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March 2008 arXiv papers — page 34

Showing 3,3013,400 of 4,524 papers

  1. Michael Baake, Matthias Birkner, Robert V. Moody

    Stochastic point processes relevant to the theory of long-range aperiodic order are considered that display diffraction spectra of mixed type, with special emphasis on explicitly computable cases together with a unified approach of reasonable generality. The latter is based on the classical theory of point processes and the Palm distribution. Several pairs o

  2. Kevin Dusling, Shu Lin

    This work calculates the first correction to the leading order qq dilepton production rates due to shear viscosity in an expanding gas. The modified rates are integrated over the space-time history of a viscous hydrodynamic simulation of RHIC collisions. The net result is a {\em hardening} of $q_\perp$ spectrum with the magnitude of the correction increasing

  3. Theresa Hecht, Andreas Weichselbaum, Jan von Delft, Ralf Bulla

    We use the numerical renormalization group method (NRG) to investigate a single-impurity Anderson model with a coupling of the impurity to a superconducting host. Analysis of the energy flow shows, in contrast to previous belief, that NRG iterations can be performed up to a large number of sites, corresponding to energy differences far below the superconduct

  4. Julien Mandon, Guy Guelachvili, Nathalie Picqué

    Molecular fingerprinting through absorption spectroscopy is a powerful analytical method. Wide spectral ranges are explored with Doppler-limited resolution. Fast data acquisition, accurate measurements of frequency, intensity, and line shape; time-resolved, selective spectra are achieved with excellent sensitivities. However, presently spectrometers are unab

  5. Peter Ozsvath, Andras Stipsicz

    We study naturality properties of the transverse invariant in knot Floer homology under contact (+1)-surgery. This can be used as a calculational tool for the transverse invariant. As a consequence, we show that the Eliashberg-Chekanov twist knots E_n are not transversely simple for n odd and n>3.

  6. Laszlo Lovasz, Balazs Szegedy

    We define an analytic version of the graph property testing problem, which can be formulated as studying an unknown 2-variable symmetric function through sampling from its domain and studying the random graph obtained when using the function values as edge probabilities. We give a characterization of properties testable this way, and extend a number of resul

  7. Ginestra Bianconi, Anthony C. C. Coolen, Conrad J. Perez Vicente

    The entropy of a hierarchical network topology in an ensemble of sparse random networks with "hidden variables" associated to its nodes, is the log-likelihood that a given network topology is present in the chosen ensemble.We obtain a general formula for this entropy,which has a clear simple interpretation in some simple limiting cases. The results p

  8. George I. Bell

    In 1979, David Fabian found a complete game of two-person Chinese Checkers in 30 moves (15 by each player) [Martin Gardner, Penrose Tiles to Trapdoor Ciphers, MAA, 1997]. This solution requires that the two players cooperate to generate a win as quickly as possible for one of them. We show, using computational search techniques, that no shorter game is possi

  9. Christian Borgs, Jennifer Chayes, Laszlo Lovasz

    For a symmetric bounded measurable function W on [0,1]^2, "moments" of W can be defined as values t(F,W) indexed by simple graphs. We prove that every such function is determined by its moments up to a measure preserving transformation of the variables. This implies that the limit of a convergent dense graph sequence is unique up to measure preservin

  10. Hyunchul Nha

    We consider the method of entanglement witness operator to verify genuine multipartite entanglement for single-particle W states involving N parties. In particular, linear optical schemes using photo detectors and beam splitters are proposed to implement two different types of witness operator in experiment. The first scheme that requires only a single measu

  11. Wei-Shu Hou

    The baryon asymmetry of the Universe requires CP violation, but the Standard Model falls short by a factor of $10^{-10}$ or more. Starting from a clue at the $B$ factories, we point out that the large Yukawa couplings of the sequential fourth generation $t^\prime$ and $b^\prime$ quarks can provide enhancement by a factor of over $10^{13}$, making the 2-3-4 g

  12. Hassan Raza, Edwin C. Kan

    We report electronic structure and electric field modulation calculations in the width direction for armchair graphene nanoribbons (acGNRs) using a semi-empirical extended Huckel theory. Important band structure parameters are computed, e.g. effectives masses, velocities and bandgaps. For the three types of acGNRs, the pz orbital tight-binding parameters are

  13. Xuelei Wang, Yanhui Xi, Yanju Zhang, Huiling Jin

    In this paper, we systematically study the contribution of the TC2 model to the single t-quark production at the Hadron colliders, specially at the LHC. The TC2 model can contribute to the cross section of the single t-quark production in two different ways. First, the existence of the top-pions and top-higgs can modify the $Wtb$ coupling via their loop cont

  14. Alexey A. Kovalev, Karel Výborný, Jairo Sinova

    We present the analytical description of the anomalous Hall effect (AHE) in a 2DEG ferromagnet within the Keldysh formalism. These results unify all three linear response approaches to anomalous Hall transport and close a long standing debate. We are able to identify a new extrinsic AHE regime dominated by a hybrid skew scattering mechanism. This new contrib

  15. Gautam Iyer, Jonathan Mattingly

    This paper is based on a formulation of the Navier-Stokes equations developed by P. Constantin and the first author (\texttt{arxiv:math.PR/0511067}, to appear), where the velocity field of a viscous incompressible fluid is written as the expected value of a stochastic process. In this paper, we take $N$ copies of the above process (each based on independent

  16. Zhi-Gang Wang

    In this article, we assume that the $(0^+,1^+)$ strange-bottom mesons are the conventional $b\bar{s}$ mesons, and calculate the electromagnetic coupling constants $d$, $g_1$, $g_2$ and $g_3$ using the light-cone QCD sum rules. Then we study the radiative decays $B_{s0}\to B_s^* γ$, $B_{s1}\to B_s γ$, $B_{s1}\to B_s^* γ$ and $B_{s1}\to B_{s0} γ$, and observe

  17. H. Y. Wang, H. J. Mo, Y. P. Jing, Y. C. Guo

    We develop a new method to reconstruct the cosmic density field from the distribution of dark matter haloes above a certain mass threshold. Our motivation is that well-defined samples of galaxy groups/clusters, which can be used to represent the dark halo population, can now be selected from large redshift surveys of galaxies, and our ultimate goal is to use

  18. Luis A. Dupont, Carlos Renteria-Marquez, Rafael H. Villarreal

    Let C be a clutter and let A be its incidence matrix. If the linear system x>=0;xA<=1 has the integer rounding property, we give a description of the canonical module and the a-invariant of certain normal subrings associated to C. If the clutter is a connected graph, we describe when the aforementioned linear system has the integer rounding property in combi

  19. Hang Dinh

    This paper has been withdrawn.

  20. Renyu Hu, Yulia V. Bogdanova, Christopher J. Owen, Claire Foullon

    This paper has been withdrawn by the author since it has been accepted for publishing in J. Geophys. Res. Please contact the American Geophysical Union for the refereed article.

  21. Keiji Oguiso

    We shall show that the Picard number of the generic fiber, in the sense of scheme, of an abelian fibered hyperkähler manifold over the projective space is always one. We then give a few applications for the Mordell-Weil group. In particular, by deforming O&#39;Grady&#39;s 10-dimensional manifold, we construct an abelian fibered hyperkähler manifold of Mordel

  22. C. J. Law, F. Yusef-Zadeh, W. D. Cotton

    We describe the results of a mJy-sensitivity, VLA survey of roughly 1 square degree near the Galactic center at 6 and 20 cm. Catalogs of compact and filamentary structures are given and compared to previous surveys of the region. Eight of the unusual, nonthermal radio filaments are detected in 6 cm polarized emission; three of these are the first such detect

  23. Lin Weng

    Associated to classical semi-simple groups and their maximal parabolics are genuine zeta functions. Naturally related to Riemann&#39;s zeta and governed by symmetries, including that of Weyl, these zetas are expected to satisfy the Riemann hypothesis.

  24. Ciprian Demeter, Christoph Thiele

    We investigate the Bilinear Hilbert Transform in the plane and the pointwise convergence of bilinear averages in Ergodic theory, arising from $\Z^2$ actions. Our techniques combine novel one and a half dimensional phase-space analysis with more standard one dimensional theory.

  25. Adam Gali, Maria Fyta, Efthimios Kaxiras

    The nitrogen-vacancy center in diamond is a promising candidate for realizing the spin qubits concept in quantum information. Even though this defect is known for a long time, its electronic structure and other properties have not yet been explored in detail. We study the properties of the nitrogen-vacancy center in diamond through density functional theory

  26. Peter J. Brown, Stephen T. Holland, Stefan Immler, Peter Milne

    We present ultravioliet (UV) observations of supernovae (SNe) obtained with the UltraViolet/Optical Telescope (UVOT) on board the Swift spacecraft. This is the largest sample of UV light curves from any single instrument and covers all major SN types and most subtypes. The UV light curves of SNe Ia are fairly homogenous while SNe Ib/c and IIP show more varie

  27. Howard Barnum, Oscar C. O. Dahlsten, Matthew Leifer, Ben Toner

    We investigate the existence of secure bit commitment protocols in the convex framework for probabilistic theories. The framework makes only minimal assumptions, and can be used to formalize quantum theory, classical probability theory, and a host of other possibilities. We prove that in all such theories that are locally non-classical but do not have entang

  28. Gabriel Gonzalez, Michael N. Leuenberger, Eduardo R. Mucciolo

    We present a careful and thorough microscopic derivation of the Kondo Hamiltonian for single-molecule magnets (SMMs) transistors. When the molecule is strongly coupled to metallic leads, we show that by applying a transverse magnetic field it is possible to topologically induce or quench the Kondo effect in the conductance of a SMM with either an integer or

  29. Rutger Hermsen, Pieter Rein ten Wolde, Sarah Teichmann

    By analyzing the spacing of genes on chromosomes, we find that transcriptional and RNA-processing regulatory sequences outside coding regions leave footprints on the distribution of intergenic distances. Using analogies between genes on chromosomes and one-dimensional gases, we constructed a statistical null model. We have used this to estimate typical upstr

  30. Vladimir Andrievskii

    We generalize the classical Bernstein theorem concerning the constructive description of classes of functions uniformly continuous on the real line. The approximation of continuous bounded functions by entire functions of exponential type on unbounded closed proper subsets of the real line is studded.

  31. A. N. Leznov

    It is shown that algebra of quantum space of the title of the present paper may be realized on usual unphysical Minkowskii one. Equations of field theory and there solutions are discussed. Solution equations of particle motion are obtained in implicit form from the classical ones.

  32. Eric C. Rowell

    We present two paradigms relating algebraic, topological and quantum computational statistics for the topological model for quantum computation. In particular we suggest correspondences between the computational power of topological quantum computers, computational complexity of link invariants and images of braid group representations. While at least parts

  33. S. Meza-Aguilar, R. E. Felix-Medina, M. A. Leyva-Lucero

    In a very recent x-ray magnetic circular dichroism experiment concerning with Ru and Rh impurities and metal films on Ag(001) substrate, no local magnetic momen ts were displayed in direct contradiction with previous theoretical works. It is thought that there can be three main reasons for this inconsistency: relaxation, alloying and many-body effects. Some

  34. Henri Gouin

    Isothermal interfacial zones are investigated starting from a local energy which can be considered as the sum of two terms: one corresponding to a medium with a uniform composition equal to the local one and a second one associated with the non-uniformity of the fluid. In an extended van der Waals theory, the volume internal energy is proposed with a gradien

  35. Ian Biringer

    Assume that M is a closed hyperbolic 3-manifold fibering over the circle with fiber a closed orientable surface of genus g. We show that if M has large diameter and its injectivity radius is bounded below, then the rank of the fundamental group of M is 2g+1.

  36. Ian Biringer, Benjamin Schmidt

    The classical Three Gap Theorem asserts that for a natural number n and a real number p, there are at most three distinct distances between consecutive elements in the subset of [0,1) consisting of the reductions modulo 1 of the first n multiples of p. Regarding it as a statement about rotations of the circle, we find results in a similar spirit pertaining t

  37. Yanir A. Rubinstein, Steve Zelditch

    We generalize the results of Song-Zelditch on geodesics in spaces of Kahler metrics on toric varieties to harmonic maps of any compact Riemannian manifold with boundary into the space of Kahler metrics on a toric variety. We show that the harmonic map equation can always be solved and that such maps may be approximated in the C^2 topology by harmonic maps in

  38. Fabio Finelli, Francesco Paci, Daniela Paoletti

    We study the impact of a stochastic background of primordial magnetic fields on the scalar contribution of CMB anisotropies and on the matter power spectrum. We give the correct initial conditions for cosmological perturbations and the exact expressions for the energy density and Lorentz force associated to the stochastic background of primordial magnetic fi

  39. James D. Wells

    I discuss how the Large Hadron Collider era should broaden our view of particle physics research, and apply this thinking to the case of Hidden Worlds. I focus on one of the simplest representative cases of a Hidden World, and detail the rich implications it has for LHC physics, including universal suppression of Higgs boson production, trans-TeV heavy Higgs

  40. K. M. Hiremath

    With reasonable assumptions and approximations, we compute the velocity of the meridional flow $U$ in the convective envelope by modified Chandrasekhar&#39;s (1956) MHD equations. The analytical solution of such a modified equation is found to be $U(x,μ) = \sum_{n=0}^\infty \bigl[u1_n x^n + u2_n x^{-(n+3)}\bigr] C_n^{3/2}(μ)$, where $x$ is non-dimensional ra

  41. Piret Kuusk, Eugen Paal

    Algebraic systems called the local geodesic loops and their tangent Akivis algebras are considered. Their possible role in theory of gravity is considered. Quantum conditions for the infinitesimal quantum events are proposed.

  42. G. Jaroszkiewicz

    Quantized detector networks (QDN) deals with quantum information exchange between observers and their apparatus rather than with systems under observation. Partial observations in QDN involve subsets of the elementary signal detectors which constitute an apparatus. We use them to prove that QDN is consistent with Einstein locality and violations of Bell-type

  43. Shou-Shu Gong, Bo Gu, Gang Su

    By means of the density matrix renormalization group (DMRG) method, the static spin structure factors and the magnetization plateaus of the trimerized Heisenberg ferromagnet-ferromagnet-antiferromagnet and antiferromagnet-antiferromagnet-ferromagnet spin chains in the presence of a magnetic field are elaborately studied. It is found that in the plateau state

  44. Jan Schepers

    For projective varieties with a certain class of &#39;mild&#39; isolated singularities and for projective threefolds with arbitrary Gorenstein canonical singularities, we show that the stringy Hodge numbers satisfy the Hard Lefschetz property. This result fits nicely with a 6-dimensional counterexample of Mustata and Payne for the Hard Lefschetz property for

  45. Jean Dolbeault, Bruno Nazaret, Giuseppe Savare

    We introduce a new class of distances between nonnegative Radon measures in Euclidean spaces. They are modeled on the dynamical characterization of the Kantorovich-Rubinstein-Wasserstein distances proposed by Benamou-Brenier and provide a wide family interpolating between the Wasserstein and the homogeneous (dual) Sobolev distances. From the point of view of

  46. W. J. H. Leylanda, R. T. Harley, M. Henini, A. J. Shields

    Measurements of spin dynamics of electrons in a degenerate two dimensional electron gas, where the Dyakonov-Perel mechanism is dominant, have been used to investigate the electron scattering time (tp*) as a function of energy near the Fermi energy. Close to the Fermi energy the spin evolution is oscillatory, indicating a quasi-collision-free regime of spin d

  47. Andrey R. Kolovsky

    The paper discusses the master equation approach to derivation of the Esaki-Tsu equation for drift current. It is shown that the relaxation term in the master equation can be identified by measuring the velocity distribution of the carriers. We also show that the standard form of the relaxation term, used earlier to derive Esaki-Tsu equation, predicts unphys

  48. C. Nutto, M. Roth, Y. Zhugzhda, J. Bruls

    Calculations of spectral darkening and visibility functions for the brightness oscillations of the Sun resulting from global solar oscillations are presented. This has been done for a broad range of the visible and infrared continuum spectrum. The procedure for the calculations of these functions includes the numerical computation of depth-dependent derivati

  49. Jean Creignou, Hervé Diet

    The linear programming method is applied to the space $\U_n(\C)$ of unitary matrices in order to obtain bounds for codes relative to the diversity sum and the diversity product. Theoretical and numerical results improving previously known bounds are derived.

  50. R. Spjut

    Helton, Lasserre, and Putinar (2008, Ann. Probability; arXiv:math/0702314) expose the relationship between three properties of a measure: the conditional triangularity property of the associated orthogonal polynomials, the zeros in the inverse condition of the truncated moment matrix, and conditional independence. The purpose of this article is to provide ex

  51. Masahiro N. Machida, Tomoaki Matsumoto, Shu-ichiro Inutsuka

    Jet driving and fragmentation process in collapsing primordial cloud are studied using three-dimensional MHD nested grid simulations. Starting from a rotating magnetized spherical cloud with the number density of n=10^3 cm^-3, we follow the evolution of the cloud up to the stellar density n=10^22 cm^-3. We calculate 36 models parameterizing the initial magne

  52. Mazen Zein, Philippe Wenger, Damien Chablat

    When moving from one arbitrary location at another, a parallel manipulator may change its assembly-mode without crossing a singularity. Because the non-singular change of assembly-mode cannot be simply detected, the actual assembly-mode during motion is difficult to track. This paper proposes a global explanatory approach to help better understand non-singul

  53. Somitra Kumar Sanadhya, Palash Sarkar

    In this note, we provide the first 22-step collisions for SHA-256 and SHA-512. Detailed technique of generating these collisions will be provided in the next revision of this note.

  54. M. Bhattacharya, P. -L. Giscard, P. Meystre

    We consider a small partially reflecting vibrating mirror coupled dispersively to a single optical mode of a high finesse cavity. We show this arrangement can be used to implement quantum squeezing of the mechanically oscillating mirror.

  55. Li Chen

    The key step of generating the well-known Hsiao code is to construct a {0,1}-check-matrix in which each column contains the same odd-number of 1&#39;s and each row contains the same number of 1&#39;s or differs at most by one for the number of 1&#39;s. We also require that no two columns are identical in the matrix. The author solved this problem in 1986 by

  56. Pablo Bianucci, Chris R. Fietz, John W. Robertson, Gennady Shvets

    We present a microresonator-based system capable of simultaneously producing time-advanced and time-delayed pulses. The effect is based on the combination of a sharp spectral feature with two orthogonally-polarized propagating waveguide modes. We include an experimental proof-of-concept implementation using a silica microsphere coupled to a tapered optical f

  57. R. K. Bhaduri, M. V. N. Murthy, M. Brack

    We consider a few-particle system of trapped neutral fermionic atoms at ultra-low temperatures, with the attractive interaction tuned to Feshbach resonance. We calculate the energies and the spatial densities of the few-body systems using a generalisation of the extended Thomas-Fermi (ETF) method, and assuming the particles obey the Haldane-Wu fractional exc

  58. Robin T. Garrod, Susanna L. Widicus Weaver, Eric Herbst

    Gas-phase processes were long thought to be the key formation mechanisms for complex organic molecules in star-forming regions. However, recent experimental and theoretical evidence has cast doubt on the efficiency of such processes. Grain-surface chemistry is frequently invoked as a solution, but until now there have been no quantitative models taking into

  59. Istvan Z. Kiss, Yumei Zhai, John L. Hudson

    Experiments are carried out with a globally coupled, externally forced population of limit-cycle electrochemical oscillators with an approximately unimodal distribution of heterogeneities. Global coupling induces mutually entrained (at frequency $ω_{1}$) states; periodic forcing produces forced-entrained ($ω_{\mathrm{F}}$) states. As a result of the interact

  60. Angelia Nedić, Alex Olshevsky, Asuman Ozdaglar, John N. Tsitsiklis

    We consider a convex unconstrained optimization problem that arises in a network of agents whose goal is to cooperatively optimize the sum of the individual agent objective functions through local computations and communications. For this problem, we use averaging algorithms to develop distributed subgradient methods that can operate over a time-varying topo

  61. Orestes P. Hastings, Edison Liang

    We use electromagnetic Particle-in-Cell codes to investigate the two-stream instability and Weibel instability when two beams of plasma collide head-on relativistically. We compare the dissipation of kinetic energies in the two cases. We also study the evolution of the resultant electron energy distribution function produced by such dissipation.

  62. Nadya Shirokova

    In the previous paper we constructed the local system of Khovanov complexes on the Vassiliev space of knots and extended it to the singular locus. In this paper we introduce the definition of the homology theory (local system) of finite type and prove the first finiteness result: the Khovanov local system restricted to the subcategory of knots of the crossin

  63. R. L. Oldershaw

    The gravitational Bohr radius (GBR) characterizes the size of a hypothetical ground state hydrogen atom wherein the binding interaction between its nucleus and its electronic structure is purely gravitational. The conventional calculation of the GBR, based on the standard Newtonian gravitational coupling constant, yields an astronomical size for the &#34;gra

  64. Deniz Gunduz, Elza Erkip, H. Vincent Poor

    Secure data compression in the presence of side information at both a legitimate receiver and an eavesdropper is explored. A noise-free, limited rate link between the source and the receiver, whose output can be perfectly observed by the eavesdropper, is assumed. As opposed to the wiretap channel model, in which secure communication can be established by exp

  65. Domenico D'Alessandro

    In this paper, we show how to use the analysis of the Lie algebra associated with a quantum mechanical system to study its dynamics and facilitate the design of controls. We give algorithms to decompose the dynamics and describe their application to the control of two coupled spin 1/2's.

  66. James D. Currie, Narad Rampersad

    Richomme asked the following question: what is the infimum of the real numbers $α$ > 2 such that there exists an infinite word that avoids $α$-powers but contains arbitrarily large squares beginning at every position? We resolve this question in the case of a binary alphabet by showing that the answer is $α$ = 7/3.

  67. Justin Sawon

    Let Y->P^n be a flat family of integral Gorenstein curves, such that the compactified relative Jacobian X=\bar{J}^d(Y/P^n) is a Lagrangian fibration. We prove that the degree of the discriminant locus Delta in P^n is at least 4n+2, and we prove that X is a Beauville-Mukai integrable system if the degree of Delta is greater than 4n+20.

  68. Ryan J. Foley, Alexei V. Filippenko, Saurabh W. Jha

    We present a complete sample of International Ultraviolet Explorer and Hubble Space Telescope ultraviolet (UV) spectra of Type Ia supernovae (SNe Ia) through 2004. We measure the equivalent width (EW) and blueshifted velocity of the minimum of the one strong UV feature, Fe II 3250. We also quantify the slope of the near-UV spectra using a new parameter, the

  69. H. R. Grigoryan, A. V. Radyushkin

    We propose an extension of the hard-wall AdS/QCD model by including the Chern-Simons term required to reproduce the chiral anomaly of QCD. In the framework of this holographic model, we study the vertex function F_{πγ^* γ^*}(Q_1^2,Q_2^2) which accumulates information about the coupling of the pion to two (in general virtual) photons. We calculate the slope o

  70. Goran Ostlin, Matthew Hayes, Daniel Kunth, J. Miguel Mas-Hesse

    We present reduced and calibrated high resolution Lyman-alpha (Lya) images for a sample of 6 local star forming galaxies. Targets were selected to represent a range in luminosity and metallicity and to include both known Lya emitters and non-emitters. Far ultraviolet imaging was carried out with the Solar Blind Channel of the ACS on HST in the F122M (Lya on-

  71. Matthew Hayes, Goran Ostlin, J. Miguel Mas-Hesse, Daniel Kunth

    [ABRIDGED] We are undertaking an imaging study of local star-forming galaxies in the Lyman-alpha (Lya) emission line using the Solar Blind Channel (SBC) of the ACS onboard the HST. Observations have been obtained in Lya and H-alpha (Ha) and 6 continuum filters between ~1500AA and the I-band. Previously (Hayes et al 2005) we demonstrated that the production o

  72. Daniel Babich, Elena Pierpaoli

    In this paper we analyze the biasing effect of point sources, either thermal Sunyaev-Zeldovich clusters or standard radio sources, on the estimated strength of the non-Gaussianity in the Cosmic Microwave Background (CMB). We show that the biggest contribution comes from the cross--correlation of the CMB with the matter density rather than from the poisson te

  73. Tsasa Lusala, Jȩdrzej Śniatycki, Jordan Watts

    We discuss properties of the regular part $S_{reg}$ of a subcartesian space $S$. We show that $S_{reg}$ is open and dense in $S$ and the restriction to $S_{reg}$ of the tangent bundle of $S$ is locally trivial.

  74. Brian Espey, Cian Crowley

    Although much is known about the nature of winds from hot stars and giants and supergiants with spectral types earlier than K, there is still much to be learned regarding the mass-loss process in cool, late-type stars. We will review the current state of research, with particular reference to observations and modelling of mass-loss from giant stars in symbio

  75. M. Junker, D. Dries, C. Welford, J. Hitchcock

    We measure the effect of a magnetic Feshbach resonance (FR) on the rate and light-induced frequency shift of a photoassociation resonance in ultracold $^7$Li. The photoassociation-induced loss rate coefficient, $K_p$, depends strongly on magnetic field, varying by more than a factor of 10$^4$ for fields near the FR. At sufficiently high laser intensities, $K

  76. Michael Kunzinger, Roman O. Popovych

    We prove that potential conservation laws have characteristics depending only on local variables if and only if they are induced by local conservation laws. Therefore, characteristics of pure potential conservation laws have to essentially depend on potential variables. This statement provides a significant generalization of results of the recent paper by Bl

  77. Francisco Vega Reyes, Jeffrey S. Urbach

    We describe an experimental and computational investigation of the ordered and disordered phases of a vibrating thin, dense granular layer composed of identical metal spheres. We compare the results from spheres with different amounts of inelasticity and show that inelasticity has a strong effect on the phase diagram. We also report the melting of an ordered

  78. G. J. McMullan, P. M. C. Rourke, M. R. Norman, A. D. Huxley

    Combining old and new de Haas-van Alphen (dHvA) and magnetoresistance data, we arrive at a detailed picture of the Fermi surface of the heavy fermion superconductor UPt3. Our work was partially motivated by a new proposal that two 5f valence electrons per formula unit in UPt3 are localized by correlation effects -- agreement with previous dHvA measurements o

  79. Michael Hermele, Ying Ran, Patrick A. Lee, Xiao-Gang Wen

    In recent work, we argued that a particular algebraic spin liquid (ASL) may be the ground state of the S = 1/2 kagome lattice Heisenberg antiferromagnet. This state, which lacks a spin gap, is appealing in light of recent experiments on herbertsmithite (ZnCu3(OH)6Cl2). Here, we study the properties of this ASL in more detail, using both the low-energy effect

  80. A. K. Monin, A. V. Zayakin

    We consider induced pair production in an external field at finite temperature. One-loop correction to the Green function of a meson is calculated semiclassically within the framework of saddle-point analysis of Schwinger proper time integrals. This correction appears to be exponentially small in terms of inverse temperature dependence. Low-temperature limit

  81. Jan O. Kleppe

    Let \sF be a coherent rank 2 sheaf on a scheme Y \subset \proj{n} of dimension at least two. In this paper we study the relationship between the functor which deforms a pair (\sF,\sigma), \sigma \in H^0(\sF), and the functor which deforms the corresponding pair (X,\xi) given as in the Serre correspondence. We prove that the scheme structure of e.g. the modul

  82. Muge Taskin

    The work of C. Bonnaf{é}, M. Geck, L. Iancu and T. Lam \cite{Geck-Lam} shows through two conjectures that $r$-domino tableaux have an important role in Kazhdan-Lusztig theory of type $B$ with unequal parameters. In this paper we provide plactic relations on signed permutations which determine whether given two signed permutations have the same insertion $r$-

  83. H. Kösters

    We point out an interesting occurrence of the sine kernel in connection with the shifted moments of the Riemann zeta function along the critical line. We discuss rigorous results in this direction for the shifted second moment and for the shifted fourth moment. Furthermore, we conjecture that the sine kernel also occurs in connection with the higher (even) s

  84. N. Bray-Ali, Z. Nussinov

    Systems with spin-orbit coupling do not conserve &#34;bare&#34; spin current $\bf{j}$. A recent proposal for a conserved spin current $\bf{J}$ [J. Shi {\it et.al} Phys. Rev. Lett. {\bf 96}, 076604 (2006)] does not flow persistently in equilibrium. We suggest another conserved spin current $\bar{\bf{J}}$ that may flow persistently in equilibrium. We give two

  85. David Soloveichik

    The behavior of some stochastic chemical reaction networks is largely unaffected by slight inaccuracies in reaction rates. We formalize the robustness of state probabilities to reaction rate deviations, and describe a formal connection between robustness and efficiency of simulation. Without robustness guarantees, stochastic simulation seems to require compu

  86. G. Vannoni, S. Gabici, F. A. Aharonian

    Radio, X-ray, and gamma-ray observations provide us with strong evidence of particle acceleration to multi-TeV energies in various astrophysical sources. Diffusive shock acceleration is one of the most successful models explaining the presence of such high-energy particles. We discuss the impact of inverse Compton losses on the shock acceleration of electron

  87. Luca Grisa

    In models of modified gravity, extra degrees of freedom usually appear. They must be removed from the spectrum because they may indicate the presence of instabilities and because otherwise the model might not agree with observation. In the present letter, we will discuss a model that modifies General Relativity through the addition of a Lorentz-violating pot

  88. CLEO Collaboration, S. B. Athar

    Using e^+e^- -> D_s^*+ D_s^- data collected near the peak D_s production energy, E_cm=4170 MeV, with the CLEO-c detector, we present the first observation of the decay D_s^+ -> proton anti-neutron. We measure a branching fraction B(D_s^+ -> p anti-n = (1.30 +- 0.36 +0.12 -0.16) x 10^-3. This is the first observation of a charmed meson decaying into a baryon-

  89. Gianfranco Casnati, Roberto Notari

    Let $k$ be an algebraically closed field and let $\Hilb_{d}^{G}(\p{N})$ be the open locus of the Hilbert scheme $\Hilb_{d}(\p{N})$ corresponding to Gorenstein subschemes. We prove that $\Hilb_{d}^{G}(\p{N})$ is irreducible for $d\le9$, we characterize geometrically its singularities for $d\le 8$ and we give some results about them when $d=9$ which give some

  90. Mariusz Kwiatkowski, Mark Pankov

    We characterize the collinearity (adjacency) relation of half-spin Grassmann spaces in terms of the relation to be opposite in the corresponding collinearity graphs. Also we show that this characterization does not hold for dual polar spaces.

  91. Tal Philosof, Ram Zamir

    For general memoryless systems, the typical information theoretic solution - when exists - has a &#34;single-letter&#34; form. This reflects the fact that optimum performance can be approached by a random code (or a random binning scheme), generated using independent and identically distributed copies of some single-letter distribution. Is that the form of t

  92. A. C. V. V. de Siqueira

    In a previous paper we built a modified Hamiltonian formalism to make possible explicit maps among manifolds. In this paper the modified formalism was generalized. As an application, we have built maps among spaces associated to spinors, as well as maps among Kaehler spaces.

  93. J. -H. Kim, S. -H. Lee, S. I. Park, M. Kenzelmann

    By combining neutron four-circle diffraction and polarized neutron diffraction techniques we have determined the complex spin structures of a multiferroic, YMn2O5, that exhibits two ferroelectric phases at low temperatures. The obtained magnetic structure has spiral components in both the low temperature ferroelectric phases that are magnetically commensurat

  94. Peter Sin, John G. Thompson

    We examine an elliptic curve constructed in an earlier paper from a certain representation of $\SL(2,\Z)$ on the space of convergent Dirichlet series. The curve is observed to be a modular curve for $Γ^1(15)$ and a certain orbit of modular functions is thereby associated with the Riemann zeta function. Explicit descriptions are given of these functions and o

  95. Zhao-Qing Feng, Gen-Ming Jin, Jun-Qing Li, Werner Scheid

    Within the framework of a dinuclear system (DNS) model, the evaporation-residue excitation functions and the quasi-fission mass yields in the $^{48}$Ca induced fusion reactions are investigated systematically and compared with available experimental data. Maximal production cross sections of superheavy nuclei based on stable actinide targets are obtained. Is

  96. Long Dang, Massimo Boninsegni, Lode Pollet

    The ground state of hard-core bosons on the square lattice with nearest and next-nearest neighbor repulsion is studied by Quantum Monte Carlo simulations. A supersolid phase with vacancy condensation and &#39;star&#39; diagonal ordering is found for filling less than a quarter. At fillings above one quarter, a supersolid phase exists between the star and the

  97. Anatole Castella

    Lawrence-Krammer representations (LK-representations for short) are linear representations of Artin-Tits groups of small type, which are of importance since they are known to be faithful when the type is spherical, or more generally when restricted to the monoid. If the construction is essentially unique for a given small and spherical type, the structure of

  98. Byung Hee An, Ki Hyoung Ko

    We propose a family of new representations of the braid groups on surfaces that extend linear representations of the braid groups on a disc such as the Burau representation and the Lawrence-Krammer-Bigelow representation.

  99. Alexander I. Kopylov, Nikolay A. Tikhonov, Sergey Fabrika, Igor Drozdovsky

    We present the first resolved-star photometry of VV124 (UGC4879) and find that this is the most isolated dwarf galaxy in the periphery of the Local Group. Based on imaging and spectroscopic follow up observations with the 6m BTA telescope, we resolve VV124 into 1560 stars down to the limiting magnitude levels of V~25.6 and I~23.9. The young blue stellar popu

  100. Clement Vidal

    This philosophical paper explores the relation between modern scientific simulations and the future of the universe. We argue that a simulation of an entire universe will result from future scientific activity. This requires us to tackle the challenge of simulating open-ended evolution at all levels in a single simulation. The simulation should encompass not