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January 2010 arXiv papers — page 45

Showing 4,4014,500 of 5,448 papers

  1. A. S. Verma, B. K. Sarkar, V. K. Jindal

    A new approach utilising the concept of ionic charge theory has been used to explain the inherent properties such as lattice thermal conductivity and bulk modulus of 3,5 and 2,6 semiconductors. The lattice thermal conductivity of these semiconductors exhibit a linear relationship when plotted on a log scale against the nearest neighbour distance but fall on

  2. A. S. Verma, B. K. Sarkar, V. K. Jindal

    In this letter we present an expression relating the cohesive energy for the A3B5 and A2B6 semiconductors with the product of their ionic charges and nearest neighbor distance. The cohesive energy values of these solids exhibits a linear relationship when plotted on a log-log scale against the nearest neighbor distance, but fall on different straight lines a

  3. Yongzhong Sun, Chao Wang, Zhifei Zhang

    We prove a blow-up criterion in terms of the upper bound of the density for the strong solution to the 3-D compressible Navier-Stokes equations. The initial vacuum is allowed. The main ingredient of the proof is \textit{a priori} estimate for an important quantity under the assumption that the density is upper bounded, whose divergence can be viewed as the e

  4. Carlo Nipoti

    A substantial fraction of the baryons of disk galaxies like the Milky Way is expected to reside in coronae of gas at the virial temperature. This is the only realistic reservoir of gas available to feed star formation in the disks. The way this feeding occurs depends crucially on whether galactic coronae can fragment into cool clouds via thermal instability.

  5. Sachindra Naik, Dipankar P. K. Banerjee, N. M. Ashok, R. K. Das

    We present results obtained from extensive near-infrared spectroscopic and photometric observations of nova V574 Pup during its 2004 outburst. The observations were obtained over four months, starting from 2004 November 25 (four days after the nova outburst) to 2005 March 20. The near-IR JHK light curve is presented - no evidence is seen from it for dust for

  6. D. M. Russell, R. P. Fender

    A common consequence of accretion onto black holes is the formation of powerful, relativistic jets that escape the system. In the case of supermassive black holes at the centres of galaxies this has been known for decades, but for stellar-mass black holes residing within galaxies like our own, it has taken recent advances to arrive at this conclusion. Here,

  7. Mubasher Jamil, M. Umar Farooq

    In this paper, we have constructed a (2+1)-dimensional wormhole using inhomogeneous and anisotropic distribution of phantom energy. We have determined the exact form of the equation of state of phantom energy that supports the wormhole structure. Interestingly, this equation of state is linear but variable one and is dependent only on the radial parameter of

  8. Martha Constantinou, Vittorio Lubicz, Haralambos Panagopoulos, Apostolos Skouroupathis

    We calculate the corrections to the amputated Green's functions of 4-fermion operators, in 1-loop Lattice Perturbation theory. The novel aspect of our calculations is that they are carried out to second order in the lattice spacing, O(a^2). We employ the Wilson/clover action for massless fermions (also applicable for the twisted mass action in the chiral

  9. A. Malakis, A. Nihat Berker, I. A. Hadjiagapiou, N. G. Fytas

    The effects of bond randomness on the phase diagram and critical behavior of the square lattice ferromagnetic Blume-Capel model are discussed. The system is studied in both the pure and disordered versions by the same efficient two-stage Wang-Landau method for many values of the crystal field, restricted here in the second-order phase transition regime of th

  10. Pavel Bleher, Steven Delvaux, Arno B. J. Kuijlaars

    We consider the random matrix model with external source, in case where the potential V(x) is an even polynomial and the external source has two eigenvalues a, -a of equal multiplicity. We show that the limiting mean eigenvalue distribution of this model can be characterized as the first component of a pair of measures (mu_1,mu_2) that solve a constrained ve

  11. E. Jespers, G. Olteanu, A. del Rio

    We give an explicit and character-free construction of a complete set of orthogonal primitive idempotents of a rational group algebra of a finite nilpotent group and a full description of the Wedderburn decomposition of such algebras. An immediate consequence is a well-known result of Roquette on the Schur indices of the simple components of group algebras o

  12. A. Matos-Abiague

    The existence of a spin-orbit coupling (SOC) induced by the gradient of the effective mass in low-dimensional heterostructures is revealed. In structurally asymmetric quasi-two-dimensional semiconductor heterostructures the presence of a mass gradient across the interfaces results in a SOC which competes with the SOC created by the electric field in the vale

  13. Laura A. Ripamonti

    This technical report summarizes the preliminary findings of a project that has been developed in 2007 by an Italian company (Datanet, based in Siracusa, Italy) togheter with two Italian research institutions: Universita' degli Studi di Milano and Universita' Bocconi. The main aim of the OS4E (Open Source for Enterprises) project, has been to investi

  14. Piotr Graczyk, Tomasz Jakubowski

    We give a series representation of the logarithm of the bivariate Laplace exponent $κ$ of $α$-stable processes for almost all $α\in (0,2]$.

  15. Arvind Rajaraman, Daniel Whiteson

    We present experimental sensitivity for the production of a fourth-generation Majorana neutrino ($N$) via an s-channel $Z$ boson $Z\to NN \to W\ell W\ell$ at hadron colliders. This channel has not been studied for the Tevatron dataset with $\int \mathcal{L}=5 $ fb$^{-1}$, where we find that a single experiment could significantly extend current 95% C.L. mass

  16. D. Manzano, R. J. Yanez, J. S. Dehesa

    The charge spreading of ground and excited states of Klein-Gordon particles moving in a Coulomb potential is quantitatively analyzed by means of the ordinary moments and the Heisenberg measure as well as by use of the most relevant information-theoretic measures of global (Shannon entropic power) and local (Fisher's information) types. The dependence of

  17. I. Beslic, L. Vranjes Markic, J. Boronat

    This work expands recent investigations in the field of spin-polarized tritium (T$\downarrow$) clusters . We report the results for the ground state energy and structural properties of large T$\downarrow$ cl usters consisting of up to 320 atoms. All calculations have been performed with variational and diffusi on Monte Carlo methods, using an accurate {\it a

  18. Paolo Piro, Richard Nock, Frank Nielsen, Michel Barlaud

    The k-nearest neighbors (k-NN) classification rule has proven extremely successful in countless many computer vision applications. For example, image categorization often relies on uniform voting among the nearest prototypes in the space of descriptors. In spite of its good properties, the classic k-NN rule suffers from high variance when dealing with sparse

  19. Zhaoshun Gao, Yanwei Ma, Dongliang Wang, Xianping Zhang

    A review of current developments in the study of chemical doping effect on the superconducting properties of MgB2 wires and tapes is presented, based on the known literature data and our own results. The critical current density of MgB2 can be improved through various kinds of dopants. Among these dopants, doping with carbon-containing materials seems to be

  20. R. Gozdyra, S. M. Dubiel, J. Cieslak

    Antianemic medicament Ascofer and ferrous gluconate, its basic iron bearing ingredient, were studied with the use of Mossbauer spectroscopy. Room temperature spectra gave a clear evidence that two phases of iron were present viz. ferrous (Fe2+) as a major one with a contribution of 85+-5%, and ferric (Fe3+) whose contribution was found to be 15+-5%. However,

  21. Stephen Pankavich, Zeina Shreif, Peter Ortoleva

    Using multiscale analysis and methods of statistical physics, we show that a solution to the N-atom Liouville Equation can be decomposed via an expansion in terms of a smallness parameter epsilon, wherein the long scale time behavior depends upon a reduced probability density that is a function of slow-evolving order parameters. This reduced probability dens

  22. Lakshmi Manasa, Krishna. S

    In this paper, we propose a procedure that given an integer reset timed automaton (IRTA) ${\cal A}$, produces a language equivalent deterministic one clock IRTA ${\cal B}$ whose size is at most doubly exponential in the size of ${\cal A}$. We prove that this bound on the number of locations is tight. Further, if integer resets are used in stopwatch automata,

  23. Henry D. Pfister

    This paper considers the derivative of the entropy rate of a hidden Markov process with respect to the observation probabilities. The main result is a compact formula for the derivative that can be evaluated easily using Monte Carlo methods. It is applied to the problem of computing the capacity of a finite-state channel (FSC) and, in the high-noise regime,

  24. Stephen Pankavich, Yinglong Miao, Jamil Ortoleva, Zeina Shreif

    An approach for simulating bionanosystems, such as viruses and ribosomes, is presented. This calibration-free approach is based on an all-atom description for bionanosystems, a universal interatomic force field, and a multiscale perspective. The supramillion-atom nature of these bionanosystems prohibits the use of a direct molecular dynamics approach for phe

  25. Jan Wiersig, Julia Unterhinninghofen, Henning Schomerus, Ulf Peschel

    We discuss electromagnetic modes in cavities formed by metamaterials with negative refraction and demonstrate that the straightforward approach to substitute negative values of the electric permittivity and the magnetic permeability leads to quasi-bound states with a negative quality factor. To ensure positive quality factors and a consistent physical interp

  26. S. M. Dubiel, J. Cieslak, W. Sturhahn, M. Sternik

    Experimental investigation as well as theoretical calculations, of the Fe-partial phonon density-of-states (DOS) for nominally Fe_52.5Cr_47.5 alloy having (a) alpha- and (b) sigma-phase structure were carried out. The former at sector 3-ID of the Advanced Photon Source, using the method of nuclear resonant inelastic X-ray scattering, and the latter with the

  27. Paola Bonizzoni, Gianluca Della Vedova, Riccardo Dondi, Yuri Pirola

    The haplotype resolution from xor-genotype data has been recently formulated as a new model for genetic studies. The xor-genotype data is a cheaply obtainable type of data distinguishing heterozygous from homozygous sites without identifying the homozygous alleles. In this paper we propose a formulation based on a well-known model used in haplotype inference

  28. S. M. Andrievsky, Monique Spite, S. A. Korotin, F. Spite

    LTE abundances of light elements in extremely metal-poor (EMP) stars have been previously derived from high quality spectra. New derivations, free from the NLTE effects, will better constrain the models of the Galactic chemical evolution and the yields of the very first supernovae. The NLTE profiles of the magnesium and potassium lines have been computed in

  29. Elmar Haller, Russell Hart, Manfred J. Mark, Johann G. Danzl

    Particles in a perfect lattice potential perform Bloch oscillations when subject to a constant force, leading to localization and preventing conductivity. For a weakly-interacting Bose-Einstein condensate (BEC) of Cs atoms, we observe giant center-of-mass oscillations in position space with a displacement across hundreds of lattice sites when we add a period

  30. Ronald J. Adler

    We give six arguments that the Planck scale should be viewed as a fundamental minimum or boundary for the classical concept of spacetime, beyond which quantum effects cannot be neglected and the basic nature of spacetime must be reconsidered. The arguments are elementary, heuristic, and plausible, and as much as possible rely on only general principles of qu

  31. David M. -T. Kuo, Yia-chung Chang

    It is illustrated that semiconductor quantum dots (QDs) embedded into an insulating matrix connected with metallic electrodes and some vacuum space can lead to significant thermal rectification effect. A multilevel Anderson model is used to investigate the thermal rectification properties of the multiple-QD junction. The charge and heat currents in the tunne

  32. Manabu Takahashi, Jun-ichi Igarashi

    We calculate the $3s$- and $4s$-core-level x-ray photoemission spectroscopy (XPS) spectra in the ferromagnetic and nonmagnetic transition metals by developing an \emph{ab initio} method. We obtain the spectra exhibiting the characteristic shapes as a function of binding energy in good agreement with experimental observations. The spectral shapes are striking

  33. S. C. Kim, P. S. Park, S. -R. Eric Yang

    In neutral graphene dots the Fermi level coincides with the Dirac points. We have investigated in the presence of a magnetic field several unusual properties of single electron states near the Fermi level of such a rectangular-shaped graphene dot with two zigzag and two armchair edges. We find that a quasi-degenerate level forms near zero energy and the numb

  34. I. C. Gebeshuber, B. Y Majlis

    Inspired by interdisciplinary work touching biology and microtribology, the authors propose a new, dynamic way of publishing research results, the establishment of a tree of knowledge and the localisation of scientific articles on this tree. 'Technomimetics' is proposed as a new method of knowledge management in science and technology: it shall help

  35. James R. A. Davenport, Eric L. Sandquist

    We probe the spatial and dynamical structure of the old open cluster M67 using photometric data from the Sloan Digital Sky Survey's sixth data release. Making use of an optimal contrast, or matched filter, algorithm, we map the distribution of high probability members of M67. We find an extended and elongated halo of likely members to a radius of nearly

  36. Masahito Hayashi, Ryutaroh Matsumoto

    From an arbitrary given channel code over a discrete or Gaussian memoryless channel, we construct a wiretap code with the strong security. Our construction can achieve the wiretap capacity under mild assumptions. The key tool is the new privacy amplification theorem bounding the eavesdropped information in terms of the Gallager function.

  37. Gergely Röst

    The time-periodic scalar delay differential equation $\dot x(t)=γf(t,x(t-1))$ is considered, which leads to a resonant bifurcation of the equilibrium at critical values of the parameter. Using Floquet theory, spectral projection and center manifold reduction, we give conditions for the stability properties of the bifurcating invariant curves and four-periodi

  38. Haruka Namatame

    It is pointed out in a class of models with large extra dimensions that the cross section of processes with virtual Kaluza-Klein graviton exchanges becomes either much smaller or much larger by many orders of magnitude than what is expected from that of the on-shell production of the Kaluza-Klein gravitons. We demonstrate how the problem arises using a toy m

  39. Hongchang Dong, Shunhua Zhang

    Let $A$ be a tame hereditary algebra over a finite field $k$ with $q$ elements, and ${\bar{A}}$ be the duplicated algebra of $A$. In this paper, we investigate the structure of Ringel-Hall algebra $\mathscr{H} (\bar{A})$ and of the corresponding composition algebra $\mathscr{C} (\bar{A})$. As an application, we prove the existence of Hall polynomials $g_{XY}

  40. Xiaoying Wang, Shugong Zhang, Tian Dong

    For the last almost three decades, since the famous Buchberger-Möller(BM) algorithm emerged, there has been wide interest in vanishing ideals of points and associated interpolation polynomials. Our paradigm is based on the theory of bivariate polynomial interpolation on cartesian point sets that gives us related degree reducing interpolation monomial and New

  41. Theja Tulabandhula

    Digital architectures for Chebyshev interpolation are explored and a variation which is word-serial in nature is proposed. These architectures are contrasted with equispaced system structures. Further, Chebyshev interpolation scheme is compared to the conventional equispaced interpolation vis-a-vis reconstruction error and relative number of samples. It is a

  42. Constantinos Kardaras

    The valuation process that economic agents undergo for investments with uncertain payoff typically depends on their statistical views on possible future outcomes, their attitudes toward risk, and, of course, the payoff structure itself. Yields vary across different investment opportunities and their interrelations are difficult to explain. For the same agent

  43. Thierry Masson, Jean-Christophe Wallet

    In this paper we consider the Spontaneous Symmetry Breaking Mechanism (SSBM) in the Standard Model of particles in the unitary gauge. We show that the computation usually presented of this mechanism can be conveniently performed in a slightly different manner. As an outcome, the computation we present can change the interpretation of the SSBM in the Standard

  44. Stanley J. Brodsky, Barbara Pasquini, Bowen Xiao, Feng Yuan

    It is an important question whether the final/initial state gluonic interactions which lead to naive-time-reversal-odd single-spin asymmetries and diffraction at leading twist can be associated in a definite way with the light-front wave function hadronic eigensolutions of QCD. We use light-front time-ordered perturbation theory to obtain augmented light-fro

  45. Yong-Seon Song, Cristiano G. Sabiu, Robert C. Nichol, Christopher J. Miller

    We present here a new parameterization for the bulk motions of galaxies and clusters (in the linear regime) that can be measured statistically from the shape and amplitude of the two-dimensional two-point correlation function. We further propose the one-dimensional velocity dispersion (v_p) of the bulk flow as a complementary measure of redshift-space distor

  46. D. Martin de Diego, S. Vilariño

    In this paper we introduce a geometric description of Lagrangian and Hamiltonian classical field theories on Lie algebroids in the framework of $k$-cosymplectic geometry. We discuss the relation between Lagrangian and Hamiltonian descriptions through a convenient notion of Legendre transformation. The theory is a natural generalization of the standard one; i

  47. Mathias Beiglböck, Henry Towsner

    Hindman's Theorem states that in any finite coloring of the integers, there is an infinite set all of whose finite sums belong to the same color. This is much stronger than the corresponding finite form, stating that in any finite coloring of the integers there are arbitrarily long finite sets with the same property. We extend the finite form of Hindman&

  48. Hong Yao, Xiao-Liang Qi

    In this paper, we obtain an exact formula for the entanglement entropy of the ground state and all excited states of the Kitaev model. Remarkably, the entanglement entropy can be expressed in a simple separable form S=S_G+S_F, with S_F the entanglement entropy of a free Majorana fermion system and S_G that of a Z_2 gauge field. The Z_2 gauge field part contr

  49. Dimitrios Giannios

    Long-duration gamma-ray bursts (GRBs) may be powered by the rotational energy of a millisecond magnetar. I argue that the GRB-driving magnetars lie at the high end of the distribution of magnetic field strengths of magnetars. The field of GRB magnetars decays on timescale of hundreds of years and can power SGR-like flares up to ~100 times more powerful than

  50. N. Iro L. D. Deming

    We present a time-dependent radiative model for the atmosphere of extrasolar planets that takes into account the eccentricity of their orbit. In addition to the modulation of stellar irradiation by the varying planet-star distance, the pseudo-synchronous rotation of the planets may play a significant role. We include both of these time-dependent effects when

  51. Lorenzo Cornalba, Miguel S. Costa, Joao Penedones

    Using the approximate conformal invariance of QCD at high energies we consider a simple AdS black disk model to describe saturation in DIS. Deep inside saturation the structure functions have the same power law scaling, F_T ~ F_L ~ 1/x^w, where w is related to the expansion rate of the black disk with energy. Furthermore, the ratio F_L /F_T is given by the u

  52. Sourav Bhattacharya, Amitabha Lahiri

    We show that, for general static or axisymmetric stationary spacetimes, a cosmological Killing horizon exists only if $R_{ab}n^{a}n^{b}< 0$ for a hypersurface orthogonal timelike $n^{a}$, at least over some portion of the region of interest of the manifold. This implies violation of the strong energy condition by the matter fields, the simplest example of wh

  53. S. Paul, L. Iapichino, F. Miniati, J. Bagchi

    We performed a set of cosmological simulations of major mergers in galaxy clusters to study the evolution of merger shocks and the subsequent injection of turbulence in the post-shock region and in the intra-cluster medium (ICM). The computations were done with the grid-based, adaptive mesh refinement hydro code Enzo, using an especially designed refinement

  54. Nathan Keller

    We show that certain statements related to the Fourier-Walsh expansion of functions with respect to a biased measure on the discrete cube can be deduced from the respective results for the uniform measure by a simple reduction. In particular, we present simple generalizations to the biased measure $μ_p$ of the Bonami-Beckner hypercontractive inequality, and

  55. Davide Batic, Piero Nicolini

    We study the stability of the noncommutative Schwarzschild black hole interior by analysing the propagation of a massless scalar field between the two horizons. We show that the spacetime fuzziness triggered by the field higher momenta can cure the classical exponential blue shift divergence, suppressing the emergence of infinite energy density in a region n

  56. Geoffrey W. Burr, Matthew J. Breitwisch, Michele Franceschini, Davide Garetto

    We survey the current state of phase change memory (PCM), a non-volatile solid-state memory technology built around the large electrical contrast between the highly-resistive amorphous and highly-conductive crystalline states in so-called phase change materials. PCM technology has made rapid progress in a short time, having passed older technologies in terms

  57. Christian. G. Boehmer, James Burnett

    This article will provide the reader with a short introduction to dark spinors, which are ELKO spinors, eingenspinors of the charge conjugation operator, applied to dark matter and dark energy.

  58. Ekaterina Amerik, Fedor Bogomolov, Marat Rovinsky

    Let X be a variety over a number field and let f: X --> X be an "interesting" rational self-map with a fixed point q. We make some general remarks concerning the possibility of using the behaviour of f near q to produce many rational points on X. As an application, we give a simplified proof of the potential density of rational points on the variety of lines

  59. Raphael Gervais Lavoie, Louis Marchildon, Dominic Rochon

    The problem of the quantum harmonic oscillator is investigated in the framework of bicomplex numbers, which are pairs of complex numbers making up a commutative ring with zero divisors. Starting with the commutator of the bicomplex position and momentum operators, and adapting the algebraic treatment of the standard quantum harmonic oscillator, we find eigen

  60. Alexander Friedland

    Neutrinos in a core-collapse supernova undergo coherent flavor transformations in their own background. We explore this phenomenon during the cooling stage of the explosion. Our three-flavor calculations reveal qualitatively new effects compared to a two-flavor analysis. These effects are especially clearly seen for the inverted mass hierarchy: we find a dif

  61. Brant E. Robertson

    The installation of the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) will revolutionize the study of high-redshift galaxy populations. Initial observations of the HST Ultra Deep Field (UDF) have yielded multiple z>~7 dropout candidates. Supplemented by the Great Observatory Origins Deep Survey (GOODS) Early Release Science (ERS) and further

  62. Jolanta Golenia, Maxim V. Pavlov, Ziemowit Popowicz, Anatoliy K. Prykarpatsky

    Short-wave perturbations in a relaxing medium, governed by a special reduction of the Ostrovsky evolution equation, and later derived by Whitham, are studied using the gradient-holonomic integrability algorithm. The bi-Hamiltonicity and complete integrability of the corresponding dynamical system is stated and an infinite hierarchy of commuting to each other

  63. G. Abal, R. Donangelo, F. L. Marquezino, R. Portugal

    The spatial search problem consists in minimizing the number of steps required to find a given site in a network, under the restriction that only oracle queries or translations to neighboring sites are allowed. In this paper, a quantum algorithm for the spatial search problem on a honeycomb lattice with $N$ sites and torus-like boundary conditions. The searc

  64. C. Valeriani, R. J. Allen, D. Marenduzzo

    We report Monte Carlo simulations of the dynamics of a &#34;chucker&#34;: a colloidal particle which emits smaller solute particles from its surface, isotropically and at a constant rate k_c. We find that the diffusion constant of the chucker increases for small k_c, as recently predicted theoretically. At large k_c the chucker diffuses more slowly due to cr

  65. Hoon Huh, Giuseppe Caire, Sung-Hyun Moon, Inkyu Lee

    We consider the downlink of a cellular network with multiple cells and multi-antenna base stations including arbitrary inter-cell cooperation, realistic distance-dependent pathloss and general &#34;fairness&#34; requirements. Beyond Monte Carlo simulation, no efficient computation method to evaluate the ergodic throughput of such systems has been provided so

  66. Daria Kosenko, Eveline Helder, Jacco Vink

    We present an analysis of the XMM-Newton and Chandra X-ray data of the young Type Ia supernova remnant 0519-69.0 in the Large Magellanic Cloud. We used data from both the Chandra ACIS and XMM-Newton EPIC-MOS instruments, and high resolution X-ray spectra obtained with the XMM-Newton Reflection Grating Spectrometer. The Chandra data show that there is a radia

  67. William Detmold, Brian C. Tiburzi, Andre Walker-Loud

    Nucleon properties are investigated in background electric fields. As the magnetic moments of baryons affect their relativistic propagation in constant electric fields, electric polarizabilities cannot be determined without knowledge of magnetic moments. This is analogous to the experimental situation, for which determination of polarizabilities from the Com

  68. Chen-Fu Chiang, Pawel Wocjan

    In a recent work [10], Poulin and one of us presented a quantum algorithm for preparing thermal Gibbs states of interacting quantum systems. This algorithm is based on Grovers&#39;s technique for quantum state engineering, and its running time is dominated by the factor D/Z(β), where D and Z(β) denote the dimension of the quantum system and its partition fun

  69. S. W. Ham, Seong-A Shim, S. K. Oh

    In the minimal supersymmetric standard model (MSSM), a strongly first-order electroweak phase transition (EWPT) is only possible in a confined parameter region where one of the scalar top quarks is lighter than the top quark and the other one is as heavy as the SUSY breaking scale. If the MSSM is enlarged to accommodate vector-like quarks and their superpart

  70. Ph. Jacquod

    We construct a novel scattering theory to investigate magnetoelectrically induced spin polarizations. Local spin polarizations generated by electric currents passing through a spin-orbit coupled mesoscopic system are measured by an external probe. The electrochemical and spin-dependent chemical potentials on the probe are controllable and tuned to values ens

  71. A. N. Gorban, A. Zinovyev

    We present several applications of non-linear data modeling, using principal manifolds and principal graphs constructed using the metaphor of elasticity (elastic principal graph approach). These approaches are generalizations of the Kohonen&#39;s self-organizing maps, a class of artificial neural networks. On several examples we show advantages of using non-

  72. J. G. Sereni, M. Gomez Berisso, G. Schmerber, A. Braghta

    The magnetic phase diagram of Ce$_2$Pd$_2$Sn is investigated through the field dependence of thermal, transport and magnetic measurements performed at low temperature. The upper transition, $T_M=4.8$ K is practically not affected by magnetic field up to B=1 T, whereas the lower one $T_C(B)$ rapidly increases from 2.1 K joining $T_M$ in a critical point at $T

  73. Christian Senger, Vladimir R. Sidorenko, Martin Bossert, Victor V. Zyablov

    We investigate threshold-based multi-trial decoding of concatenated codes with an inner Maximum-Likelihood decoder and an outer error/erasure (L+1)/L-extended Bounded Distance decoder, i.e. a decoder which corrects e errors and t erasures if e(L+1)/L + t <= d - 1, where d is the minimum distance of the outer code and L is a positive integer. This is a genera

  74. N. Andruskiewitsch, F. Fantino, M. Graña, L. Vendramin

    We show that every finite-dimensional complex pointed Hopf algebra with group of group-likes isomorphic to a sporadic group is a group algebra, except for the Fischer group Fi22, the Baby Monster and the Monster. For these three groups, we give a short list of irreducible Yetter-Drinfeld modules whose Nichols algebra is not known to be finite-dimensional.

  75. Thomas Church, Benson Farb

    Let I_g,* denote the (pointed) Torelli group. This is the group of homotopy classes of homeomorphisms of the genus g >= 2 surface S_g with a marked point, acting trivially on H := H_1(S_g). In 1983 Johnson constructed a beautiful family of invariants tau_i: H_i(I_g,*) -> /\^{i+2} H for 0 <= i <= 2g-2, using a kind of Abel-Jacobi map for families, in order to

  76. N. Andruskiewitsch, F. Fantino, M. Graña, L. Vendramin

    In this notes we give details of the proofs performed with GAP of the theorems of our paper &#34;Pointed Hopf Algebras over the Sporadic Simple Groups&#34;.

  77. Edward Anderson

    Relational particle mechanics models (RPM&#39;s) are useful models for the problem of time in quantum gravity and other foundational issues in quantum cosmology. Some concrete examples of scalefree RPM&#39;s have already been studied, but it is the case with scale that is needed for the semiclassical and dilational internal time approaches to the problem of

  78. Elise Filotas, Martin Grant, Lael Parrott, Per Arne Rikvold

    The significant role of space in maintaining species coexistence and determining community structure and function is well established. However, community ecology studies have mainly focused on simple competition and predation systems, and the relative impact of positive interspecific interactions in shaping communities in a spatial context is not well unders

  79. J. B. Natowitz, G. Ropke, S. Typel, D. Blaschke

    The symmetry energy of nuclear matter is a fundamental ingredient in the investigation of exotic nuclei, heavy-ion collisions and astrophysical phenomena. New data from heavy-ion collisions can be used to extract the free symmetry energy and the internal symmetry energy at subsaturation densities and temperatures below 10 MeV. Conventional theoretical calcul

  80. U. Gran, J. Gutowski, G. Papadopoulos

    We show that all M-theory backgrounds which admit more than 29 Killing spinors are maximally supersymmetric. In particular, we find that the supercovariant curvature of all backgrounds which preserve 30 supersymmetries, subject to field equations and Bianchi identities, vanishes, and that there are no such solutions which arise as discrete quotients of maxim

  81. Hui Shi, Jun-Hui Zhao, J. L. Han

    We present high-resolution continuum images of the W51e2 complex processed from archival data of the Submillimeter Array (SMA) at 0.85 and 1.3 mm and the Very Large Array (VLA) at 7 and 13 mm. We also made line images and profiles of W51e2 for three hydrogen radio recombination lines (H26α, H53α, and H66α) and absorption of two molecular lines of HCN(4-3) an

  82. David Mond, Mathias Schulze

    We describe two situations where adding the adjoint divisor to a divisor D with smooth normalization yields a free divisor. Both also involve stability or versality. In the first, D is the image of a corank one stable germ of a map from complex n-space to complex (n+1)-space, and is not free. In the second, D is the discriminant of a versal deformation of a

  83. Peng Cheng, Bing Shen, Jiangping Hu, Hai-Hu Wen

    Resistivity, Hall effect, magnetoresistance and DC magnetization were measured in Mn and Zn doped Ba$_{0.5}$K$_{0.5}$Fe$_{2}$As$_{2}$ samples. It is found that the Mn-doping can depress the superconducting transition temperature drastically with a rate of $ΔT_c$/Mn-1% = -4.2 K, while that by Zn-doping is negligible. Detailed analysis reveals that the Mn-dopi

  84. L. Aggoun, F. Benamira, L. Guechi

    In this comment, we show that the solutions of the-wave Dirac equation for deformed generalized Pöschl-Teller potential obtained by Wei et al are valid only for $q\geq1$ and $\frac{1}{2α}\ln{q}<r<\infty$. When $0<q<1$, we prove that the energy eigenvalues for the bound states are given by the solution of a transcendental equation involving the hypergeometric

  85. Giacomo Mauro D&#39;Ariano

    After reviewing recently suggested operational &#34;principles of the quantumness&#34;, I address the problem on whether Quantum Theory (QT) and Special Relativity (SR) are unrelated theories, or instead, if the one implies the other. I show how SR can be indeed derived from causality of QT, within the computational paradigm &#34;the universe is a huge quant

  86. J. Mauritsson, T. Remetter, M. Swoboda, K. Klunder

    We present an interferometric pump-probe technique for the characterization of attosecond electron wave packets (WPs) that uses a free WP as a reference to measure a bound WP. We demonstrate our method by exciting helium atoms using an attosecond pulse with a bandwidth centered near the ionization threshold, thus creating both a bound and a free WP simultane

  87. K. Shigechi, P. Zinn-Justin

    We provide simple rules for the computation of Kazhdan--Lusztig polynomials in the maximal parabolic case. They are obtained by filling regions delimited by paths with &#34;Dyck strips&#34; obeying certain rules. We compare our results with those of Lascoux and Schützenberger.

  88. Wei Hong, Ping Xu

    In this note, we compute the Poisson cohomology groups for any Poisson Del Pezzo surface.

  89. F. J. Gallego, M. González, B. P. Purnaprajna

    In this article we study the deformation of finite maps and show how to use this deformation theory to construct varieties with given invariants in a projective space. Among other things, we prove a criterion that determines when a finite map can be deformed to a one--to--one map. We use this criterion to construct new simple canonical surfaces with differen

  90. Patrizio Frosini, Claudia Landi

    Motivated by the problem of dealing with incomplete or imprecise acquisition of data in computer vision and computer graphics, we extend results concerning the stability of persistent homology with respect to function perturbations to results concerning the stability with respect to domain perturbations. Domain perturbations can be measured in a number of di

  91. M. C. B. Abdalla, M. E. X. Guimaraes, J. M. Hoff da Silva

    In this work, we review and extend the so-called consistency conditions for the existence of a braneworld scenario in arbitrary dimensions in the Brans-Dicke (BD) gravitational theory. After that, we consider the particular case of a five-dimensional scenario which seems to have phenomenological interesting implications. We show that, in the BD framework, it

  92. P. Popovich, A. V. Boris, O. V. Dolgov, A. A. Golubov

    The specific heat of high-purity $\rm Ba_{0.68}K_{0.32}Fe_2As_2$ single crystals with the highest reported superconducting $T_c$ = 38.5 K was studied. The electronic specific heat, $C_p$, below $T_c$ shows two gap features, with $Δ_1 \approx 11$ meV and $Δ_2 \approx 3.5$ meV obtained from an $α$-model analysis. The reduced gap value, $2Δ^{\rm max} / k_B T_c

  93. Roumen Tsekov

    Quantum diffusion is studied via dissipative Madelung hydrodynamics. Initially the wave packet spreads ballistically, than passes for an instant through normal diffusion and later tends asymptotically to a sub-diffusive law. It is shown that the apparent quantum diffusion coefficient is not a universal physical parameter since it depends on the initial wave

  94. Angelo Tartaglia, Matteo Luca Ruggiero, Emiliano Capolongo

    We introduce an operational approach to the use of pulsating sources, located at spatial infinity, for defining a relativistic positioning and navigation system, based on the use of four-dimensional bases of null four-vectors, in flat spacetime. As a prototypical case, we show how pulsars can be used to define such a positioning system. The reception of the

  95. Kausik Pal, Abhee K. Dutt-Mazumder

    We calculate the dimensionless Fermi liquid parameters (FLPs), $F_{0,1}^{sym}$ and $F_{0,1}^{asym}$, for spin asymmetric dense quark matter. In general, the FLPs are infrared divergent due to the exchange of massless gluons. To remove such divergences, the Hard Density Loop (HDL) corrected gluon propagator is used. The FLPs so determined are then invoked to

  96. E. G. van Putten, A. Lagendijk, A. P. Mosk

    In turbid materials it is impossible to concentrate light into a focus with conventional optics. Recently it has been shown that the intensity on a dyed probe inside a turbid material can be enhanced by spatially shaping the wave front of light before it enters a turbid medium. Here we show that this enhancement is due to concentration of light energy to a s

  97. V. Vacca, M. Murgia, F. Govoni, L. Feretti

    The goal of this work is to investigate the power spectrum of the magnetic field associated with the giant radio halo in the galaxy cluster A665. For this, we present new deep Very Large Array total intensity and polarization observations at 1.4 GHz. We simulated Gaussian random three-dimensional turbulent magnetic field models to reproduce the observed radi

  98. Lusaka Bhattacharya, Pradip Roy

    We calculate the $p_T$ distributions of jet conversion photons from {\em Quark Gluon Plasma} with pre-equilibrium momentum-space anisotropy. A phenomenological model has been used for the time evolution of hard momentum scale $p_{\rm hard}(τ)$ and anisotropy parameter $ξ(τ)$. As a result of pre-equilibrium momentum-space anisotropy, we find significant modif

  99. Jing Wang, Bang-Fen Zhu, Ren-Bao Liu

    A pure spin current formed by opposite spins moving in opposite directions is a rank-2 axial tensor which breaks the inversion symmetry. Thus a spin current has a second-order optical susceptibility, with unique polarization-dependence determined by the symmetry properties of the current. In particular, a longitudinal spin current, in which the spin polariza

  100. R. Rehammar, R. Magnusson, A. I. Fernandez-Dominguez, H. Arwin

    Carbon nanofibers (CNF) are used as components of planar photonic crystals. Square and rectangular lattices and random patterns of vertically aligned CNF were fabricated and their properties studied using ellipsometry. We show that detailed information such as symmetry directions and the band structure of these novel materials can be extracted from considera