June 2006 arXiv papers — page 14

C. Möllenhoff, C. C. Popescu, R. J. Tuffs

We present corrections for the change in the apparent scalelengths, central surface brightnesses and axis ratios due to the presence of dust in pure disk galaxies, as a function of inclination, central face-on opacity in the B-band (tau^f_B) and wavelength. The correction factors were derived from simulated images of disk galaxies created using geometries fo

M. C. Wiedner, G. Wieching, F. Bielau, M. Emprechtinger

The THz atmospheric windows centered at roughly 1.3 and 1.5~THz, contain numerous spectral lines of astronomical importance, including three high-J CO lines, the N+ line at 205 microns, and the ground transition of para-H2D+. The CO lines are tracers of hot (several 100K), dense gas; N+ is a cooling line of diffuse, ionized gas; the H2D+ line is a non-deplet

A. Brunthaler, C. Henkel, W. J. G. de Blok, M. J. Reid

We compare the number of detected 22 GHz H2O masers in the Local Group galaxies M31, M33, NGC6822, IC10, IC1613, DDO187, GR8, NGC185, and the Magellanic Clouds with the water maser population of the Milky Way. To accomplish this we searched for water maser emission in the two Local Group galaxies M33 and NGC6822 using the Very Large Array (VLA) and incorpora

Csaba Gal, Francisco Mueller-Sanchez

LIINUS/SERPIL is a design study to augment LBTs interferometric beam combiner camera LINC-NIRVANA with imaging spectroscopy. The FWHM of the interferometric main beam at 1.5 micron will be about 10 mas, offering unique imaging and spectroscopic capabilities well beyond the angular resolution of current 8-10m telescopes. At 10 mas angular scale, e.g., one res

Giuseppe Vacanti, Ernst-Jan Buis

We address the question of to what accuracy remote sensing images of the surface of planets can be matched, so that the possible displacement of features on the surface can be accurately measured. This is relevant in the context of the libration experiment aboard the European Space Agency's BepiColombo mission to Mercury. We focus here only on the algori

J. H. Knapen, R. J. Allen, H. I Heaton, N. Kuno

Context At least a fraction of the atomic hydrogen in spiral galaxies is suspected to be the result of molecular hydrogen which has been dissociated by radiation from massive stars. Aims In this paper, we extend our earlier set of data from a small region of the Western spiral arm of M81 with CO observations in order to study the interplay between the radiat

S. Schanne

The International Gamma-Ray Astrophysics Laboratory, i.e. the INTEGRAL satellite of ESA, in orbit since about 3 years, performs gamma-ray observations of the sky in the 15 keV to 8 MeV energy range. Thanks to its imager IBIS, and in particular the ISGRI detection plane based on 16384 CdTe pixels, it achieves an excellent angular resolution (12 arcmin) for po

H. Bruntt, J. Southworth, G. Torres, A. J. Penny

Determinations of stellar mass and radius with realistic uncertainties at the level of 1% provide important constraints on models of stellar structure and evolution. We present a high-precision light curve of the A0IV star Psi Centauri, from the star tracker on board the WIRE satellite and the Solar Mass Ejection Imager camera on the Coriolis spacecraft. The

Christophe Pinte, Francois Menard, Gaspard Duchene, Pierre Bastien

We present a new continuum 3D radiative transfer code, MCFOST, based on a Monte-Carlo method. MCFOST can be used to calculate (i) monochromatic images in scattered light and/or thermal emission, (ii) polarisation maps, (iii) interferometric visibilities, (iv) spectral energy distributions and (v) dust temperature distributions of protoplanetary disks. Severa

Somenath Chakrabarty

It is shown that in strongly magnetized neutron stars, there exist upper limits of magnetic field strength, beyond which the self energies for both neutron and proton components of neutron star matter become complex in nature. As a consequence they decay within the strong interaction time scale. However, in the ultra-strong magnetic field case, when the zero

Anthony Challinor

The temperature anisotropies and polarization of the cosmic microwave background (CMB) radiation provide a window back to the physics of the early universe. They encode the nature of the initial fluctuations and so can reveal much about the physical mechanism that led to their generation. In this contribution we review what we have learnt so far about early-

P. P. Tennekes, J. Harju, M. Juvela, L. V. Toth

Aims. The purpose of this study is to investigate the distributions of the isomeric molecules HCN and HNC and estimate their abundance ratio in the protostellar core Cha-MMS1 located in Chamaeleon {\sc i}. Methods. The core was mapped in the J=1-0 rotational lines of HCN, HNC, and HN13C. The column densities of H13CN, HN13C, H15NC and NH3 were estimated towa

Kenji Bekki, Eric Peng

Recent spectroscopic observations of planetary nebulae (PNe) in several elliptical galaxies have revealed structural and kinematical properties of the outer stellar halo regions. In order to elucidate the origin of the properties of these planetary nebula systems (PNSs), we consider the merger scenario in which an elliptical galaxy is formed by merging of sp

Michael A. Dopita, Joerg Fischera, Ralph S. Sutherland, Lisa J. Kewley

We examine, from a theoretical viewpoint, how the physical parameters of HII regions are controlled in both normal galaxies and in starburst environments. These parameters are the HII region luminosity function, the time-dependent size, the covering fraction of molecular clouds, the pressure in the ionized gas and the ionization parameter. The factors which

Paul Halpern

We calculate the total energy of Taub's 1951 exact solution for a Bianchi type IX geometry using several different energy-localization procedures, including the prescriptions of Einstein, Papapetrou, Landau-Lifshitz and Moller. We compare these results to those for other anisotropic geometries, and comment on their relationship to Rosen's conjecture

E. V. Shuryak

Cold fermionic atoms are known to enter the universal strongly coupled regime as their scattering length $a$ gets large compared to the inter-particle distances. Recent experimental data provide important critical parameters of such system. We argue that quarks may enter the same regime due to marginal binding of diquarks, and if so one can use its universal

Robert C. Fletcher

There have been a number of papers proposing that the light speed of a homogeneous and isotropic universe is variable. This paper outlines a simple way that the vectors and tensors of special relativity can be extended to allow such a variable light speed and show how the field equation of general relativity can also be extended with particular application t

Fernando Izaurieta, Eduardo Rodríguez, Patricio Salgado

We propose an outgrowth of the expansion method introduced by de Azcarraga et al. [Nucl. Phys. B 662 (2003) 185]. The basic idea consists in considering the direct product between an abelian semigroup S and a Lie algebra g. General conditions under which relevant subalgebras can systematically be extracted from S \times g are given. We show how, for a partic

Mark R. Krumholz, James M. Stone, Thomas A. Gardiner

We present a method for simulating the evolution of HII regions driven by point sources of ionizing radiation in magnetohydrodynamic media, implemented in the three-dimensional Athena MHD code. We compare simulations using our algorithm to analytic solutions and show that the method passes rigorous tests of accuracy and convergence. The tests reveal several

K. M. Huffenberger, H. K. Eriksen, F. K. Hansen

Using a set of multifrequency cross spectra computed from the 3 year WMAP sky maps, we fit for the unresolved point-source contribution. For a white-noise power spectrum, we find a Q-band amplitude of A=0.011 +/- 0.001 muK^2 sr (antenna temperature), significantly smaller than the value of 0.017 +/- 0.002 muK^2 sr used to correct the spectra in the WMAP rele

Masahiro Takada

(abridged) A wide-field galaxy redshift survey allows one to probe galaxy clustering at largest spatial scales, which carries an invaluable information on horizon-scale physics complementarily to the cosmic microwave background (CMB). Assuming the planned survey consisting of z~1 and z~3 surveys with areas of 2000 and 300 square degrees, respectively, we stu

Z. W. Chong, M. Cvetic, H. Lu, C. N. Pope

Supersymmetric black holes in five-dimensional gauged supergravity must necessarily be rotating, and so in order to study the passage to black holes away from supersymmetry, it is of great interest to obtain non-extremal black holes that again have non-zero rotation. In this paper we find a simple framework for describing non-extremal rotating black holes in

Jan Petter Morten, Arne Brataas, Wolfgang Belzig

We consider transport in a three terminal device attached to one superconducting and two normal metal terminals, using the circuit theory of mesoscopic superconductivity. We compute the nonlocal conductance of the current out of the first normal metal terminal in response to a bias voltage between the second normal metal terminal and the superconducting term

Dror Bar-Natan, Scott Morrison

We give a simple proof of Lee's result from [Adv. Math. 179 (2005) 554-586; arXiv:math.GT/0210213], that the dimension of the Lee variant of the Khovanov homology of a c-component link is 2^c, regardless of the number of crossings. Our method of proof is entirely local and hence we can state a Lee-type theorem for tangles as well as for knots and links.

Michael Usher

Let X_1, X_2 be symplectic 4-manifolds containing symplectic surfaces F_1,F_2 of identical positive genus and opposite squares. Let Z denote the symplectic sum of X_1 and X_2 along the F_k. Using relative Gromov--Witten theory, we determine precisely when the symplectic 4-manifold Z is minimal (i.e., cannot be blown down); in particular, we prove that Z is m

William Arveson

Starting with a unit-preserving normal completely positive map L: M --> M acting on a von Neumann algebra - or more generally a dual operator system - we show that there is a unique reversible system α: N --> N (i.e., a complete order automorphism αof a dual operator system N) that captures all of the asymptotic behavior of L, called the {\em asymptotic lift

Yacine Mehtar-Tani

We calculate the classical gluon field of a fast projectile passing through a dense medium. We show that this allows us to calculate both the initial state gluon production in proton-nucleus collisions and the final state gluon radiation off a hard parton produced in nucleus-nucleus collisions. This unified description of these two phenomena makes the relati

A. M. Ghezelbash

We present new M2 and M5 brane solutions in M-theory based on transverse self-dual Bianchi type IX space. All the other recently M2 and M5 branes constructed on transverse self-dual Taub-NUT, Egughi-Hanson and Atiyah-Hitchin spaces are special cases of this solution. The solution provides a smooth transition from Eguchi-Hanson type I based M branes to corres

Laura Portinari, Jesper Sommer-Larsen

We present predictions on the evolution of the Tully-Fisher (TF) relation with redshift, based on cosmological N-body/hydrodynamical simulations of disc galaxy formation and evolution. The simulations invoke star formation and stellar feedback, chemical evolution with non-instantaneous recycling, metallicity dependent radiative cooling and effects of a meta-

D. B. McReynolds

In this article we construct closed, isospectral, non-isometric locally symmetric manifolds. We have three main results. First, we construct arbitrarily large sets of closed, isospectral, non-isometric manifolds. Second, we show the growth of size these sets of isospectral manifolds as a function of volume is super-polynomial. Finally, we construct pairs of

Manabu Irisawa, Yoshishige Kobayashi, Shin Sasaki

We investigate deformed superconformal symmetries on non(anti)commutative (super)spaces from the point of view of the Drinfel'd twisted symmetries. We classify all possible twist elements derived from an abelian subsector of the superconformal algebra. The symmetry breaking caused by the non(anti)commutativity of the (super)spaces is naturally interprete

Huy Tai Ha, Adam Van Tuyl

We use the correspondence between hypergraphs and their associated edge ideals to study the minimal graded free resolution of squarefree monomial ideals. The theme of this paper is to understand how the combinatorial structure of a hypergraph H appears within the resolution of its edge ideal I(H). We discuss when recursive formulas to compute the graded Bett

C. Marquet, G. Soyez, Bo-Wen Xiao

It was recently noticed that high-energy scattering processes in QCD have a stochastic nature. An event-by-event scattering amplitude is characterised by a saturation scale which is a random variable. The statistical ensemble of saturation scales formed with all the events is distributed according to a probability law whose cumulants have been recently compu

Erik Talvila

Let $f$ be a distribution (generalised function) on the real line. If there is a continuous function $F$ with real limits at infinity such that $F'=f$ (distributional derivative) then the distributional integral of $f$ is defined as $\int_{-\infty}^\infty f = F(\infty) - F(-\infty)$. It is shown that this simple definition gives an integral that includes

A. R. Its, B. -Q. Jin, V. E. Korepin

We consider entanglement in the ground state of the XY spin model on infinite chain. We use von Neumann entropy of a sub-system as a measure of entanglement. The entropy of a large block of neighboring spins approaches a constant as the size of the block increases. We prove rigorously expression for limiting entropy which was published before. We observe tha

Anthony Sudbery

Alice and Bob use Aravind's version of a Bell-Kochen-Specker paradox to fend off awkward questions about what exactly they were doing in Amsterdam last week.

Tobias Berger

We study the arithmetic of Eisenstein cohomology classes (in the sense of G. Harder) for symmetric spaces associated to GL_2 over imaginary quadratic fields. We prove in many cases a lower bound on their denominator in terms of a special L-value of a Hecke character providing evidence for a conjecture of Harder that the denominator is given by this L-value.

Sergio Ferrara, Eric G. Gimon, Renata Kallosh

We present explicit U-duality invariants for the R, C, Q, O$ (real, complex, quaternionic and octonionic) magic supergravities in four and five dimensions using complex forms with a reality condition. From these invariants we derive an explicit entropy function and corresponding stabilization equations which we use to exhibit stationary multi-center 1/2 BPS

A. H. Rezaeian, H. J. Pirner

We study a possible transition between symmetric nuclear matter and the diquark Bose-Einstein condensate (BEC) matter at zero temperature. We find that chiral restoration transition is first order and coincides with deconfinement. We investigate various possible coexistence patterns which may emerge from the first order deconfinement phase transition by assu

Przemyslaw Malkiewicz, Wlodzimierz Piechocki

We examine the transition of a particle across the singularity of the compactified Milne (CM) space. Quantization of the phase space of a particle and testing the quantum stability of its dynamics are consistent to one another. One type of transition of a quantum particle is described by a quantum state that is continuous at the singularity. It indicates the

Tadafumi Ohsaku

We examine several algebraic properties of the noncommutive $z$-plane and Riemann surfaces. The starting point of our investigation is a two-dimensional noncommutative field theory, and the framework of the theory will be converted into that of a complex coordinate system. The basis of noncommutative complex analysis is obtained thoroughly, and the considera

Stefano Bellucci, Sergio Ferrara, Murat Gunaydin, Alessio Marrani

We study the critical points of the black hole scalar potential $V_{BH}$ in N=2, d=4 supergravity coupled to $n_{V}$ vector multiplets, in an asymptotically flat extremal black hole background described by a 2(n_{V}+1)-dimensional dyonic charge vector and (complex) scalar fields which are coordinates of a special Kähler manifold. For the case of homogeneous

A. G. Ramm

If $A_q(β, α, k)$ is the scattering amplitude, corresponding to a potential $q\in L^2(D)$, where $D\subset\R^3$ is a bounded domain, and $e^{ikα\cdot x}$ is the incident plane wave, then we call the radiation pattern the function $A(β):=A_q(β, α, k)$, where the unit vector $α$, the incident direction, is fixed, and $k>0$, the wavenumber, is fixed. It is show

R. Boughezal, M. Czakon

We present a new set of high precision numerical values of four-loop single-scale vacuum integrals, which we subsequently use to obtain the non-singlet corrections to the rho parameter at O(GF mt^2 as^3). Our result for Delta rho is in agreement with the recent calculation [1].

Artur R. Pietrykowski

Recently an interesting idea has been put forward by Robinson and Wilczek that incorporation of quantized gravity in the framework of abelian and nonabelian gauge theories results in a correction to the running of gauge coupling and, in consequence, to increase of the Grand Unification scale and to the asymptotic freedom. In this paper it is shown by explici

A. G. Ramm

Let $A_q(α',α,k)$ be the scattering amplitude, corresponding to a local potential $q(x)$, $x\in\R^3$, $q(x)=0$ for $|x|>a$, where $a>0$ is a fixed number, $α',α\in S^2$ are unit vectors, $S^2$ is the unit sphere in $\R^3$, $α$ is the direction of the incident wave, $k^2>0$ is the energy. We prove that given an arbitrary function $f(α')\in L^2(S^2

Claire David

Finite difference schemes are here solved by means of a linear matrix equation. The theoretical study of the related algebraic system is exposed, and enables us to minimize the error due to a finite difference approximation.

Mark Alford, David Blaschke, Alessandro Drago, Thomas Klahn

Ozel, in a recent reanalysis of EXO 0748-676 observational data (astro-ph/0605106), concluded that quark matter probably does not exist in the center of compact stars. We show that the data is actually consistent with the presence of quark matter in compact stars.

Klaus Fredenhagen, Felix Reszewski

It is shown how states of a quantum mechanical particle in the Schroedinger representation can be approximated by states in the so-called polymer representation. The result may shed some light on the semiclassical limit of loop quantum gravity.

Steven Dale Cutkosky

In this paper a concise, complete proof of resolution of singularities of 3-folds in positive characteristic (>5) is given. The first proof of this theorem was given by Abhyankar in 1966. The resolution morphism in our proof is an isomorphism over the nonsingular locus.

Alastair Kay, Jiannis K. Pachos, Wolfgang Dür, Hans J. Briegel

In this paper, a purification protocol is presented and its performance is proven to be optimal when applied to a particular subset of graph states that are subject to local Z-noise. Such mixed states can be produced by bringing a system into thermal equilibrium, when it is described by a Hamiltonian which has a particular graph state as its unique ground st

Raghavan Rangarajan, Narendra Sahu

Models of leptogenesis are constrained by the low reheat temperature at the end of reheating associated with the gravitino bound. However a detailed view of reheating, in which the maximum temperature during reheating, $\Tmax$, can be orders of magnitude higher than the reheat temperature, allows for the production of heavy Majorana neutrinos needed for lept

Gabriella De Lucia, Jeremy Blaizot

We use semi-analytic techniques to study the formation and evolution of brightest cluster galaxies (BCGs). We show the extreme hierarchical nature of these objects and discuss the limits of simple ways to capture their evolution. In a model where cooling flows are suppressed at late times by AGN activity, the stars of BCGs are formed very early (50 per cent

Badis Ydri

It is found that noncommutative U(1) gauge field on the fuzzy sphere S^2_N is equivalent in the quantum theory to a commutative 2-dimensional U(N) gauge field on a lattice with two plaquettes in the axial gauge A_1=0. This quantum equivalence holds in the fuzzy sphere-weak coupling phase in the limit of infinite mass of the scalar normal component of the gau

A. I. Akimenko, F. Bobba, F. Giubileo, V. Gudimenko

The tunneling spectra of YBa2Cu3O7 break-junctions have been investigated for the tunneling direction close to the node one. The zero-bias conductance peak (ZBCP) and Josephson current have been studied with temperature and magnetic field. The observed deep splitting of ZBCP which starts at Ts<20-30K is in agreement with the theory for the dx2-y2+-is order p

Denjoe O'Connor, Badis Ydri

We find using Monte Carlo simulation the phase structure of noncommutative U(1) gauge theory in two dimensions with the fuzzy sphere S^2_N as a non-perturbative regulator. There are three phases of the model. i) A matrix phase where the theory is essentially SU(N) Yang-Mills reduced to zero dimension . ii) A weak coupling fuzzy sphere phase with constant spe

M. Crocce, S. Pueblas, R. Scoccimarro

We study the impact of setting initial conditions in numerical simulations using the standard procedure based on the Zel&#39;dovich approximation (ZA). As it is well known from perturbation theory, ZA initial conditions have incorrect second and higher-order growth and therefore excite long-lived transients in the evolution of the statistical properties of d

J. H. Field

Observation of the decay of muons produced in the Earth&#39;s atmosphere by cosmic ray interactions provides a graphic illustration of the counter-intuitive space-time predictions of special relativity theory. Muons at rest in the atmosphere decaying simultaneously are subject to a universal time-dilatation effect when viewed from a moving frame and so are a

Remco van der Hofstad, Peter Mörters, Nadia Sidorova\tsup

We study the parabolic Anderson problem, that is, the heat equation $\partial_tu=Δu+ξu$ on $(0,\infty)\times{\mathbb{Z}}^d$ with independent identically distributed random potential $\{ξ(z):z\in{\mathbb{Z}}^d\}$ and localized initial condition $u(0,x)={\mathbf{1}}_0(x)$. Our interest is in the long-term behavior of the random total mass $U(t)=\sum_zu(t,z)$ o

Jorge Bellorin, Patrick Meessen, Tomas Ortin

We show that requiring unbroken supersymmetry everywhere in black-hole-type solutions of N=2,d=4 supergravity coupled to vector supermultiplets ensures in most cases absence of naked singularities. We formulate three specific conditions which we argue are equivalent to the requirement of global supersymmetry. These three conditions can be related to absence

Eugen Paal

The derivative Noether currents generated by continuous Moufang tranformations are constructed and their equal-time commutators are found. The corresponding charge algebra turns out to be a birepresentation of the tangent Mal&#39;ltsev algebra of an analytic Moufang loop.

Sergey N. Solodukhin

A recent proposal by Ryu and Takayanagi for a holographic interpretation of entanglement entropy in conformal field theories dual to supergravity on anti-de Sitter (adS) is generalized to include entanglement entropy of black holes living on the boundary of adS. The generalized proposal is verified in boundary dimensions $d=2$ and $d=4$ for both the UV diver

W. A. Majewski

The new arguments based on Majorana fermions indicating that non-completely positive maps can describe open quantum evolution are presented.

Richard Vale

We determine the structure of category $\cO$ for the rational Cherednik algebra of $G(m,1,n)$ in the case where the $\KZ$ functor satisfies a condition called \emph{separating simples}. As a consequence, we show that the property of having exactly $N-1$ simple modules, where $N$ is the number of simple modules of $G(m,1,n)$, determines the Ariki-Koike algebr

B Collaboration, I. Abt

The inclusive production cross sections of the strange vector mesons K*0, K*0bar, and phi have been measured in interactions of 920 GeV protons with C, Ti, and W targets with the HERA-B detector at the HERA storage ring. Differential cross sections as a function of rapidity and transverse momentum have been measured in the central rapidity region and for tra

E. Gorsky

A functional equation for the motivic integral corresponding to the Milnor number of an arc is derived using the Denef-Loeser formula for the change of variables. Its solution is a function of five auxiliary parameters, it is unique up to multiplication by a constant and there is a simple recursive algorithm to find its coefficients. The method is universal

Ignacio Cascos, Ilya Molchanov

We describe a general framework for measuring risks, where the risk measure takes values in an abstract cone. It is shown that this approach naturally includes the classical risk measures and set-valued risk measures and yields a natural definition of vector-valued risk measures. Several main constructions of risk measures are described in this abstract axio

Michael Barot, Dirk Kussin, Helmut Lenzing

For the cluster category of a hereditary or a canonical algebra, equivalently for the cluster category of the hereditary category of coherent sheaves on a weighted projective line, we study the Grothendieck group with respect to an admissible triangulated structure.

Ben Freivogel, Yasuhiro Sekino, Leonard Susskind, Chen-Pin Yeh

In this paper we provide some circumstantial evidence for a holographic duality between bubble nucleation in an eternally inflating universe and a Euclidean conformal field theory. The holographic correspondence (which is different than Strominger&#39;s dS/CFT duality) relates the decay of (3+1)-dimensional de Sitter space to a two-dimensional CFT. It is not

Da-Ming Chen, HongSheng Zhao

We calculate the strong lensing probability as a function of the image-separation $Δθ$ in TeVeS (tensor-vector-scalar) cosmology, which is a relativistic version of MOND (MOdified Newtonian Dynamics). The lens, often an elliptical galaxy, is modeled by the Hernquist profile. We assume a flat cosmology with $Ω_b=1-Ω_Λ=0.04$ and the simplest interpolating func

A. Zazunov, D. Feinberg, Thierry Martin

Josephson transport through a single molecule or carbon nanotube is considered in the presence of a local vibrational mode coupled to the electronic charge. The ground-state solution is obtained exactly in the limit of a large superconducting gap, and is extended to the general case by variational analysis. Coherent charge fluctuations are entangled with non

Sameer Murthy, Jan Troost

We study D-branes in the superstring background R^{3,1} \times SL(2,R)_{k=1}/U(1) which are extended in the cigar direction. Some of these branes are new. The branes realize flavor in the four dimensional N=1 gauge theories on the D-branes localized at the tip of the cigar. We study the analytic properties of the boundary conformal field theories on these br

Dipendra Prasad, Rainer Schulze-Pillot

Following the work of Harris and Kudla we prove a more general form of a conjecture of Jacquet relating the non-vanishing of a certain period integral to non-vanishing of the central critical value of a certain $L$-function. As a consequence we deduce certain local results about the existence of $GL_2(k)$-invariant linear forms on irreducible, admissible rep

G. Stefanek

The elliptic flow of Lambda hyperons has been measured by the NA49 collaboration at the CERN-SPS in semi-central Pb+Pb collisions at 158A GeV. The standard method of correlating particles with the event plane was used. Measurements of v2 near mid-rapidity are reported as a function of rapidity, centrality and transverse momentum. Elliptic flow of Lambda part

Ali Mostafazadeh

Emphasizing the physical constraints on the formulation of a quantum theory based on the standard measurement axiom and the Schroedinger equation, we comment on some conceptual issues arising in the formulation of PT-symmetric quantum mechanics. In particular, we elaborate on the requirements of the boundedness of the metric operator and the diagonalizabilit

Robert J. Vanderbei, Egemen Kolemen

We give a self-contained modern linear stability analysis of a system of n equal mass bodies in circular orbit about a single more massive body. Starting with the mathematical description of the dynamics of the system, we form the linear approximation, compute all of the eigenvalues of the linear stability matrix, and finally derive inequalities that guarant

María Del Mar Gallardo, Christophe Joubert, Pedro Merino

The well-known problem of state space explosion in model checking is even more critical when applying this technique to programming languages, mainly due to the presence of complex data structures. One recent and promising approach to deal with this problem is the construction of an abstract and correct representation of the global program state allowing to

Soon-Tae Hong, Joohan Lee, Tae Hoon Lee, Phillial Oh

We study the supersymmetric quantum mechanics of an isospin particle in the background of spherically symmetric Yang-Mills gauge field. We show that on $S^{2}$ the number of supersymmetries can be made arbitrarily large for a specific choice of the spherically symmetric SU(2) gauge field. However, the symmetry algebra containing the supercharges becomes nonl

S. R. Muniz, S. D. Jenkins, T. A. B. Kennedy, D. S. Naik

We have realized a conical matter wave lens. The repulsive potential of a focused laser beam was used to launch a Bose-Einstein condensate into a radially expanding wavepacket whose perfect ring shape was ensured by energy conservation. In spite of significant interactions between atoms, the spatial and velocity widths of the ring along its radial dimension

Hai Fu, Alan Stockton

We present Gemini Multiobject Spectrograph integral field spectroscopy of the extended emission-line region associated with quasar 3C 249.1. The kinematics of the ionized gas measured from the [O III] $λ$5007 line is rather complex and cannot be explained globally by a simple dynamical model, but some clouds can be modeled individually as having locally line

Tatsuya Yamasaki, Shoichi Yamada

We investigated the structure of the spherically symmetric accretion flows through the standing shock wave onto the proto-neutron star in the post-bounce phase of the collapse-driven supernova. We assume that the accretion flow is in a steady state controlled by the neutrino luminosity and mass accretion rate that are kept constant. We obtain solutions of th

C. S. Lam

Observed neutrino mixing can be described by a tribimaximal MNS matrix. The resulting neutrino mass matrix in the basis of a diagonal charged lepton mass matrix is both 2-3 symmetric and magic. By a magic matrix, I mean one whose row sums and column sums are all identical. I study what happens if 2-3 symmetry is broken but the magic symmetry is kept intact.

Tomohiko Sakaguchi, Kouji Kashiwa, Masayuki Matsuzaki, Hiroaki Kouno

We test the stability of the mean-field solution in the Nambu--Jona-Lasinio model. For stable solutions with respect to both the σand πdirections, we investigate effects of the mesonic loop corrections of 1/N_c, which correspond to the next-to-leading order in the 1/N_c expansion, on the high density chiral phase transition. The corrections weaken the first

Andrew J. Blumberg, Michael A. Mandell

We prove a conjecture of Rognes by establishing a localization cofiber sequence of spectra, K(Z) to K(ku) to K(KU) to Sigma K(Z), for the algebraic K-theory of topological K-theory. We deduce the existence of this sequence as a consequence of a devissage theorem identifying the K-theory of the Waldhausen category of Postnikov towers of modules over a connect

D. J. Wineland, J. Britton, R. J. Epstein, D. Leibfried

We consider a method to reduce the kinetic energy in a low-order mode of a miniature cantilever. If the cantilever contributes to the capacitance of a driven RF circuit, a force on the cantilever exists due to the electric field energy stored in the capacitance. If this force acts with an appropriate phase shift relative to the motion of the cantilever, it c

Pawel Wocjan, Shengyu Zhang

A central problem in quantum computing is to identify computational tasks which can be solved substantially faster on a quantum computer than on any classical computer. By studying the hardest such tasks, known as BQP-complete problems, we deepen our understanding of the power and limitations of quantum computers. We present several BQP-complete problems, in

B. Roy, P. Roy

We use the Gazeau-Klauder formalism to construct coherent states of non-Hermitian quantum systems. In particular we use this formalism to construct coherent state of a PT symmetric system. We also discuss construction of coherent states following Klauder&#39;s minimal prescription.

Chang-Ho Hong, Hyung-Jin Yang

In 2004, Ba An Nguyen [Phys. Lett. A 328, 6-10] has presented a Quantum Dialogue scheme for simultaneously communicating their messages. In this comment, we show that the quantum dialogue scheme is not secure against the intercept-and-resend attack and we propose a modified scheme which is secure against that attack.

Jan Bouda, Josef Sprojcar

We propose a protocol for anonymous distribution of quantum information which can be used in two modifications. In the first modification the receiver of the message is publicly known, but the sender remains unknown (even to receiver). In the second modification the sender is known, but the receiver is unknown (even to sender). Our protocol achieves this goa

Stephen Jewson, Jeremy Penzer, Christopher Casey

In previous work, we have shown how to combine long and short historical baselines to make predictions of future hurricane numbers. We now ask: how should such combinations change if we are interested in predicting the future number of intense hurricanes?

Frank W. Bentrem, William E. Avera, John Sample

We detail acoustic backscatter processing for characterization and mapping of the ocean bottom.

Piotr Fronczak, Agata Fronczak, Janusz A. Holyst

Using data retrieved from the INSPEC database we have quantitatively discussed a few syndromes of the publish-or-perish phenomenon, including continuous growth of rate of scientific productivity, and continuously decreasing percentage of those scientists who stay in science for a long time. Making use of the maximum entropy principle and fluctuation-dissipat

Florian Dufey

An old classical one-particle helix model for optical activity, first proposed by Drude, is reconsidered here. The quantum Drude model is very instructive because the optical activity can be calculated analytically without further approximations apart from the Rosenfeld long wavelength approximation. While it was generally believed that this model, when trea

Jonathan Meagher, Stephen Jewson

One possible method for the year-ahead prediction of hurricane numbers would be to make a year-ahead prediction of sea surface temperature (SST), and then to apply relationships that link SST to hurricane numbers. As a first step towards setting up such a system this article compares three simple statistical methods for the year-ahead prediction of the relev

W. R. Gibbs, B. Loiseau

The contribution of the box and crossed two-pion-exchange diagrams to proton-proton scattering at 90$^{\circ}_{c.m.}$ is calculated in the laboratory momentum range up to 12 GeV/c. Relativistic form factors related to the nucleon and pion size and representing the pion source distribution based on the quark structure of the hadronic core are included at each

A. Sibirtsev, H. -W. Hammer, U. -G. Meißner, A. W. Thomas

We study coherent and incoherent phi-meson photoproduction from nuclei. The available data are analyzed in terms of single and coupled channel photoproduction. It is found that the data on coherent photoproduction can be well reproduced within a single channel optical model and show only little room for omega-phi mixing. These data indicate a normal distorti

M. Valverde, J. E. Amaro, J. Nieves, C. Maieron

We use a correlated local Fermi gas (LFG) model, which accounts also for long distance corrections of the RPA type and final-state interactions, to compute the polarization of the final lepton in charged-current quasielastic neutrino scattering. The present model has been successfully used in recent studies of inclusive neutrino nucleus processes and muon ca

G. P. Kamuntavicius, A. Masalaite, S. Mickevicius

We start from a system of six interacting constituent quarks and examine how the picture of two nucleons can change when substructure of the nucleons are taken into account.

J. M. Yao, H. Chen, J. Meng

The time-odd triaxial relativistic mean field approach is developed and applied to the investigation of the ground-state properties of light odd-mass nuclei near the double-closed shells. The nuclear magnetic moments including the isoscalar and isovector ones are calculated and good agreement with Schmidt values is obtained. Taking $^{17}$F as an example, th

Bin Zhang

J/psi production and collective flow is studied with a coalescence model based on phase space distribution of charm quarks from a multi-phase transport model simulation of relativistic heavy ion collisions. Both the yield and the flow of J/psi particles are sensitive to charm quark final state interactions. As the charm quark rescattering cross section incre