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January 2008 arXiv papers

Showing 1–100 of 4,749 papers

  1. P. A. Ritto

    It is feasible to obtain any basic rule of the already known Quantum Mechanics applying the Hamilton-Jacobi formalism to an interacting system of 2 fermionic degrees of freedom. The interaction between those fermionic variables unveils also a primitive spin and zitterbewegung.

  2. Richard P. Kent

    Let H and K be subgroups of a free group of ranks h and k \geq h. We prove the following strong form of Burns' inequality: rank(H \cap K) - 1 \leq 2(h-1)(k-1) - (h-1)(rank(H \vee K) -1). A corollary of this, also obtained by L. Louder and D. B. McReynolds, has been used by M. Culler and P. Shalen to obtain information regarding the volumes of hyperbolic

  3. F. Darabi

    We study a gravitational model in which scale transformations play the key role in obtaining dynamical $G$ and $Λ$. We take a scale non-invariant gravitational action with a cosmological constant and a gravitational coupling constant. Then, by a scale transformation, through a dilaton field, we obtain a new action containing cosmological and gravitational co

  4. P. Huang, N. Kersting, H. H. Yang

    We present an improved method of reconstructing New Physics (NP) masses from invariant mass endpoints. While the traditional method focuses on a single NP decay, our method considers the decays of two or more NP particles ($ABC...$) in a grander decay chain: $ anything \to ABC... \to ... \to jets + leptons$. Though the center-of-mass energy $E_{CM}$ of `anyt

  5. Diego Bombardelli, Davide Fioravanti, Marco Rossi

    Anomalous dimension and higher conserved charges in the $sl(2)$ sector of ${\cal N}=4$ SYM for generic spin $s$ and twist $L$ are described by using a novel kind of non-linear integral equation (NLIE). The latter can be derived under typical situations of the SYM sectors, i.e. when the scattering need not depend on the difference of the rapidities and these,

  6. Michelangelo L. Mangano

    I discuss the basic elements of the process that will lead to the discovery of possible new phenomena at the LHC. We review the status of the tools available to model the Standard Model backgrounds, and the role that such tools can play in the discovery phase, and in the exploration of the features and parameters of such new phenomena.

  7. Emanuele Berti, Marta Volonteri

    Using recent results from numerical relativity simulations of black hole mergers, we revisit previous studies of cosmological black hole spin evolution. We show that mergers are very unlikely to yield large spins, unless alignment of the spins of the merging holes with the orbital angular momentum is very efficient. We analyze the spin evolution in three spe

  8. Carles Bretó, Daihai He, Edward L. Ionides, Aaron A. King

    The purpose of time series analysis via mechanistic models is to reconcile the known or hypothesized structure of a dynamical system with observations collected over time. We develop a framework for constructing nonlinear mechanistic models and carrying out inference. Our framework permits the consideration of implicit dynamic models, meaning statistical mod

  9. Ogul Arslan

    A family of LDPC codes, called LU(3,q) codes, has been constructed from q-regular bipartite graphs. Recently, P. Sin and Q. Xiang determined the dimensions of these codes in the case that q is a power of an odd prime. They also obtained a lower bound for the dimension of an LU(3,q) code when q is a power of 2. In this paper we prove that this lower bound is

  10. M. Cerchez, R. Jung, J. Osterholz, T. Toncian

    We report on the first absorption experiments of sub-10 fs high-contrast Ti:Sa laser pulses incident on solid targets. The very good contrast of the laser pulse assures the formation of a very small pre-plasma and the pulse interacts with the matter close to solid density. Experimental results indicate that p-polarized laser pulses are absorbed up to 80 perc

  11. Chris Quigg

    I recall the place of neutrinos in the electroweak theory and summarize what we know about neutrino mass and flavor change. I next review the essential characteristics expected for relic neutrinos and survey what we can say about the neutrino contribution to the dark matter of the Universe. Then I discuss the standard-model interactions of ultrahigh-energy n

  12. Edward G. Effros

    Some of the important inequalities associated with quantum entropy are immediate algebraic consequences of the Hansen-Pedersen-Jensen inequality. A general argument is given in terms of the matrix perspective of an operator convex function. A matrix analogue of Maréchal's extended perspectives provides additional inequalities, including a $p+q\leq 1$ res

  13. Sanghamitra Deb, David M. Goldberg, Vede J. Ramdass

    We present Particle-Based Lensing (PBL), a new technique for gravitational lensing mass reconstructions of galaxy clusters. Traditionally, most methods have employed either a finite inversion or gridding to turn observational lensed galaxy ellipticities into an estimate of the surface mass density of a galaxy cluster. We approach the problem from a different

  14. Elena D'Onghia, George Lake

    We consider the possibility that the Magellanic Clouds were the largest members of a group of dwarf galaxies that entered the Milky Way (MW) halo at late times. Seven of the eleven brightest satellites of the MW may have been part of this system. The proximity of some dwarfs to the plane of the orbit of the Large Magellanic Cloud (LMC) has been used to argue

  15. M. Casals, S. R. Dolan, P. Kanti, E. Winstanley

    We study in detail the scalar-field Hawking radiation emitted into the bulk by a higher-dimensional, rotating black hole. We numerically compute the angular eigenvalues, and solve the radial equation of motion in order to find transmission factors. The latter are found to be enhanced by the angular momentum of the black hole, and to exhibit the well-known ef

  16. Ulrich Mosel

    In this talk I give a short review of theoretical results on the properties of hadrons in cold, equilibrium nuclear matter. I then discuss the observable consequences of any changes of these properties inside the medium in actual experiments. I demonstrate that any experimental verification of in-medium effects requires a state-of-the-art treatment of the re

  17. S. Marchesini, S. Boutet, A. E. Sakdinawat, M. J. Bogan

    Advances in the development of free-electron lasers offer the realistic prospect of high-resolution imaging to study the nanoworld on the time-scale of atomic motions. We identify X-ray Fourier Transform holography, (FTH) as a promising but, so far, inefficient scheme to do this. We show that a uniformly redundant array (URA) placed next to the sample, multi

  18. N. Brodskiy, J. Dydak, B. Labuz, A. Mitra

    We define Peano covering maps and prove basic properties analogous to classical covers. Their domain is always locally path-connected but the range may be an arbitrary topological space. One of characterizations of Peano covering maps is via the uniqueness of homotopy lifting property for all locally path-connected spaces. Regular Peano covering maps over pa

  19. Andrey O. Matveev

    We establish monotone bijections between subsequences of the Farey sequences and the halfsequences of Farey subsequences associated with elements of the Boolean lattices.

  20. Meng-Chwan Tan, Junya Yagi

    We explore the nonperturbative aspects of the chiral algebras of N = (0,2) sigma models, which perturbatively are intimately related to the theory of chiral differential operators (CDOs). The grading by charge and scaling dimension is anomalous if the first Chern class of the target space is nonzero. This has some nontrivial consequences for the chiral algeb

  21. Wing Yan Yip, Sofia Olhede, David Stephens

    This paper presents hedging strategies for European and exotic options in a Levy market. By applying Taylor's Theorem, dynamic hedging portfolios are con- structed under different market assumptions, such as the existence of power jump assets or moment swaps. In the case of European options or baskets of European options, static hedging is implemented. I

  22. Liang Xiao

    Let $k$ be a complete discretely valued field of equal characteristic $p > 0$ with possibly imperfect residue field and let $G_k$ be its Galois group. We prove that the conductors computed by the arithmetic ramification filtrations on $G_k$ coincide with the differential Artin conductors and Swan conductors of Galois representations of $G_k$. As a consequenc

  23. Y. V. Fyodorov, Y. Wei, M. R. Zirnbauer

    We revisit a long standing issue in the theory of disordered electron systems and their effective description by a non-linear sigma model: the hyperbolic Hubbard-Stratonovich (HS) transformation in the bosonic sector. For time-reversal invariant systems without spin this sector is known to have a non-compact orthogonal symmetry O(p,q). There exists an old pr

  24. John Weir

    We prove that the eigenvalues of a certain highly non-self-adjoint operator that arises in fluid mechanics correspond, up to scaling by a positive constant, to those of a self-adjoint operator with compact resolvent; hence there are infinitely many real eigenvalues which accumulate only at $\pm \infty$. We use this result to determine the asymptotic distribu

  25. F. Galliano, S. C. Madden, A. G. G. M. Tielens, E. Peeters

    We present the results of a systematic study of mid-IR spectra of Galactic regions, Magellanic HII regions, and galaxies of various types (dwarf, spiral, starburst), observed by the satellites ISO and Spitzer. We study the relative variations of the 6.2, 7.7, 8.6 and 11.3 micron features inside spatially resolved objects (such as M82, M51, 30 Doradus, M17 an

  26. F. A. Dolan, H. Osborn

    The results of Romelsberger for a N=1 superconformal index counting protected operators, satisfying a BPS condition and which cannot be combined to form long multiplets, are analysed further. The index is expressible in terms of single particle superconformal characters for N=1 scalar and vector multiplets. For SQCD, involving SU(N_c) gauge groups and approp

  27. E. G. Ferreiro, F. Fleuret, A. Rakotozafindrabe

    We present a new approach to estimate the effect of the gluon shadowing in nucleus+nucleus collisions and its consequences on the J/psi production yield. Using kinematical information available from the measured J/psi production in proton+proton collisions at \sqrt s = 200 GeV, we build a Glauber Monte Carlo code which takes into account shadowing in two alt

  28. E. Passos, A. Yu. Petrov

    We demonstrate generation of the two-dimensional Chern-Simons-like Lorentz-breaking action via an appropriate Lorentz-breaking coupling of scalar and spinor fields at zero as well as at the finite temperature and via the noncommutative fields method and study the dispersion relations corresponding to this action.

  29. Szymon Gladysz, Julian C. Christou, L. William Bradford, Lewis C. Roberts

    We have investigated the temporal variability and statistics of the "instantaneous" Strehl ratio. The observations were carried out with the 3.63-m AEOS telescope equipped with a high-order adaptive optics system. In this paper Strehl ratio is defined as the peak intensity of a single short exposure. We have also studied the behaviour of the phase va

  30. Sabino Matarrese, Licia Verde

    It has long been known how to analytically relate the clustering properties of the collapsed structures (halos) to those of the underlying dark matter distribution for Gaussian initial conditions. Here we apply the same approach to physically motivated non-Gaussian models. The techniques we use were developed in the 1980s to deal with the clustering of peaks

  31. M. Schechter, P. C. E. Stamp

    The form of the low-temperature interactions between defects in neutral glasses is reconsidered. We analyse the case where the defects can be modelled either as simple 2-level tunneling systems, or tunneling rotational impurities. The coupling to strain fields is determined up to 2nd order in the displacement field. It is shown that the linear coupling gener

  32. Sergiu I. Vacaru

    We propose an unified approach to loop quantum gravity and Fedosov quantization of gravity following the geometry of double spacetime fibrations and their quantum deformations. There are considered pseudo-Riemannian manifolds enabled with 1) a nonholonomic 2+2 distribution defining a nonlinear connection (N-connection) structure and 2) an Arnowitt-Deser-Misn

  33. Abhijit Champanerkar, Ilya Kofman

    It is conjectured that the Khovanov homology of a knot is invariant under mutation. In this paper, we review the spanning tree complex for Khovanov homology, and reformulate this conjecture using a matroid obtained from the Tait graph (checkerboard graph) G of a knot diagram K. The spanning trees of G provide a filtration and a spectral sequence that converg

  34. Luca De Sanctis, Francesco Guerra

    We study the mean field dilute model of a ferromagnet. We find and prove an expression for the free energy density at high temperature, and at temperature zero. We find the critical line of the model, separating the phase with zero magnetization from the phase with symmetry breaking. We also compute exactly the entropy at temperature zero, which is strictly

  35. Plamen Iliev

    We construct a commutative algebra A_z, generated by d algebraically independent q-difference operators acting on variables z_1, z_2,..., z_d, which is diagonalized by the multivariable Askey-Wilson polynomials P_n(z) considered by Gasper and Rahman [6]. Iterating Sears' transformation formula, we show that the polynomials P_n(z) possess a certain dualit

  36. Ulrich Nierste, Stephanie Trine, Susanne Westhoff

    We show that the decay mode B -> D tau nu is competitive with and complementary to B -> tau nu in the search for charged-Higgs effects. Updating the relevant form factors, we find that the differential distribution in the decay chain B -> D nu tau[-> pi nu] excellently discriminates between Standard-Model and charged-Higgs contributions. By measuring the D a

  37. Scipio Cuccagna

    We consider radial solutions of a mass supercritical monic NLS and we prove the existence of a set, which looks like a hypersurface, in the space of finite energy functions, invariant for the flow and formed by solutions which converge to ground states.

  38. C. Di Franco, M. Paternostro, D. I. Tsomokos, S. F. Huelga

    We propose a protocol for perfect quantum state transfer that is resilient to a broad class of realistic experimental imperfections, including noise sources that could be modelled either as independent Markovian baths or as certain forms of spatially correlated environments. We highlight interesting connections between the fidelity of state transfer and quan

  39. M. Albaladejo, J. A. Oller

    We have performed a coupled channel study of the meson-meson S-waves involving isospins (I) 0, 1/2 and 3/2 up to 2 GeV. For the first time the channels ππ, K\bar{K}, ηη, σσ, ηη', η'η', ρρ, ωω, ωϕ$, ϕϕ, a_1πand π^*πare considered. All the resonances with masses below 2 GeV for I=0 and 1/2 are generated by the approach. We identify the f_0(1710) an

  40. Matthieu Josuat-Vergès

    The pattern-avoiding fillings of Young diagrams we study arose from Postnikov's work on positive Grassman cells. They are called Le-diagrams, and are in bijection with decorated permutations. Other closely-related diagrams are interpreted as acyclic orientations of some bipartite graphs. The definition of the diagrams is the same but the avoided patterns

  41. Marco Astorino, Fabrizio Canfora, Cristian Martinez, Luca Parisi

    A Kallen-Lehman approach to 3D Ising model is analyzed numerically both at low and high temperature. It is shown that, even assuming a minimal duality breaking, one can fix three parameters of the model to get a very good agreement with the MonteCarlo results at high temperatures. With the same parameters the agreement is satisfactory both at low and near cr

  42. George Koutsoumbas, Eleftherios Papantonopoulos, George Siopsis

    We study the perturbative behaviour of charged topological-AdS black holes. We calculate both analytically and numerically the quasi-normal modes of the electromagnetic and gravitational perturbations. Keeping the charge-to-mass ratio constant, we show that there is a second-order phase transition at a critical temperature at which the mass of the black hole

  43. Mehrdad Adibzadeh, P. Q. Hung

    We present the results of relic density calculations for cold dark matter candidates coming from a model of dark energy and dark matter, which is described by an asymptotically free gauge group SU(2)_Z (QZD) with a coupling constant alpha_Z ~ 1 at very low scale of Lambda_Z ~ 10^(-3) eV while alpha_Z ~ weak coupling at high energies. The dark matter candidat

  44. Francis Bonahon

    We adapt some of the methods of quantum Teichmüller theory to construct a family of representations of the pure braid group of the sphere.

  45. Dariusz Miskowiec, Peter Braun-Munzinger

    A Nd:YAG laser was used to simulate charged particle tracks at known positions in the CERES Time Projection Chamber at the CERN SPS. The system was primarily developed to study the response of the readout electronics and to calibrate the electron drift velocity. Further applications were the determination of the gating grid transparency, the chamber position

  46. O. Steiner, R. Rezaei, W. Schaffenberger, S. Wedemeyer-Böhm

    Observations with the Hinode space observatory led to the discovery of predominantly horizontal magnetic fields in the photosphere of the quiet internetwork region. Here we investigate realistic numerical simulations of the surface layers of the Sun with respect to horizontal magnetic fields and compute the corresponding polarimetric response in the Fe I 630

  47. S. Balestra, S. Cecchini, M. Cozzi, M. Errico

    The SLIM experiment was a large array of nuclear track detectors located at the Chacaltaya high altitude Laboratory (5230 m a.s.l.). The detector was in particular sensitive to Intermediate Mass Magnetic Monopoles, with masses 10^5 < M <10^{12} GeV. From the analysis of the full detector exposed for more than 4 years a flux upper limit of 1.3 x 10^{-15} cm^{

  48. I. L. Buchbinder, I. B. Samsonov

    We consider the formulation and quantization of the N=3 superparticle model, both with and without central charge. Without the central charge the action possesses U(3) invariance and therefore is naturally quantized in the N=3 harmonic superspace. The quantization reproduces the N=3 supergauge strength multiplets, described by analytic N=3 superfields and a

  49. Jason Glyndwr Ulery

    We present results of 2-particle jet-like correlations, with high pT h+- triggers and identified pi+-, p, and pbar triggers in d+Au and Au+Au collisions and 3-particle jet-like azimuthal correlations in pp, d+Au, and Au+Au collisions at sqrt(s)=200 GeV. These results use data from the STAR TPC during RHIC runs II, III, and IV. Modifications in 2-particle cor

  50. Mark Dykman, Ira B. Schwartz, Alexandra S. Landsman

    We investigate stochastic extinction in an epidemic model and the impact of random vaccinations in large populations. We show that, in the absence of vaccinations, the effective entropic barrier for extinction displays scaling with the distance to the bifurcation point, with an unusual critical exponent. Even a comparatively weak Poisson-distributed vaccinat

  51. Alex Kamenev, Baruch Meerson

    We develop a theory of first passage processes in stochastic non-equilibrium systems of birth-death type using two closely related epidemiological models as examples. Our method employs the probability generating function technique in conjunction with the eikonal approximation. In this way the problem is reduced to finding the optimal path to extinction: a h

  52. Thomas Chambrion, Paolo Mason, Mario Sigalotti, Ugo Boscain

    We prove approximate controllability of the bilinear Schrödinger equation in the case in which the uncontrolled Hamiltonian has discrete non-resonant spectrum. The results that are obtained apply both to bounded or unbounded domains and to the case in which the control potential is bounded or unbounded. The method relies on finite-dimensional techniques appl

  53. Maxim V. Barkov, Serguei S. Komissarov

    We present numerical simulations of cold, axisymmetric, magnetically driven relativistic outflows. The outflows are initially sub-Alfvénic and Poynting flux-dominated, with total--to--rest-mass energy flux ratio up to $μ\sim 620$. To study the magnetic acceleration of jets we simulate flows confined within a funnel with rigid wall of prescribed shape, which

  54. Stefan Mashkevich, Stéphane Ouvry

    At 6th order in perturbation theory, the random magnetic impurity problem at second order in impurity density narrows down to the evaluation of a single Feynman diagram with maximal impurity line crossing. This diagram can be rewritten as a sum of ordinary integrals and nested double integrals of products of the modified Bessel functions $K_ν$ and $I_ν$, wit

  55. Antonio Mura, Gianni Pagnini

    In this paper we study a parametric class of stochastic processes to model both fast and slow anomalous diffusion. This class, called generalized grey Brownian motion (ggBm), is made up off self-similar with stationary increments processes (H-sssi) and depends on two real parameters alpha in (0,2) and beta in (0,1]. It includes fractional Brownian motion whe

  56. Sergey Dobrokhotov, Michel Rouleux

    We extend to the semi-classical setting the Maupertuis-Jacobi correspondance for a pair of hamiltonians $(H(x,hD_x), {\cal H}(x,hD_x)$. If ${\cal H}(p,x)$ is completely integrable, or has merely has invariant diohantine torus $Λ$ in energy surface ${\cal E}$, then we can construct a family of quasi-modes for $H(x,hD_x)$ at the corresponding energy $E$. This

  57. G. A. Edgar

    From the simplest point of view, transseries are a new kind of expansion for real-valued functions. But transseries constitute much more than that--they have a very rich (algebraic, combinatorial, analytic) structure. The set of transseries is a large ordered field, extending the real number field, and endowed with additional operations such as exponential,

  58. Joachim Kupsch

    It is the aim of this paper to summarize results about the construction of amplitudes, which rigorously satisfy Mandelstam analyticity, crossing symmetry, and (at least partly) the constraints imposed by elastic and inelastic unitarity. The results are discussed under particular emphasis of a strong increase of the absorptive part of the forward amplitude an

  59. H. Andreka, J. X. Madarasz, I. Nemeti, G. Szekely

    A part of relativistic dynamics (or mechanics) is axiomatized by simple and purely geometrical axioms formulated within first-order logic. A geometrical proof of the formula connecting relativistic and rest masses of bodies is presented, leading up to a geometric explanation of Einstein&#39;s famous $E=mc^2$. The connection of our geometrical axioms and the

  60. K. A. Bugaev, V. K. Petrov, G. M. Zinovjev

    The influence of medium dependent finite width of the QGP bags on their equation of state is analyzed on a basis of an exactly solvable model with the general mass-volume spectrum of these bags. It is arguing that the consistent statistical description of the QGP bags is achieved for the width proportional to the square root of their volume. The model allows

  61. Tatiana Shulman, Victor Shulman

    We look for an effective description of the algebra D_{Lie}(X,B) of operators on a bimodule X over an algebra B, generated by inner derivations. It is shown that in some important examples D_{Lie}(X,B) consists of all elementary operators x\to \sum_i a_ixb_i satisfying the conditions $\sum_i a_ib_i = \sum_i b_ia_i = 0. The Banach algebraic versions of these

  62. P. Henseler, B. Shapiro

    The phenomenon of random intensity patterns, for waves propagating in the presence of disorder, is well known in optics and in mesoscopic physics. We study this phenomenon for cold atomic gases expanding, by a diffusion process, in a weak random potential. We show that the density-density correlation function of the expanding gas is strongly affected by diso

  63. Sameer M. Ikhdair, Ramazan Sever

    We present the exact solution of the Klein-Gordon equation in D-dimensions in the presence of the noncentral equal scalar and vector pseudoharmonic potential plus the new ring-shaped potential using the Nikiforov-Uvarov method. We obtain the exact bound-state energy levels and the corresponding eigen functions for a spin-zero particles. We also find that the

  64. N. T. Faber, C. M. Boily, S. Portegies Zwart

    We implement an efficient method to quantify time-dependent orbital complexity in gravitational $N$-body simulations. The technique, which we name DWaTIM, is based on a discrete wavelet transform of velocity orbital time series. The wavelet power-spectrum is used to measure trends in complexity continuously in time. We apply the method to the test cases N=3

  65. S. Ponnusamy, A. Vasudevarao, M. Vuorinen

    In this paper we determine the region of variability for spirallike funcions with respect to a boundary point. In the final section we graphically illustrate the region of variability for several sets of parameters.

  66. A. M. Gilbertson, M. Fearn, J. H. Jefferson, B. N. Murdin

    The spin-orbit (SO) coupling parameters for lowest conduction subband due to structural (SIA) and bulk (BIA) inversion asymmetry are calculated for a range of carrier densities in [001]-grown delta-doped n-type InSb/In1-xAlxSb asymmetric quantum wells using the established 8 band k.p formalism [PRB 59,8 R5312 (1999)]. We present calculations for conditions o

  67. Leslie V. Woodcock

    Recent values for virial coefficients up to B12, when expressed in powers of density relative to maximum close packing,lead to a closed equation-of-state for the equilibrium fluid. The series obtained converges for all densities;it becomes negative and diverges to a negative pole at maximum packing. MD data for 64000 spheres in the metastable region shows th

  68. Gilbert Levitt

    Given an automorphism of a free group $F_n$, we consider the following invariants: $e$ is the number of exponential strata (an upper bound for the number of different exponential growth rates of conjugacy classes); $d$ is the maximal degree of polynomial growth of conjugacy classes; $R$ is the rank of the fixed subgroup. We determine precisely which triples

  69. P. A. Thomas, M. J. Drinkwater, E. Evstigneeva

    This paper investigates the possibility that UCD galaxies in the Fornax cluster are formed by the threshing of nucleated, early-type dwarf galaxies (hereafter dwarf galaxies). Similar to the results of Cote et al. (2006) for the Virgo cluster, we show that the Fornax Cluster observations are consistent with a single population in which all dwarfs are nucleat

  70. Vitaly Bychkov, Mikhail Modestov, Mattias Marklund

    The problem of the Darrieus-Landau instability at a discontinuous deflagration front in a compressible flow is solved. Numerous previous attempts to solve this problem suffered from the deficit of boundary conditions. Here, the required additional boundary condition is derived rigorously taking into account the internal structure of the front. The derived co

  71. Alessandro Fiasconaro, Werner Ebeling, Ewa Gudowska-Nowak

    We give an overview over recent studies on the model of Active Brownian Motion (ABM) coupled to reservoirs providing free energy which may be converted into kinetic energy of motion. First, we present an introduction to a general concept of active Brownian particles which are capable to take up energy from the source and transform part of it in order to perf

  72. Adam J. Rothman, Peter J. Bickel, Elizaveta Levina, Ji Zhu

    The paper proposes a method for constructing a sparse estimator for the inverse covariance (concentration) matrix in high-dimensional settings. The estimator uses a penalized normal likelihood approach and forces sparsity by using a lasso-type penalty. We establish a rate of convergence in the Frobenius norm as both data dimension $p$ and sample size $n$ are

  73. X. L. Lei

    Effects of resonant acoustic phonon scattering on magnetoresistivity are examined in two-dimensional electron systems at low temperatures by using a balance-equation magnetotransport scheme direct controlled by the current. The experimentally observed resonances in linear resistivity are shown to result from the conventional bulk phonon modes in a GaAs-based

  74. Michael Joswig, Katja Kulas

    A polytrope is a tropical polytope which at the same time is convex in the ordinary sense. A $d$-dimensional polytrope turns out to be a tropical simplex, that is, it is the tropical convex hull of $d+1$ points. This statement is equivalent to the known fact that the Segre product of two full polynomial rings (over some field $K$) has the Gorenstein property

  75. Joseph Geraci

    We present a simple construction that maps quantum circuits to graphs and vice-versa. Inspired by the results of D.A. Lidar linking the Ising partition function with quadratically signed weight enumerators (QWGTs), we also present a BQP-complete problem for the additive approximation of a function over hypergraphs related to the generating function of Euleri

  76. Kelli Talaska

    For a planar directed graph G, Postnikov&#39;s boundary measurement map sends positive weight functions on the edges of G onto the appropriate totally nonnegative Grassmann cell. We establish an explicit formula for Postnikov&#39;s map by expressing each Pluecker coordinate as a ratio of two combinatorially defined polynomials in the edge weights, with posit

  77. Michael R. Peterson, Th. Jolicoeur, S. Das Sarma

    The fractional quantum Hall effect (FQHE) in the second orbital Landau level at filling factor 5/2 remains enigmatic and motivates our work. We consider the effect of the quasi-2D nature of the experimental FQH system on a number of FQH states (fillings 1/3, 1/5, 1/2) in the lowest, second, and third Landau levels (LLL, SLL, TLL,) by calculating the overlap,

  78. De-Min Li, Bing Ma

    With the assumption that the $X(1835)$ and $η(1760)$ recently observed by the BES Collaboration are the $3\,^1S_0$ meson states, the strong decays of these two states are investigated in the $^3P_0$ decay model. We find that the predicted total widths of the $X(1835)$ and $η(1760)$ can be reasonably reproduced with the $X(18350)-η(1760)$ mixing angle lying o

  79. Alexander Bolonkin

    Author suggests and researches a new revolutionary method for changing the climates of entire countries or portions thereof, obtaining huge amounts of cheap water and energy from the atmosphere. In this paper is presented the idea of cheap artificial inflatable mountains, which may cardinally change the climate of a large region or country. Additional benefi

  80. Shenghui Su, Shuwang Lv

    This paper gives the definitions of an anomalous super-increasing sequence and an anomalous subset sum separately, proves the two properties of an anomalous super-increasing sequence, and proposes the REESSE2+ public-key encryption scheme which includes the three algorithms for key generation, encryption and decryption. The paper discusses the necessity and

  81. X. W. C. Faber

    For a projective variety X defined over a field K, there is a special class of self-morphisms of X called algebraic dynamical systems. In this paper we take K to be the function field of a smooth curve and prove that at each place of K, subvarieties of X of dynamically small height are equidistributed on the associated Berkovich analytic space. We carefully

  82. David Broadhurst

    A proof is found for the elliptic integral evaluation of the Bessel moment $$M:=\int_0^\infty t I_0^2(t)K_0^2(t)K_0(2t) {\rm d}t ={1/12} {\bf K}(\sin(π/12)){\bf K}(\cos(π/12)) =\frac{Γ^6(\frac13)}{64π^22^{2/3}}$$ resulting from an angular average of a 2-loop 4-point massive Feynman diagram, with one internal mass doubled. This evaluation follows from contour

  83. C. Scott Wylie, Cheol-Min Ghim, David A. Kessler, Herbert Levine

    A mutator is an allele that increases the mutation rate throughout the genome by disrupting some aspect of DNA replication or repair. Mutators that increase the mutation rate by the order of 100 fold have been observed to spontaneously emerge and achieve high frequencies in natural populations and in long-term laboratory evolution experiments with \textit{E.

  84. Murray Gerstenhaber, Anthony Giaquinto

    We introduce the notion of the \textit{principal element} of a Frobenius Lie algebra $\f$. The principal element corresponds to a choice of $F\in \f^*$ such that $F[-,-]$ non-degenerate. In many natural instances, the principal element is shown to be semisimple, and when associated to $\sl_n$, its eigenvalues are integers and are independent of $F$. For cert

  85. F. Nitti

    I review recent work toward constructing, via five-dimensional holographic duals, four-dimensional theories in which spin-2 states (gravitons) are emergent. The basic idea is to extend to gravity model-building the applications of holographic duality to phenomenology construction.

  86. L. Xiao, E. Fürst, W. Reich, J. L. Han

    (Abridged) S147 is a large faint shell-type supernova remnant (SNR). Its remarkable spectral break at cm-wavelengths is an important physical property to characterize the SNR evolution. However, the spectral break is based on radio observations with limited precision. We made new radio continuum and polarization observations of S147 at 11cm and at 6cm with t

  87. Yi Qi, T. Brintlinger, John Cumings

    Recently, significant interest has emerged in fabricated systems that mimic the behavior of geometrically-frustrated materials. We present the full realization of such an artificial spin ice system on a two-dimensional kagome lattice and demonstrate rigid adherence to the local ice rule by directly counting individual pseudo-spins. The resulting spin configu

  88. Guido Altarelli, Richard D. Ball, Stefano Forte

    We extend our previous results on small-x resummation in the pure Yang--Mills theory to full QCD with nf quark flavours, with a resummed two-by-two matrix of resummed quark and gluon splitting functions. We also construct the corresponding deep-inelastic coefficient functions, and show how these can be combined with parton densities to give fully resummed de

  89. Martin Argerami, Pedro Massey

    Let M be a II_1 factor, A a masa in M and E the unique conditional expectation on A. Under some technical assumptions on the inclusion of A in M, which hold true for any semiregular masa of a separable factor, we show that for every discrete a in the positive part of the unit ball of A it is possible to find a projection p in M such that E(p)=a$. We also sho

  90. Terence Chan, Alex Grant

    One of the main theoretical motivations for the emerging area of network coding is the achievability of the max-flow/min-cut rate for single source multicast. This can exceed the rate achievable with routing alone, and is achievable with linear network codes. The multi-source problem is more complicated. Computation of its capacity region is equivalent to de

  91. Ryo Kanada, Fumiko Takagi, Macoto Kikuchi

    How molecular motors like Kinesin regulates the affinity to the rail protein in the process of ATP hydrolysis remains to be uncovered. To understand the regulation mechanism, we investigate the structural fluctuation of KIF1A in different nucleotide states that are realized in the ATP hydrolysis process by molecular dynamics simulations of Go-like model. We

  92. Ognyan Kounchev, Hermann Render

    A moment problem is presented for a class of signed measures which are termed pseudo-positive. Our main result says that for every pseudo-positive definite functional (subject to some reasonable restrictions) there exists a representing pseudo-positive measure. The second main result is a characterization of determinacy in the class of equivalent pseudo-posi

  93. M. Adda-Bedia, E. Katzav, D. Vella

    We solve the Percus-Yevick equation in two dimensions by reducing it to a set of simple integral equations. We numerically obtain both the pair correlation function and the equation of state for a hard disc fluid and find good agreement with available Monte-Carlo calculations. The present method of resolution may be generalized to any even dimension.

  94. K. Wu, L. L. Kiss

    Context: We investigate the distribution of optically high and low states of the system AM Herculis (AM Her). Aims: We determine the state duty cycles, and their relationships with the mass transfer process and binary orbital evolution of the system. Methods: We make use of the photographic plate archive of the Harvard College Observatory between 1890 and 19

  95. Asish K. Kundu, P. Nordblad, C. N. R. Rao

    While La0.7Ba0.3MnO3 is a ferromagnetic metal (TC = 340 K) with longrange ordering, Nd0.7Ba0.3MnO3 shows a transition around 150 K with a small increase in magnetization, but remains an insulator at all temperatures. Gd0.7Ba0.3MnO3 is non-magnetic and insulating at all temperatures. Low field dc magnetization and ac susceptibility measurements reveal the pre

  96. Amihood Amir, Klim Efremenko, Oren Kapah, Ely Porat

    This paper presents a new technique for deterministic length reduction. This technique improves the running time of the algorithm presented in \cite{LR07} for performing fast convolution in sparse data. While the regular fast convolution of vectors $V_1,V_2$ whose sizes are $N_1,N_2$ respectively, takes $O(N_1 \log N_2)$ using FFT, using the new technique fo

  97. S. Simón-Díaz, J. García-Rojas, G. Stasińska, C. Esteban

    We present some results of an on-going project aimed at studying a sample of Galactic HII regions ionized by a single massive star to test the predictions of modern generation stellar atmosphere codes in the H Lyman continuum. The observations collected for this study comprise the optical spectra of the corresponding ionizing stars, along with imaging and lo

  98. Zhiwu Lin

    We consider linear instability of solitary waves of several classes of dispersive long wave models. They include generalizations of KDV, BBM, regularized Boussinesq equations, with general dispersive operators and nonlinear terms. We obtain criteria for the existence of exponentially growing solutions to the linearized problem. The novelty is that we dealt w

  99. J. Méndez-Abreu, J. A. L. Aguerri, E. M. Corsini

    We studied the fraction and properties of bars in a sample of about 3000 galaxies extracted from SDSS-DR5. This represents a volume limited sample with galaxies located between redshift 0.01<z<0.04, absolute magnitude Mr>-20, and inclination i < 60. Interacting galaxies were excluded from the sample. The fraction of barred galaxies in our sample is 45%. We f

  100. J. Méndez-Abreu, J. A. L. Aguerri, E. M. Corsini, E. Simonneau

    The structural parameters of a magnitude-limited sample of 148 unbarred S0-Sb galaxies were derived to study the correlations between bulge and disk parameters as well as the probability distribution function (PDF) of the intrinsic equatorial ellipticity of bulges. A new algorithm (GASP2D) was used to perform the bidimensional bulge-disk decomposition of the