March 2008 arXiv papers — page 10
Showing 901–1,000 of 4,524 papers
Gravitational collapse of a spherical star with heat flow as a possible energy mechanism of gamma-ray bursts
gr-qcZhe Chang, Cheng-Bo Guan, Chao-Guang Huang, Xin Li
We investigate the gravitational collapse of a spherically symmetric, inhomogeneous star, which is described by a perfect fluid with heat flow and satisfies the equation of state $p=ρ/3$ at its center. In the process of the gravitational collapsing, the energy of the whole star is emitted into space. And the remaining spacetime is a Minkowski one without a r
The Equivalence between Uniqueness and Continuous Dependence of Solution for BSDEs with Continuous Coefficient
math.PRGuangyan Jia, Zhiyong Yu
In this paper, we will prove that, if the coefficient $g=g(t,y,z)$ of a BSDE is assumed to be continuous and linear growth in $(y,z)$, then the uniqueness of solution and continuous dependence with respect to $g$ and the terminal value $ξ$ are equivalent.
Yeow Meng Chee, Son Hoang Dau, Alan C. H. Ling, San Ling
This correspondence introduces two new constructive techniques to complete the determination of the sizes of optimal q-ary codes of constant weight three and distance four.
Yeow Meng Chee, San Ling
The design of large libraries of oligonucleotides having constant GC-content and satisfying Hamming distance constraints between oligonucleotides and their Watson-Crick complements is important in reducing hybridization errors in DNA computing, DNA microarray technologies, and molecular bar coding. Various techniques have been studied for the construction of
R. -P. Kudritzki, M. A. Urbaneja, F. Bresolin, N. Przybilla
A supergiants are objects in transition from the blue to the red (and vice versa) in the uppermost HRD. They are the intrinsically brightest "normal" stars at visual light with absolute visual magnitudes up to -9. They are ideal to study young stellar populations in galaxies beyond the Local Group to determine chemical composition and evolution, inte
Quantitative Spectroscopy of 24 A supergiants in the Sculptor galaxy NGC 300: Flux weighted gravity luminosity relationship, metallicity and metallicity gradient
astro-phR. -P. Kudritzki, M. A. Urbaneja, F. Bresolin, N. Przybilla
A quantitative spectral analysis of 24 A supergiants in the Sculptor Group spiral galaxy NGC 300 at a distance of 1.9 Mpc is presented. A new method is introduced to analyze low resolution (~5 AE) spectra, which yields metallicities accurate to 0.2 dex including the uncertainties arising from the errors in Teff (5%) and log g (0.2 dex). For the first time th
The Directional Dependence of Apertures, Limits and Sensitivity of the Lunar Cherenkov Technique to a UHE Neutrino Flux
astro-phC. W. James, R. J. Protheroe
We use computer simulations to obtain the directional-dependence of the lunar Cherenkov technique for ultra-high energy (UHE) neutrino detection. We calculate the instantaneous effective area of past lunar Cherenkov experiments as a function of neutrino arrival direction, and hence the directional-dependence of the combined limit imposed by GLUE and the expe
Huaiyu Duan, George M. Fuller, J. Carlson
We discuss a new kind of astrophysical transport problem: the coherent evolution of neutrino flavor in core collapse supernovae. Solution of this problem requires a numerical approach which can simulate accurately the quantum mechanical coupling of intersecting neutrino trajectories and the associated nonlinearity which characterizes neutrino flavor conversi
Zarija Lukić, Darren Reed, Salman Habib, Katrin Heitmann
The dark matter halo mass function is a key repository of cosmological information over a wide range of mass scales, from individual galaxies to galaxy clusters. N-body simulations have established that the friends-of-friends (FOF) mass function has a universal form to a surprising level of accuracy (< 10%). The high-mass tail of the mass function is exponen
Sara C. Billey, Stephen A. Mitchell
We give a bijection between certain colored partitions and the elements in the quotient of an affine Weyl group modulo its Weyl group. By Bott's formula these colored partitions give rise to some partition identities. In certain types, these identities have previously appeared in the work of Bousquet-Melou-Eriksson, Eriksson-Eriksson and Reiner. In other
J. Trier Frederiksen
We present a numerical study of Gamma-Ray Burst - Circumburst Medium interaction and plasma preconditioning via Compton scattering. The simulation tool employed is a unique hybrid model; it combines a highly parallelized (Vlasov) particle-in-cell approach with continuous weighting of particles and a sub-Debye Monte-Carlo binary particle interaction framework
Hariharan Narayanan
We consider the question of averaging on a graph that has one sparse cut separating two subgraphs that are internally well connected. While there has been a large body of work devoted to algorithms for distributed averaging, nearly all algorithms involve only {\it convex} updates. In this paper, we suggest that {\it non-convex} updates can lead to significan
Roman Bezrukavnikov, Pavel Etingof
We introduce parabolic induction and restriction functors for rational Cherednik algebras, and study their basic properties. Then we discuss applications of these functors to representation theory of rational Cherednik algebras. In particular, we prove the Gordon-Stafford theorem about Morita equivalence of the rational Cherednik algebra for type A and its s
Juan R. Cortes, Jeffrey D. P. Kenney, Eduardo Hardy
We present distance estimates for eleven peculiar Virgo cluster spiral galaxies based on measurements of the stellar kinematics of their central 2 kpc. Stellar circular velocities were obtained using two-integral dynamical models. Distances were obtained by comparing, at each radius, the stellar circular velocities with synthetic H_alpha rotation curves deri
Filippo Radicchi, José Javier Ramasco, Alain Barrat, Santo Fortunato
Recently, it has been claimed that some complex networks are self-similar under a convenient renormalization procedure. We present a general method to study renormalization flows in graphs. We find that the behavior of some variables under renormalization, such as the maximum number of connections of a node, obeys simple scaling laws, characterized by critic
Tracing the Mass-Dependent Star Formation History of Late-Type Galaxies using X-ray Emission: Results from the Chandra Deep Fields
astro-phB. D. Lehmer, W. N. Brandt, D. M. Alexander, E. F. Bell
We report on the X-ray evolution over the last ~9 Gyr of cosmic history (i.e., since z = 1.4) of late-type galaxy populations in the Chandra Deep Field-North and Extended Chandra Deep Field-South (CDF-N and E-CDF-S, respectively; jointly CDFs) survey fields. Our late-type galaxy sample consists of 2568 galaxies, which were identified using rest-frame optical
Doron L. Bergman, Congjun Wu, Leon Balents
We study ``frustrated'' hopping models, in which at least one energy band, at the maximum or minimum of the spectrum, is dispersionless. The states of the flat band(s) can be represented in a basis which is fully localized, having support on a vanishing fraction of the system in the thermodynamic limit. In the majority of examples, a dispersive band
Amy Forestell, Karl Gebhardt
We present line-of-sight stellar velocity distributions of elliptical galaxy NGC 821 obtained to approximately 100 arcsec (over 2 effective radii) with long-slit spectroscopy from the Hobby-Eberly Telescope. Our measured stellar line-of-sight velocity distributions are larger than the planetary nebulae measurements at similar radii. We fit axisymmetric orbit
H. M. Antia, Sarbani Basu, S. M. Chitre
Available helioseismic data now span almost the entire solar activity cycle 23 making it possible to study solar-cycle related changes of the solar rotation rate in detail. In this paper we study how the solar rotation rate, in particular, the zonal flows change with time. In addition to the zonal flows that show a well known pattern in the solar convection
Liudmila Joukovskaya
Open string field theory in the level truncation approximation is considered. It is shown that the energy conservation law determines the existence of rolling tachyon solution. The coupling of the open string field theory action to a Friedmann-Robertson-Walker metric is considered and as a result the new time dependent rolling tachyon solution is presented a
Vimal Simha, Gary Steigman
We explore constraints on extensions to the standard models of cosmology and particle physics which modify the early-Universe expansion rate S = H'/H (parametrized by the effective number of neutrinos N_nu). The constraints on N_nu and the baryon density parameter (eta_B = n_B/n_gamma = 10^(-10)*eta_10) from BBN at 20 minutes are compared with those from
P. Hraskó
The phenomenon of unipolar induction consists in generating electric field by uniformly rotating permanent magnets made of either conducting or dielectric substance. The origin of the field around conducting magnets is explained and calculated in Sect. 1. Dielectrics are considered in Sect. 2, where the role of the electric moment due to moving magnetic dipo
Inversion of marine heat flow measurements by expansion of the temperature decay function
physics.geo-phAndreas Hartmann, Heinrich Villinger
Marine heat flow data, obtained with a Lister-type probe, consists of two temperature decay curves, frictional and heat pulse decay. Both follow the same physical model of a cooling cylinder. The mathematical model describing the decays is non-linear as to the thermal sediment parameters thus a direct inversion is not possible. To overcome this difficulty, t
Finite-size scaling of the entanglement entropy of the quantum Ising chain with homogeneous, periodically modulated and random couplings
cond-mat.stat-mechFerenc Igloi, Yu-Cheng Lin
Using free-fermionic techniques we study the entanglement entropy of a block of contiguous spins in a large finite quantum Ising chain in a transverse field, with couplings of different types: homogeneous, periodically modulated and random. We carry out a systematic study of finite-size effects at the quantum critical point, and evaluate subleading correctio
Benjamin Allen
We highlight the underlying category-theoretic structure of measures of information flow. We present an axiomatic framework in which communication systems are represented as morphisms, and information flow is characterized by its behavior when communication systems are combined. Our framework includes a variety of discrete, continuous, and, conjecturally, qu
R. M. Lutchyn, L. Cywinski, Cody P. Nave, S. Das Sarma
We consider quantum decoherence in solid-state systems by studying the transverse dynamics of a single qubit interacting with a fermionic bath and driven by external pulses. Our interest is in investigating the extent to which the lost coherence can be restored by the application of external pulses to the qubit. We show that the qubit evolution under various
D. Rodriguez-Gomez, J. Ward
We analyse various $U(1)_{EM}$ form factors of mesons at strong coupling in an $\mathcal{N}=2$ flavored version of $\mathcal{N}=4$ $SYM$ which becomes conformal in the UV. The quark mass breaks the conformal symmetry in the IR and generates a mass gap. In the appropriate limit, the gravity dual is described in terms of probe $D7$-branes in $AdS_5\times S^5$.
Lieven Le Bruyn
This note tells you how to construct a k(n)-dimensional family of (isomorphism classes of) irreducible representations of dimension n for the three string braid group B_3, where k(n) is an admissible function of your choosing; for example take k(n) = [ n/2 ] +1 as in arXiv:0803.2778 and arXiv:0803.2785.
X. H. Chen, T. Wu, G. Wu, R. H. Liu
Since the discovery of high-transition temperature ($T_c$) superconductivity in layered copper oxides, extensive efforts have been devoted to explore the higher $T_c$ superconductivity. However, the $T_c$ higher than 40 K can be obtained only in the copper oxide superconductors so far. The highest reported value of $T_c$ for non-copper-oxide bulk superconduc
Marc Lelarge, Jean Bolot
Getting agents in the Internet, and in networks in general, to invest in and deploy security features and protocols is a challenge, in particular because of economic reasons arising from the presence of network externalities. Our goal in this paper is to carefully model and quantify the impact of such externalities on the investment in, and deployment of, se
Carrier-wave steepened pulses and gradient-gated high-order harmonic generation using linear ramp waveforms
physics.atom-phS. B. P. Radnor, L. E. Chipperfield, P. Kinsler, G. H. C. New
We show how to optimize the process of high-harmonic generation (HHG) by gating the interaction using the field gradient of a driving pulse with a linear ramp waveform. Since maximized field gradients are efficiently generated by self-steepening processes, we first present a generalized theory of optical carrier-wave self-steepened (CSS) pulses. This goes be
Kevin Schawinski, Stephen Justham, Christian Wolf, Philipp Podsiadlowski
Massive stars undergo a violent death when the supply of nuclear fuel in their cores is exhausted, resulting in a catastrophic "core-collapse" supernova. Such events are usually only detected at least a few days after the star has exploded. Observations of the supernova SNLS-04D2dc with the Galaxy Evolution Explorer space telescope reveal a radiative
Timothy E. Saunders, John T. Chalker
We study geometrically frustrated antiferromagnets with magnetoelastic coupling. Frustration in these systems may be relieved by a structural transition to a low temperature phase with reduced lattice symmetry. We examine the statistical mechanics of this transition and the effects on it of quenched disorder, using Monte Carlo simulations of the classical He
Nonzero U_{e3}, CP violation and leptogenesis in a see-saw type softly broken A_4 symmetric model
hep-phBiswajit Adhikary, Ambar Ghosal
We have shown that non-zero U_{e3} is generated in a see-saw type softly broken A_4 symmetric model through a single parameter perturbation in m_D in a single element. We have explored all possible 9 cases to study the neutrino mixing angles considering the best fitted values of Δm_{\odot}^2 and Δm_{atm}^2 with all parameters real. We have extended our analy
Bernhard Hanke
A well known conjecture in the theory of transformation groups states that if p is a prime and (Z/p)^r acts freely on a product of k spheres, then r is less than or equal to k. We prove this assertion if p is large compared to the dimension of the product of spheres. The argument builds on tame homotopy theory for non simply connected spaces.
Robin D. Morris, Johann Cohen-Tanugi
In contrast to previous analyses, we demonstrate a Bayesian approach to the estimation of the CKM phase $α$ that is invariant to parameterization. We also show that in addition to {\em computing} the marginal posterior in a Bayesian manner, the distribution must also be {\em interpreted} from a subjective Bayesian viewpoint. Doing so gives a very natural int
Generation of homogeneous granular packings: Contact dynamics method with coupling to an external pressure bath
physics.comp-phM. Reza Shaebani, Tamas Unger, Janos Kertesz
The contact dynamics method (CD) is an efficient simulation technique of dense granular media where unilateral and frictional contact problems for a large number of rigid bodies have to be solved. In this paper we present a modified version of the contact dynamics to generate homogeneous random packings of rigid grains. CD is coupled to an external pressure
Benjamin Dassinger, Robert Feger, Thomas Mannel
We perform a complete "Michel parameter" analysis of all possible helicity structures which can appear in the process $B \to X_c \ell \barν_\ell$. We take into account the full set of operators parametrizing the effective Hamiltonian and include the complete one-loop QCD corrections as well as the non-perturbative contributions. The moments of the le
Antongiulio Fornasiero, Tamara Servi
We consider definably complete and Baire expansions of ordered fields: every definable subset of the domain of the structure has a supremum and the domain can not be written as the union of a definable increasing family of nowhere dense sets. Every expansion of the real field is definably complete and Baire. So is every o-minimal expansion of a field. Howeve
Lukasz Szulc
A simplified theory of the diagonal Bianchi type I model coupled with a massless scalar field in loop quantum cosmology is constructed according to the $\barμ$ scheme. Kinematical and physical sectors of the theory are under good analytical control as well as the scalar constraint operator. Although it is possible to compute numerically the nonsingular evolu
G. W. Wilson, D. Hughes, I. Aretxaga, H. Ezawa
Deep 1.1 mm continuum observations of 1E0657-56 (the "Bullet Cluster") taken with the millimeter-wavelength camera AzTEC on the 10-m Atacama Submillimeter Telescope Experiment (ASTE), have revealed an extremely bright (S$_{\rm{1.1mm}}=15.9$ mJy) unresolved source. This source, MMJ065837-5557.0, lies close to a maximum in the density of underlying mas
Michael Cwikel
Known or essentially known results about duals of interpolation spaces are presented, taking a point of view sometimes slightly different from the usual one. Particular emphasis is placed on Alberto Calderon's theorem describing the duals of his complex interpolation spaces [A_0,A_1]_θ. The pace is slow, since these notes are intended for graduate studen
Electroproduction of $ϕ(1020)$ mesons at $1.4\leq Q^2\leq$ GeV$^2$ measured with the CLAS spectrometer
nucl-exJ. P. Santoro, E. S. Smith, M. Garcon, M. Guidal
Electroproduction of exclusive $ϕ$ vector mesons has been studied with the CLAS detector in the kinematical range $1.4\leq Q^2\leq 3.8$ GeV$^{2}$, $0.0\leq t^{\prime}\leq 3.6$ GeV$^{2}$, and $2.0\leq W\leq 3.0$ GeV. The scaling exponent for the total cross section as $1/(Q^2+M_ϕ^2)^n$ was determined to be $n=2.49\pm 0.33$. The slope of the four-momentum tran
Ofer Aharony, David Kutasov
We study the holographic map between long open strings, which stretch between D-branes separated in the bulk space-time, and operators in the dual boundary theory. We focus on a generalization of the Sakai-Sugimoto holographic model of QCD, where the simplest chiral condensate involves an operator of this type. Its expectation value is dominated by a semi-cl
S. Sponar, J. Klepp, R. Loidl, S. Filipp
We have observed the stationary interference oscillations of a triple-entangled neutron state in an interferometric experiment. Time-dependent interaction with two radio-frequency (rf) fields enables coherent manipulation of an energy degree of freedom in a single neutron. The system is characterized by a multiply entangled state governed by a Jaynes-Cumming
Anisotropic cosmological models with spinor and scalar fields and viscous fluid in presence of a $Λ$ term: qualitative solutions
gr-qcBijan Saha, Victor Rikhvitsky
The study of a self-consistent system of interacting spinor and scalar fields within the scope of a Bianchi type I (BI) gravitational field in presence of a viscous fluid and $Λ$ term has been carried out. The system of equations defining the evolution of the volume scale of BI universe, energy density and corresponding Hubble constant has been derived. The
The Knight field and the local nuclear dipole-dipole field in an (In,Ga)As quantum dot ensemble
cond-mat.otherT. Auer, R. Oulton, A. Bauschulte, D. R. Yakovlev
We present a comprehensive investigation of the electron-nuclear system of negatively charged InGaAs/GaAs self-assembled quantum dots under the influence of weak external magnetic fields (up to 2 mT). We demonstrate that, in contrast to conventional semiconductor systems, these small fields have a profound influence on the electron spin dynamics, via the hyp
Jarno Talponen
We will introduce the countable separation property (CSP) of Banach spaces X, which is defined as follows: For each subset \mathcal{F} of X^{\ast}, which separates X, there exists a countable separating subset \mathcal{F}_{0} of \mathcal{F}. All separable Banach spaces have CSP and plenty of examples of non-separable CSP spaces are provided. Connections of C
Statistics of the zeros of zeta functions in families of hyperelliptic curves over a finite field
math.NTDmitry Faifman, Zeev Rudnick
We study the fluctuations in the distribution of zeros of zeta functions of a family of hyperelliptic curves defined over a fixed finite field, in the limit of large genus. According to the Riemann Hypothesis for curves, the zeros all lie on a circle. Their angles are uniformly distributed, so for a curve of genus g a fixed interval I will contain 2g|I| angl
Magnetic properties of BaCdVO(PO_4)_2: a strongly frustrated spin-1/2 square lattice close to the quantum critical regime
cond-mat.str-elR. Nath, A. A. Tsirlin, H. Rosner, C. Geibel
We report magnetization and specific heat measurements on polycrystalline samples of BaCdVO(PO_4)_2 and show that this compound is a S=1/2 frustrated square lattice with ferromagnetic nearest-neighbor (J_1) and antiferromagnetic next-nearest-neighbor (J_2) interactions. The coupling constants J_1\simeq -3.6 K and J_2\simeq 3.2 K are determined from a fitting
Daniel Raible, Henning Fernau
In {\sc MaxSat}, we ask for an assignment which satisfies the maximum number of clauses for a boolean formula in CNF. We present an algorithm yielding a run time upper bound of $O^*(2^{\frac{1}{6.2158}})$ for {\sc Max-2-Sat} (each clause contains at most 2 literals), where $K$ is the number of clauses. The run time has been achieved by using heuristic priori
Liangpan Li
Let $\mathbb{F}_q$ denote a finite field of $q$ elements. Define a set $B\subset\mathbb{F}_q^n$ to be Nikodym if for each $x\in B^{c}$, there exists a line $L$ such that $L\cap B^c=\{x\}.$ The main purpose of this note is to show that the size of every Nikodym set is at least $C_n\cdot q^n$, where $C_n$ depends only on $n$.
Sergey Smirnov, Dario Bercioux, Milena Grifoni, Klaus Richter
We predict the possibility to generate a finite stationary spin current by applying an unbiased ac driving to a quasi-one-dimensional asymmetric periodic structure with Rashba spin-orbit interaction and strong dissipation. We show that under a finite coupling strength between the orbital degrees of freedom the electron dynamics at low temperatures exhibits a
M. Kürster, M. Endl, S. Reffert
Context. Brown dwarf companions to stars at separations of a few AU or less are rare objects, and none have been found so far around early-type M dwarfs M0V-M5V). With GJ 1046 (M2.5V), a strong candidate for such a system with a separation of 0.42 AU is presented. Aims. We aim at constraining the mass of the companion in order to decide whether it is a brown
A. G. Akeroyd, Chuan Hung Chen, S. Recksiegel
The measurement of B->tau nu at the B factories provides important constraints on the parameter tan beta/m_H^+- in the context of models with two Higgs doublets. Limits on this decay from e+e- collisions at the Z peak were sensitive to the sum of B->tau nu and B_c->tau nu. Due to the possibly sizeable contribution from B_c->tau nu we suggest that a signal fo
Tomasz Bulik, Krzysztof Belczynski, Andrea Prestwich
We investigate the future evolution of two extragalactic X-ray binaries: IC10 X-1 and NGC300 X-1. Each of them consists of a high mass BH ($\sim 20-30 \msun$) accreting from a massive WR star companion ($\gtrsim 20 \msun$), and both are located in low metallicity galaxies. We analyze the current state of the systems and demonstrate that both systems will ver
Tension between scalar/pseudoscalar new physics contribution to B_s --> mu+ mu- and B --> K mu+ mu-
hep-phAshutosh Kumar Alok, Amol Dighe, S. Uma Sankar
New physics in the form of scalar/pseudoscalar operators cannot lower the semileptonic branching ratio B(B --> K mu+ mu-) below its standard model value. In addition, we show that the upper bound on the leptonic branching ratio B(B_s --> mu+ mu-) sets a strong constraint on the maximum value of B(B --> K mu+ mu-) in models with multiple Higgs doublets: with
Takeo Kojima
The q-oscillator representation for the Borel subalgebra of the affine symmetry $U_q(sl_N^)$ is presented. By means of this q-oscillator representation, we give the free field realizations of the Baxter's Q-operator $Q_j(t)$, $\bar{Q}_j(t)$ for the W-algebra $W_N$. We give the functional relations of the $T$-$Q$ operators, including the higher-rank gener
Vincent Thomas Francois Renard, O. A. Tkachenko, V. A. Tkachenko, T. Ota
An unusual increase of the conductance with temperature is observed in clean quantum point contacts for conductances larger than 2e^2/h. At the same time a positive magnetoresistance arises at high temperatures. A model accounting for electron-electron interactions mediated by bound- aries (scattering on Friedel oscillations) qualitatively describes the obse
A. V. Novikov-Borodin
The off-site continuums are proposed for the cosmological models of the galaxies and the Universe. It is shown that many visual properties of galaxies and the Universe may be described on frames of the off-site continuums methodology. In cosmological scale, the appearance of off-site objects is quite similar to the influence of the 'dark matter' and
K. Bahlali, Abouo Elouaflin, E. Pardoux
We study the asymptotic behavior of solution of semi-linear PDEs. Neither periodicity nor ergodicity will be assumed. In return, we assume that the coefficients admit a limit in Cesaro sense. In such a case, the averaged coefficients could be discontinuous. We use probabilistic approach based on weak convergence for the associated backward stochastic differe
S. M. Gerasyuta, E. E. Matskevich
The masses of S-wave bottom baryons are calculated in the framework of coupled-channel formalism. The relativistic three-quark equations for the bottom baryons using the dispersion relation technique are found. The approximate solutions of these equations based on the extraction of leading singularities of the amplitude are obtained. The calculated mass valu
Flux dependent MeV self-ion- induced effects on Au nanostructures: Dramatic mass transport and nano-silicide formation
cond-mat.mtrl-sciJ. Ghatak, M. Umananda Bhatta, B. Sundaravel, K. G. M. Nair
We report a direct observation of dramatic mass transport due to 1.5 MeV Au2+ ion impact on isolated Au nanostructures of an average size 7.6 nm and a height 6.9 nm that are deposited on Si (111) substrate under high flux (3.2x10^10 to 6.3x10^12 ions cm-2 s-1) conditions. The mass transport from nanostructures found to extend up to a distance of about 60 nm
Huan Xu, Constantine Caramanis, Shie Mannor
We consider regularized support vector machines (SVMs) and show that they are precisely equivalent to a new robust optimization formulation. We show that this equivalence of robust optimization and regularization has implications for both algorithms, and analysis. In terms of algorithms, the equivalence suggests more general SVM-like algorithms for classific
Daniel Alayon-Solarz
We discuss the proof of a certain integral theorem obtained by C. G. Cullen, originally stated on the class of the analytic intrinsic functions on the quaternions. It is shown that this integral theorem is true for a larger class of quaternionic functions.
I. E. Shparlinski
We consider a generalisation of the classical Lehmer problem about the parity distribution of an integer and its modular inverse. We use some known estimates of exponential sums to study a more general question of simultaneous distribution of the residues of any fixed number of negative and positive powers of integers in prescribed arithmetic progressions. I
N. Andruskiewitsch, F. Fantino
We present techniques that allow to decide that the dimension of some pointed Hopf algebras associated with non-abelian groups is infinite. These results are consequences of arXiv:0803.2430v1. We illustrate each technique with applications.
P. W. Schuck
The differential affine velocity estimator (DAVE) developed in Schuck (2006) for estimating velocities from line-of-sight magnetograms is modified to directly incorporate horizontal magnetic fields to produce a differential affine velocity estimator for vector magnetograms (DAVE4VM). The DAVE4VM's performance is demonstrated on the synthetic data from th
Edgardo S. Cheb-Terrab, Austin D. Roche
In this paper we present a decision procedure for computing pFq hypergeometric solutions for third order linear ODEs, that is, solutions for the classes of hypergeometric equations constructed from the 3F2, 2F2, 1F2 and 0F2 standard equations using transformations of the form {x -> F(x), y -> P(x) y}, where F(x) is rational in x and P(x) is arbitrary. A comp
M. Cecilia Gimenez, Antonio J. Ramirez-Pastor, Ezequiel P. M. Leiva
The deposition of a metal on a foreign substrate is studied by means of grand canonical Monte Carlo simulations and a lattice-gas model with pair potential interactions between nearest neighbors. The influence of temperature and surface defects on adsorption isotherms and differential heat of adsorption is considered. The general trends can be explained in t
Yauhen Radyna, Yakov Radyno, Anna Sidorik
We characterize Hilbert spaces in the class of all Banach spaces using Fourier transform of vector-valued functions over the field $Q_p$ of $p$-adic numbers. Precisely, Banach space $X$ is isomorphic to a Hilbert one if and only if Fourier transform $F: L_2(Q_p,X)\to L_2(Q_p,X)$ in space of functions, which are square-integrable in Bochner sense and take val
Ali Nazari, Sandeep Pradhan, Achilleas Anastasopoulos
In this work, a new lower bound for the maximal error probability of a two-user discrete memoryless (DM) multiple-access channel (MAC) is derived. This is the first bound of this type that explicitly imposes independence of the users' input distributions (conditioned on the time-sharing auxiliary variable) and thus results in a tighter sphere-packing exp
G. Soto, M. G. Moreno-Armenta, A. Reyes-Serrato
Scandium nitride (ScN) is a semiconducting transition metal nitride for which there are not identified dopants. We present local density functional calculations, in supercell approach, for ScN doped with O and C in N-sites and Ca and Ti in Sc-sites. Small additions of these atoms have the effect of shifting the Fermi level within the electronic band structur
Robust quantum cryptography with a heralded single-photon source based on the decoy-state method
quant-phQin Wang, Wei Chen, Guilherme Xavier, Marcin Swillo
In this paper, we describe a robust quantum cryptography scheme with a heralded single photon source based on the decoy-state method, which has been shown by numerical simulations to be advantageous compared with many other practical schemes not only with respect to the secure key generation rate but also to secure transmission distance. We have experimental
Zdenek Stuchlik, Jiri Kovar
Pseudo-Newtonian gravitational potential describing the gravitational field of static and spherically symmetric black holes in the universe with a repulsive cosmological constant is introduced. In order to demonstrate the accuracy of the pseudo-Newtonian approach, the related effective potential for test-particle motion is constructed and compared with its g
S. Ghosh, D. W. Steuerman, B. Maertz, K. Ohtani
Electric field enhanced electron spin coherence is characterized using time-resolved Faraday rotation spectroscopy in n-type ZnO epilayers grown by molecular beam epitaxy. An in-plane dc electric field E almost doubles the transverse spin lifetime at 20 K, without affecting the effective g-factor. This effect persists till high temperatures, but decreases wi
F. Winterberg
Recent progress towards the non-fission ignition of thermonuclear micro-explosions raises the prospect for a revival of the nuclear bomb propulsion idea, both for the fast transport of large payloads within the solar system and the launch into earth orbit without the release of fission products into the atmosphere. To reach this goal three areas of research
Joseph A. Morrone, Roberto Car
In this work, a path integral Car-Parrinello molecular dynamics simulation of liquid water is performed. It is found that the inclusion of nuclear quantum effects systematically improves the agreement of first principles simulations of liquid water with experiment. In addition, the proton momentum distribution is computed utilizing a recently developed open
Lukas Jahnke, Jan W. Kantelhardt
For more than a century Liesegang patterns -- self-organized, quasi-periodic structures occurring in diffusion-limited chemical reactions with two components -- have been attracting scientists. The pattern formation can be described by four basic empirical laws. In addition to many experiments, several models have been devised to understand the formation of
Mikhail Nesterenko, Adnan Vora
Geometric routing algorithms like GFG (GPSR) are lightweight, scalable algorithms that can be used to route in resource-constrained ad hoc wireless networks. However, such algorithms run on planar graphs only. To efficiently construct a planar graph, they require a unit-disk graph. To make the topology unit-disk, the maximum link length in the network has to
Katie M. Chynoweth, Glen I. Langston, Min S. Yun, Felix J. Lockman
We have observed a 3 degree x 3 degree area centered on the M81/M82 group of galaxies using the Robert C. Byrd Green Bank Telescope (GBT) in a search for analogs to the High Velocity Clouds (HVCs) of neutral hydrogen found around our galaxy. The velocity range from -605 to -85 km/s and 25 to 1970 km/s was searched for HI clouds. Over the inner 2 degrees x 2
Ben R. Oppenheimer, Douglas Brenner, Sasha Hinkley, Neil Zimmerman
The young star AB Aurigae is surrounded by a complex combination of gas-rich and dust dominated structures. The inner disk which has not been studied previously at sufficient resolution and imaging dynamic range seems to contain very little gas inside a radius of least 130 astronomical units (AU) from the star. Using adaptive-optics coronagraphy and polarime
Kristen Menou, Zoltan Haiman, Bence Kocsis
The notion that microparsec-scale black holes can be used to probe gigaparsec-scale physics may seem counterintuitive, at first. Yet, the gravitational observatory LISA will detect cosmologically-distant coalescing pairs of massive black holes, accurately measure their luminosity distance and help identify an electromagnetic counterpart or a host galaxy. A w
Nicolas B. Cowan, Eric Agol
We describe how to generate a longitudinal brightness map for a tidally locked exoplanet from its phase function light curve. We operate under a number of simplifying assumptions, neglecting limb darkening/brightening, star spots, detector ramps, as well as time-variability over a single planetary rotation. We develop the transformation from a planetary brig
Thomas Hartman, Andrew Strominger
Two-dimensional Maxwell-dilaton quantum gravity on AdS_2 with radius $\ell$ and a constant electric field E is studied. In conformal gauge, this is equivalent to a CFT on a strip. In order to maintain consistent boundary conditions, the usual conformal diffeomorphisms must be accompanied by a certain U(1) gauge transformation. The resulting conformal transfo
Lunar dust characterization by polarimetric signature. I. Negative polarization branch of sphere aggregates of various porosities
astro-phD. T. Richard, S. S. Davis
Context. In support of NASA's exploration program and the return to the Moon, the polarimetric signature of dispersed individual Lunar regolith dust grains is studied to enable the characterization of the dust exopsheric environment by remote, in-situ, and standoff sensing. Aims. We explore the value of the negative polarization branch (NPB) as a signatu
Xiao-Liang Qi, Taylor L. Hughes, Srinivas Raghu, Shou-Cheng Zhang
We construct time reversal invariant topological superconductors and superfluids in two and three dimensions which are analogous to the recently discovered quantum spin Hall and three-d $Z_2$ topological insulators respectively. These states have a full pairing gap in the bulk, gapless counter-propagating Majorana states at the boundary, and a pair of Majora
T. J. Davidge
The properties of the brightest resolved stars in an arc that was originally identified by Sun et al. (2005) and is located in the extraplanar regions of M82 are discussed. The stars form an elongated structure that is traced over a projected area of 3.0 x 0.8 kpc. The integrated brightness is M_V ~ -11, while the total stellar mass is between 3 x 10^5 and 2
Timothy H. Boyer
One should not confuse a physical constant with a theory which incorporates the constant. Planck's constant h can appear in classical or quantum theories.
David S. Berman, Laura C. Tadrowski, Daniel C. Thompson
This paper examines various aspects of the recently proposed theory of coincident membranes by Bagger and Lambert. These include the properties of open membranes and the resulting boundary theory with an interpretation in terms of the fivebrane and marginal supersymmetric deformations of the interactions with the relation to the holographic dual.
M. A. Durnev
Using the quark-antiquark interactions obtained in the framework of the bootstrap method we construct a potential model, investigate the possibility of describing of heavy quarkonia and calculate the bottomonium spectrum. The potential of the interaction was obtained as a nonrelativistic limit of the relativistic quark-antiquark amplitudes Q{\bar Q} -> Q\bar
Y. Hui, Julian H. Krolik
We have chosen 6 Ultra-Luminous X-ray sources from the {\it XMM-Newton} archive whose spectra have high signal-to-noise and can be fitted solely with a disk model without requiring any power-law component. To estimate systematic errors in the inferred parameters, we fit every spectrum to two different disk models, one based on local blackbody emission (KERRB
A. Isella, E. Tatulli, A. Natta, L. Testi
In this Letter we investigate the origin of the near-infrared emission of the Herbig Ae star MWC 758 on sub-astronomical unit (AU) scales using spectrally dispersed low resolution (R=35) AMBER/VLTI interferometric observations both in the H ($1.7 μ$m) and K ($2.2 μ$m) bands. We find that the K band visibilities and closure phases are consistent with the pres
Certain Properties of Pythagorean Triangles involving the interior diameter, and the exterior diameters
math.GMKonstantine "Hermes" Zelator
There are four characteristic circles for each triangle on a plane. All for are tangential to the three straight lines containing the triangles' three sides. Three are exterior circles, the fourth is the in-circle. When the triangle is Pythagorean, the four diameters are integers. Consider a Pythagorean triangle with the property that one leglength is a
Robert K. Soberman, Maurice Dubin
The big bang hypothesis is widely accepted despite numerous physics conflicts. It rests upon two experimental supports, galactic red shift and the cosmic microwave background. Both are produced by dark matter, shown here to be hydrogen dominated aggregates with a few percent of helium nodules. Scattering from these non-radiating intergalactic masses produce
S. Esposito
The physicists working in several areas of research know quite well the name of Ettore Majorana, since it is currently associated to fundamental concepts like {\it Majorana neutrinos} in particle physics and cosmology or {\it Majorana fermions} in condensed matter physics. But, probably, very few is known about other substantial contributions of that ingenio
Alexander A. Katz, Oleg Friedman
In the present paper we obtain an intrinsic characterization of real locally C*-algebras (projective limits of projective families of real C*-algebras) among complete real lmc *-algebras, and of locally JB-algebras (projective limits of projective families of JB-algebras) among complete fine Jordan locally multiplicatively-convex topological algebras.
A solution in 3 dimensions for current in a semiconductor under high level injection from a point contact
cond-mat.otherMike W. Denhoff
The standard equations for semiconductor device analysis were solved by specifying the electron and hole current injected at a small contact, assuming high-level injection. Calculated current-voltage characteristics were fit to measurements of a single point breakdown in an ultrathin dielectric. It was found that the minority carrier injection level was abou
Alexander A. Katz
We introduce and study continuous fields of JB-algebras (which are real non-associate analogues of C*-algebras). In particular, we show that for the universal enveloping C*-algebra C*sub-u(B) for the JB-algebra B defined by a continuous field of JB-algebras A-sub-t, t belongs to T, on a locally compact space T, there exists a decomposition of C*-sub-u(B) int
R. P. Kraft, M. J. Hardcastle, G. R. Sivakoff, A. Jordán
We present preliminary results from a deep (600 ks) {\em Chandra} observation of the hot interstellar medium of the nearby early-type galaxy Centaurus A (Cen A). We find a surface brightness discontinuity in the gas $\sim$3.5 kpc from the nucleus spanning a 120$^\circ$ arc. The temperature of the gas is 0.60$\pm$0.05 and 0.68$\pm$0.10 keV, interior and exter