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November 2010 arXiv papers — page 64

Showing 6,3016,400 of 6,505 papers

  1. Boris Komitov, Stefano Sello, Peter Duchlev, Momchil Dechev

    The subject of this paper is the existence and stability of solar cycles with durations in the range of 20-250 years. Five types of data series are used: 1) The Zurich series (1749-2009 AD), the mean annual International sunspot number Ri, 2) The Group sunspot number series Rh (1610-1995 AD), 3) The simulated extended sunspot Rsi number from Extended time se

  2. Michael Sagraloff

    We introduce a new approach to isolate the real roots of a square-free polynomial $F=\sum_{i=0}^n A_i x^i$ with real coefficients. It is assumed that each coefficient of $F$ can be approximated to any specified error bound. The presented method is exact, complete and deterministic. Due to its similarities to the Descartes method, we also consider it practica

  3. Alexandre I. Danilenko, Valery V. Ryzhikov

    Given an ergodic flow $T=(T_t)_{t\in\Bbb R}$, let $I(T)$ be the set of reals $s\ne 0$ for which the flows $(T_{st})_{t\in\Bbb R}$ and $T$ are isomorphic. It is proved that $I(T)$ is a Borel subset of $\Bbb R^*$. It carries a natural Polish group topology which is stronger than the topology induced from $\Bbb R$. There exists a mixing flow $T$ such that $I(T)

  4. Andrei Leonidov, Mihail Alfimov

    Full quantum calculation of the in-medium Cherenkov gluon emission by gluon current in transparent media without dispersion is discussed.

  5. Daniel Butter, Sergei M. Kuzenko

    We address the problem of classifying all N=2 supercurrent multiplets in four space-time dimensions. For this purpose we consider the minimal formulation of N=2 Poincare supergravity with a tensor compensator, and derive its linearized action in terms of three N=2 off-shell multiplets: an unconstrained scalar superfield, a vector multiplet, and a tensor mult

  6. B. Baykant Alagoz

    In the paper, a theoretical work is done for investigating effects of splitting data sequence into packs of data set. We proved that a partitioning of data sequence is possible to find such that the entropy rate at each subsequence is lower than entropy rate of the source. Effects of sequence partitioning on overall compression rate are argued on the bases o

  7. A. Lyapin, H. J. Schreiber, M. Viti, C. Adolphsen

    The International Linear Collider and other proposed high energy e+ e- machines aim to measure with unprecedented precision Standard Model quantities and new, not yet discovered phenomena. One of the main requirements for achieving this goal is a measurement of the incident beam energy with an uncertainty close to 1e-4. This article presents the analysis of

  8. Hunpyo Lee, Yu-Zhong Zhang, Harald O. Jeschke, Roser Valenti

    Motivated by the unexplored complexity of phases present in the multiorbital Hubbard model, we analyze in this work the behavior of a degenerate two-orbital anisotropic Hubbard model at half filling where both orbitals have equal bandwidths and one orbital is constrained to be paramagnetic (PM), while the second one is allowed to have an antiferromagnetic (A

  9. Thomas Cederborg, Pierre-Yves Oudeyer

    Imitation learning in robots, also called programing by demonstration, has made important advances in recent years, allowing humans to teach context dependant motor skills/tasks to robots. We propose to extend the usual contexts investigated to also include acoustic linguistic expressions that might denote a given motor skill, and thus we target joint learni

  10. Takuro Abe, Hiroaki Terao, Atsushi Wakamiko

    Let $\A$ be an irreducible Coxeter arrangement and $W$ be its Coxeter group. Then $W$ naturally acts on $\A$. A multiplicity $\bfm : \A\rightarrow \Z$ is said to be equivariant when $\bfm$ is constant on each $W$-orbit of $\A$. In this article, we prove that the multi-derivation module $D(\A, \bfm)$ is a free module whenever $\bfm$ is equivariant by explicit

  11. Carmen Rodriguez-Gonzalvez, Malak Olamaie, Matthew L. Davies, Andy C. Fabian

    We present 13.9-18.2 GHz observations of the Sunyaev-Zel'dovich (SZ) effect towards Abell 2146 using the Arcminute Microkelvin Imager (AMI). The cluster is detected with a peak SNR ratio of 13 sigma in the radio source subtracted map. Comparison of the SZ and X-ray images suggests that they both have extended regions which lie approximately perpendicular

  12. Yasushi Komori, Kohji Matsumoto, Hirofumi Tsumura

    We define zeta-functions of weight lattices of compact connected semisimple Lie groups. If the group is simply-connected, these zeta-functions coincide with ordinary zeta-functions of root systems of associated Lie algebras. In this paper we consider the general connected (but not necessarily simply-connected) case, prove the explicit form of Witten's vo

  13. Michael Assaf, Mauro Mobilia

    The mean fixation time of a deleterious mutant allele is studied beyond the diffusion approximation. As in Kimura's classical work [M. Kimura, Proc. Natl. Acad. Sci. U.S.A. Vol.77, 522 (1980)], that was motivated by the problem of fixation in the presence of amorphic or hypermorphic mutations, we consider a diallelic model at a single locus comprising a

  14. T. Gehrmann, N. Greiner

    We present the automation of a subtraction method for photon radiation using the dipole formalism within the MadGraph framework. The subtraction terms are implemented both in dimensional regularization and mass regularization for massless and massive cases and non-collinear-safe observables are accounted for.

  15. Peter Eichelsbacher, Bastian Martschink

    In the present paper we obtain rates of convergence for the limit theorems of the density vector in the Curie-Weiss-Potts model via Stein's Method of exchangeable pairs. Our results include Kolmogorov bounds for multivariate normal approximation in the whole domain $β\geq 0$ and $h\geq 0$, where $β$ is the inverse temperature and $h$ an exterior field. I

  16. Jaime Gaspar

    We refute the conjecture that all negative translations are intuitionistically equivalent by giving two counterexamples. Then we characterise the negative translations intuitionistically equivalent to the usual ones.

  17. Takuya Ikuta, Akihiro Munemasa

    A spin model (for link invariants) is a square matrix $W$ which satisfies certain axioms. For a spin model $W$, it is known that $W^TW^{-1}$ is a permutation matrix, and its order is called the index of $W$. F. Jaeger and K. Nomura found spin models of index 2, by modifying the construction of symmetric spin models from Hadamard matrices. The aim of this pap

  18. V. A. Karmanov

    A brief review of relativistic effects in few-body systems, of theoretical approaches, recent developments and applications is given. Manifestations of relativistic effects in the binding energies, in the electromagnetic form factors and in three-body observables are demonstrated. The three-body forces of relativistic origin are also discussed.

  19. Joachim Asch, Tomas Kalvoda, Pavel Stovicek

    We study the dynamics of a classical nonrelativistic charged particle moving on a punctured plane under the influence of a homogeneous magnetic field and driven by a periodically time-dependent singular flux tube through the hole. We observe an effect of resonance of the flux and cyclotron frequencies. The particle is accelerated to arbitrarily high energies

  20. Paul Mansfield, Adam Wardlow

    We construct infinite-dimensional symmetries of the two dimensional equation which results from the dimensional reduction of the self-duality condition in (2, 2) signature space-time. These are symmetries of the dimensionally reduced Chalmers-Siegel action and so hold off-shell.

  21. Felipe J. Llanes-Estrada, Katja Waidelich

    We propose the left-side electrification of multilane motorways in suburban areas as a practical way of implementing on-road charging in order to reduce the weight and price of electrically-powered automobiles. These could then be supplied energy en-route, significantly reducing the weight and cost of vehicle-mounted batteries. Our theoretical study is based

  22. Fabrice Gamboa, Jan Nagel, Alain Rouault, Jens Wagener

    We consider the moment space $\mathcal{M}_n^{K}$ corresponding to $p \times p$ complex matrix measures defined on $K$ ($K=[0,1]$ or $K=\D$). We endow this set with the uniform law. We are mainly interested in large deviations principles (LDP) when $n \rightarrow \infty$. First we fix an integer $k$ and study the vector of the first $k$ components of a random

  23. Michael C. Garrett, Adrian Ratnapala, Eikbert D. van Ooijen, Christopher J. Vale

    We study the formation of a Bose-Einstein condensate in a cigar-shaped three-dimensional harmonic trap, induced by the controlled addition of an attractive "dimple" potential along the weak axis. In this manner we are able to induce condensation without cooling due to a localized increase in the phase space density. We perform a quantitative analysis

  24. S. M. Liddle, T. Narayanan, W. C. K. Poon

    We study phase separation and transient gelation in a mixture consisting of polydisperse colloids and non-adsorbing polymers, where the ratio of the average size of the polymer to that of the colloid is approximately 0.063. Unlike what has been reported previously for mixtures with somewhat lower colloid polydispersity, the addition of polymers does not expa

  25. Yasuhiko Yamada

    We give an explicit differential equation which is expected to determine the instanton partition function in the presence of the full surface operator in N=2 SU(N) gauge theory. The differential equation arises as a quantization of a certain Hamiltonian system of isomonodromy type discovered by Fuji, Suzuki and Tsuda.

  26. Niclas Wyllard

    A general class of W-algebras can be constructed from the affine sl(N) algebra by (quantum) Drinfeld-Sokolov reduction and are classified by partitions of N. Surface operators in an N=2 SU(N) 4d gauge theory are also classified by partitions of N. We argue that instanton partition functions of N=2 gauge theories in the presence of a surface operator can also

  27. Jesse Alt

    Using the theory of Weyl structures, we give a natural generalization of the notion of essential conformal structures and conformal Killing fields to arbitrary parabolic geometries. We show that a parabolic structure is inessential whenever the automorphism group acts properly on the base space. As a corollary of the generalized Ferrand-Obata theorem proved

  28. J. C. Fabris, T. C. C. Guio, M. Hamani Daouda, O. F. Piattella

    The generalized Chaplygin gas model represents an attempt to unify dark matter and dark energy. It is characterized by a fluid with an equation of state $p = - A/ρ^α$. It can be obtained from a generalization of the DBI action for a scalar, tachyonic field. At background level, this model gives very good results, but it suffers from many drawbacks at perturb

  29. Ebrahim Ghorbani

    We determine all graphs whose matching polynomials have at most five distinct zeros. As a consequence, we find new families of graphs which are determined by their matching polynomial.

  30. Masamichi Ishihara

    The author studied the effects of the environment described by Tsallis statistics in quantum mechanics, when the deviation from Boltzmann-Gibbs (BG) statistics is small. The $x^{4}$ model was used and the squeeze angle caused by the difference between Tsallis and BG statistics was calculated perturbatively in the mean field approximation as a function of the

  31. Yuichi Mizutani, Tomohiro Inagaki

    A relativistic neutral scalar field is investigated on the basis of the Schwinger-Dyson equation in the non-equilibrium thermo field dynamics. A time evolution equation for a distribution function is obtained from a diagonalization condition for the Schwinger-Dyson equation. An explicit expression of the time evolution equation is calculated in the $λϕ^4$ in

  32. Michael Kunzinger, Roman O. Popovych

    We analyze the relationship of generalized conditional symmetries of evolution equations to the formal compatibility and passivity of systems of differential equations as well as to systems of vector fields in involution. Earlier results on the connection between generalized conditional invariance and generalized reduction of evolution equations are revisite

  33. Kenta Fuji, Keisuke Inoue, Keisuke Shinomiya, Takao Suzuki

    The higher order Painleve system of type D^{(1)}_{2n+2} was proposed by Y. Sasano as an extension of the sixth Painleve equation for the affine Weyl group symmetry with the aid of algebraic geometry for Okamoto initial value space. In this article, we give it as the monodromy preserving deformation of a Fuchsian system.

  34. Guillaume Aubrun

    Let W be a Wishart random matrix of size d^2 times d^2, considered as a block matrix with d times d blocks. Let Y be the matrix obtained by transposing each block of W. We prove that the empirical eigenvalue distribution of Y approaches a non-centered semicircular distribution when d tends to infinity. We also show the convergence of extreme eigenvalues towa

  35. Mikhail Skopenkov, Helmut Pottmann, Philipp Grohs

    A Laguerre minimal surface is an immersed surface in the Euclidean space being an extremal of the functional \int (H^2/K - 1) dA. In the present paper, we prove that the only ruled Laguerre minimal surfaces are up to isometry the surfaces R(u,v) = (Au, Bu, Cu + D cos 2u) + v (sin u, cos u, 0), where A, B, C, D are fixed real numbers. To achieve invariance un

  36. B. R. Schlei

    In this paper we present a new method, which allows for the construction of triangular isosurfaces from three-dimensional data sets, such as 3D image data and/or numerical simulation data that are based on regularly shaped, cubic lattices. This novel volume-enclosing surface extraction technique, which has been named VESTA, can produce up to six different re

  37. Xin-Qiang Li, Fang Su, Ya-Dong Yang

    According to heavy-meson chiral perturbation theory, the vector form factor $f_+(q^2)$ of exclusive semi-leptonic decay $B\to π\ell ν$ is closely related, at least in the soft-pion region (i.e., $q^{2} \sim (m_B-m_π)^2$), to the strong coupling $g_{B^* Bπ}$ or the normalized coupling $\hat g$. Combining the precisely measured $q^2$ spectrum of $B\to π\ell ν$

  38. Dmitry Ioffe, Yvan Velenik

    We survey recent results and open questions on the ballistic phase of stretched polymers in both annealed and quenched random environments.

  39. Masato Nozawa

    It has been shown that the 4-dimensional Einstein-Maxwell-dilaton theory allows a Bogomol'nyi-type inequality for an arbitrary dilaton coupling constant $α$, and that the bound is saturated if and only if the (asymptotically flat) spacetime admits a nontrivial spinor satisfying the gravitino and the dilatino Killing spinor equations. The present paper re

  40. Junji Hisano, Shohei Sugiyama

    In the minimal supersymmetric standard model, large left-right mixing of stau's is sometimes intriguing from phenomenological viewpoints. However, too large left-right mixing is not acceptable since the electroweak-breaking vacuum becomes metastable. In this paper the vacuum transition rate is evaluated by using semiclassical techniques, and constraints

  41. Yuri Kornyushin

    Concentrated electric field and its energy in materials, containing nanofibers, are discussed. It is shown that the electric field in the vicinity of the end of a fiber is proportional to the external applied field and to the fiber length, whilst it is inversely proportional to the fiber diameter. Specific electrostatic energy of a fiber in a sample under th

  42. Thad Szabo, Elena Pierpaoli, Feng Dong, Antonio Pipino

    We present a new cluster catalog extracted from the Sloan Digital Sky Survey Data Release 6 (SDSS DR6) using an adaptive matched filter (AMF) cluster finder. We identify 69,173 galaxy clusters in the redshift range 0.045 $\le z <$ 0.78 in 8420 sq. deg. of the sky. We provide angular position, redshift, richness, core and virial radii estimates for these clus

  43. Tzyh Haur Yang, Miguel Navascués, Lana Sheridan, Valerio Scarani

    We propose a method to generate analytical quantum Bell inequalities based on the principle of Macroscopic Locality. By imposing locality over binary processings of virtual macroscopic intensities, we establish a correspondence between Bell inequalities and quantum Bell inequalities in bipartite scenarios with dichotomic observables. We discuss how to improv

  44. Arkady Berenstein, Vladimir Retakh

    We give an elementary proof of the Kontsevich conjecture that asserts that the iterations of the noncommutative rational map K_r:(x,y)-->(xyx^{-1},(1+y^r)x^{-1}) are given by noncommutative Laurent polynomials.

  45. Martin Lenz, Sebastian Wüster, Christopher J. Vale, Norman R. Heckenberg

    The study of dynamical tunnelling in a periodically driven anharmonic potential probes the quantum-classical transition via the experimental control of the effective Planck&#39;s constant for the system. In this paper we consider the prospects for observing dynamical tunnelling with ultracold atoms in magnetic microtraps on atom chips. We outline the driven

  46. Sergei V. Ketov, Alexei A. Starobinsky

    We find the natural embedding of the (R+R^2)-inflationary model into the recently constructed N=1 F(\cal R)-supergravity. It gives a simple and viable realization of chaotic inflation in supergravity. The only requirement for a slow-roll inflation is the existence of the (\cal R)^3-term with an anomalously large coefficient in Taylor expansion of the F(\cal

  47. Gregory D. Fleishman, Gelu M. Nita, Dale E. Gary

    The coming years will see routine use of solar data of unprecedented spatial and spectral resolution, time cadence, and completeness in the wavelength domain. To capitalize on the soon to be available radio facilities such as the expanded OVSA, SSRT and FASR, and the challenges they present in the visualization and synthesis of the multi-frequency datasets,

  48. Jonathan Dahl

    We show that suitable convex energy functionals on a quadratic Wasserstein space satisfy a maximum principle on minimal networks. We explore consequences of this maximum principle for the structure of minimal networks.

  49. Weiming Liu, Sanjiang Li

    The cardinal direction calculus (CDC) proposed by Goyal and Egenhofer is a very expressive qualitative calculus for directional information of extended objects. Early work has shown that consistency checking of complete networks of basic CDC constraints is tractable while reasoning with the CDC in general is NP-hard. This paper shows, however, if allowing so

  50. Chris Godsil

    Let $X$ be a graph on $n$ vertices with with adjacency matrix $A$ and let $H(t)$ denote the matrix-valued function $\exp(iAt)$. If $u$ and $v$ are distinct vertices in $X$, we say perfect state transfer from $u$ to $v$ occurs if there is a time $τ$ such that $|H(τ)_{u,v}| = 1$. Our chief problem is to characterize the cases where perfect state transfer occur

  51. P. -G. Reinhard, J. A. Maruhn, A. S. Umar, V. E. Oberacker

    We investigate the presence of spatial localization in nuclei using a method that maps the nucleon same-spin pair probability and is based on the density-matrix. The method is used to study spatial localization of light nuclei within the Hartree-Fock approximation. We show that the method provides an alternative tool for studying spatial localization in comp

  52. Andrew J. Wells, J. S. Wettlaufer, Steven A. Orszag

    We take a numerical approach to analyze the mechanisms controlling the spacing of chimneys -- channels devoid of solid -- in two-dimensional mushy layers formed by solidifying a binary alloy. Chimneys are the principal conduits through which buoyancy effects transport material out of the mushy layer and into the liquid from which it formed. Experiments show

  53. Emerson Sadurni, Wolfgang P. Schleich

    Is it possible to trap a quantum particle in an open geometry? In this work we deal with the boundary value problem of the stationary Schroedinger (or Helmholtz) equation within a waveguide with straight segments and a rectangular bending. The problem can be reduced to a one dimensional matrix Schroedinger equation using two descriptions: oblique modes and c

  54. Mireille Sarkiss, Ghaya Rekaya-Ben Othman, Mohamed Oussama Damen, Jean-Claude Belfiore

    Perfect Space-Time Codes (STC) are optimal codes in their original construction for Multiple Input Multiple Output (MIMO) systems. Based on Cyclic Division Algebras (CDA), they are full-rate, full-diversity codes, have Non-Vanishing Determinants (NVD) and hence achieve Diversity-Multiplexing Tradeoff (DMT). In addition, these codes have led to optimal distri

  55. Xinhua Zhang, Ankan Saha, S. V. N. Vishwanathan

    Nesterov&#39;s accelerated gradient methods (AGM) have been successfully applied in many machine learning areas. However, their empirical performance on training max-margin models has been inferior to existing specialized solvers. In this paper, we first extend AGM to strongly convex and composite objective functions with Bregman style prox-functions. Our un

  56. Lloyd J. Edwards

    Using the LRT statistic, a model R^2 is proposed for the generalized linear mixed model for assessing the association between the correlated outcomes and fixed effects. The R^2 compares the full model to a null model with all fixed effects deleted.

  57. M. Wiescher, T. Rauscher

    Nuclear reaction rates determine the abundances of isotopes in stellar burning processes. A multitude of reactions determine the reaction flow pattern which is described in terms of reaction network simulations. The reaction rates are determined by laboratory experiments supplemented by nuclear reaction and structure theory. We will discuss the experimental

  58. Andrew J. Macdonald, Peter C. W. Holdsworth, Roger G. Melko

    We examine the onset of classical topological order in a nearest-neighbor kagome ice model. Using Monte Carlo simulations, we characterize the topological sectors of the groundstate using a non-local cut measure which circumscribes the toroidal geometry of the simulation cell. We demonstrate that simulations which employ global loop updates that are allowed

  59. Mihail N. Kolountzakis, Gary L. Miller, Richard Peng, Charalampos E. Tsourakakis

    The number of triangles is a computationally expensive graph statistic which is frequently used in complex network analysis (e.g., transitivity ratio), in various random graph models (e.g., exponential random graph model) and in important real world applications such as spam detection, uncovering of the hidden thematic structure of the Web and link recommend

  60. E. R. Parkin, J. M. Pittard, M. G. Hoare, N. J. Wright

    The supersonic stellar and disk winds possessed by massive young stellar objects will produce shocks when they collide against the interior of a pre-existing bipolar cavity (resulting from an earlier phase of jet activity). The shock heated gas emits thermal X-rays which may be observable by spaceborne observa- tories such as the Chandra X-ray Observatory. H

  61. C. D. Fosco, F. C. Lombardo, F. D. Mazzitelli

    We study dissipative effects due to inertial forces acting on matter fields confined to accelerated boundaries in $1+1$, $2+1$, and $3+1$ dimensions. These matter fields describe the internal degrees of freedom of `mirrors&#39; and impose, on the surfaces where they are defined, boundary conditions on a fluctuating `vacuum&#39; field. We construct different

  62. Michael Crumley

    The principle of tannakian duality states that any neutral tannakian category is tensorially equivalent to the category Rep_k G of finite dimensional representations of some affine group scheme G and field k, and conversely. Originally motivated by an attempt to find a first-order explanation for generic cohomology of algebraic groups, we study neutral tanna

  63. Anabella T. Araudo

    The main goal of this thesis is to study the physical processes that can produce non-thermal emission at high energies in astrophysical objects capable to accelerate particles up to relativistic velocities. In particular, we have studied the gamma-ray emission produced in cosmic sources with different spatial scales, from young stellar objects to clusters of

  64. Thomas M. Brown, Kailash Sahu, Jay Anderson, Jason Tumlinson

    We present new UV-to-IR stellar photometry of four low-extinction windows in the Galactic bulge, obtained with the Wide Field Camera 3 on the Hubble Space Telescope (HST). Using our five bandpasses, we have defined reddening-free photometric indices sensitive to stellar effective temperature and metallicity. We find that the bulge populations resemble those

  65. Wieland Staessens, Bert Vercnocke

    In these lecture notes, we take a closer look at the calculation of scattering amplitudes for the bosonic string. It is believed that string theories form the UV completions of (super)gravity theories. Support for this claim can be found in the (on-shell) scattering amplitudes of strings. On the other hand, studying these string scattering amplitudes opens a

  66. Gregory A. Phelps, Pierre Meystre

    We investigate theoretically the influence of laser phase noise on the cooling and heating of a generic cavity optomechanical system. We derive the back-action damping and heating rates and the mechanical frequency shift of the radiation pressure-driven oscillating mirror, and derive the minimum phonon occupation number for small laser linewidths. We find th

  67. Inder Jeet Taneja

    In this short note we shall give connection between the most perfect &#34;Khajuraho&#34; magic square of order 4x4 discovered in 10th century and the &#34;Lo-Shu&#34; magic square of order 3x3 with the day October 1, 2010, i.e., 01.10.2010. The day has only three digits 0, 1 and 2. Here we have given an equivalent version of Khajuraho magic square using only

  68. Raul Isea

    Resumen: El desarrollo de nuevos medicamentos es un problema complejo que carece de una solución única y automática desde un punto de vista computacional, debido a la carencia de programas que permitan manejar grandes volúmenes de información que están distribuidos a lo largo de todo el mundo entre múltiples bases de datos. Por ello se describe una metodolog

  69. Jeffrey K. J. Fogel, Thomas J. Bethell, Edwin A. Bergin, Nuria Calvet

    We present results from a model of the chemical evolution of protoplanetary disks. In our models we directly calculate the changing propagation and penetration of a high energy radiation field with Lyman alpha radiation included. We also explore the effect on our models of including dust grain settling. We find that, in agreement with earlier studies, the ev

  70. Benjamin P Brown, Matthew K Browning, Allan S Brun, Mark S Miesch

    When stars like our Sun are young they rotate rapidly and are very magnetically active. We explore dynamo action in rapidly rotating suns with the 3-D MHD anelastic spherical harmonic (ASH) code. The magnetic fields built in these dynamos are organized on global-scales into wreath-like structures that span the convection zone. Wreath-building dynamos can und

  71. Tapash Chakraborty

    Graphene, a single atomic layer of graphite, first isolated in 2004, has made a quantum leap in the exploration of the physics of two-dimensional electron systems. Since the initial report of its discovery, many thousands of papers have been published, attempting to explain every aspect of the exotic electronic properties of this system. The graphene euphori

  72. Nicholas J. Wright, Jeremy J. Drake, Francesca Civano

    We present an analysis of the X-ray properties of a sample of solar- and late-type field stars identified in the Chandra Cosmic Evolution Survey (COSMOS), a deep (160ks) and wide (0.9 deg2) extragalactic survey. The sample of 60 sources was identified using both morphological and photometric star/galaxy separation methods. We determine X-ray count rates, ext

  73. Markus Uhlmann, Genta Kawahara, Alfredo Pinelli

    We present numerically determined travelling-wave solutions for pressure-driven flow through a straight duct with a square cross-section. This family of solutions represents typical coherent structures (a staggered array of counter-rotating streamwise vortices and an associated low-speed streak) on each wall. Their streamwise average flow in the cross-sectio

  74. Philip Nutzman, Ronald L. Gilliland, Peter R. McCullough, David Charbonneau

    We present observations of three distinct transits of HD 17156b obtained with the Fine Guidance Sensors (FGS) on board the Hubble Space Telescope} (HST). We analyzed both the transit photometry and previously published radial velocities to find the planet-star radius ratio R_p/R_s = 0.07454 +/- 0.00035, inclination i=86.49 +0.24/-0.20 deg, and scaled semi-ma

  75. Stephen R. Kane, David Ciardi, Debra Fischer, Greg Henry

    Transiting planet discoveries have largely been restricted to the short-period or low-periastron distance regimes due to the bias inherent in the geometric transit probability. Through the refinement of planetary orbital parameters, and hence reducing the size of transit windows, long-period planets become feasible targets for photometric follow-up. Here we

  76. Ronald L. Gilliland, Peter R. McCullough, Edmund P. Nelan, Timothy M. Brown

    Observations conducted with the Fine Guidance Sensor on Hubble Space Telescope (HST) providing high cadence and precision time-series photometry were obtained over 10 consecutive days in December 2008 on the host star of the transiting exoplanet HD 17156b. During this time 10^12 photons (corrected for detector deadtime) were collected in which a noise level

  77. Alyson Brooks, Adam Solomon, Fabio Governato, Jacqueline McCleary

    A sample of very high resolution cosmological disk galaxy simulations is used to investigate the evolution of galaxy disk sizes back to redshift 1 within the Lambda CDM cosmology. Artificial images in the rest frame B band are generated, allowing for a measurement of disk scale lengths using surface brightness profiles as observations would, and avoiding any

  78. Nicolas B. Cowan, Eric Agol

    We present a semi-analytic model atmosphere for close-in exoplanets that captures the essential physics of phase curves: orbital and viewing geometry, advection, and re-radiation. We calibrate the model with the well-characterized transiting planet, HD 189733b, then compute light curves for seven of the most eccentric transiting planets. We present phase var

  79. Kevin Schawinski, Daniel A. Evans, Shanil Virani, C. Megan Urry

    Galaxy formation is significantly modulated by energy output from supermassive black holes at the centers of galaxies which grow in highly efficient luminous quasar phases. The timescale on which black holes transition into and out of such phases is, however, unknown. We present the first measurement of the shutdown timescale for an individual quasar using X

  80. Joshua J. Adams, Guillermo A. Blanc, Gary J. Hill, Karl Gebhardt

    We present a catalog of emission-line galaxies selected solely by their emission-line fluxes using a wide-field integral field spectrograph. This work is partially motivated as a pilot survey for the upcoming Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). We describe the observations, reductions, detections, redshift classifications, line fluxes, an

  81. Alicia N. Aarnio, Keivan G. Stassun, W. Jeffrey Hughes, Sarah L. McGregor

    In an effort to examine the relationship between flare flux and corresponding CME mass, we temporally and spatially correlate all X-ray flares and CMEs in the LASCO and GOES archives from 1996 to 2006. We cross-reference 6,733 CMEs having well-measured masses against 12,050 X-ray flares having position information as determined from their optical counterpart

  82. Dennis Sullivan

    This short paper is dedicated to Mauricio Peixoto who abstracted the practical theory of ODE&#39;s and to David Rand who applied the subsequent powerful abstract theory to practical problems.

  83. Diego F. M. Oliveira, Marko Robnik

    Some dynamical properties of time-dependent driven elliptical-shaped billiard are studied. It was shown that for the conservative time-dependent dynamics the model exhibits the Fermi acceleration [Phys. Rev. Lett. 100, 014103 (2008)]. On the other hand, it was observed that damping coefficients upon collisions suppress such phenomenon [Phys. Rev. Lett. 104,

  84. Michael Strickland, Jens O. Andersen, Lars E. Leganger, Nan Su

    Naively resummed perturbative approximations to the thermodynamic functions of QCD do not converge at phenomenologically relevant temperatures. Here we review recent results of a three-loop hard-thermal-loop perturbation theory calculation of the thermodynamic functions of a quark-gluon plasma for general N_c and N_f. We show comparisons of our recent result

  85. José Bento, Morteza Ibrahimi, Andrea Montanari

    We consider linear models for stochastic dynamics. To any such model can be associated a network (namely a directed graph) describing which degrees of freedom interact under the dynamics. We tackle the problem of learning such a network from observation of the system trajectory over a time interval $T$. We analyze the $\ell_1$-regularized least squares algor

  86. Andrew W. Howard, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer

    We report the discovery of planets orbiting two bright, nearby early K dwarf stars, HD 97658 and Gl 785. These planets were detected by Keplerian modelling of radial velocities measured with Keck-HIRES for the NASA-UC Eta-Earth Survey. HD 97658 b is a close-in super-Earth with minimum mass Msini = 8.2 +/- 1.2 M_Earth, orbital period P = 9.494 +/- 0.005 d, an

  87. Jacob Bien, Ya Xu, Michael W. Mahoney

    The CUR decomposition provides an approximation of a matrix $X$ that has low reconstruction error and that is sparse in the sense that the resulting approximation lies in the span of only a few columns of $X$. In this regard, it appears to be similar to many sparse PCA methods. However, CUR takes a randomized algorithmic approach, whereas most sparse PCA met

  88. Ricardo G. Duran, Marcela Sanmartino, Marisa Toschi

    This work deals with the system $(-Δ)^m u= a(x) v^p$, $(-Δ)^m v=b(x) u^q$ with Dirichlet boundary condition in a domain $Ω\subset\RR^n$, where $Ω$ is a ball if $n\ge 3$ or a smooth perturbation of a ball when $n=2$. We prove that, under appropriate conditions on the parameters ($a,b,p,q,m,n$), any non-negative solution $(u,v)$ of the system is bounded by a c

  89. Constantia Alexandrou, Eric B. Gregory, Tomasz Korzec, Giannis Koutsou

    We present first results on the axial and pseudoscalar $Δ$ form factors. The analysis is carried out in the quenched approximation where statistical errors are small and the lattice set-up can be investigated relatively quickly. We also present an analysis with a hybrid action using staggered sea quarks and domain-wall valence fermions.

  90. Sergey Kovalenko, Heinrich Päs, Ivan Schmidt

    Lepton number violating processes are a typical problem in theories with a low quantum gravity scale. In this paper we examine lepton number violation (LNV) in theories with a saturated black hole bound on a large number of species. Such theories have been advocated recently as a possible solution to the hierarchy problem and an explanation of the smallness

  91. Samir AbdelRahman, Basma Hassan, Reem Bahgat

    Email Retrieval task has recently taken much attention to help the user retrieve the email(s) related to the submitted query. Up to our knowledge, existing email retrieval ranking approaches sort the retrieved emails based on some heuristic rules, which are either search clues or some predefined user criteria rooted in email fields. Unfortunately, the user u

  92. J. P. Maier, G. A. H. Walker, D. A. Bohlender, F. J. Mazzotti

    We present strong evidence that the broad, diffuse interstellar bands (DIBs) at 4881 and 5450\,Åare caused by the $B\,^1$B$_1$\,$\leftarrow$\,$X\,^1$A$_1$ transition of H$_2$CCC (l-C$_3$H$_2$). The large widths of the bands are due to the short lifetime of the $B\,^1$B$_1$ electronic state. The bands are predicted from absorption measurements in a neon matri

  93. W. M. Alberico, A. Beraudo, A. De Pace, A. Molinari

    We study the stochastic dynamics of c and b quarks in the hot plasma produced in nucleus-nucleus collisions at RHIC and LHC, providing results for the nuclear modification factor R_AA and the elliptic flow coefficient v_2 of the single-electron spectra arising from their semi-leptonic decays. The initial QQbar pairs are generated using the POWHEG code, imple

  94. Sara Miner More, Pavel Naumov

    A collaboration network is a graph formed by communication channels between parties. Parties communicate over these channels to establish secrets, simultaneously enforcing interdependencies between the secrets. The paper studies properties of these interdependencies that are induced by the topology of the network. In previous work, the authors developed a co

  95. D. J. Walton, J. C. Gladstone, T. P. Roberts, A. C. Fabian

    Since their discovery, Ultraluminous X-ray sources (ULXs) have attracted attention due to their combination of extreme luminosities and extra-nuclear locations. However, they are a fairly rare phenomenon, and attempts to investigate the general properties of the population have been hindered by a relative lack of known sources. Here, we present a large catal

  96. Anita Kumari, Javier F. Pulecio, Sanjukta Bhanja

    As devices continue to scale, imperfections in the fabrication process will have a more substantial impact on the reliability of a system. In Magnetic Cellular Automata (MCA) data is transferred through the coupling of neighboring cells via magnetic force fields. Due to the size of the switching cells, usually of the order of nanometers or smaller, MCA can b

  97. Anton Zorich

    Moduli spaces of Abelian and quadratic differentials are stratified by multiplicities of zeroes; connected components of the strata correspond to ergodic components of the Teichmuller geodesic flow. It is known that the strata are not necessarily connected; the connected components were recently classified by M. Kontsevich and the author and by E. Lanneau. T

  98. Amelia Carolina Sparavigna

    We propose a survey of the literature about archaeological and geophysical researches and on the paleoclimatology of the basin of Titicaca Lake, in connection with the agricultural system of the raised fields. Here again we discuss the use of Google Maps and satellite imagery as fundamental tools to understand this ancient agricultural system and its role in

  99. Marko A. Rodriguez, Peter Neubauer

    A multi-relational graph maintains two or more relations over a vertex set. This article defines an algebra for traversing such graphs that is based on an $n$-ary relational algebra, a concatenative single-relational path algebra, and a tensor-based multi-relational algebra. The presented algebra provides a monoid, automata, and formal language theoretic fou

  100. F. Wolny, Y. Obukhov, T. Mühl, U. Weissker

    We have characterized a new Magnetic Force Microscopy (MFM) probe based on an iron filled carbon nanotube (FeCNT) using MFM imaging on permalloy (Py) disks saturated in a high magnetic field perpendicular to the disk plane. The experimental data are accurately modeled by describing the FeCNT probe as having a single magnetic monopole at its tip whose effecti