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May 2010 arXiv papers — page 29

Showing 2,8012,900 of 5,722 papers

  1. Joakim Munkhammar

    The theory of gravity has undergone somewhat of a revolution lately. Gravity is no longer a fundamental force it seems, but rather an effect of holographic entropy. Building on the works by Jacobsson, Padmanabhan and Verlinde we review the concept of Newtonian gravity as an entropic force and discuss a possible general action approach to Verlinde's theor

  2. Ron Lenk

    In this article we look at the class of positive-energy density wormholes introduced by Eiroa and Simeone, and ask the question "How close can we come to building this wormhole with normal, electrically charged matter?" Using a series expansion, we determine that the stress-energy tensor of the metric can be made arbitrarily close to that of a charge

  3. Satoki Matsushita, Yu-Lin Chen

    We conducted the observational tests of a phase correction scheme for the Atacama Compact Array (ACA) of the Atacama Large Millimeter and submillimeter Array (ALMA) using the Submillimeter Array (SMA). Interferometers at millimeter- and submillimeter-wave are highly affected by the refraction induced by water vapor in the troposphere, which results as phase

  4. P. G. Martin, M. -A. Miville-Deschenes, A. Roy, J. -P. Bernard

    In Herschel images of the Galactic plane and many star forming regions, a major factor limiting our ability to extract faint compact sources is cirrus confusion noise, operationally defined as the "statistical error to be expected in photometric measurements due to confusion in a background of fluctuating surface brightness". The histogram of the flu

  5. S. M. Nazrul Alam, Zygmunt Haas

    In some underwater sensor networks, sensor nodes may be deployed at various depths of an ocean making those networks three-dimensional (3D). While most terrestrial sensor networks can usually be modeled as two dimensional (2D) networks, these underwater sensor networks must be modeled as 3D networks. This leads to new research challenges in the area of netwo

  6. J. A. Rodón, A. Zavagno, J. -P. Baluteau, L. D. Anderson

    Context: Sh2-104 is a Galactic H ii region with a bubble morphology, detected at optical and radio wavelengths. It is considered the first observational confirmation of the collect-and-collapse model of triggered star-formation. Aims: We aim to analyze the dust and gas properties of the Sh2-104 region to better constrain its effect on local future generation

  7. R. A. Pepino, J. Cooper, D. Meiser, D. Z. Anderson

    We derive a quantum master equation to treat quantum systems interacting with multiple reservoirs. The formalism is used to investigate atomic transport across a variety of lattice configurations. We demonstrate how the behavior of an electronic diode, a field-effect transistor, and a bipolar junction transistor can be realized with neutral, ultracold atoms

  8. Ö. O. Soykal, M. E. Flatté

    The coherent dynamics of a coupled photonic cavity and a nanomagnet is explored as a function of nanomagnet size. For sufficiently strong coupling eigenstates involving highly entangled photon and spin states are found, which can be combined to create coherent states. As the size of the nanomagnet increases its coupling to the photonic mode also monotonicall

  9. E. M. de Gouveia Dal Pino, P. P. Piovezan, L. H. S. Kadowaki

    It was proposed earlier that the relativistic ejections observed in microquasars could be produced by violent magnetic reconnection episodes at the inner disk coronal region. Here we revisit this model, which employs a standard accretion disk description and fast magnetic reconnection theory, and discuss the role of magnetic reconnection and associated heati

  10. Ashutosh Nayyar, Demosthenis Teneketzis

    We consider a sequential problem in decentralized detection. Two observers can make repeated noisy observations of a binary hypothesis on the state of the environment. At any time, any of the two observers can stop and send a final message to the other observer or it may continue to take more measurements. After an observer has sent its final message, it sto

  11. I. De Looze, M. Baes, S. Zibetti, J. Fritz

    We use the Science Demonstration Phase data of the Herschel Virgo Cluster Survey to search for dust emission of early-type dwarf galaxies in the central regions of the Virgo Cluster as an alternative way of identifying the interstellar medium.We present the first possible far-infrared detection of cluster early-type dwarf galaxies: VCC781 and VCC951 are dete

  12. M. Baes, M. Clemens, E. M. Xilouris, J. Fritz

    The origin of the far-infrared emission from the nearby radio galaxy M87 remains a matter of debate. Some studies find evidence of a far-infrared excess due to thermal dust emission, whereas others propose that the far-infrared emission can be explained by synchrotron emission without the need for an additional dust emission component. We present Herschel PA

  13. M. Grossi, L. K. Hunt, S. Madden, C. Vlahakis

    We present the dust properties of a small sample of Virgo cluster dwarf galaxies drawn from the science demonstration phase data set of the Herschel Virgo Cluster Survey. These galaxies have low metallicities (7.8 < 12 + log(O/H) < 8.3) and star-formation rates < 10^{-1} M_{sun}/yr. We measure the spectral energy distribution (SED) from 100 to 500 um and der

  14. M. W. L. Smith, C. Vlahakis, M. Baes, G. J. Bendo

    We present a resolved dust analysis of three of the largest angular size spiral galaxies, NGC 4501 and NGC 4567/8, in the Herschel Virgo Cluster Survey (HeViCS) Science Demonstration field. Herschel has unprecedented spatial resolution at far-infrared wavelengths and with the PACS and SPIRE instruments samples both sides of the peak in the far infrared spect

  15. M. S. Clemens, A. P. Jones, A. Bressan, M. Baes

    Passive early-type galaxies (ETGs) provide an ideal laboratory for studying the interplay between dust formation around evolved stars and its subsequent destruction in a hot gas. Using Spitzer-IRS and Herschel data we compare the dust production rate in the envelopes of evolved AGB stars with a constraint on the total dust mass. Early-type galaxies which app

  16. L. Cortese, J. I. Davies, M. Pohlen, M. Baes

    By combining Herschel-SPIRE observations obtained as part of the Herschel Virgo Cluster Survey with 21 cm HI data from the literature, we investigate the role of the cluster environment on the dust content of Virgo spiral galaxies.We show for the first time that the extent of the dust disk is significantly reduced in HI-deficient galaxies, following remarkab

  17. J. I. Davies, M. Baes, G. J. Bendo, S. Bianchi

    We describe the Herschel Virgo Cluster Survey (HeViCS) and the first data obtained as part of the Science Demonstration Phase (SDP). The data cover a central 4x4 sq deg region of the cluster. We use SPIRE and PACS photometry data to produce 100, 160, 250, 350 and 500 micron luminosity functions (LFs) for optically bright galaxies that are selected at 500 mic

  18. Svante Janson, Sokhna M&#39;Baye, Philip Protter

    We give sufficient conditions on the underlying filtration such that all totally inaccessible stopping times have compensators which are absolutely continuous. If a semimartingale, strong Markov process X has a representation as a solution of a stochastic differential equation driven by a Wiener process, Lebesgue measure, and a Poisson random measure, then a

  19. Mats Boij, Enrico Carlini, Anthony V. Geramita

    We generalize an example, due to Sylvester, and prove that any monomial of degree $d$ in $\mathbb R[x_0, x_1]$, which is not a power of a variable, cannot be written as a linear combination of fewer than $d$ powers of linear forms.

  20. Junsheng Fang, Mingchu Gao, Roger R. Smith

    A triple of finite von Neumann algebras $B\subseteq N\subseteq M$ is said to have the relative weak asymptotic homomorphism property if there exists a net of unitary operators $\{u_λ\}_{λ\in Λ}$ in $B$ such that $$\lim_λ|\mathbb{E}}_B(xu_λy)-{\mathbb{E}}_B({\mathbb{E}}_N(x)u_λ{\mathbb{E}}_N(y))\|_2=0$$ for all $x,y\in M$. We prove that a triple of finite von

  21. Patricio Sanhueza, Guido Garay, Leonardo Bronfman, Diego Mardones

    We present molecular line observations, made with angular resolutions of ~20&#34;, toward the filamentary infrared dark cloud G34.43+0.24 using the APEX [CO(3-2), 13CO(3-2), C18O(3-2) and CS(7-6) transitions], Nobeyama 45 m [CS(2-1), SiO(2-1), C34S(2-1), HCO+(1-0), H13CO+(1-0) and CH3OH(2-1) transitions], and SEST [CS(2-1) and C18O(2-1) transitions] telescop

  22. Yaroslav V. Kartashov, Victor A. Vysloukh

    We consider waveguide array in which defect channels with reduced refractive index are spaced periodically and the light guiding is achieved due to Bragg reflection. We show that tunneling between defects can be inhibited using out-of-phase longitudinal modulation of refractive index exclusively in defect channels. Tunneling inhibition is almost perfect for

  23. S. R. Pottasch, J. Bernard-Salas

    Context: In recent years mid- and far infrared spectra of planetary nebulae have been analysed and lead to more accurate abundances. It may be expected that these better abundances lead to a better understanding of the evolution of these objects. Aims: The observed abundances in planetary nebulae are compared to those predicted by the models of Karakas (2003

  24. Alessio Recati, Sandro Stringari

    Using density functional theory in a time dependent approach we determine the frequencies of the compressional modes of the normal phase of a Fermi gas at unitarity as a function of its polarization. Our energy functional accounts for the typical elastic deformations exhibited by Landau theory of Fermi liquids. The comparison with the available experiments i

  25. Sourish Dutta, Stephen D. H. Hsu, Robert J. Scherrer

    We propose a class of simple dark energy models which predict a late-time dark radiation component and a distinctive time-dependent equation of state $w(z)$ for redshift $z < 3$. The dark energy field can be coupled strongly enough to Standard Model particles to be detected in colliders, and the model requires only modest additional particle content and litt

  26. Tomislav Ivezic

    In a recent paper [A. O. Sushkov, S. Eckel and S. K. Lamoreaux, Phys. Rev. A 79, 022118 (2009), arXiv:0810.2756 ] the authors measured the EDM-induced magnetization M that is given by Eq. (1) in their paper. Such an expression for M is a consequence of the generally accepted opinion that both dipole moments, a MDM m and an EDM d, are proportional to the spin

  27. E. Ostrovsky, L. Sirota

    In this paper we obtain the non-asymptotic norm estimations of Besov&#39;s type between the norms of a functions in different Bilateral Grand Lebesgue spaces (BGLS). We also give some examples to show the sharpness of these inequalities.

  28. S. Boixo, E. Knill, R. D. Somma

    Consider a path of non-degenerate eigenstates of unitary operators or Hamiltonians with minimum eigenvalue gap G. The eigenpath traversal problem is to transform one or more copies of the initial to the final eigenstate. Solutions to this problem have applications ranging from quantum physics simulation to optimization. For Hamiltonians, the conventional way

  29. Mikhail Tyaglov

    We describe a wide class of polynomials, which is a natural generalization of Hurwitz stable polynomials. We also give a detailed account of so-called self-interlacing polynomials, which are dual to Hurwitz stable polynomials but have only real and simple zeroes. All proofs are given using properties of rational functions mapping the upper half-plane of the

  30. Sarbani Basu, H. M. Antia

    We have analyzed available full-disc data from the Michelson Doppler Imager (MDI) on board SoHO using the &#34;ring diagram&#34; technique to determine the behavior of solar meridional flows over solar cycle 23 in the outer 2% of the solar radius. We find that the dominant component of meridional flows during solar maximum was much lower than that during the

  31. Bryce Croll, Loic Albert, David Lafrenière, Ray Jayawardhana

    We present near-infrared Ks-band photometry bracketing the secondary eclipse of the hot Jupiter TrES-2b using the Wide-field Infrared Camera on the Canada-France-Hawaii Telescope. We detect its thermal emission with an eclipse depth of 0.062 +/- 0.012% (5-sigma). Our best-fit secondary eclipse is consistent with a circular orbit (a 3-sigma upper limit on the

  32. Sergio Benvenuti, Amihay Hanany, Noppadol Mekareeya

    The moduli space of k G-instantons on R^4 for a classical gauge group G is known to be given by the Higgs branch of a supersymmetric gauge theory that lives on Dp branes probing D(p + 4) branes in Type II theories. For p = 3, these (3 + 1) dimensional gauge theories have N = 2 supersymmetry and can be represented by quiver diagrams. The F and D term equation

  33. Don N. Page

    Normally one thinks of the motion of the planets around the Sun as a highly classical phenomenon, so that one can neglect quantum gravity in the Solar System. However, classical chaos in the planetary motion amplifies quantum uncertainties so that they become very large, giving huge quantum gravity effects. For example, evidence suggests that Uranus may even

  34. Rak-Kyeong Seong, Dimitri D. Vvedensky

    We propose a method of characterizing radial networks based on a partition function associated with the structural triangulation of the network. The internal energy, Helmholtz free energy, and entropy derived from the partition function are used to group similar networks together and to interrogate the history of their development. We illustrate our methodol

  35. M. A. Thompson, D. J. B. Smith, J. A. Stevens, M. J. Jarvis

    Aims: We aim to demonstrate that the Herschel ATLAS (H-ATLAS) is suitable for a blind and unbiased survey for debris disks by identifying candidate debris disks associated with main sequence stars in the initial science demonstration field of the survey. We show that H-ATLAS reveals a population of far-infrared/sub-mm sources that are associated with stars o

  36. Peter T. Winslow, Kris Sigurdson, John N. Ng

    We demonstrate a new model which uses an ADD type braneworld scenario to produce a multi-state theory of dark matter. Compactification of the extra dimensions onto a sphere leads to the association of a single complex scalar in the bulk with multiple Kaluza-Klein towers in an effective four-dimensional theory. A mutually interacting multi-state theory of dar

  37. S. Knysh, V. Smelyanskiy

    Two recent preprints [B. Altshuler, H. Krovi, and J. Roland, &#34;Quantum adiabatic optimization fails for random instances of NP-complete problems&#34;, arXiv:0908.2782 and &#34;Anderson localization casts clouds over adiabatic quantum optimization&#34;, arXiv:0912.0746] argue that random 4th order perturbative corrections to the energies of local minima of

  38. Krzysztof Bolejko, William R. Stoeger

    The present-day Universe appears to be homogeneous on very large scales. Yet when the casual structure of the early Universe is considered, it becomes apparent that the early Universe must have been highly inhomogeneous. The current paradigm attempts to answer this problem by postulating the inflation mechanism However, inflation in order to start requires a

  39. Kirti Joshi

    We introduce and study arithmetic spin structures on elliptic curves. We show that there is a unique isogeny class of elliptic curves over $\F_{p^2}$ which carries a unique arithmetic spin structure and provides a geometric object of weight 1/2 in the sense of Deligne and Grothendieck. This object is thus a candidate for $\Q(1/4)$.

  40. Kirti Joshi, V. B. Mehta

    We study the Picard groups of moduli spaces in positive characteristics and we give a &#34;$p$-adic&#34; proof that the Picard group of moduli of vector bundles of fixed determinant is isomorphic to the group of integers. Along the way we prove that the local fundamental group scheme of a normal unirational projective variety is trivial. This is reminiscent

  41. Kirti Joshi

    We prove the following: (1) if $X$ is ordinary, the Fulton-MacPherson configuration space $X[n]$ is ordinary for all $n$; (2) the moduli of stable $n$-pointed curves of genus zero is ordinary. (3) More generally we show that a wonderful compactification $X_\sg$ is ordinary if and only if $(X,\sg)$ is an ordinary building set. This implies the ordinarity of m

  42. Kirti Joshi, Cameron McLeman

    We investigate class field towers of number fields obtained as fixed fields of modular representations of the absolute Galois group of the rational numbers. First, for each $k\in\{12,16,18,20,22,26\}$, we give explicit rational primes $ł$ such that the fixed field of the mod-$ł$ representation attached to the unique normalized cusp eigenforms of weight $k$ o

  43. Julien Garaud, Mikhail S. Volkov

    We carry out a detailed stability analysis of the superconducting vortex solutions in the Weinberg-Salam theory described in Nucl.Phys. B826 (2010) 174. These vortices are characterized by constant electric current $I$ and electric charge density $I_0$, for ${I}\to 0$ they reduce to Z strings. We consider the generic field fluctuations around the vortex and

  44. D. G. C. McKeon

    The Dirac constraint formalism is used to analyze the first order form of the Einstein-Hilbert action in d > 2 dimensions. Unlike previous treatments, this is done without eliminating fields at the outset by solving equations of motion that are independent of time derivatives when they correspond to first class constraints. As anticipated by the way in which

  45. Donald Marolf

    While extreme black hole spacetimes with smooth horizons are known at the level of mathematics, we argue that the horizons of physical extreme black holes are effectively singular. Test particles encounter a singularity the moment they cross the horizon, and only objects with significant back-reaction can fall across a smooth (now non-extreme) horizon. As a

  46. Kirti Joshi

    We consider a variant of a question of N. Koblitz. For an elliptic curve $E/\Q$ which is not $\Q$-isogenous to an elliptic curve with torsion, Koblitz has conjectured that there exists infinitely many primes $p$ such that $N_p(E)=#E(\F_p)=p+1-a_p(E)$ is also a prime. We consider a variant of this question. For a newform $f$, without CM, of weight $k\geq 4$,

  47. S. Bloemen, T. R. Marsh, D. Steeghs, R. H. Østensen

    We present high-speed spectroscopic observations of the intermediate polar DQ Herculis. Doppler tomography of two He I lines reveals a spiral density structure in the accretion disc around the white dwarf primary. The spirals look very similar to the spirals seen in dwarf novae during outburst. DQ Her is the first well established intermediate polar in which

  48. Hendrik Bluhm, Sandra Foletti, Izhar Neder, Mark Rudner

    Qubits, the quantum mechanical bits required for quantum computing, must retain their fragile quantum states over long periods of time. In many types of electron spin qubits, the primary source of decoherence is the interaction between the electron spins and nuclear spins of the host lattice. For electrons in gate defined GaAs quantum dots, previous spin ech

  49. Brett Altschul

    Violations of Lorentz boost symmetry in the electron and photon sectors can be constrained by studying several different high-energy phenomenon. Although they may not lead to the strongest bounds numerically, measurements made in terrestrial laboratories produce the most reliable results. Laboratory bounds can be based on observations of synchrotron radiatio

  50. Toshiyuki Kikuta

    We give two congruence properties of Hermitian modular forms of degree 2 over $\mathbb{Q}(\sqrt{-1})$ and $\mathbb{Q}(\sqrt{-3})$. The one is a congruence criterion for Hermitian modular forms which is generalization of Sturm&#39;s theorem. Another is the well-definedness of the $p$-adic weight for Hermitian modular forms.

  51. Bogdan Nica

    We give a brief account of the interplay between spectral morphisms, K-theory, and stable ranks in the context of Banach algebras.

  52. Iain A. Brown

    Magnetic fields appear to be a generic feature of the early universe and are a natural source of secondary CMB non-Gaussianity. In recent years the statistical nature of the stresses of a primordial magnetic field has been well studied. In this paper we confirm and extend these studies at one- and two-point level, and present analytical results for a wide ra

  53. V. Könyves, Ph. André, A. Men&#39;shchikov, N. Schneider

    The origin and possible universality of the stellar initial mass function (IMF) is a major issue in astrophysics. One of the main objectives of the Herschel Gould Belt Survey is to clarify the link between the prestellar core mass function (CMF) and the IMF. We present and discuss the core mass function derived from Herschel data for the large population of

  54. Lizhen Ji, Andreas Weber

    We prove pointwise bounds for $L^2$ eigenfunctions of the Laplace-Beltrami operator on locally symmetric spaces with $\mathbb{Q}$-rank one if the corresponding eigenvalues lie below the continuous part of the $L^2$ spectrum. Furthermore, we use these bounds in order to obtain some results concerning the $L^p$ spectrum.

  55. Theodoros Tsagaris, Ajay Jasra, Niall Adams

    We present an online approach to portfolio selection. The motivation is within the context of algorithmic trading, which demands fast and recursive updates of portfolio allocations, as new data arrives. In particular, we look at two online algorithms: Robust-Exponentially Weighted Least Squares (R-EWRLS) and a regularized Online minimum Variance algorithm (O

  56. Jan Winter

    The possibility of treating colour in one-loop amplitude calculations alike the other quantum numbers is briefly discussed for semi-numerical algorithms based on generalized unitarity and parametric integration techniques. Numerical results are presented for the calculation of virtual corrections in multi-gluon scattering.

  57. Lizhen Ji, Peer Kunstmann, Andreas Weber

    In this paper we study the Riesz transform on complete and connected Riemannian manifolds $M$ with a certain spectral gap in the $L^2$ spectrum of the Laplacian. We show that on such manifolds the Riesz transform is $L^p$ bounded for all $p \in (1,\infty)$. This generalizes a result by Mandouvalos and Marias and extends a result by Auscher, Coulhon, Duong, a

  58. V. Khalack, F. LeBlanc, B. B. Behr

    The aim of this study is to search for observational evidence of vertical iron stratification in the atmosphere of fourteen blue horizontal-branch (BHB) stars. We have found from our numerical simulations that five BHB stars: B22, B186 in the globular cluster NGC 288, WF2-820, WF2-2692 in M13 and B203 in M15 show clear signatures of the vertical stratificati

  59. Robert Gray, António Malheiro

    It is proved that, given a (von Neumann) regular semigroup with finitely many left and right ideals, if every maximal subgroup is presentable by a finite complete rewriting system, then so is the semigroup. To achieve this, the following two results are proved: the property of being defined by a finite complete rewriting system is preserved when taking an id

  60. Alexey Pak, Mikhail Rogal, Matthias Steinhauser

    QCD corrections to inclusive Higgs boson production at the LHC are evaluated at next-to-next-to leading order. By performing asymptotic expansion of the cross section near the limit of infinitely heavy top quark we obtained a few first top mass-suppressed terms. The corrections to the hadronic cross sections are found to be small compared to the scale uncert

  61. B. Geelhoed

    The variance of the concentration in a sample can be estimated using knowledge of the particle masses, concentrations and the parameter for the dependent selection of particles. A number of variance estimators are constructed including a class of hybrid estimators.

  62. M. Neupane, P. Richard, Y. -M. Xu, K. Nakayama

    We have performed a systematic photoemission study of the chemical potential shift as a function of carrier doping in a pnictide system based on BaFe$_2$As$_2$. The experimentally determined chemical potential shift is consistent with the prediction of a rigid band shift picture by the renormalized first-principle band calculations. This leads to an electron

  63. Antoine Julien, Jean Savinien

    In this second paper, we study the case of substitution tilings of R^d. The substitution on tiles induces substitutions on the faces of the tiles of all dimensions j=0, ..., d-1. We reconstruct the tiling&#39;s equivalence relation in a purely combinatorial way using the AF-relations given by the lower dimensional substitutions. We define a Bratteli multi-di

  64. F. J. Sanchez-Salcedo, V. Lora

    The survival of unbound density substructure against orbital mixing imposes strong constraints on the slope of the underlying gravitational potential and provides a new test on modified gravities. Here we investigate whether the interpretation that the stellar clump in Ursa Minor (UMi) dwarf spheroidal galaxy is a `dynamical fossil&#39; is consistent with Mo

  65. V. M. Krasnov

    I derive simple non-local dynamic boundary conditions, suitable for modelling of radiation emission from stacked Josephson junctions, and employ them for analysis of flux-flow emission from intrinsic Josephson junctions in high-$T_c$ superconductors. It is shown that due to the lack of Lorenz contraction of fluxons in stacked junctions, high quality geometri

  66. C. Beck

    I report observations of unusually strong photospheric and chromospheric velocity oscillations in and near the leading sunspot of NOAA 10781 on 03 July 2005. I investigate an impinging wave as a possible origin of the velocity pattern, and the changes of the wave after the passage through the magnetic fields of the sunspot. The wave pattern found consists of

  67. The IceCube Collaboration, R. Abbasi

    We report the first observation of an anisotropy in the arrival direction of cosmic rays with energies in the multi TeV region in the Southern sky using data from the IceCube detector. Between June 2007 and March 2008, the partially-deployed IceCube detector was operated in a configuration with 1320 digital optical sensors distributed over 22 strings at dept

  68. B. Husemann, S. F. Sánchez, L. Wisotzki, K. Jahnke

    We present VIMOS integral field spectroscopy of the brightest radio-quiet QSO on the southern sky HE 1029-1401 at a redshift of z=0.086. Standard decomposition techniques for broad-band imaging are extended to integral field data in order to deblend the QSO and host emission. We perform a tentative analysis of the stellar continuum finding a young stellar po

  69. I. V. Artamkin

    Asymptotic expansions of Gaussian integrals may often be interpreted as generating functions for certain combinatorial objects (graphs with additional data). In this article we discuss a general approach to all such cases using colored graphs. We prove that the generating power series for such graphs satisfy the same system of partial differential equations

  70. Roberto Beneduci

    A commutative POV measure $F$ with real spectrum is characterized by the existence of a PV measure $E$ (the sharp reconstruction of $F$) with real spectrum such that $F$ can be interpreted as a randomization of $E$. This paper focuses on the relationships between this characterization of commutative POV measures and Neumark&#39;s extension theorem. In partic

  71. P. Royer, L. Decin, R. Wesson, M. J. Barlow

    With a luminosity > 10^5 Lsun and a mass-loss rate of about 2.10-4 Msun/yr, the red supergiant VY CMa truly is a spectacular object. Because of its extreme evolutionary state, it could explode as supernova any time. Studying its circumstellar material, into which the supernova blast will run, provides interesting constraints on supernova explosions and on th

  72. F. Mantovani, A. Rossetti, W. Junor, D. J. Saikia

    We report VLBA polarimetric observations of the CSS sources 3C119, 3C318, and 3C343 at 5 and 8.4 GHz. The CSS source 3C119 has source rest-frame RM values up to ~10200 rad/m**2 in a region which coincides with a change in the direction of the inner jet. This component is located ~325 pc from the core, which is variable and has a peaked radio spectrum. In the

  73. Amina Chebira, Matthew Fickus, Dustin G. Mixon

    In this paper we characterize and construct novel oversampled filter banks implementing fusion frames. A fusion frame is a sequence of orthogonal projection operators whose sum can be inverted in a numerically stable way. When properly designed, fusion frames can provide redundant encodings of signals which are optimally robust against certain types of noise

  74. Victor H. Moll, Sinai Robins, Kirk Soodhalter

    We study the action of the Hecke operators Un on the set of hy- pergeometric functions, as well as on formal power series. We show that the spectrum of these operators on the set of hypergeometric functions is the set n^a with a an integer and n a positive integer, and that the polylogarithms play a dominant role in the study of the eigenfunctions of the Hec

  75. Jorge Melendez, Luca Casagrande, Ivan Ramirez, Martin Asplund

    We present NLTE Li abundances for 88 stars in the metallicity range -3.5 < [Fe/H] < -1.0. The effective temperatures are based on the infrared flux method with improved E(B-V) values obtained mostly from interstellar NaI D lines. The Li abundances were derived through MARCS models and high-quality UVES+VLT, HIRES+Keck and FIES+NOT spectra, and complemented w

  76. E. Athanassoula, M. Romero-Gomez, A. Bosma, J. J. Masdemont

    In a series of papers, we propose a theory to explain the formation and properties of rings and spirals in barred galaxies. The building blocks of these structures are orbits guided by the manifolds emanating from the unstable Lagrangian points located near the ends of the bar. In this paper, the last of the series, we present more comparisons of our theoret

  77. Shiv K. Sethi, Zoltán Haiman, Kanhaiya Pandey

    It has been proposed that primordial gas in early dark matter halos, with virial temperatures above 10^4 K, can avoid fragmentation and undergo rapid collapse, possibly resulting in a supermassive black hole (SMBH). This requires the gas to avoid cooling and to remain at temperatures near T=10^4 K. We show that this condition can be satisfied in the presence

  78. Stefan Boettner, Victor H. Moll

    The table of Gradshteyn and Ryzhik contains many entries that are related to elliptic integrals. We present a systematic derivation of some of them.

  79. Matthew Albano, Tewodros Amdeberhan, Erin Beyerstedt, Victor H. Moll

    The table of Gradshteyn and Ryzhik contains some integrals that can be reduced to the Frullani type. We present a selection of them.

  80. Ioannis Brouzos, Sascha Zöllner, Peter Schmelcher

    We investigate few-boson systems in finite one-dimensional multi-well traps covering the full interaction crossover from uncorrelated to fermionized particles. Our treatment of the ground state properties is based on the numerically exact Multi-Configurational Time-Dependent Hartree method. For commensurate filling we trace the fingerprints of localisation,

  81. Giorgio Brida, Ivo Pietro Degiovanni, Marco Genovese, Maria Luisa Rastello

    We propose and demonstrate experimentally a new method based on the spatial entanglement for the absolute calibration of analog detector. The idea consists on measuring the sub-shot-noise intensity correlation between two branches of parametric down conversion, containing many pairwise correlated spatial modes. We calibrate a scientific CCD camera and a prel

  82. S. Laplace

    The in-situ commissioning of the ATLAS liquid argon calorimeter is taking place since three years. During this period, it has been fully tested by means of frequent calibration runs, and the analysis of the large cosmic muon data samples and of the few beam splash events that occurred on September 10th, 2008. This has allowed to obtain a stable set of calibr

  83. A. Yurgens

    I numerically analyze Joule heating in large Bi2212 mesas while taking into account typical thermal conductivities and their temperature dependencies of all the materials involved in the heat dissipation and its removal. Such mesas are used in experiments on THz-range radiation. The analysis shows that the temperature increases with bias current and is distr

  84. Hai Wang, Pui-Wai Ma, C. H. Woo

    We performed first-principle calculations on the exchange interaction (EI) between atoms in BCC-Fe strained volumetrically. Our results show that the volume-dependence of the EI deviates considerably from the Bethe-Slater curve. This behavior is discussed in terms of the on-site and/or inter-site direct exchange interactions between electrons.

  85. Ellyn K. Baines, Harold A. McAlister, Theo A. ten Brummelaar, Nils H. Turner

    Of the over 450 exoplanets known to date, more than 420 of them have been discovered using radial velocity studies, a method that tells nothing about the inclination of the planet&#39;s orbit. Because it is more likely that the companion is a planetary-mass object in a moderate- to high-inclination orbit than a low-mass stellar object in a nearly face-on orb

  86. Caleb A. Scharf

    A small percentage of normal stars harbor giant planets that orbit within a few tenths of an astronomical unit. At such distances the potential exists for significant tidal and magnetic field interaction resulting in energy dissipation that may manifest as changes within the stellar corona. We examine the X-ray emission of stars hosting planets and find a po

  87. Hiromichi Kuriyama, Jobu Matsuno, Seiji Niitaka, Masaya Uchida

    Single-crystalline thin film of an iridium dioxide polymorph Ir2O4 has been fabricated by the pulsed laser deposition of LixIr2O4 precursor and the subsequent Li-deintercalation using soft chemistry. Ir2O4 crystallizes in a spinel (AB2O4) without A cations in the tetrahedral site, which is isostructural to lambda-MnO2. Ir ions form a pyrochlore sublattice, w

  88. Xuewei Deng, Huaijin Ren, Yuanlin Zheng, Kun Liu

    Significantly enhanced second order nonlinearity resulting from local symmetry breaking in domain walls is reported. By this new giant nonlinearity, novel hexagonally, conically and trigonally distributed second harmonic beams closely related to domain wall patterns are generated without contribution of reciprocal vectors. Experimental results show that such

  89. Charles B. Thorn

    The purpose of this article is to extend the lightcone worldsheet lattice description of string theory to include the Neveu-Schwarz model. We model each component of the fermionic worldsheet field by a critical Ising model. We show that a simple choice of boundary conditions for the Ising variables leads to the half integer modes required by the model. We id

  90. T. G. Mueller, E. Lellouch, J. Stansberry, C. Kiss

    The goal of the Herschel Open Time Key programme &#34;TNOs are Cool!&#34; is to derive the physical and thermal properties for a large sample of Centaurs and trans-Neptunian objects (TNOs), including resonant, classical, detached and scattered disk objects. We present results for seven targets either observed in PACS point-source, or in mini scan-map mode. S

  91. Nicholas W. Taylor, Lawrence E. Kidder, Saul A. Teukolsky

    Current spectral simulations of Einstein&#39;s equations require writing the equations in first-order form, potentially introducing instabilities and inefficiencies. We present a new penalty method for pseudo-spectral evolutions of second order in space wave equations. The penalties are constructed as functions of Legendre polynomials and are added to the eq

  92. R. Geurts, M. V. Milošević, F. M. Peeters

    The effects of the coupling between two electronic condensates in two-gap mesoscopic superconductors are studied within the Ginzburg-Landau theory using a finite difference technique. In applied magnetic field, we derive the dependency of the size of the vortex on the sample size and the strength of the Josephson coupling. In addition, we elaborate on the de

  93. M. Q. Cai, Y. Zheng, B. Wang, G. W. Yang

    We theoretically showed that the spontaneous polarization in ferroelectric (FE) nanowires (NWs) can be considerably enhanced due to the nanosize confinement by the first-principles calculations. The spontaneous polarization along the wire direction in a fully-relaxed PbTiO3 NW with 1.8 nm diameter is 1.26 times higher than that of bulk counterpart. The tensi

  94. Jan-Erik Roos

    Graded skew-commutative rings occur often in practice. Here are two examples: 1) The cohomology ring of a compact three-dimensional manifold. 2) The cohomology ring of the complement of a hyperplane arrangement (the Orlik-Solomon algebra). We present some applications of the homological theory of these graded skew-commutative rings. In particular we find com

  95. Yohai Meiron, Ari Laor

    The stalling radius of a merging massive binary black hole (BBH) is expected to be below 0&#34;.1 even in nearby galaxies (Yu 2002), and thus BBHs are not expected to be spatially resolved in the near future. However, as we show below, a BBH may be detectable through the significantly anisotropic stellar velocity distribution it produces on scales 5-10 times

  96. K. Ammari, D. Mercier, V. Régnier, J. Valein

    We consider $N$ Euler-Bernoulli beams and $N$ strings alternatively connected to one another and forming a particular network which is a chain beginning with a string. We study two stabilization problems on the same network and the spectrum of the corresponding conservative system: the characteristic equation as well as its asymptotic behavior are given. We

  97. David A. Herrera-Martí, Austin G. Fowler, David Jennings, Terry Rudolph

    A new implementation of the topological cluster state quantum computer is suggested, in which the basic elements are linear optics, measurements, and a two-dimensional array of quantum dots. This overcomes the need for non-linear devices to create a lattice of entangled photons. We give estimates of the minimum efficiencies needed for the detectors, fusion g

  98. Iyengar. S, N Apte, A. A. Roy, S. Sanyal

    Over the years, communication speed of networks has increased from a few Kbps to several Mbps, as also the bandwidth demand, Communication Protocols, however have not improved to that extent. With the advent of Wavelength Division Multiplexing (WDM), it is now possible to &#34;tune&#34; protocols to current and future demands. The purpose of this paper is to

  99. Gabor Szederkenyi, Katalin M. Hangos, Tamas Peni

    This paper presents new results about the optimization based generation of chemical reaction networks (CRNs) of higher deficiency. Firstly, it is shown that the graph structure of the realization containing the maximal number of reactions is unique if the set of possible complexes is fixed. Secondly, a mixed integer programming based numerical procedure is g

  100. E. I. Jafarov, J. Van der Jeugt

    We study the time evolution of a single spin excitation state in certain linear spin chains, as a model for quantum communication. Some years ago it was discovered that when the spin chain data (the nearest neighbour interaction strengths and the magnetic field strengths) are related to the Jacobi matrix entries of Krawtchouk polynomials or dual Hahn polynom