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March 2010 arXiv papers — page 20

Showing 1,9012,000 of 5,984 papers

  1. Marie-Françoise Bidaut-Véron, Marta Garcia-Huidobro, Cecilia Yarur

    In this article we study the positive solutions of the parabolic semilinear system of competitive type \[ \left\{\begin{array} [c]{c}% u_{t}-Δu+v^{p}=0, v_{t}-Δv+u^{q}=0, \end{array} \right. \] in $Ω\times\left(0,T\right) $, where $Ω$ is a domain of $\mathbb{R}^{N},$ and $p,q>0,$ $pq\neq1.$ Despite of the lack of comparison principles, we prove local upper e

  2. Tianjun Li, James A. Maxin, Dimitri V. Nanopoulos, Joel W. Walker

    We study gravity mediated supersymmetry breaking in ${\cal F}$-SU(5) and its low-energy supersymmetric phenomenology. The gaugino masses are not unified at the traditional grand unification scale, but we nonetheless have the same one-loop gaugino mass relation at the electroweak scale as minimal supergravity (mSUGRA). We introduce parameters testable at the

  3. Anton Ilderton, Joakim Lundin, Mattias Marklund

    We review the effects of strong background fields in noncommutative QED. Beginning with the noncommutative Maxwell and Dirac equations, we describe how combined noncommutative and strong field effects modify the propagation of fermions and photons. We extend these studies beyond the case of constant backgrounds by giving a new and revealing interpretation of

  4. Fabio Pizzolato, Noam Soker

    We show that cold clumps in the intra--cluster medium (ICM) efficiently lose their angular momentum as they fall in, such that they can rapidly feed the central AGN and maintain a heating feedback process. Such cold clumps are predicted by the cold feedback model, a model for maintaining the ICM in cooling flows hot by a feedback process. The clumps very eff

  5. P. H. Conlon, J. T. Chalker

    We discuss the origin of spin correlations observed in neutron scattering experiments on the paramagnetic phase of a number of frustrated spinel compounds, most notably ZnCr2O4. These correlations are striking for two reasons. First, they have been interpreted as evidence for the formation of weakly interacting hexagonal clusters of spins. Second, they are v

  6. Federico Agustin Membiela, Mauricio Bellini

    Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin and evolution of seminal inflaton and electromagnetic fields in the early inflationary universe from a 5D vacuum state. We use simultaneously the Lorentz and Feynman gauges. Our formalism is naturally not conformal invariant on the effective 4D de Sitter metric, wh

  7. Olivier Glass, Franck Sueur, Takeo Takahashi

    We consider the motion of a rigid body immersed in an incompressible perfect fluid which occupies a three-dimensional bounded domain. For such a system the Cauchy problem is well-posed locally in time if the initial velocity of the fluid is in the Holder space C^{1,r}. In this paper we prove that the smoothness of the motion of the rigid body may be only lim

  8. Markus Diehl, Lech Szymanowski

    We study the form factors of the quark tensor currents in the pion at large squared momentum transfer Q^2. It turns out that certain form factors can be evaluated using collinear factorization, whereas others receive important contributions from the end-point regions of the longitudinal quark momenta in the pion. We derive simple analytic expressions for the

  9. Thomas Gasenzer, Stefan Kessler, Jan M. Pawlowski

    The theory of real-time quantum many-body dynamics as put forward in Ref. [arXiv:0710.4627] is evaluated in detail. The formulation is based on a generating functional of correlation functions where the Keldysh contour is closed at a given time. Extending the Keldysh contour from this time to a later time leads to a dynamic flow of the generating functional.

  10. F. Belgiorno, S. L. Cacciatori, G. Ortenzi, L. Rizzi

    We consider a 4D model for photon production induced by a %superluminal refractive index perturbation in a dielectric medium. We show that, in this model, we can infer the presence of a Hawking type effect. This prediction shows up both in the analogue Hawking framework, which is implemented in the pulse frame and relies on the peculiar properties of the eff

  11. Pierre R. Bertrand, Mehdi Fhima, Arnaud Guillin

    This paper deals with off-line detection of change points for time series of independent observations, when the number of change points is unknown. We propose a sequential analysis like method with linear time and memory complexity. Our method is based at first step, on Filtered Derivative method which detects the right change points but also false ones. We

  12. Matthew England

    We develop the theory of Abelian functions associated with cyclic trigonal curves by considering two new cases. We investigate curves of genus six and seven and consider whether it is the trigonal nature or the genus which dictates certain areas of the theory. We present solutions to the Jacobi inversion problem, sets of relations between the Abelian functio

  13. A. A. Zheltukhin

    Recently Kuzenko and McCarty observed the cancellation of 4-derivative terms in the $D=4 {\cal N}=1$ Volkov-Akulov supersymmetric action for the fermionic Nambu-Goldstone field. Here is presented a simple algebraic proof of the cancellation based on using the Majorana bispinors and Fiertz identities. The cancellation shows a difference between the Volkov-Aku

  14. Jason F. Ralph, Joshua Combes, Howard M. Wiseman

    In this paper, we demonstrate that interleaved sampling techniques can be used to characterize the Hamiltonian of a qubit and its environmental decoherence rate. The technique offers a significant advantage in terms of the number of measurements that are required to characterize a qubit. When compared to the standard Nyquist-Shannon sampling rate, the saving

  15. Harold Steinacker

    A introductory review to emergent noncommutative gravity within Yang-Mills Matrix models is presented. Space-time is described as a noncommutative brane solution of the matrix model, i.e. as submanifold of \R^D. Fields and matter on the brane arise as fluctuations of the bosonic resp. fermionic matrices around such a background, and couple to an effective me

  16. Daniel N. Blaschke, Harold Steinacker

    We show how gravitational actions, in particular the Einstein-Hilbert action, can be obtained from additional terms in Yang-Mills matrix models. This is consistent with recent results on induced gravitational actions in these matrix models, realizing space-time as 4-dimensional brane solutions. It opens up the possibility for a controlled non-perturbative de

  17. Thomas Meinguet

    Maxima of moving maxima of continuous functions (CM3) are max-stable processes aimed at modeling extremes of continuous phenomena over time. They are defined as Smith and Weissman's M4 processes with continuous functions rather than vectors. After standardization of the margins of the observed process into unit-Fréchet, CM3 processes can model the remain

  18. Michiko Fujii, Masaki Iwasawa, Yoko Funato, Junichiro Makino

    Within the distance of 1 pc from the Galactic center (GC), more than 100 young massive stars have been found. The massive stars at 0.1-1 pc from the GC are located in one or two disks, while those within 0.1 pc from the GC, S-stars, have an isotropic distribution. How these stars are formed is not well understood, especially for S-stars. Here we propose that

  19. Paulo M. Sá, Alfredo B. Henriques

    We investigate the generation of gravitational waves in the hybrid quintessential inflationary model. The full gravitational-wave energy spectrum is calculated using the method of continuous Bogoliubov coefficients. The post-inflationary kination period, characteristic of quintessential inflationary models, leaves a clear signature on the spectrum, namely, a

  20. Jevgenijs Ivanovs

    We consider a Markov-modulated Brownian motion reflected to stay in a strip [0,B]. The stationary distribution of this process is known to have a simple form under some assumptions. We provide a short probabilistic argument leading to this result and explaining its simplicity. Moreover, this argument allows for generalizations including the distribution of t

  21. W. Z. Jia, L. F. Wei

    For a quantum system with broken parity symmetry, selection rules can not hold and cyclic transition structures are generated. With these loop-transitions we discuss how to achieve inversionless gain of the probe field by properly setting the control and auxiliary fields. Possible implementations of our generic proposal with specific physical objects with br

  22. M. Umar Farooq, Muneer A. Rashid, Mubasher Jamil

    We present the new agegraphic dark energy model by introducing the quantum corrections to the entropy-area relation in the setup of loop quantum gravity. Employing this new form of dark energy, we investigate the model of interacting dark energy and derive its equation of state. We study the correspondence between the tachyon, K-essence and dilaton scalar fi

  23. M. E. Zhitomirsky, Hirokazu Tsunetsugu

    Competing ferro- and antiferromagnetic exchange interactions may lead to the formation of bound magnon pairs in the high-field phase of a frustrated quantum magnet. With decreasing field, magnon pairs undergo a Bose-condensation prior to the onset of a conventional one-magnon instability. We develop an analytical approach to study the zero-temperature proper

  24. Chloé Perin, Rizos Sklinos

    We show that any non abelian free group $\F$ is strongly $\aleph_0$-homogeneous, i.e. that finite tuples of elements which satisfy the same first-order properties are in the same orbit under $\Aut(\F)$. We give a characterization of elements in finitely generated groups which have the same first-order properties as a primitive element of the free group. We d

  25. N. Chandrachani Devi, Anjan A Sen

    We study the general evolution of spherical over-densities for thawing class of dark energy models. We model dark energy with scalar fields having canonical as well as non-canonical kinetic energy. For non-canonical case, we consider models where the kinetic energy is of the Born-Infeld Form. We study various potentials like linear, inverse-square, exponenti

  26. Andreas Thom

    We prove that a finitely generated group contains a sequence of non-trivial elements which converge to the identity in every compact homomorphic image if and only if the group is not virtually abelian.

  27. Jan Maas, Jan van Neerven, Pierre Portal

    We study, in $L^{1}(\R^n;γ)$ with respect to the gaussian measure, non-tangential maximal functions and conical square functions associated with the Ornstein-Uhlenbeck operator by developing a set of techniques which allow us, to some extent, to compensate for the non-doubling character of the gaussian measure. The main result asserts that conical square fun

  28. Damiano Fulghesu, Filippo Viviani

    In this paper we compute the integral Chow ring of the stack of smooth uniform cyclic covers of the projective line and we give explicit generators.

  29. F. Loran, M. M. Sheikh-Jabbari

    Banados-Teitelboim-Zanelli (BTZ) black holes are constructed by orbifolding AdS3 geometry by boost transformations of its O(2,2) isometry group. Here we construct a new class of solutions to AdS3 Einstein gravity, orientifolded BTZ or O-BTZ for short, which in general, besides the usual BTZ orbifolding, involve orbifolding (orientifolding) by a Z_2 part of O

  30. Garima Mishra, D. Giri, M. S. Li, S. Kumar

    Dynamics of a single stranded DNA, which can form a hairpin have been studied in the constant force ensemble. Using Langevin dynamics simulations, we obtained the force-temperature diagram, which differs from the theoretical prediction based on the lattice model. Probability analysis of the extreme bases of the stem revealed that at high temperature, the hai

  31. Muhammad Javed, Bashir Ahmad, Shahid Hussain, Shakeel Ahmad

    Software engineering is one of the most recent additions in various disciplines of system engineering. It has emerged as a key obedience of system engineering in a quick succession of time. Various Software Engineering approaches are followed in order to produce comprehensive software solutions of affordable cost with reasonable delivery timeframe with less

  32. Prasad Basu, Rahul Srivastava, Sachindeo Vaidya

    We derive the thermal correlators for twisted quantum fields on noncommutative spacetime. We show that the thermal expectation value of the number operator is same as in commutative spacetime, but that higher correlators are sensitive to the noncommutativity parameters $θ^{μν}$.

  33. Indranil Biswas, Norbert Hoffmann

    Let X and X' be compact Riemann surfaces of genus at least 3, and let G and G' be nonabelian reductive complex groups. If one component M_G^d(X) of the moduli space for semistable principal G-bundles over X is isomorphic to another component M_{G'}^{d'}(X'), then X is isomorphic to X'.

  34. Qi Zhou, S. Das Sarma

    We propose an exactly solvable model to reveal the physics of the interplay between interaction and disorder in bosonic systems. Considering interacting bosons in a double-well potential, in which disorder is mimicked by taking the energy level mismatch between the two wells to be randomly distributed, we find "two negatives make a positive" effect.

  35. Yefim Semenovitch Levin

    We show that for a detector rotating in a random classical zero-point electromagnetic or massless scalar field at T=0 thermal effects exist. The rotating reference system is constructed as an infinite set of Frenet-Seret tetrads defined so that the detector is at rest in a tetrad at each proper time. Correlation functions, more exactly their frequency spectr

  36. Myungseok Eune, Wontae Kim

    We reconsider a recently proposed action for a free particle which is compatible with Hořava-Lifshitz gravity, and then obtain the subluminal and the superluminal limits without gauge ambiguity in terms of Hamiltonian formulation.

  37. Maria Ximena Fernandez, Emmanuel Momjian, Christopher J. Salter, Tapasi Ghosh

    We present results from an on-going survey for the HI 21 cm line and the OH 18 cm lines in IR galaxies with the Arecibo 305 m Radio Telescope. The observations of 85 galaxies extracted from the 2 Jy IRAS-NVSS sample in the R.A. (B1950) range 20 h-00 h are reported in this paper. We detected the HI 21 cm line in 82 of these galaxies, with 18 being new detecti

  38. J. Bakosi, J. R. Ristorcelli

    In assumed probability density function (pdf) methods of turbulent combustion, the shape of the scalar pdf is assumed a priori and the pdf is parametrized by its moments for which model equations are solved. In non-premixed flows the beta distribution has been a convenient choice to represent the mixture fraction in binary mixtures or a progress variable in

  39. Yoshihiko Nonomura

    In THz wave emission from intrinsic Josephson junctions in in-plane magnetic fields, emission intensity strongly depends on the surface impedance $Z$ similarly to the case without external magnetic fields. Cavity resonance modes are stabilized for $Z \ge 3$, and the fundamental mode gives the strongest emission. As the in-plane magnetic field increases for a

  40. Sou-Cheng T. Choi, Christopher C. Paige, Michael A. Saunders

    CG, SYMMLQ, and MINRES are Krylov subspace methods for solving symmetric systems of linear equations. When these methods are applied to an incompatible system (that is, a singular symmetric least-squares problem), CG could break down and SYMMLQ's solution could explode, while MINRES would give a least-squares solution but not necessarily the minimum-leng

  41. Yu-Quan Ma, Shu Chen, Heng Fan, Wu-Ming Liu

    We propose a generalized quantum geometric tenor to understand topological quantum phase transitions, which can be defined on the parameter space with the adiabatic evolution of a quantum many-body system. The generalized quantum geometric tenor contains two different local measurements, the non-Abelian Riemannian metric and the non-Abelian Berry curvature,

  42. Gerald Höhn

    We give a new and simple proof of a theorem of Garza estimating the height (or Mahler measure) of an algebraic number with real conjugates.

  43. Sun Daochun, Gu Zhendong, Liu Weiqun, Yue Chao

    In this paper, we define an ordering relation for a set of complex numbers, and research the properties and theorems of the ordering, solve some simple complex inequalities with the ordering.

  44. José Aliste-Prieto, Daniel Coronel

    In this paper we study linearly repetitive Delone sets and prove, following the work of Bellissard, Benedetti and Gambaudo, that the hull of a linearly repetitive Delone set admits a properly nested sequence of box decompositions (tower system) with strictly positive and uniformly bounded (in size and norm) transition matrices. This generalizes a result of D

  45. Rachel Stevenson, Jan Kleyna, David Jewitt

    We present results from a wide-field imaging campaign at the Canada-France-Hawaii Telescope to study the spectacular outburst of comet 17P/Holmes in late 2007. Using image-processing techniques we probe inside the spherical dust coma and find sixteen fragments having both spatial distribution and kinematics consistent with isotropic ejection from the nucleus

  46. Rajgopal Kannan, Costas Busch

    We study {\em bottleneck routing games} where the social cost is determined by the worst congestion on any edge in the network. In the literature, bottleneck games assume player utility costs determined by the worst congested edge in their paths. However, the Nash equilibria of such games are inefficient since the price of anarchy can be very high and propor

  47. Thomas Hartlep, Alexander G. Kosovichev, Junwei Zhao, Nagi N. Mansour

    We show that under certain conditions, subsurface structures in the solar interior can alter the average acoustic power observed at the photosphere above them. By using numerical simulations of wave propagation, we show that this effect is large enough for it to be potentially used for detecting emerging active regions before they appear on the surface. In o

  48. Alexander Kushnerov

    Switched-Capacitor Converters (SCC) suffer from a fundamental power loss deficiency which make their use in some applications prohibitive. The power loss is due to the inherent energy dissipation when SCC operate between or outside their output target voltages. This drawback was alleviated in this work by developing two new classes of SCC providing binary an

  49. M. Gorchtein, C. J. Horowitz, M. J. Ramsey-Musolf

    We consider the dispersion correction to elastic parity violating electron-proton scattering due to \gammaZ exchange. In a recent publication, this correction was reported to be substantially larger than the previous estimates. In this paper, we study the dispersion correction in greater detail. We confirm the size of the disperion correction to be 6% for th

  50. Dirk Blomker, Marco Romito

    We show the existence and uniqueness of solutions (either local or global for small data) for an equation arising in different aspects of surface growth. Following the work of Koch and Tataru we consider spaces critical with respect to scaling and we prove our results in the largest possible critical space such that weak solutions are defined. The uniqueness

  51. Saar Rahav, Shaul Mukamel

    By subjecting a dynamical system to a series of short pulses and varying several time delays we can obtain multidimensional characteristic measures of the system. Multidimensional Kullback-Leibler response function (KLRF), which are based on the Kullback-Leibler distance between the initial and final states, are defined. We compare the KLRF, which are nonlin

  52. C. Ferkinhoff, S. Hailey-Dunsheath, T. Nikola, S. C. Parshley

    We have made the first detections of the 88 micron [OIII] line from galaxies in the early Universe, detecting the line from the lensed AGN/starburst composite systems APM 08279+5255 at z = 3.911 and SMM J02399-0136 at z = 2.8076. The line is exceptionally bright from both systems, with apparent (lensed) luminosities ~10^11 L_solar. For APM 08279, the [OIII]

  53. Mariam Bouhmadi-Lopez, Vitor Cardoso, Andrea Nerozzi, Jorge V. Rocha

    A possible process to destroy a black hole consists on throwing point particles with sufficiently large angular momentum into the black hole. In the case of Kerr black holes, it was shown by Wald that particles with dangerously large angular momentum are simply not captured by the hole, and thus the event horizon is not destroyed. Here we reconsider this ged

  54. Svetlana G. Jorstad, Alan P. Marscher, Valeri M. Larionov, Iván Agudo

    We analyze the behavior of the parsec-scale jet of the quasar 3C~454.3 during pronounced flaring activity in 2005-2008. Three major disturbances propagated down the jet along different trajectories with Lorentz factors $Γ>$10. The disturbances show a clear connection with millimeter-wave outbursts, in 2005 May/June, 2007 July, and 2007 December. High-amplitu

  55. B. Lancor, E. Babcock, R. Wyllie, T. G. Walker

    We present measurements, using two complementary methods, of the breakdown of atomic angular momentum selection rules in He-broadened Rb vapor. Atomic dark states are rendered weakly absorbing due to fine-structure mixing during Rb-He collisions. The effect substantially increases the photon demand for optical pumping of dense vapors.

  56. Pruet Kalasuwan, Gabriel Mendoza, Anthony Laing, Tomohisa Nagata

    We show how an entangled cluster state encoded in the polarization of single photons can be straightforwardly expanded by deterministically entangling additional qubits encoded in the path degree of freedom of the constituent photons. This can be achieved using a polarization--path controlled-phase gate. We experimentally demonstrate a practical and stable r

  57. Hugh S. Hudson, Yan Li

    The corona at solar minimum generally differs greatly from that during active times. We discuss the current Cycle 23/24 minimum from the point of view of the occurrence of flares and CMEs (Coronal Mass Ejections). By comparison with the previous minimum, the flare/CME ratio diminished by almost an order of magnitude. This suggests that the environmental effe

  58. Ayush Gupta, Andy Elby

    Researchers have argued against deficit-based explanations of students' troubles with mathematical sense-making, pointing instead to factors such as epistemology: students' beliefs about knowledge and learning can hinder them from activating and integrating productive knowledge they have. In this case study of an engineering major solving problems (a

  59. Mayank Kabra, Annie L. Conery, Eyleen J. O'Rourke, Xin Xie

    High-throughput screening (HTS) using model organisms is a promising method to identify a small number of genes or drugs potentially relevant to human biology or disease. In HTS experiments, robots and computers do a significant portion of the experimental work. However, one remaining major bottleneck is the manual analysis of experimental results, which is

  60. Leif Svalgaard, Hugh S. Hudson

    The solar F10.7 index is has been a reliable and sensitive activity index since 1947. As with other indices, it has been showing unusual behavior in the Cycle 23/24 minimum. The origins of the solar microwave flux lie in a variety of features, and in two main emission mechanisms: free-free and gyroresonance. In past solar cycles F10.7 has correlated well wit

  61. S. Capozziello, S. Vignolo

    We study the initial value formulation of metric-affine f(R)-gravity in presence of a Klein-Gordon scalar field acting as source of the field equations. Sufficient conditions for the well-posedness of the Cauchy problem are formulated. This result completes the analysis of the same problem already considered for other sources.

  62. M. L. McCollough, K. I. I. Koljonen, D. C. Hannikainen

    Cygnus X-3 is a unique microquasar. Its X-ray emission shows a very strong 4.8-hour orbital modulation. But its mass-donating companion is a Wolf-Rayet star. Also unlike most other X-ray binaries Cygnus X-3 is relatively bright in the radio virtually all of the time (the exceptions being the quenched states). Cygnus X-3 also undergoes giant radio outbursts (

  63. Peter Duersch, Joerg Oechssler, Burkhard C. Schipper

    It is well known that the rock-paper-scissors game has no pure saddle point. We show that this holds more generally: A symmetric two-player zero-sum game has a pure saddle point if and only if it is not a generalized rock-paper-scissors game. Moreover, we show that every finite symmetric quasiconcave two-player zero-sum game has a pure saddle point. Further

  64. George Siopsis, Jason Therrien

    We calculate analytically properties of holographic superconductors in the probe limit. We analyze the range $1/2 < Δ< 3$, where $Δ$ is the dimension of the operator that condenses. We obtain the critical temperature in terms of a solution to a certain eigenvalue problem. Near the critical temperature, we apply perturbation theory to determine the temperatur

  65. Peter Duersch, Joerg Oechssler, Burkhard C. Schipper

    We show that for many classes of symmetric two-player games, the simple decision rule &#34;imitate-the-best&#34; can hardly be beaten by any other decision rule. We provide necessary and sufficient conditions for imitation to be unbeatable and show that it can only be beaten by much in games that are of the rock-scissors-paper variety. Thus, in many interest

  66. P. Lunkenheimer, S. Krohns, S. Riegg, S. G. Ebbinghaus

    Many transition-metal oxides show very large (&#34;colossal&#34;) magnitudes of the dielectric constant and thus have immense potential for applications in modern microelectronics and for the development of new capacitance-based energy-storage devices. In the present work, we thoroughly discuss the mechanisms that can lead to colossal values of the dielectri

  67. Mark T. Sargent, E. Schinnerer, E. Murphy, C. L. Carilli

    Previous observational studies of the infrared (IR)-radio relation out to high redshift employed any detectable star forming systems at a given redshift within the restricted area of cosmological survey fields. Consequently, the evolution inferred relies on a comparison between the average IR/radio properties of (i) very IR-luminous high-z sources and (ii) m

  68. Haishi Ning, Cong Ling, Kin K. Leung

    Not only is network coding essential to achieve the capacity of a single-session multicast network, it can also help to improve the throughput of wireless networks with multiple unicast sessions when overheard information is available. Most previous research aimed at realizing such improvement by using perfectly overheard information, while in practice, espe

  69. Luis G. C. Rego, L. F. Santos, V. S. Batista

    Coherent optical control schemes exploit the coherence of laser pulses to change the phases of interfering dynamical pathways in order to manipulate dynamical processes. These active control methods are closely related to dynamical decoupling techniques, popularized in the field of Quantum Information. Inspired by Nuclear Magnetic Resonance (NMR) spectroscop

  70. Louis E. Strigari, Carlos S. Frenk, Simon D. M. White

    We investigate whether the subhalos of Lambda-CDM galaxy halos have potentials consistent with the observed properties of Milky Way satellites, particularly those with high-quality photometric and kinematic data: Fornax, Leo I, Sculptor, Sextans, and Carina. We compare spherical models with isotropic velocity dispersion tensors to the observed, circularly av

  71. J. D. Younger, G. G. Fazio, M. L. N. Ashby, F. Civano

    We present high-resolution 345 GHz interferometric observations of two extreme luminous (L_{IR}>10^{13} L_sun), submillimetre-selected galaxies (SMGs) in the COSMOS field with the Submillimeter Array (SMA). Both targets were previously detected as unresolved point-sources by the SMA in its compact configuration, also at 345 GHz. These new data, which provide

  72. Sarbani Basu, Anne-Marie Broomhall, William J. Chaplin, Yvonne Elsworth

    The Birmingham Solar-Oscillations Network (BiSON) has collected helioseismic data over three solar cycles. We use these data to determine how the internal properties of the Sun during this minimum differ from the previous two minima. The cycle 24 data show oscillatory differences with respect to the other two sets, indicating relatively localized changes in

  73. Assaf Naor

    We survey connections between the theory of bi-Lipschitz embeddings and the Sparsest Cut Problem in combinatorial optimization. The story of the Sparsest Cut Problem is a striking example of the deep interplay between analysis, geometry, and probability on the one hand, and computational issues in discrete mathematics on the other. We explain how the key ide

  74. Philip Kaaret, Hua Feng, Diane S. Wong, Lian Tao

    We present Hubble Space Telescope observations in the far UV of the ultraluminous X-ray source in NGC 6946 associated with the optical nebula MF 16. Both a point-like source coincident with the X-ray source and the surrounding nebula are detected in the FUV. The point source has a flux of 5E-16 erg s^-1 cm^-2 Ang^-1 and the nebula has a flux of 1.6E-15 erg s

  75. Bianca L. Cerchiai, Bert van Geemen

    There is a intriguing relation between quantum information theory and super gravity, discovered by M.J. Duff and S. Ferrara. It relates entanglement measures for qubits to black hole entropy, which in a certain case involves the quartic invariant on the 56-dimensional representation of the Lie group E7. In this paper we recall the relatively straightforward

  76. Rabi Bhattacharya, Susan Holmes

    We provide an explanation of the main ideas underlying Götze&#39;s main result in using Stein&#39;s method. We also provide detailed derivations of various intermediate estimates. Curiously, we are led to a different dimensional dependence of the constant than that given Götze&#39;s paper. We would like to dedicate this to Charles Stein on the occasion of hi

  77. Sebastian White

    In diffractive interactions of protons or nuclei a violent collision can occur that leaves the forward going particle completely intact -with probability determined by the structure of the proton or nucleus. At very high energies these collisions also occur with both incident particles remaining intact. This is called central exclusive production. If a new p

  78. Fedor Nazarov, Mikhail Sodin

    By random complex zeroes we mean the zero set of a random entire function whose Taylor coefficients are independent complex-valued Gaussian variables, and the variance of the k-th coefficient is 1/k!. This zero set is distribution invariant with respect to isometries of the complex plane. Extending the previous results of Sodin and Tsirelson, we compute the

  79. S. B. Pandey, C. A. Swenson, D. A. Perley, C. Guidorzi

    The optical-infrared afterglow of the LAT-detected long duration burst, GRB 090902B, has been observed by several instruments. The earliest detection by ROTSE-IIIa occurred 80 minutes after detection by the GBM instrument onboard the Fermi Gamma-Ray Space Telescope, revealing a bright afterglow and a decay slope suggestive of a reverse shock origin. Subseque

  80. Larry Guth

    This is an expository essay about systolic geometry. It describes a central theorem in the subject and why the proof is difficult. Then it discusses different metaphors which suggest ways to approach the problem. The metaphors connect the systolic inequality to minimal surfaces, topological dimension, scalar curvature, and hyperbolic geometry.

  81. Evelina Erlacher, Michael Grosser

    As early as 1972, Penrose - in a purely formal way - introduced a &#34;discontinuous coordinate transformation&#34;, which relates a continuous representation of the metric of impulsive pp-waves to a discontinuous one. On the basis of the invertibility concept for generalized functions developed recently by the first author, we show that this discontinuous c

  82. Abhijit Gadde, Leonardo Rastelli, Shlomo S. Razamat, Wenbin Yan

    We derive an integral representation for the superconformal index of the strongly-coupled N=2 superconformal field theory with E_6 flavor symmetry. The explicit expression of the index allows highly non-trivial checks of Argyres-Seiberg duality and of a class of S-dualities conjectured by Gaiotto.

  83. Rosine Lallement, Eric Quemerais, Philippe Lamy, Jean-Loup Bertaux

    We update the SOHO/SWAN H Lyman-alpha brightness analysis to cover the 1996-2008 time interval. A forward model applied to the intensity maps provides the latitude and time dependence of the interstellar Hydrogen ionisation rate over more than a full solar cycle. The hydrogen ionisation, being almost entirely due to charge-exchange with solar wind ions, refl

  84. R. Garcia, L. F. Mello, J. Sotomayor

    Given a non circular spacial closed curve whose total torsion is an integer multiple of $2π$, we construct a germ of a smooth surface that contains it as a hyperbolic principal cycle.

  85. Francisco J. Perez-Reche, Sergei N. Taraskin, Luciano da F. Costa, Franco M. Neri

    One of the challenges in epidemiology is to account for the complex morphological structure of hosts such as plant roots, crop fields, farms, cells, animal habitats and social networks, when the transmission of infection occurs between contiguous hosts. Morphological complexity brings an inherent heterogeneity in populations and affects the dynamics of patho

  86. Ayush Gupta, Brian A. Danielak, Andrew Elby

    An established body of literature shows that a student&#39;s affect can be linked to her epistemological stance [1]. In this literature, the epistemology is generally taken as a belief or stance toward a discipline, and the affective stance applies broadly to a discipline or classroom culture. A second, emerging line of research, however, shows that a studen

  87. Fedor Nazarov, Mikhail Sodin

    In these notes, we describe the recent progress in understanding the zero sets of two remarkable Gaussian random functions: the Gaussian entire function with invariant distribution of zeroes with respect to isometries of the complex plane, and Gaussian spherical harmonics on the two-dimensional sphere.

  88. Delphine Dupont

    In this paper, we go into the study of the 2-category SSS_Σof Σ-constructible stacks. The notions of constructible stack was introduced by D. Treumann. It is a natural generalization of constructible sheaf. D. Treumann has also introduced the exit-path 2-category, which is a stratified version of the fundamental 2-groupoid and he has showed that these two 2-

  89. Simon Cantin, Carmelle Robert, Mercedes Mollá, Anne Pellerin

    We present OASIS observations obtained at the Canada-France-Hawaii Telescope for the SB(rs)c galaxy NGC 4900. About 800 spectra in the wavelength range 4700-5500 AA and 6270- 7000 AA have been collected with a spatial resolution of ~50 pc. This galaxy is part of a sample to study the stellar populations and their history in the central region of galaxies. In

  90. J. Kokalj, P. Prelovsek

    Studying the dynamical spin structure factor in frustrated spin chains with spontaneously dimerized ground state we show that besides the gapped spin-wave excitations there appears at finite temperatures also a sharp central peak. The latter can be attributed to deconfined spinons, accounted well within the variational approach. The central peak remains well

  91. H. Monteiro, W. S. Dias, T. C. Caetano

    We present a new technique to fit color-magnitude diagrams of open clusters based on the Cross-Entropy global optimization algorithm. The method uses theoretical isochrones available in the literature and maximizes a weighted likelihood function based on distances measured in the color-magnitude space. The weights are obtained through a non parametric techni

  92. Stephen Fletcher, Roger New, Anne-Marie Broomhall, William Chaplin

    Although there are now some tentative signs that the start of cycle 24 has begun there is still considerable interest in the somewhat unusual behaviour of the current solar minimum and the apparent delay in the true start of the next cycle. While this behaviour is easily tracked by observing the change in surface activity a question can also be asked about w

  93. C. Samanta

    A simultaneous description of non-strange nuclei, hypernuclei and multiply-strange nuclear systems is provided by a single mass formula which is shown to be useful for estimating binding energies of nuclear systems over a wide mass range, including the light mass nuclei. It not only provides a good fit to the existing experimental data on hyperon-separation

  94. Gernot Akemann, Martin Bender

    We consider a family of chiral non-Hermitian Gaussian random matrices in the unitarily invariant symmetry class. The eigenvalue distribution in this model is expressed in terms of Laguerre polynomials in the complex plane. These are orthogonal with respect to a non-Gaussian weight including a modified Bessel function of the second kind, and we give an elemen

  95. R. Bernhard, R. Field, R. Chierici, M. Cacciari

    The objective of this first workshop on Multiple Partonic Interactions (MPI) at the LHC is to raise the profile of MPI studies, summarizing the legacy from the older phenomenology at hadronic colliders and favouring further specific contacts between the theory and experimental communities. The MPI are experiencing a growing popularity and are currently widel

  96. Nemesio Rodriguez-Fernandez, Mario Tafalla, Frederic Gueth, Rafael Bachiller

    The isocyanic acid (HNCO) presents an extended distribution in the centers of the Milky Way and the spiral galaxy IC342. Based on the morphology of the emission and the HNCO abundance with respect to H2, several authors made the hypothesis that HNCO could be a good tracer of interstellar shocks. Here we test this hypothesis by observing a well-known Galactic

  97. Nan Yu, Massimo Tinto

    We present a new general design approach of a broad-band detector of gravitational radiation that relies on two atom interferometers separated by a distance L. In this scheme, only one arm and one laser will be used for operating the two atom interferometers. We consider atoms in the atom interferometers not only as perfect inertial reference sensors, but al

  98. S. T. Dawkins, R. Chicireanu, M. Petersen, J. Millo

    We have developed an ultra-stable source in the deep ultraviolet, suitable to fulfill the interrogation requirements of a future fully-operational lattice clock based on neutral mercury. At the core of the system is a Fabry-Pérot cavity which is highly impervious to temperature and vibrational perturbations. The mirror substrate is made of fused silica in or

  99. Luigi Foschini

    Let&#39;s take stock of the situation on one of the most studied astrophysical phenomena during the latest years: the jets escaping from protostars, stellar singularities, GRB and active galactic nuclei.

  100. David H. Hathaway, Peter E. Williams, Manfred Cuntz

    We produce a 10-day series of simulated Doppler images at a 15-minute cadence that reproduces the spatial and temporal characteristics seen in the SOHO/MDI Doppler data. Our simulated data contains a spectrum of cellular flows with but two necessary components --- a granule component that peaks at wavenumbers of about 4000 and a supergranule component that p