January 2009 arXiv papers — page 40

Khaled Elbassioni, Rajiv Raman, Saurabh Ray, Rene Sitters

In the \emph{tollbooth problem}, we are given a tree $\bT=(V,E)$ with $n$ edges, and a set of $m$ customers, each of whom is interested in purchasing a path on the tree. Each customer has a fixed budget, and the objective is to price the edges of $\bT$ such that the total revenue made by selling the paths to the customers that can afford them is maximized. A

Edmund A. Di Marzio

The Lorentz transformation is derived without assuming the existence of Maxwell's equations, or that the speed of light is a constant, or even that light exists. This leads us logically to sonsider the existence of a primal field called stuff which at every space-time point is traveling in every posssible direction with the speed of light. All physical q

Ayah Lazar, Ehud Nakar, Tsvi Piran

Randomly oriented relativistic emitters in a relativistically expanding shell provides an alternative to internal shocks as a mechanism for producing GRBs' variable light curves with efficient conversion of energy to radiation. In this model the relativistic outflow is broken into small emitters moving relativistically in the outflow's rest frame. Va

Han Frederic

References to the works of Iliev-Ranestad and Kuznetsov added. ----- In a first part we detail the construction, on a general Fano 4-fold of genus 9, of a canonical set of four stable vector bundles of rank 2, and prove that they are rigid. Those results were already known by Iliev-Ranestad and Kuznetsov with different purposes. In a second part we show that

Ilia Gogoladze, Rizwan Khalid, Qaisar Shafi, Hasan Yuksel

Dark matter neutralinos in the constrained minimal supersymmetric model (CMSSM) may account for the recent cosmic ray electron and positron observations reported by the PAMELA and ATIC experiments either through self annihilation or via decay. However, to achieve this, both scenarios require new physics beyond the 'standard' CMSSM, and a unified expl

Benjamin K. Tippett

The Penrose inequality has so far been proven in cases of spherical symmetry and in cases of zero extrinsic curvature. The next simplest case worth exploring would be non-spherical, non-rotating black holes with non-zero extrinsic curvature. Following Karkowski et al.'s construction of prolate black holes, we define initial data on an asymptotically flat

Sandy Irani

We examine whether it is possible for one-dimensional translationally-invariant Hamiltonians to have ground states with a high degree of entanglement. We present a family of translationally invariant Hamiltonians {H_n} for the infinite chain. The spectral gap of H_n is Omega(1/poly(n)). Moreover, for any state in the ground space of H_n and any m, there are

Domagoj Kuic

Generalized virial theorem for quantum mechanical nonrelativistic and relativistic systems with translational and rotational symmetry is derived in the form of the commutator between the generator of dilations G and the Hamiltonian H. If the conditions of translational and rotational symmetry together with the additional conditions of the theorem are satisfi

Chuanwei Zhang, Sumanta Tewari, S. Das Sarma

We consider the anomalous thermoelectric transport in gapped single and bilayer graphene where the gap may be due to broken inversion symmetry. In the presence of the gap, non-trivial Berry phase effects can be shown to mediate a transverse thermoelectric voltage in response to an applied temperature gradient even in the absence of a perpendicular magnetic f

Tomas Liko

We study the mechanics of D-dimensional isolated horizons (IHs) for Einstein gravity in the presence of arbitrary p-form matter fields. This generalizes the analysis of Copsey and Horowitz to non-stationary spacetimes and therefore the local first law to include non-monopolar (dipole) charges. The only requirement for the local first law to hold is that the

John Ellis

Almost all extensions of the Standard Model predict the existence of charged Higgs bosons. This talk focuses on the minimal supersymmetric extension of the Standard Model (MSSM), which is relatively predictive. The outlook for detecting supersymmetric particles and Higgs bosons at the LHC are discussed, as are the prospects for finding indirect effects of su

Daniel R. Reynolds, John C. Hayes, Pascal Paschos, Michael L. Norman

We consider a PDE system comprising compressible hydrodynamics, flux-limited diffusion radiation transport and chemical ionization kinetics in a cosmologically-expanding universe. Under an operator-split framework, the cosmological hydrodynamics equations are solved through the Piecewise Parabolic Method, as implemented in the Enzo community hydrodynamics co

Z. C. Tu

The elastic, piezoelectric, electronic, and optical properties of a single ZnO monolayer (SZOML) with graphene-like structure are investigated from the first-principles calculations. The phonon dispersion curves contain three acoustic and three optical branches. At $Γ$ point, the out-of-plane acoustic mode has an asymptotic behavior $ω(q)=Bq^2$ with $B=1.385

Daniel Gottesman, M. B. Hastings

We study the relationship between entanglement and spectral gap for local Hamiltonians in one dimension. The area law for a one-dimensional system states that for the ground state, the entanglement of any interval is upper-bounded by a constant independent of the size of the interval. However, the possible dependence of the upper bound on the spectral gap De

Sean M. Carroll, Matthew C. Johnson, Lisa Randall

Taking the extremal limit of a non-extremal Reissner-Nordstr\"om black hole (by externally varying the mass or charge), the region between the inner and outer event horizons experiences an interesting fate -- while this region is absent in the extremal case, it does not disappear in the extremal limit but rather approaches a patch of $AdS_2\times S^2$. In ot

Pedro D. Alvarez, Jose L. Cortes, Peter A. Horvathy, Mikhail S. Plyushchay

A supersymmetric spin-1/2 particle in the noncommutative plane, subject to an arbitrary magnetic field, is considered, with particular attention paid to the homogeneous case. The system has three different phases, depending on the magnetic field. Due to supersymmetry, the boundary critical phase which separates the sub- and super-critical cases can be viewed

P. Sikivie, Q. Yang

We show that cold dark matter axions thermalize and form a Bose-Einstein condensate. We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC, axions differ from ordinary cold dark matter in the non-linear regime of structure formation and upon entering the horizo

Lijun Gou, Jeffrey E. McClintock, Jifeng Liu, Ramesh Narayan

The first extragalactic X-ray binary, LMC X-1, was discovered in 1969. In the 1980s, its compact primary was established as the fourth dynamical black-hole candidate. Recently, we published accurate values for the mass of the black hole and the orbital inclination angle of the binary system. Building on these results, we have analyzed 53 X-ray spectra obtain

T. Vogel

In \cite{confol} Y. Eliashberg and W. Thurston gave a definition of tight confoliations. We give an example of a tight confoliation $ξ$ on $T^3$ violating the Thurston-Bennequin inequalities. This answers a question from \cite{confol} negatively. Although the tightness of a confoliation does not imply the Thurston-Bennequin inequalities, it is still possible

Damiano Testa, Anthony Várilly-Alvarado, Mauricio Velasco

We prove that the Cox ring of a smooth rational surface with big anticanonical class is finitely generated. We classify surfaces of this type that are blow-ups of the plane at distinct points lying on a (possibly reducible) cubic.

Marco Roncadelli, Aldo Treves, Roberto Turolla

We derive a strong upper bound on the amount of Primordial Black Holes (PBHs) that can still be present in the Universe. Gravitational capture of PBHs by the Milky Way stars during their formation and subsequent accretion would produce a dramatic depletion of disk stars and especially of white dwarfs, unless the average cosmic density and mass of PBHs are se

Einan Gardi, Lorenzo Magnea

We study the factorization of soft and collinear singularities in dimensionally-regularized fixed-angle scattering amplitudes in massless gauge theories. Our factorization is based on replacing the hard massless partons by light-like Wilson lines, and defining gauge-invariant jet and soft functions in dimensional regularization. In this scheme the factorized

Monica Tosi

The colour-magnitude diagrams of resolved stellar populations are the best tool to study the star formation histories of the host galactic regions. In this review the method to derive star formation histories by means of synthetic colour-magnitude diagrams is briefly outlined, and the results of its application to resolved galaxies of various morphological t

L. Ciotti, J. P. Ostriker, D. Proga

The importance of the radiative feedback from SMBHs at the centers of elliptical galaxies is not in doubt, given the well established relations among electromagnetic output, black hole mass and galaxy optical luminosity. In addition, feedback due to mechanical and thermal deposition of energy from jets and winds emitted by the accretion disk around the centr

H. Uhrenholt, S. Åberg, P. Möller, T. Ichikawa

A microscopic nuclear level-density model is presented. The model is a completely combinatorial (micro-canonical) model based on the folded-Yukawa single-particle potential and includes explicit treatment of pairing, rotational and vibrational states. The microscopic character of all states enables extraction of level distribution functions with respect to p

M. Giersz, D. C. Heggie

We describe Monte Carlo models for the dynamical evolution of the nearby globular cluster NGC 6397. The code includes treatments of two-body relaxation, most kinds of three- and four-body interactions involving primordial binaries and those formed dynamically, the Galactic tide, and the internal evolution of both single and binary stars. We arrive at a set o

Ramon van Handel

The nonlinear filter for an ergodic signal observed in white noise is said to achieve maximal accuracy if the stationary filtering error vanishes as the signal to noise ratio diverges. We give a general characterization of the maximal accuracy property in terms of various systems theoretic notions. When the signal state space is a finite set explicit necessa

M. O. Goerbig, J. -N. Fuchs, G. Montambaux, F. Piechon

The relativistic Landau levels in the layered organic material alpha-(BEDT-TTF)_2I_3 [BEDT-TTF=bis(ethylenedithio)tetrathiafulvalene] are sensitive to the tilt of the Dirac cones, which, as in the case of graphene, determine the low-energy electronic properties under appropriate pressure. We show that an applied inplane electric field, which happens to be in

B. S. Ham, J. Hahn

Ultralong trapping of light has been observed in an optically dense three-level solid medium interacting with a pair of counterpropagating coupling fields. Unlike the light trapping based on standing-wave gratings excited by the same frequency pair of counterpropagating light fields (M. Bajcsy et al., Nature 426, 638 (2003)), the present method uses resonant

Eri Asakawa, Masaki Asano, Keisuke Fujii, Tomonori Kusano

We investigate a possibility of precision measurements for parameters of the Littlest Higgs model with T-parity at the International Linear Collider (ILC). The model predicts new gauge bosons (AH, ZH, and WH), among which the heavy photon (AH) is a candidate for dark matter. The masses of these new gauge bosons strongly depend on the vacuum expectation value

S. Morisi

We consider a model based on A4 semidirect product (Ze x Zmu x Ztau) flavor symmetry for Tri-Bimaximal lepton mixing with two scalar A4-triplets whose vacuum expectation values have the same alignment. Neutrino masses are generated through effective dimension five Weinberg operators. Charged leptons mass hierarchies are generated with an additional Froggatt-

Elisa Bernardini

IceCube is a cubic-kilometer neutrino telescope under construction at the geographic South Pole. Once completed it will comprise 4800 optical sensors deployed on 80 vertical strings at depths in the ice between 1450 and 2450 meters. Part of the array is already operational and data was recorded in the configurations with 9 (year 2006/2007), 22 (year 2007/200

Itaï Ben Yaacov, Alexander Berenstein, Stefano Ferri

It is well-known that a topological group can be represented as a group of isometries of a reflexive Banach space if and only if its topology is induced by weakly almost periodic functions (see \cite{Shtern:CompactSemitopologicalSemigroups}, \cite{Megrelishvili:OperatorTopologies} and \cite{Megrelishvili:TopologicalTransformations}). We show that for a metri

Ruth Gregory, Armalivia Leksono, Bina Mistry

We explore the problem of braneworld black holes in the heterotic braneworld scenario of Lukas, Ovrut, Stelle and Waldram (LOSW). We show that black string solutions are unstable, and demonstrate some unusual asymptotics in the linearized metric. We also solve the fully coupled brane and bulk Einstein equations, finding an exact, though singular, solution wh

Robert Balawender, Andrzej Holas

A general formulation of the equilibrium state of a many-electron system in terms of a (mixed-state, ensemble) density matrix operator in the Fock space, based on the maximum entropy principle, is introduced. Various characteristic functions/functionals are defined and investigated: the basic Massieu function for fully open thermodynamic system (ensemble), t

Julien Bringer, Herve Chabanne, Bruno Kindarji

Biometrics make human identification possible with a sample of a biometric trait and an associated database. Classical identification techniques lead to privacy concerns. This paper introduces a new method to identify someone using his biometrics in an encrypted way. Our construction combines Bloom Filters with Storage and Locality-Sensitive Hashing. We appl

G. Kaniadakis

It is well known that the particular form of the two-particle correlation function, in the collisional integral of the classical Boltzmman equation, fix univocally the entropy of the system, which turn out to be the Boltzmann-Gibbs-Shannon entropy. In the ordinary relativistic Boltzmann equation, some standard generalizations, with respect its classical vers

O. Sikora, F. Pollmann, N. Shannon, K. Penc

Excitations which carry "fractional" quantum numbers are known to exist in one dimension in polyacetylene, and in two dimensions, in the fractional quantum Hall effect. Fractional excitations have also been invoked to explain the breakdown of the conventional theory of metals in a wide range of three-dimensional materials. However the existence of fr

A. Frankowski, B. Famaey, S. Van Eck, M. Mayor

This paper is the second one in a series devoted to the study of properties of binaries involving M giants. The binary frequency of field M giants is derived and compared with the binary fraction of K giants. Diagrams of the CORAVEL spectroscopic parameter Sb (measuring the average line-width) vs. radial-velocity standard deviation for our samples are used t

Mitsuhiro Miyazaki

We define the concept of a doset Hibi ring and a generalized doset Hibi ring which are subrings of a Hibi ring and are normal affine semigrouprings. We apply the theory of (generalized) doset Hibi rings to analyze the rings of absolute orthogonal invariants and absolute special orthogonal invariants and show that these rings are normal and Cohen-Macaulay and

E. Donth

A new thermodynamics for liquids related to von Laue's approach (1917) substitutes some particle priors of Gibb's rational thermodynamics. This allows the definition of a new dynamic entity ($G$ defect) whose diffusion properties also claim a largest causal region ($F$ speckle). In the frame of the hidden charge model \cite{this part} it is discussed

K. S. Babu, Yanzhi Meng, Zurab Tavartkiladze

We show that in supersymmetric models with gauged B-L symmetry, there is a new source for cosmological lepton asymmetry. The Higgs bosons responsible for B-L gauge symmetry breaking decay dominantly into right-handed sneutrinos \tilde{N} and \tilde{N}* producing an asymmetry in \tilde{N} over \tilde{N}*. This can be fully converted into ordinary lepton asymm

E. Donth

Culminating-point filter construction for particle points is distinguished from torus construction for wave functions in the tangent objects of their neighborhoods. Both constructions are not united by a general manifold diffeomorphism, but are united by a map of a hidden conformal $S^{1}\times S^{3}$ charge with harmonic (Maxwell) potentials into a physical

Raanan Nordon, Ehud Behar, Noam Soker, Joel H. Kastner

X-rays from planetary nebulae (PNs) are believed to originate from a shock driven into the fast stellar wind (v ~ 1000 km/s) as it collides with an earlier circumstellar slow wind (v ~ 10 km/s). In theory, the shocked fast wind (hot bubble) and the ambient cold nebula can remain separated by magnetic fields along a surface referred to as the contact disconti

Prasanta K. Panigrahi, Vivek M. Vyas, T. Shreecharan

We show that the gauge field induced due to non-uniform hopping, in gapped graphene, can give rise to a non-BCS type of superconductivity. Unlike the conventional mechanisms, this superconductivity phenomena does not require any pairing. We estimate the critical temperature for superconducting-to-normal transition via Berezinskii-Kosterlitz-Thouless mechanis

Jong-Phil Lee

Unparticles are realized by deconstruction in higher extra dimensions. It is shown that in this framework when the scale invariance is broken, the corresponding spectral function of the unparticle is shifted by an amount of the breaking scale. The result strongly supports the conventional ansatz for the spectral function of the unparticle in the literature.

Santanu K. Maiti

Quantum transport for different models of isomer molecules attached to two semi-infinite leads is studied on the basis of Green's function technique. Electronic transport properties are significantly affected by (a) the relative position of the atoms in these molecules and (b) the molecule-to-lead coupling strength of these molecular bridge systems.

Stephan Hoyer, David A. Meyer

We give the first example of faster transport with a quantum walk on an inherently directed graph, on the directed line with a variable number of self-loops at each vertex. These self-loops can be thought of as adding a number of small dimensions. This is a discrete time quantum walk using the Fourier transform coin, where the walk proceeds a distance $Θ(1)$

Bojan Mohar, Jesus Salas

We prove that for the class of three-colorable triangulations of a closed oriented surface, the degree of a four-coloring modulo 12 is an invariant under Kempe changes. We use this general result to prove that for all triangulations T(3L,3M) of the torus with 3<= L <= M, there are at least two Kempe equivalence classes. This result implies in particular that

Stefan Müller

We prove that a compactly supported homeomorphism of a smooth manifold of dimension greater or equal to 5 can be approximated uniformly by compactly supported diffeomorphisms if and only if it is isotopic to a diffeomorphism. If the given homeomorphism is in addition volume preserving, then it can be approximated uniformly by volume preserving diffeomorphism

Benny Walther, Bernd Bruegmann, Doreen Mueller

Black hole binaries on non-eccentric orbits form an important subclass of gravitational wave sources, but it is a non-trivial issue to construct numerical initial data with minimal initial eccentricity for numerical simulations. We compute post-Newtonian orbital parameters for quasi-spherical orbits using the method of Buonanno, Chen and Damour (2006) and ex

M. Moniez

We present the results of the EROS2 search for the hidden galactic matter of the halo through the gravitational microlensing of stars in the Magellanic clouds. Microlensing was also searched for and found in the Milky-Way plane, where foreground faint stars are expected to lens background stars. A total of 67 million of stars were monitored over a period of

Petre Dita

A novel method to obtain parametrizations of complex inverse orthogonal matrices is provided. These matrices are natural generalizations of complex Hadamard matrices which depend on non zero complex parameters. The method we use is via doubling the size of inverse complex conference matrices. When the free parameters take values on the unit circle the invers

Yoshihisa Kitazawa, Toshikazu Negi

We investigate the vertex operators of the supergravity multiplet in IIB(IKKT) matrix model by calculating the disk amplitudes, exploiting the technique of conformal field theory. The vertex operators of IIB matrix model are given as the coupling of a closed string and open strings which are introduced by the existence of D(-1)-branes. We consider the most g

Shaaban Khalil, Hye-Sung Lee, Ernest Ma

In a left-right gauge model of particle interactions, the left-handed fermion doublet (nu,e)_L is connected to its right-handed counterpart (n,e)_R through a scalar bidoublet so that e_L pairs with e_R, and nu_L with n_R to form mass terms. Suppose the latter link is severed without affecting the former, then n_R is not the mass partner of nu_L, and as we sh

Takashi Hirai

Josephson current in superconductor/insulator/superconductor junction is studied theoretically. It is well known that when the zero-energy resonance state exists both side of superconducting interface, the behaver of the temperature dependence of the critical Josephson current is striking enhancement at low temperature. On the other hand it is reported that

T. P. Singh

The cosmological constant problem is principally concerned with trying to understand how the zero-point energy of quantum fields contributes to gravity. Here we take the approach that by addressing a fundamental unresolved issue in quantum theory we can gain a better understanding of the problem. Our starting point is the observation that the notion of class

G. C. Tewari, T. S. Tripathi, A. K. Rastogi

The electrical, thermal conductivity and Seebeck coefficient of the quenched, annealed and slowly cooled phases of the layer compound CuCrS2 have been reported between 15K to 300K. We also confirm the antiferromagnetic transition at 40K in them by our magnetic measurements between 2K and 300K. The crystal flakes show a minimum around 100K in their in-plane r

S. V. Anathpindika

In this second paper of the sequel of two papers, we further investigate the problem of molecular cloud (MC) collision. Anathpindika (2009) (hereafter paper I) considered highly supersonic cloud collisions and examined the effect of bending and shearing instabilities on the shocked gas slab. We now consider moderately supersonic cloud collisions (precollisio

Y. Juarez, R. Maiolino, R. Mujica, M. Pedani

We investigate the metallicity of the broad line region (BLR) of a sample of 30 quasars in the redshift range 4<z<6.4, by using near-IR and optical spectra. We focus on the ratio of the broad lines (SiIV1397+OIV]1402)/CIV1549, which is a good metallicity tracer of the BLR. We find that the metallicity of the BLR is very high even in QSOs at z~6. The inferred

J. Farihi, M. Jura, B. Zuckerman

Spitzer Space Observatory IRAC and MIPS photometric observations are presented for 20 white dwarfs with T < 20,000 K and metal-contaminated photospheres. A warm circumstellar disk is detected at GD 16 and likely at PG 1457-086, while the remaining targets fail to reveal mid-infrared excess typical of dust disks, including a number of heavily polluted stars.

Mitsutoshi Fujita, Wei Li, Shinsei Ryu, Tadashi Takayanagi

We present three holographic constructions of fractional quantum Hall effect (FQHE) via string theory. The first model studies edge states in FQHE using supersymmetric domain walls in N=6 Chern-Simons theory. We show that D4-branes wrapped on CP^1 or D8-branes wrapped on CP^3 create edge states that shift the rank or the level of the gauge group, respectivel

Robert L. Griess

Given a rational lattice and suitable set of linear transformations, we construct a cousin lattice. Sufficient conditions are given for integrality, evenness and unimodularity. When the input is a Barnes-Wall lattice, we get multi-parameter series of cousins. There is a subseries consisting of unimodular lattices which have ranks $2^{d-1}\pm 2^{d-k-1}$, for

Davide Gaiotto, Alessandro Tomasiello

We deform the recently proposed holographic duality between the ABJM N=6 Chern-Simons-matter theory and type IIA string theory in AdS4xCP3. We add a non-zero Romans mass F_0, whose dual we identify as the sum of the Chern-Simons levels for the two gauge groups. One can naturally identify four different theories, with different amounts of supersymmetry and of

Herbert W. Hamber

I review the lattice approach to quantum gravity, and how it relates to the non-trivial ultraviolet fixed point scenario of the continuum theory. After a brief introduction covering the general problem of ultraviolet divergences in gravity and other non-renormalizable theories, I cover the general methods and goals of the lattice approach. An underlying them

J. L. Han, P. B. Demorest, W. van Straten, A. G. Lyne

We report on polarimetric observations of 100 pulsars centered on 774 MHz, made using the Green Bank Telescope, presenting their polarization profiles and polarized flux densities and comparing them with previous observations when possible. For 67 pulsars, these are the first such measurements made. Polarization profiles of 8 millisecond pulsars in our sampl

C. Erven, X. Ma, R. Laflamme, G. Weihs

We investigate a quantum key distribution (QKD) scheme which utilizes a biased basis choice in order to increase the efficiency of the scheme. The optimal bias between the two measurement bases, a more refined error analysis, and finite key size effects are all studied in order to assure the security of the final key generated with the system. We then implem

Marcelo Muniz S. Alves, Eliezer Batista

Partial actions of Hopf algebras can be considered as a generalization of partial actions of groups on algebras. Among important properties of partial Hopf actions, it is possible to assure the existence of enveloping actions. This allows to extend several results from the theory of partial group actions to the Hopf algebraic setting. In this article, we exp

Dmytro Gavinsky

We present a two-player communication task that can be solved by a protocol of polylogarithmic cost in the simultaneous message passing model with classical communication and shared entanglement, but requires exponentially more communication in the classical interactive model. Our second result is a two-player nonlocality game with input length $n$ and outpu

Guo-Yong Zhang, Yong Chen, Wei-Kai Qi, Shao-Meng Qin

We study the cyclic dominance of three species in two-dimensional constrained Newman-Watts networks with a four-state variant of the rock-paper-scissors game. By limiting the maximal connection distance $R_{max}$ in Newman-Watts networks with the long-rang connection probability $p$, we depict more realistically the stochastic interactions among species with

Peter Elliott, Kieron Burke, Morrel H. Cohen, Adam Wasserman

Partition density functional theory is a formally exact procedure for calculating molecular properties from Kohn-Sham calculations on isolated fragments, interacting via a global partition potential that is a functional of the fragment densities. An example is given and consequences discussed.

Casey Blood

In the many-worlds interpretations (MWIs) of Everett and others, if I am the observer, there are several versions of me but no version is singled out as the one corresponding to my perceptions. However, it can be shown that the probability law implies one version must be singled out. Thus MWIs do not provide a sufficient basis for probability. If we are to h

Victor Eliashberg

The paper tackles four basic questions associated with human brain as a learning system. How can the brain learn to (1) mentally simulate different external memory aids, (2) perform, in principle, any mental computations using imaginary memory aids, (3) recall the real sensory and motor events and synthesize a combinatorial number of imaginary events, (4) dy

N. Lyaskovska

By definition, the sharp packing index $\ind_P^\sharp(A)$ of a subset $A$ of an abelian group $G$ is the smallest cardinal $κ$ such that for any subset $B\subset G$ of size $|B|\geκ$ the family $\{b+A:b\in B\}$ is not disjoint. We prove that an infinite Abelian group $G$ contains a subset $A$ with given index $\ind_P^\sharp(A)=κ$ if and only if one of the fo

Anthony J. Annunziata, Daniel F. Santavicca, Joel D. Chudow, Luigi Frunzio

We investigate the performance of superconducting nanowire photon detectors fabricated from ultra-thin Nb. A direct comparison is made between these detectors and similar nanowire detectors fabricated from NbN. We find that Nb detectors are significantly more susceptible than NbN to thermal instability (latching) at high bias. We show that the devices can be

Baris Altunkaynak, Phillip Grajek, Michael Holmes, Gordon Kane

We begin a systematic study of how gaugino mass unification can be probed at the CERN Large Hadron Collider (LHC) in a quasi-model independent manner. As a first step in that direction we focus our attention on the theoretically well-motivated mirage pattern of gaugino masses, a one-parameter family of models of which universal (high scale) gaugino masses ar

Nick Indriolo, Brian D. Fields, Benjamin J. McCall

Diffuse interstellar clouds show large abundances of H_3^+ which can be maintained only by a high ionization rate of H_2. Cosmic rays are the dominant ionization mechanism in this environment, so the large ionization rate implies a high cosmic-ray flux, and a large amount of energy residing in cosmic rays. In this paper we find that the standard propagated c

H. S. Liszt

Methods: The microscopic equations of H2-formation and protonation are integrated numerically over time in such a manner that the overall structures evolve self-consistently under benign conditions. Results: The equilibrium H2 formation timescale in an H I cloud with N(H) ~ 4x10^{20}/cm^2 is 1-3 x 10^7 yr, nearly independent of the assumed density or H2 form

Su Ying Quek, Maria Kamenetska, Michael L. Steigerwald, Hyoung Joon Choi

Molecular-scale components are expected to be central to nanoscale electronic devices. While molecular-scale switching has been reported in atomic quantum point contacts, single-molecule junctions provide the additional flexibility of tuning the on/off conductance states through molecular design. Thus far, switching in single-molecule junctions has been attr

John P. Blakeslee, Andres Jordan, Simona Mei, Patrick Cote

We present g-z color and z-band surface brightness fluctuations (SBF) measurements for 43 early-type galaxies in the Fornax cluster imaged with HST/ACS. These are combined with measurements for Virgo cluster galaxies to derive a revised, nonlinear calibration of the z-band SBF absolute magnitude as a function of g-z. In all, we tabulate recalibrated SBF dist

Norberto Gutierrez, Yolanda Lozano

We present a worldvolume effective action suitable for the study of the confined phase of a (Dp,anti-Dp) system at weak coupling, and we identify the mechanism by which the fundamental string arises from this action when the Dp and the anti-Dp annihilate. We construct an explicit dual action, appropriate for the strong coupling regime, which realizes a gener

M. Kamenetska, M. Koentopp, A. C. Whalley, Y. S. Park

We analyze the formation and evolution statistics of single molecule junctions bonded to gold electrodes using amine, methyl sulfide and dimethyl phosphine link groups by measuring conductance as a function of junction elongation. For each link, maximum elongation and formation probability increase with molecular length, strongly suggesting that processes ot

C. M. V. Impellizzeri, J. P. McKean, P. Castangia, A. L. Roy

Water masers are found in dense molecular clouds closely associated with supermassive black holes in the centres of active galaxies. Based upon the understanding of the local water maser luminosity function, it was expected that masers at intermediate and high redshifts would be extremely rare, but galaxies at redshifts z > 2 might be quite different from th

Oleg L. Berman, Godfrey Gumbs, P. M. Echenique

We calculate the low-frequency magnetoplasmon excitation spectrum for a square array of quantum dots on a two-dimensional (2D) graphene layer. The confining potential is linear in the distance from the center of the quantum dot. The electron eigenstates in a magnetic field and confining potential are mapped onto a 2D plane of electron-hole pairs in an effect

Oleg R. Musin

I. J. Schoenberg proved that a function is positive definite in the unit sphere if and only if this function is a nonnegative linear combination of Gegenbauer polynomials. This fact play a crucial role in Delsarte&#39;s method for finding bounds for the density of sphere packings on spheres and Euclidean spaces. One of the most excited applications of Delsar

David Andriot

We study Minkowski supersymmetric flux vacua of type II string theory. Based on the work by M. Grana, R. Minasian, M. Petrini and A. Tomasiello, we briefly explain how to reformulate things in terms of Generalized Complex Geometry, which appears to be a natural framework for these compactifications. In particular, it provides a mathematical characterization

Fabio Bresolin, Emma Ryan-Weber, Robert C. Kennicutt, Quinton Goddard

We have obtained deep multi-object optical spectra of 49 HII regions in the outer disk of the spiral galaxy M83 (=NGC 5236) with the FORS2 spectrograph at the Very Large Telescope. The targets span the range in galactocentric distance between 0.64 and 2.64 times the R25 isophotal radius (5.4-22.3 kpc), and 31 of them are located at R>R25, thus belonging to t

J. Lorenzo Diaz-Cruz

We suggest that dark matter can be identified with a stable composite fermion X^0, that arises within the holographic AdS/CFT models, where the Higgs boson emerges as a composite pseudo-goldstone boson. The predicted properties of X^0 satisfies the cosmological bounds, with m_X = O(TeV). Thus, through a deeper understanding of the mechanism of electroweak sy

A. Z. Msezane, Z. Felfli, D. Sokolovski

A novel method is proposed that uses very slow electron elastic collisions with atoms to identify their presence through the observation of tenuously bound (electron impact energy, E<0.1 eV) and weakly bound (E<1 eV) negative ions, formed as Regge resonances during the collisions.

Arash Hariri, K. Navi, Reza Rastegar

-Residue Number System (RNS) is a valuable tool for fast and parallel arithmetic. It has a wide application in digital signal processing, fault tolerant systems, etc. In this work, we introduce the 3-moduli set {2^n, 2^{2n}-1, 2^{2n}+1} and propose its residue to binary converter using the Chinese Remainder Theorem. We present its simple hardware implementat

Dennis Bessada, Oswaldo D. Miranda

We study in this paper three different theories of gravitation with massive gravitons - the modified Fierz-Pauli (FP) model, Massive Gravity and the bimetric theory proposed by Visser - in linear perturbation theory around a Minkowski and a flat FRW background. For the TT tensor perturbations we show that the three theories give rise to the same dynamical eq

A. A. Vidotto, M. Opher, V. Jatenco-Pereira, T. I. Gombosi

We investigate magnetized solar-like stellar winds by means of self-consistent three-dimensional (3D) magnetohydrodynamics (MHD) numerical simulations. We analyze winds with different magnetic field intensities and densities as to explore the dependence on the plasma-beta parameter. By solving the fully ideal 3D MHD equations, we show that the plasma-beta pa

Gerald A. Miller

We relate the three-dimensional infinite momentum frame spatial charge density of the pion to its electromagnetic form factor. Diverse treatments of the measured form factor data including: phenomenological fits, non-relativistic quark models, the application of perturbative QCD, QCD sum rules, holographic QCD, and the Nambu Jona-Lasinio (NJL) model all lead

H. S. Liszt

Context: Over the past thirty years a wealth of observations of CO and other molecules in optical/uv absorption in diffuse clouds has accumulated for which no comparable CO emission line data exist. Aims: To acquire mm-wave J=1-0 CO emission line profiles toward a substantial sample of commonly-studied optical/uv absorption line targets and to compare with t

Jan Perina, Jaromir Krepelka, Jan Perina, Maria Bondani

Two strongly-pumped parametric interactions are simultaneously realized in a single nonlinear crystal in order to generate three strongly correlated optical fields. By combining together the outputs of two of the three detectors measuring intensities of the generated fields, we obtain the joint photocount statistics between the single field and the sum of th

Vilmos Komornik, Anna Chiara Lai, Marco Pedicini

Expansions in noninteger bases often appear in number theory and probability theory, and they are closely connected to ergodic theory, measure theory and topology. For two-letter alphabets the golden ratio plays a special role: in smaller bases only trivial expansions are unique, whereas in greater bases there exist nontrivial unique expansions. In this pape

H. S. Liszt

Aims: We show the existence of a small family of inner-galaxy dust lanes and dust lane standing shocks beyond the two major ones that were previously known to exist Methods: We analyze images of CO emission in the inner regions of the Galaxy Results: The peculiar kinematics of the major dust lane features are repeated in several other distinct instances at l

H. S. Liszt, J. Pety, K. Tachihara

Methods: 12CO emission is imaged in position and position-velocity space analyzed statistically, and then compared with maps of total reddening and with models of the C+ - CO transition in H2-bearing diffuse clouds. Results: Around Zeta Oph, 12CO emission appears in two distinct intervals of reddening centered near EBV = 0.4 and 0.65 mag, of which < 0.2 mag

Audrey Galametz, Daniel Stern, Peter R. M. Eisenhardt, Mark Brodwin

We present the surface density of luminous active galactic nuclei (AGN) associated with a uniformly selected galaxy cluster sample identified in the 8.5 square degree Bootes field of the NOAO Deep Wide-Field Survey. The clusters are distributed over a large range of redshift (0 < z < 1.5) and we identify AGN using three different selection criteria: mid-IR c

A. M. Bigatti, M. Caboara, L. Robbiano

In this paper we describe how an idea centered on the concept of self-saturation allows several improvements in the computation of Groebner bases via Buchberger&#39;s Algorithm.