October 2009 arXiv papers — page 13
Showing 1,201–1,300 of 6,002 papers
M. Feroci, E. Costa, E. Del Monte, I. Donnarumma
SuperAGILE is the hard X-ray monitor of the AGILE gamma ray mission, in orbit since 23$^{rd}$ April 2007. It is an imaging experiment based on a set of four independent silicon strip detectors, equipped with one-dimensional coded masks, operating in the nominal energy range 18-60 keV. The main goal of SuperAGILE is the observation of cosmic sources simultane
Alberto Leccardi, Mariachiara Rossetti, Silvano Molendi
Aims. We aim to provide constraints on evolutionary scenarios in clusters. One of our main goals is to understand whether, as claimed by some, the cool core/non-cool core division is established once and for all during the early history of a cluster. Methods. We employ a sample of about 60 objects to classify clusters according to different properties: we ch
Millimagnitude Photometry for Transiting Extrasolar Planetary Candidates. V. Follow-up of 30 OGLE Transits. New Candidates
astro-ph.EPP. Pietrukowicz, D. Minniti, R. F. Diaz, J. M. Fernandez
We used VLT/VIMOS images in the V band to obtain light curves of extrasolar planetary transits OGLE-TR-111 and OGLE-TR-113, and candidate planetary transits: OGLE-TR-82, OGLE-TR-86, OGLE-TR-91, OGLE-TR-106, OGLE-TR-109, OGLE-TR-110, OGLE-TR-159, OGLE-TR-167, OGLE-TR-170, OGLE-TR-171. Using difference imaging photometry, we were able to achieve millimagnitude
S. Aubry, L. Proville
The propagation of pressure fronts (impact solutions) in 1D chains of atoms coupled by anharmonic potentials between nearest neighbor and submitted to damping forces preserving uniform motion, is investigated. Travelling fronts between two regions at different uniform pressures are found numerically and well approximate analytically. It is proven that there
János Barát, Péter Hajnal, Yixun Lin, Aifeng Yang
Nancy G. Kinnersley and Michael A. Langston has determined the excluded minors for the class of graphs with path-width at most two by computer. Their list consisted of 110 graphs. Such a long list is difficult to handle and gives no insight to structural properties. We take a different route, and concentrate on the building blocks and how they are glued toge
Hung Ngoc Nguyen, Pham Huu Tiep
We prove that the restriction of any absolutely irreducible representation of Steinberg's triality groups $^3D_4(q)$ in characteristic coprime to q to any proper subgroup is reducible
Manya V. Afonso, José M. Bioucas-Dias, Mário A. T. Figueiredo
We propose a new fast algorithm for solving one of the standard formulations of image restoration and reconstruction which consists of an unconstrained optimization problem where the objective includes an $\ell_2$ data-fidelity term and a non-smooth regularizer. This formulation allows both wavelet-based (with orthogonal or frame-based representations) regul
Ruth Charney, Kim Ruane, Nathaniel Stambaugh, Anna Vijayan
We study the automorphisms of graph products of cyclic groups, a class of groups that includes all right-angled Coxeter and right-angled Artin groups. We show that the group of automorphism generated by partial conjugations is itself a graph product of cyclic groups providing its defining graph does not contain any separating intersection of links (SIL). In
Hung Ngoc Nguyen
We classify the irreducible complex characters of the symplectic groups $Sp_{2n}(q)$ and the orthogonal groups $Spin_{2n}^\pm(q)$, $Spin_{2n+1}(q)$ of degrees up to the bound D, where $D=(q^n-1)q^{4n-10}/2$ for symplectic groups, $D=q^{4n-8}$ for orthogonal groups in odd dimension, and $D=q^{4n-10}$ for orthogonal groups in even dimension.
O. V. Selyugin
Taking into account the electromagnetic and gravitational form factors, calculated from a new set of $t $-dependent GPDs, a new model including the soft and hard pomerons is build. In the framework of this model the ualitative description of all existing experimental data at $\sqrt{s} \leq 52.8 $ GeV, including the Coulomb range and large momentum transfers,
I. Donnarumma, G. Pucella, V. Vittorini, F. D'Ammando
We report on the second AGILE multiwavelength campaign of the blazar 3C 454.3 during the first half of December 2007. This campaign involved AGILE, Spitzer, Swift,Suzaku,the WEBT consortium,the REM and MITSuME telescopes,offering a broad band coverage that allowed for a simultaneous sampling of the synchrotron and inverse Compton (IC) emissions.The 2-week AG
S. J. Fegan, D. Sanchez, Fermi LAT Collaboration, :
We report on observations of TeV-selected AGN made during the first 5.5 months of observations with the Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope (Fermi). In total, 96 AGN were selected for study, each being either (i) a source detected at TeV energies (28 sources) or (ii) an object that has been studied with TeV instruments and
R. K. Bhaduri, M. V. N. Murthy, M. K. Srivastava
Consider two identical atoms in a spherical harmonic oscillator interacting with a zero-range interaction which is tuned to produce an s-wave zero-energy bound state. The quantum spectrum of the system is known to be exactly solvable. We note that the same partial wave quantum spectrum is obtained by the one-dimensional scale-invariant inverse square potenti
Marcelo B. Ribeiro
This article reviews an approach for constructing a simple relativistic fractal cosmology whose main aim is to model the observed inhomogeneities of the distribution of galaxies by means of the Lemaitre-Tolman solution of Einstein's field equations for spherically symmetric dust in comoving coordinates. This model is based on earlier works developed by L. Pi
Martin Bauer
I present a review of phenomenological implications of the Randall-Sundrum (RS) model with bulk fermions and brane-localized Higgs boson. Modifications to the W-boson mass, corrections to the Peskin-Takeuchi parameters and to the Z -> bb couplings will be discussed. From these observables severe bounds on the mass scale of Kaluza-Klein (KK) modes arise. Cons
John Southworth, T. C. Hinse, M. Dominik, M. Glitrup
We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocussing we achieve a photometric precision of 0.47 to 0.83 mmag per observation over complete transit events. The data are analysed using the JKTEBOP code and three diffe
Lalitha Sankar, Jan Vondrak, H. Vincent Poor
Sufficient conditions required to achieve the interference-free capacity region of ergodic fading K-user interference channels (IFCs) are obtained. In particular, this capacity region is shown to be achieved when every receiver decodes all K transmitted messages such that the channel statistics and the waterfilling power policies for all K (interference-free
Velimir Bardek, Stjepan Meljanac, Daniel Meljanac
We consider a large N, two-family Calogero and matrix model in the Hamiltonian, collective-field approach. The Bogomol'nyi limit appears and the solutions to the coupled Bogomol'nyi-Prasad-Sommerfeld equations are given by the static soliton configurations. We find all solutions close to constant and construct exact one-parameter solutions in the str
Clemens P. Kiessig, Michael Plumacher
We investigate the validity of using thermal masses in the kinematics of final states in the decay rate of heavy neutrinos in leptogenesis calculations. We find that using thermal masses this way is a reasonable approximation, but corrections arise through quantum statistical distribution functions and leptonic quasiparticles.
Xu Feng, Karl Jansen, Dru B. Renner
Using two flavors of maximally twisted mass fermions, we calculate the S-wave pion-pion scattering length in the isospin I=2 channel and the P-wave pion-pion scattering phase in the isospin I=1 channel. In the former channel, the lattice calculations are performed at pion masses ranging from 270 MeV to 485 MeV. We use chiral perturbation theory at next-to-le
Nicolas Chopin, Pierre Del Moral, Sylvain Rubenthaler
Several particle algorithms admit a Feynman-Kac representation such that the potential function may be expressed as a recursive function which depends on the complete state trajectory. An important example is the mixture Kalman filter, but other models and algorithms of practical interest fall in this category. We study the asymptotic stability of such parti
Guy David, Tatiana Toro
We extend the proof of Reifenberg's Topological Disk Theorem to allow the case of sets with holes, and give sufficient conditions on a set $E$ for the existence of a bi-Lipschitz parameterization of $E$ by a $d$-dimensional plane or smooth manifold. Such a condition is expressed in terms of square summability for the P. Jones numbers $β_1(x,r)$. In parti
LOPES Collaboration, W. D. Apel, J. C. Arteaga, T. Asch
The antenna array LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from Extensive Air Showers. The coincident measurements allow us to reconstruct the electric field strength at observation level in dependence of general EAS parameters. In the present
Multi-core architectures: Complexities of performance prediction and the impact of cache topology
cs.PFJan Treibig, Georg Hager, Gerhard Wellein
The balance metric is a simple approach to estimate the performance of bandwidth-limited loop kernels. However, applying the method to in-cache situations and modern multi-core architectures yields unsatisfactory results. This paper analyzes the in uence of cache hierarchy design on performance predictions for bandwidth-limited loop kernels on current mainst
Lauri K. Haikala, Bo Reipurth
Cometary globule 12 is a relatively little investigated medium- and low mass star forming region 210 pc above the Galactic plane. NIR J, H, and Ks imaging and stellar photometry is used to analyse the stellar content and the structure of CG 12. Several new members and member candidates of the CG 12 stellar cluster were found. The new members include in parti
Torsten Boeker
The centers of most galaxies in the local universe are occupied by compact, barely resolved sources. Based on their structural properties, position in the fundamental plane, and integrated spectra, these sources clearly have a stellar origin. They are therefore called "nuclear star clusters" (NCs) or "stellar nuclei". NCs are found in galaxie
Coexisting multiple dynamic states generated by magnetic field in Bi-2212 stacked Josephson junctions
cond-mat.supr-conYong-Duk Jin, Hu-Jong Lee, A. E. Koshelev, Gil-Ho Lee
Josephson vortices in naturally stacked Bi-2212 tunneling junctions display rich dynamic behavior that derives from the coexistence of three basic states: static Josephson vortex lattice, coherently moving lattice, and incoherent quasiparticle tunneling state. Rich structure of hysteretic branches observed in the current-voltage characteristics can be unders
R. Bindu, Ganesh Adhikary, Sudhir K. Pandey, Kalobaran Maiti
We investigate the spectral evolution of an antiferromagnetic insulator, La$_{0.2}$Sr$_{0.8}$MnO$_3$ exhibiting linear specific heat using state-of-the-art high resolution photoemission spectroscopy. Experimental spectral functions exhibit Fermi liquid like energy dependence at all the temperatures studied. Room temperature spectrum possess finite density of
Ben Davies, Don F. Figer, Rolf-Peter Kudritzki, Christine Trombley
Magnetars are young neutron stars with extreme magnetic fields (B > 10^{14}-10^{15}G). How these fields relate to the properties of their progenitor stars is not yet clearly established. However, from the few objects associated with young clusters it has been possible to estimate the initial masses of the progenitors, with results indicating that a very mass
Mark Kambites
We study the way in which the abstract structure of a small overlap monoid is reflected in, and may be algorithmically deduced from, a small overlap presentation. We show that every C(2) monoid admits an essentially canonical C(2) presentation; by counting canonical presentations we obtain asymptotic estimates for the number of non-isomorphic monoids admitti
Vincent Mathieu
In constituent models, glueballs are described as bound states of effective gluons. The dynamical mass generation lead to a gluon mass without violating gauge invariance. One can then consider three degrees of freedom for those effective massive gluons. However, models with only two degrees of freedom are shown to be in better agreement with the lattice glue
Serguei A. Mokhov, Yingying She
This game is meant to be extension of the overly-beaten pacman-style game (code-named "Yet Another Pacman 3D Adventures", or YAP3DAD) from the proposed ideas and other projects with advance visual and computer graphics features, including a-game-in-a-game approach. The project is an open-source project published on SourceForge.net for possible future
V. I. Yukalov, S. Gluzman
The problem is analyzed of extrapolating power series, derived for an asymptotically small variable, to the region of finite values of this variable. The consideration is based on the self-similar approximation theory. A new method is suggested for defining the odd self-similar factor approximants by employing an optimization procedure. The method is illustr
Eiji Konishi, Jnanadeva Maharana
Compactification of type IIB theory on torus, in the presence of fluxes, is considered. The reduced effective action is expressed in manifestly S-duality invariant form. Cosmological solutions of the model are discussed in several cases in the Pre-Big Bang scenario.
O. Shevtsov, Yu. Klymenko
Based on the nearest-neighbor tight-binding model, we present analytical description of low-energy electron transport through a symmetrical junction of two semimetal armchair ribbons. The results obtained demonstrate the transmission suppression in the vicinity of the neutrality point except for the junction of the ribbons consisting of 3p-1 and 3p+5 dimer l
Alexander Streltsov
In Phys. Rev. Lett. 80, 2245 (1998) an explicit expression for entanglement of formation for any two qubit state was given. Based on this result we present an expression for the Bures measure of entanglement for two qubit states. This measure was proposed in Phys. Rev. A 57, 1619 (1998), where the authors showed that it satisfies all properties every entangl
Xin Chen, Xue-Mei Li, Bo Wu
The aim of the paper is to study the pinned Wiener measure on the loop space over a simply connected compact Riemannian manifold together with the Hilbert space structure induced by Mallianvin calculus and the induced Ornstein- Uhlenbeck operator. We give a concrete estimate for the weak Poincare inequality for the O-U Dirichlet form on loop space over simpl
Vector and scalar form factors for K- and D-meson semileptonic decays from twisted mass fermions with Nf = 2
hep-latS. Di Vita, B. Haas, F. Mescia, V. Lubicz
We present lattice results for the form factors relevant in the K -> pion and D -> pion semileptonic decays, obtained from simulations with two flavors of dynamical twisted-mass fermions and pion masses as light as 260 MeV. For K -> pion decays we discuss the estimates of the main sources of systematic uncertainties, including the quenching of the strange qu
Measurement of the atmospheric muon flux with a 4 GeV threshold in the ANTARES neutrino telescope
astro-ph.HEANTARES collaboration
A new method for the measurement of the muon flux in the deep-sea ANTARES neutrino telescope and its dependence on the depth is presented. The method is based on the observation of coincidence signals in adjacent storeys of the detector. This yields an energy threshold of about 4 GeV. The main sources of optical background are the decay of 40K and the biolum
Calibration issues in estimating variability of the fine structure constant (alpha) with cosmic time
astro-ph.COMiriam Centurión, Paolo Molaro, Sergei Levshakov
Laser Comb Wavelength calibration shows that the ThAr one is locally unreliable with possible deviations of up to 100 m/s within one order range, while delivering an overall 1 m/s accuracy (Wilken et al 2009). Such deviation corresponds to delta alpha/alpha ~ 7E-6 for a FeII-MgII pair. Comparison of line shifts among the 5 FeII lines, with almost identical s
T. Kanna, K. Sakkaravarthi, C. Senthil Kumar, M. Lakshmanan
In this paper, we have studied the integrability nature of a system of three coupled Gross-Pitaevskii type nonlinear evolution equations arising in the context of spinor Bose-Einstein condensates by applying the Painlevé singularity structure analysis. We show that only for two sets of parametric choices, corresponding to the known integrable cases, the syst
V. Bertone, P. Dimopoulos, R. Frezzotti, V. Gimenez
We compute non-perturbatively the B-parameters of the complete basis of four-fermion operators needed to study the Kaon oscillations in the SM and in its supersymmetric extension. We perform numerical simulations with two dynamical maximally twisted sea quarks at three values of the lattice spacing on configurations generated by the ETMC. Unwanted operator m
Orest Hrycyna, Jakub Mielczarek, Marek Szydlowski
The dynamical systems methods are used to study evolution of the polymerised scalar field cosmologies with the cosmological constant. We have found all evolutional paths admissible for all initial conditions on the two-dimensional phase space. We have shown that the cyclic solutions are generic. The exact solution for polymerised cosmology is also obtained.
Performance limitations for sparse matrix-vector multiplications on current multicore environments
cs.PFGerald Schubert, Georg Hager, Holger Fehske
The increasing importance of multicore processors calls for a reevaluation of established numerical algorithms in view of their ability to profit from this new hardware concept. In order to optimize the existent algorithms, a detailed knowledge of the different performance-limiting factors is mandatory. In this contribution we investigate sparse matrix-vecto
Z. Paragi, S. Frey, B. Campbell, A. Moor
The e-VLBI technique offers a unique opportunity for users to probe the milliarcsecond (mas) scale structure of unidentified radio sources, and organise quick follow-up observations in case of detection. Here we report on e-EVN results for a peculiar radio source that has been suggested to act as a gravitational lens. However the lensing galaxy has not been
Sarah Lilienthal, Michel Mandjes
In this paper we study coordinated multipath routing at the flow-level in networks with routes of length one. As a first step the static case is considered, in which the number of flows is fixed. A clustering pattern in the rate allocation is identified, and we describe a finite algorithm to find this rate allocation and the clustering explicitly. Then we co
V. N. Melnikov
A review of different cosmological models in diverse dimensions leading to a relatively small time variation of the effective gravitational constant G is presented. Among them: 4-dimensional general scalar-tensor model, multidimensional vacuum model with two curved Einstein spaces, multidimensional model with multicomponent anisotropic "perfect fluid"
G. Galletta, M. D'Alessandro, G. Bertoloni, F. Castellani
We present the biological results of some experiments performed in the Padua simulators of planetary environments, named LISA, used to study the limit of bacterial life on the planet Mars. The survival of Bacillus strains for some hours in Martian environment is shortly discussed.
Bohdan Grzadkowski, Jose Wudka
We argue that adding gauge-singlet real scalars to the Standard Model can both ameliorate the little hierarchy problem and provide a realistic source of Dark Matter. Masses of the scalars should be in the 1-3 TeV range, while the lowest cutoff of the (unspecified) UV completion of the model must be ~> 5 TeV, depending on the Higgs boson mass and the number o
T. Saito, M. N. Chernodub, Atsushi Nakamura, V. I. Zakharov
We study influence of center vortices on infrared properties of gluons in the deconfinement phase of quenched QCD. We observe a significant suppression of the magnetic component of the gluon propagator in the low-momentum region after the vortices are removed from the gluon configurations. The propagator of the electric gluon stays almost unaffected by the v
Charlotte Hardouin
We propose in this paper a Galois theory of $q$-difference equations where q is a root of unity. This theory is the q difference analogue of the Galois theory of iterative differential equations, that is differential equations over fields of positive characteristic. This theory contains and generalizes the Galois theory of q difference equations developed by
A. Haungs, KASCADE-Grande Collaboration
KASCADE-Grande is a multi-detector experiment at Forschungszentrum Karlsruhe, Germany for measuring extensive air showers in the primary energy range of 100 TeV to 1 EeV. This contribution attempts to provide a synopsis of the current results of the experiment. In particular, the reconstruction of the all-particle energy spectrum in the range of 10 PeV to 1
Wenlin Gong, Shensheng Han
For ghost imaging, pursuing high resolution images and short acquisition times required for reconstructing images are always two main goals. We report an image reconstruction algorithm called compressive sampling (CS) reconstruction to recover ghost images. By CS reconstruction, ghost imaging with both super-resolution and a good signal-to-noise ratio can be
Nicola Lanata`, Paolo Barone, Michele Fabrizio
We study by the Gutzwiller approximation the melting of the valence bond crystal phase of a bilayer Hubbard model at sufficiently large inter-layer hopping. We find that a superconducting domain, with order parameter $d_{z^2-r^2}$, $z$ being the inter-layer direction and $r$ the intra-layer one, is stabilized variationally close to the half-filled non-magnet
Identification and Characterisation of Technological Topics in the Field of Molecular Biology
stat.APIvana Roche, Dominique Besagni, Claire François, Marianne Hörlesberger
This paper focuses on methodological approaches for characterising the specific topics within a technological field based on scientific literature data. We introduce a diachronic clustering analysis approach and some bibliometric indicators. The results are visualised with the software-tool Stanalyst [1]. We are applying our methods to the field "Molecul
Garcia de Andrade
Earlier Chicone, Latushkin and Montgomery-Smith [Comm Math Phys (1997)] have shown that a fast dynamo in compact two-dimensional manifold can be supported as long as its Riemannian curvature be negative. Recently Klebanov and Maldacena [Phys Today (2008)] showed that a similar flat spacetime embedding of a 2D negative Riemannian hyperbolic embedding in 2+1-D
Jean-Philippe Drouhard
We propose to address the problem of how to know students' knowledge in an entirely new approach called ?epistemography? which is, roughly, an attempt to describe the structure of this knowledge. We claim that what is to be known is made of five tightly interrelated organised systems: the mathematical universe, the system of semio-linguistic representati
Spectral classification of emission-line galaxies from the Sloan Digital Sky Survey. I. An improved classification for high redshift galaxies
astro-ph.COFabrice Lamareille
We study the spectral classification of emission-line galaxies as star-forming galaxies or Active Galactic Nuclei (AGNs). From the Sloan Digital Sky Survey (SDSS) high quality data, we define an improved classification to be used for high redshift galaxies. We classify emission-line galaxies of the SDSS according to the latest standard recipe using [Oiii]500
Naoki Seto
Gravitational waves from cosmological double neutron star binaries can be significantly demagnified by strong gravitational lensing effect, and the proposed future missions such as BBO or DECIGO might miss some of the demagnified GW signals below a detection threshold. The undetectable binaries would form a GW foreground which might hamper detection of a ver
Jeong-Yup Lee, Robert V. Moody, Boris Solomyak
We show that for multi-colored Delone point sets with finite local complexity and uniform cluster frequencies the notions of pure point diffraction and pure point dynamical spectrum are equivalent.
Melinda Y. Han, Juliana C. Brant, Philip Kim
We report an electron transport study of lithographically fabricated graphene nanoribbons of various widths and lengths at different temperatures. At the charge neutrality point, a length-independent transport gap forms whose size is inversely proportional to the width. In this gap, electron is localized, and charge transport exhibits a transition between si
Greg Markowsky
An interpretation of selected parts of Newton's Principia, with modern notation and methods. Keplers Laws are derived from an inverse square law using Newton's methods.
Sukanta Deb, Harinder P. Singh
We present a careful and detailed light curve analysis of RR Lyrae stars in the Small Magellanic Cloud (SMC) discovered by the Optical Gravitational Lensing Experiment (OGLE) project. Out of 536 single mode RR Lyrae stars selected from the database, we have investigated the physical properties of 335 `normal looking' RRab stars and 17 RRc stars that have
Characterization and on-sky demonstration of an integrated photonic spectrograph for astronomy
astro-ph.IMN. Cvetojevic, J. S. Lawrence, S. C. Ellis, J. Bland-Hawthorn
We present results from the first on-sky demonstration of a prototype astronomical integrated photonic spectrograph (IPS) using the Anglo-Australian Telescope near-infrared imaging spectrometer (IRIS2) at Siding Spring Observatory to observe atmospheric molecular OH emission lines. We have succeeded in detecting upwards of 27 lines, and demonstrated the prac
Arthur Kosowsky
MOND is a phenomenological modification of Newton's law of gravitation which reproduces the dynamics of galaxies, without the need for additional dark matter. This paper reviews the basics of MOND and its application to dwarf galaxies. MOND is generally successful at reproducing stellar velocity dispersions in the Milky Way's classical dwarf elliptic
Marianna Ridderstad
In Minoan art, symbols for celestial objects were depicted frequently and often in a religious context. The most common were various solar and stellar symbols. The palace of Knossos was amply decorated with these symbols. The rituals performed in Knossos and other Minoan palaces included the alteration of light and darkness, as well as the use of reflection.
Yaroslav Vorobets
We study dynamics of a substitution subshift given by the substitution a->aca, b->d, c->b, d->c that is related to the Grigorchuk group. This dynamical system is shown to be, up to a countable set, conjugated to the binary odometer.
M. G. Kozlov, A. V. Lapinov, S. A. Levshakov
We estimate sensitivity coefficients to variation of the fine-structure constant alpha and electron-to-proton mass ratio mu for microwave Lambda-type transitions in CH molecule and for inversion-rotational transitions in partly deuterated ammonia NH2D. Sensitivity coefficients for these systems are large and strongly depend on the quantum numbers of the tran
Paolo Amore
We develop powerful numerical and analytical techniques for the solution of the Helmholtz equation on general domains. We prove two theorems: the first theorem provides an exact formula for the ground state of an arbirtrary membrane, while the second theorem generalizes this result to any excited state of the membrane. We also develop a systematic perturbati
Shijong Ryang
For the asymptotic string solution in AdS_3 which is represented by the AdS_3 Poincare coordinates and yields the planar multi-gluon scattering amplitude at strong coupling in arXiv:0904.0663, we express it by the AdS_4 Poincare coordinates and demonstrate that the hexagonal and octagonal Wilson loops surrounding the string surfaces take closed contours cons
Ken Yamamoto, Yoshihiro Yamazaki
Asymptotic analysis on some statistical properties of the random binary-tree model is developed. We quantify a hierarchical structure of branching patterns based on the Horton-Strahler analysis. We introduce a transformation of a binary tree, and derive a recursive equation about branch orders. As an application of the analysis, topological self-similarity a
Svjetlan Feretic
Back in the early days of polyomino enumeration, a model called column-convex polyominoes was introduced and its area generating function was found. That generating function is rational: the numerator has degree four and the denominator has degree three. Let a column-duplex polyomino be a polyomino whose columns can have either one or two connected component
Greg Markowsky
This paper proves a generalization of the Butterfly Theorem, a classical Euclidean result, which is valid in the complex projective plane.
Svjetlan Feretic, Anthony J. Guttmann
Column-convex polyominoes were introduced in 1950's by Temperley, a mathematical physicist working on "lattice gases". By now, column-convex polyominoes are a popular and well-understood model. There exist several generalizations of column-convex polyominoes; an example is a model called multi-directed animals. In this paper, we introduce a new s
Li Ma, Baiyu Liu
In this paper, by the method of moving planes, we establish the monotonicity and symmetry properties of convex solutions for Monge-Ampere systems on bounded smooth planar domains.
Matthew B. Day
For any right-angled Artin group, we show that its outer automorphism group contains either a finite-index nilpotent subgroup or a nonabelian free subgroup. This is a weak Tits alternative theorem. We find a criterion on the defining graph that determines which case holds. We also consider some examples of solvable subgroups, including one that is not virtua
Li Ma, Liang Cheng
In this paper, we study global existence and blow up properties to $L^p$ norm preserving non-local heat flows. We first study two kinds of $L^p$ norm preserving non-local flows and prove that these flows have the global solutions. Finally, we give a example to show that one kind of this heat flow may blow up in $L^{\infty}$ norm though its $L^p$ norm is pres
Dynamical study of the possible molecular state X(3872) with the s-channel one gluon exchange interaction
hep-phBao-Kai Wang, Xiao-Lin Chen, Wei-Zhen Deng
The recently observed X(3872) resonance, which is difficult to be assigned a conventional $c\bar{c}$ charmonium state in the quark model, may be interpreted as a molecular state. Such a molecular state is a hidden flavor four quark state because of its charmonium-like quantum numbers. The s-channel one gluon exchange is an interaction which only acts in the
Hubert L. Bray, Marcus A. Khuri
We introduce a generalized version of the Jang equation, designed for the general case of the Penrose Inequality in the setting of an asymptotically flat space-like hypersurface of a spacetime satisfying the dominat energy condition. The appropriate existence and regularity results are established in the special case of spherically symmetric Cauchy data, and
M. E. Brown, D. Ragozzine, J. Stansberry, W. C. Fraser
The Kuiper belt object Orcus and its satellite Vanth form an unusual system in the Kuiper belt. Orcus is amongst the largest objects known in the Kuiper belt, but the relative size of Vanth is much larger than that of the tiny satellites of the other large objects. From Hubble Space Telescope observations we find that Orcus and Vanth have different visible c
Youngbin Lee, Sukang Bae, Houk Jang, Sukjae Jang
We developed means to produce wafer scale, high-quality graphene films as large as 3 inch wafer size on Ni and Cu films under ambient-pressure and transfer them onto arbitrary substrates through instantaneous etching of metal layers. We also demonstrated the applications of the large-area graphene films for the batch fabrication of field-effect transistor (F
On the Self-Consistent Event Biasing Schemes for Monte Carlo Simulations of Nanoscale MOSFETs
physics.comp-phSharnali Islam, Mihail Nedjalkov, Shaikh Ahmed
Different techniques of event biasing have been implemented in the particle-based Monte Carlo simulations of a 15nm n-channel MOSFET. The primary goal is to achieve enhancement in the channel statistics and faster convergence in the calculation of terminal current. Enhancement algorithms are especially useful when the device behavior is governed by rare even
Nigel R. Cooper, Zoran Hadzibabic
We propose a method to measure the superfluid fraction of an atomic gas. The method involves the use of a vector potential generated by optical beams with non-zero angular momentum to simulate uniform rotation. The induced change in angular momentum of the atomic gas can be measured spectroscopically. This allows a direct determination of the superfluid frac
A theorem for the existence of Majorana fermion modes in spin-orbit-coupled semiconductors
cond-mat.str-elSumanta Tewari, Jay D. Sau, S. Das Sarma
We prove an index theorem for the existence of Majorana zero modes in a semiconducting thin film with a sizable spin-orbit coupling when it is adjacent to an s-wave superconductor. The theorem, which is analogous to the Jackiw-Rebbi index theorem for the zero modes in mass domain walls in one-dimensional Dirac theory, applies to vortices with odd flux quantu
Hide-Kazu Tanaka
The SciBooNE experiment (Fermilab) recently published results of a search for charged current coherent pion production in neutrino mode: muon neutrinos scattering on carbon. The results of this study are that no evidence for coherent pion production is observed, and SciBooNE set 90% confidence level upper limits on the cross section ratio of charged current
Rajashekar Annaji, Shrisha Rao
This paper proposes a parallel approach for the Vector Quantization (VQ) problem in image processing. VQ deals with codebook generation from the input training data set and replacement of any arbitrary data with the nearest codevector. Most of the efforts in VQ have been directed towards designing parallel search algorithms for the codebook, and little has h
Christian P. Robert, Jean-Michel Marin
This solution manual contains the unabridged and original solutions to all the exercises proposed in Bayesian Core, along with R programs when necessary.
Bruno Galvan
Permanent spatial decomposition (PSD) is the (hypothesized) property of the wave function of a macroscopic system of decomposing into localized permanently non-overlapping parts when it spreads over a macroscopic region. The typical example of this phenomenon is the measurement process, in which the wave function of the laboratory (quantum system + apparatus
Vasili Perebeinos, Phaedon Avouris
We present a study of transport in graphene devices on polar insulating substrates using a tight-binding model. The mobility is computed using a multiband Boltzmann treatment. We provide the scaling of the surface polar phonon contribution to the low-field mobility with carrier density, temperature, and distance from the substrate. At high bias, we find that
Corrigendum: The base change fundamental lemma for central elements in parahoric Hecke algebras
math.RTThomas J. Haines
This note corrects a minor misstatement in section 2 of the paper in the title (arXiv:0808.3426). It also addresses some related issues. The error does not affect the main results of that paper, but nevertheless this corrigendum seems necessary to avoid potential confusion.
R. K. Prinja, S. E. Hodges, M. A. Urbaneja, D. L. Massa
We present optical ESO time-series and UV archival (FUSE, HST, IUE) spectroscopy of the H-rich central star of He 2-138. Our study targets the central star wind in a very young planetary nebula, and explores physical conditions that may provide clues to the nature of the preceding post-AGB super-wind phases of the star. We provide evidence for a dense, slowl
Ø. Ryan, M. Debbah
Different types of convolution operations involving large Vandermonde matrices are considered. The convolutions parallel those of large Gaussian matrices and additive and multiplicative free convolution. First additive and multiplicative convolution of Vandermonde matrices and deterministic diagonal matrices are considered. After this, several cases of addit
Andrea Tosin, Luigi Preziosi
We present a multiphase mathematical model for tumor growth which incorporates the remodeling of the extracellular matrix and describes the formation of fibrotic tissue by tumor cells. We also detail a full qualitative analysis of the spatially homogeneous problem, and study the equilibria of the system in order to characterize the conditions under which fib
Steen Hannestad, Jacob Brandbyge
The cosmic neutrino background anisotropy is calculated for massive neutrino states by solving the full Boltzmann equation. The effect of weak gravitational lensing, including the Limber approximation, is also derived for massive particles, and subsequently applied to the case of massive neutrinos.
Comparison between shape optimization and volumic level set approximation for geometrical functionals
math.NAT. Milcent
We propose to differentiate a general curvature functional with two different approaches. In the first one we compute the derivative with the tools of shape optimization and in the second one we compute the derivative of a volumic approximation of the functional with respect to a level set function. We show that the two previous approaches give the same resu
A. P. Balachandran, A. Ibort, G. Marmo, M. Martone
In this paper, we further develop the analysis started in an earlier paper on the inequivalence of certain quantum field theories on noncommutative spacetimes constructed using twisted fields. The issue is of physical importance. Thus it is well known that the commutation relations among spacetime coordinates, which define a noncommutative spacetime, do not
Youssef Rami
Let $X$ be a finite type simply connected rationally elliptic CW-complex with Sullivan minimal model $(ΛV, d)$ and let $k\geq 2$ the biggest integer such that $d=\sum_{i\geq k}d_i$ with $d_i(V)\subseteq Λ^iV$. We show that: $cat(X_{\mathbb{Q}}) = depht(ΛV, d_k)$ if and only if $(ΛV,d_{k})$ is elliptic. This result is obtained by introducing tow new spectral
M. A. Zubkov
We suggest the model with the gauge group $ ... \otimes SU(6) \otimes SU(5)\otimes SU(4) \otimes SU(3) \otimes SU(2) \otimes U(1)$. This group is the infinite continuation of the gauge group $SU(4) \otimes SU(3) \otimes SU(2) \otimes U(1)$ of Farhi - Susskind model. The constructed model contains fermions from the fundamental representations of any SU(N) sub
Mikhail N. Smolyakov
We discuss a model providing two different stationary background solutions with flat and $dS_{4}$ metric on the branes under the same values of the fundamental parameters. It is shown that only an additional fine-tuning of the brane scalar field potentials can provide a separation between two background solutions.
Getting the astrophysics and particle physics of dark matter out of next-generation direct detection experiments
astro-ph.COAnnika H. G. Peter
The next decade will bring massive new data sets from experiments of the direct detection of weakly interacting massive particle (WIMP) dark matter. The primary goal of these experiments is to identify and characterize the dark-matter particle species. However, mapping the data sets to the particle-physics properties of dark matter is complicated not only by