and instead indicative of a very bottom-heavy stellar initial mass function (IMF). Due to the large mass-to-light r

A. Belloche, R. T. Garrod, H. S. P. Müller, K. M. Menten

In recent years, organic molecules of increasing complexity have been found toward the prolific Galactic center source Sagittarius B2. We wish to explore the degree of complexity that the interstellar chemistry can reach in star-forming regions. We carried out a complete line survey of the hot cores Sgr B2(N) and (M) with the IRAM 30 m telescope in the 3 mm

CDMS Collaboration

We report on the first axion search results from the Cryogenic Dark Matter Search (CDMS) experiment at the Soudan Underground Laboratory. An energy threshold of 2 keV for electron-recoil events allows a search for possible solar axion conversion into photons or local Galactic axion conversion into electrons in the germanium crystal detectors. The solar axion

Michael McGuigan

We discuss separate and integrated approaches to building scalable solar power plants and wildlife sanctuaries. Both solar power plants and wildlife sanctuaries need a lot of land. We quantify some of the requirements using various estimates of the rate of solar power production as well as the rate of adding wildlife to a sanctuary over the time range 2010-2

L. Brenneman, J. M. Miller, K. Nandra, M. Volonteri

Since the seminal work of Penrose (1969) and Blandford & Znajek (1977), it has been realized that black hole spin may be an important energy source in astrophysics. The radio-loud/radio-quiet dichotomy in the AGN population is usually attributed to differences in black hole spin, with correlations between black hole spin and host galaxy morphology being hypo

Luca Scala

Let $M$ a compact connected orientable 4-manifold. We study the space $Ξ$ of $Spin^c$-structures of fixed fundamental class, as an infinite dimensional principal bundle on the manifold of riemannian metrics on $M$. In order to study perturbations of the metric in Seiberg-Witten equations, we study the transversality of universal equations, parametrized with

T. I. Larchenkova, A. A. Lutovinov

We consider the possibility of detecting intermediate-mass ($10^3-10^4 M_{\odot}$) black holes, whose existence at the centers of globular clusters is expected from optical and infrared observations, using precise pulse arrival timing for the millisecond pulsars in globular clusters known to date. For some of these pulsars closest to the cluster centers, we

AAS WGLA, :, Nancy Brickhouse, John Cowan

As the Stars and Stellar Evolution (SSE) panel is fully aware, the next decade will see major advances in our understanding of these areas of research. To quote from their charge, these advances will occur in studies of the Sun as a star, stellar astrophysics, the structure and evolution of single and multiple stars, compact objects, SNe, gamma-ray bursts, s

David Jewitt

The Centaurs are recent escapees from the Kuiper belt that are destined either to meet fiery oblivion in the hot inner regions of the Solar system or to be ejected to the interstellar medium by gravitational scattering from the giant planets. Dynamically evolved Centaurs, when captured by Jupiter and close enough to the Sun for near-surface water ice to subl