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March 2008 arXiv papers — page 19

Showing 1,8011,900 of 4,524 papers

  1. D. F. Urban, A. Komnik

    We analyze the spectrum of electron density oscillations in an interacting one-dimensional electron system with an impurity. The system's inhomogeneity is characterized by different values of Fermi wave vectors $k_F=k_{L/R}$ on left/right side of the scatterer, leading to a Landauer dipole formation. We demonstrate, that while in the noninteracting syste

  2. Dietmar Weinmann, Rodolfo A. Jalabert, Axel Freyn, Gert-Ludwig Ingold

    We consider one-dimensional transport through an interacting region in series with a point-like one-body scatterer. When the conductance of the interacting region is perfect, independently of the interaction strength, a nonlocal interaction effect yields a total conductance of the composed system that depends on the interaction strength and is lower than the

  3. D0 Collaboration, V. Abazov

    We measure the ttbar production cross section in ppbar collisions at sqrt{s}=1.96 TeV in the lepton+jets channel. Two complementary methods discriminate between signal and background, b-tagging and a kinematic likelihood discriminant. Based on 0.9 fb-1 of data collected by the D0 detector at the Fermilab Tevatron Collider, we measure sigma_ttbar=7.62+/-0.85

  4. Marcin Kostur, Lukasz Machura, Jerzy Luczka, Peter Talkner

    We investigate an optimal regime of negative-valued conductance, emerging in a resistively and capacitively shunted Josephson junction, which is driven simultaneously by both, a time-periodic (ac) and a constant (dc) current. We analyze the current-voltage characteristics in the regime of absolute negative conductance. We additionally explore the stability o

  5. A. W. Thomas

    We derive the consequences of the Myhrer-Thomas explanation of the proton spin problem for the distribution of orbital angular momentum on the valence and sea quarks. After QCD evolution these results are found to be in very good agreement with both recent lattice QCD calculations and the experimental constraints from Hermes and JLab.

  6. Wei-Xing Zhou

    It is ubiquitous in natural and social sciences that two variables, recorded temporally or spatially in a complex system, are cross-correlated and possess multifractal features. We propose a new method called multifractal detrended cross-correlation analysis (MF-DXA) to investigate the multifractal behaviors in the power-law cross-correlations between two re

  7. L. Giusti, P. Hernandez, S. Necco, C. Pena

    We investigate two-point correlation functions of left-handed currents computed in quenched lattice QCD with the Neuberger-Dirac operator. We consider two lattice spacings a~0.09,0.12 fm and two different lattice extents L~ 1.5, 2.0 fm; quark masses span both the p- and the epsilon-regimes. We compare the results with the predictions of quenched chiral pertu

  8. C. Hertling, Yu. Manin, C. Teleman

    In the first section of this note we show that the Theorem 1.8.1 of Bayer--Manin ([BaMa]) can be strengthened in the following way: {\it if the even quantum cohomology of a projective algebraic manifold $V$ is generically semi--simple, then $V$ has no odd cohomology and is of Hodge--Tate type.} In particular, this addressess a question in [Ci]. In the second

  9. A. De Masi, I. Merola, E. Presutti, Y. Vignaud

    In this paper we study a continuum version of the Potts model. Particles are points in R^d, with a spin which may take S possible values, S being at least 3. Particles with different spins repel each other via a Kac pair potential. In mean field, for any inverse temperature there is a value of the chemical potential at which S+1 distinct phases coexist. For

  10. G. Thalhammer, G. Barontini, L. De Sarlo, J. Catani

    We produce Bose-Einstein condensates of two different species, $^{87}$Rb and $^{41}$K, in an optical dipole trap in proximity of interspecies Feshbach resonances. We discover and characterize two Feshbach resonances, located around 35 and 79 G, by observing the three-body losses and the elastic cross-section. The narrower resonance is exploited to create a d

  11. Pham Thuc Tuyen, Do Quoc Tuan

    In this paper, we have found the string solution in the SUSY Skyrme model. Moreover, the mechanics of decay of SUSY - string was discussed.

  12. Alexander Gruneis, Denis Vyalikh

    We present an approach to monitor and control the strength of the hybridization between electronic states of graphene and metal surfaces. Inspecting the distribution of the $π$ band in a high-quality graphene layer synthesized on Ni(111) by angle-resolved photoemission, we observe a new "kink" feature which indicates a strong hybridization between $π

  13. C. Iliadis, C. Angulo, P. Descouvemont, M. Lugaro

    The 16O(p,gamma)17F reaction rate is revisited with special emphasis on the stellar temperature range of T=60-100 MK important for hot bottom burning in asymptotic giant branch (AGB) stars. We evaluate existing cross section data that were obtained since 1958 and, if appropriate, correct published data for systematic errors that were not noticed previously,

  14. Hidehiko Kamiya, Akimichi Takemura, Hiroaki Terao

    An integral coefficient matrix determines an integral arrangement of hyperplanes in R^m. After modulo q reduction, the same matrix determines an arrangement A_q of "hyperplanes" in Z^m. In the special case of central arrangements, Kamiya, Takemura and Terao [J. Algebraic Combin., to appear] showed that the cardinality of the complement of A_q in Z_q^

  15. C. Qi, D. J. Wilner, Y. Aikawa, G. A. Blake

    We present Submillimeter Array (SMA) observations of several deuterated species in the disk around the classical T Tauri star TW Hydrae at arcsecond scales, including detections of the DCN J=3-2 and DCO+ J=3-2 lines, and upper limits to the HDO 3(1,2)-2(2,1), ortho-H2D+ 1(1,0)-1(1,1) and para-D2H+ 1(1,0)-1(0,1) transitions. We also present observations of th

  16. Tunna Baruah, Mark R. Pederson, Rajendra R. Zope

    We investigate the vibrational stability and the electronic structure of the proposed icosahedral fullerene-like cage structure of B80 [Szwacki, Sadrzadeh, and Yakobson, Phys. Rev. Lett. {\bf 98}, 166804 (2007)] by an all electron density functional theory using polarized Gaussian basis functions containing 41 basis functions per atom. The vibrational analys

  17. I. G. Bostrem, Jun-ichiro Kishine, A. S. Ovchinnikov

    We show that the bulk transport magnetic current is generated by the moving magnetic kink crystal (chiral soliton lattice) formed in the chiral helimagnet under the static magnetic field applied perpendicular to the helical axis. The current is caused by the non-equilibrium transport momentum with the kink mass being determined by the spin fluctuations aroun

  18. Ming-Jing Zhao, Shao-Ming Fei, Zhi-Xi Wang

    We generalize the Schmidt-correlated states to multipartite systems. The related equivalence under SLOCC, the separability, entanglement witness, entanglement measures of negativity, concurrence and relative entropy are investigated in detail for the generalized Schmidt-correlated states.

  19. Gunnar Carlsson, Christopher L. Douglas, Bjørn Ian Dundas

    We investigate higher topological cyclic homology as an approach to studying chromatic phenomena in homotopy theory. Higher topological cyclic homology is constructed from the fixed points of a version of topological Hochschild homology based on the n-dimensional torus, and we propose it as a computationally tractable cousin of n-fold iterated algebraic K-th

  20. M. M. Qazilbash, A. A. Schafgans, K. S. Burch, S. J. Yun

    The optical/infrared properties of films of vanadium dioxide (VO2) and vanadium sesquioxide (V2O3) have been investigated via ellipsometry and near-normal incidence reflectance measurements from far infrared to ultraviolet frequencies. Significant changes occur in the optical conductivity of both VO2 and V2O3 across the metal-insulator transitions at least u

  21. Daisuke Jido, Tetsuo Hyodo, Atsushi Hosaka

    The structure of N(1535) is discussed in dynamical and symmetry aspects based on chiral symmetry. We find that the N(1535) in chiral unitary model has implicitly some components other than meson-baryon one. We also discuss the N(1535) in the chiral doublet picture.

  22. V. S. Khrapai, A. A. Shashkin, M. G. Trokina, V. T. Dolgopolov

    We directly measure the chemical potential jump in the low-temperature limit when the filling factor traverses the nu = 1/3 and nu = 2/5 fractional gaps in two-dimensional (2D) electron system in GaAs/AlGaAs single heterojunctions. In high magnetic fields B, both gaps are linear functions of B with slopes proportional to the inverse fraction denominator, 1/q

  23. Graciela Gelmini, Efunwande Osoba, Sergio Palomares-Ruiz, Silvia Pascoli

    It is commonly assumed that the cosmological and astrophysical bounds on the mixings of sterile with active neutrinos are much more stringent than those obtained from laboratory measurements. We point out that in scenarios with a very low reheating temperature T_RH << 100 MeV at the end of (the last episode of) inflation or entropy creation, the abundance of

  24. I. Schuster, A. Kubanek, A. Fuhrmanek, T. Puppe

    Optical nonlinearities typically require macroscopic media, thereby making their implementation at the quantum level an outstanding challenge. Here we demonstrate a nonlinearity for one atom enclosed by two highly reflecting mirrors. We send laser light through the input mirror and record the light from the output mirror of the cavity. For weak laser intensi

  25. Shuang Wang, Yang Zhang, Tian-Yang Xia, Hai-Xing Miao

    As predicted by quantum chromodynamics(QCD), around $T\sim 190$ MeV in the early universe, the QCD transition occurs during which the quarks are combined into the massive hadrons. This process reduces the effective relativistic degree of freedom, and causes a change in the expansion behavior of the universe. Similarly, the $e^+e^-$ annihilation occurred arou

  26. A. Kartavtsev, D. Besak

    We investigate the influence of primordial perturbations of the energy density and space--time metric on the generation of the lepton and baryon asymmetries. In the weak and strong washout regimes baryon isocurvature perturbations with amplitudes of the same order as those of the CMB perturbations are generated on scales of order of the respective Hubble sca

  27. Nathan Reading, David E Speyer

    In a series of previous papers, we studied sortable elements in finite Coxeter groups, and the related Cambrian fans. We applied sortable elements and Cambrian fans to the study of cluster algebras of finite type and the noncrossing partitions associated to Artin groups of finite type. In this paper, as the first step towards expanding these applications bey

  28. V. Ongun Özçelik, A. Nihat Berker

    The Blume-Emery-Griffiths spin glass is studied by renormalization-group theory in d=3. The boundary between the ferromagnetic and paramagnetic phases has first-order and two types of second-order segments. This topology includes an inverted tricritical point, first-order transitions replacing second-order transitions as temperature is lowered. The phase dia

  29. S. Savaglio, K. Glazebrook, D. Le Borgne

    We present the most extensive and complete study of the properties for the largest sample (46 objects) of gamma-ray burst (GRB) host galaxies. The redshift interval and the mean redshift of the sample are 0<z<6.3 and z=0.96 (look-back time: 7.2 Gyr), respectively; 89% of the hosts are at z <~ 1.6. Optical-near-infrared (NIR) photometry and spectroscopy are u

  30. Travis R. Beals, Kevin P. Hynes, Barry C. Sanders

    We introduce a simple, practical approach with probabilistic information-theoretic security to solve one of quantum key distribution&#39;s major security weaknesses: the requirement of an authenticated classical channel to prevent man-in-the-middle attacks. Our scheme employs classical secret sharing and partially trusted intermediaries to provide arbitraril

  31. Alireza Shabani, Kurt Jacobs

    For quantum systems with high purity, we find all observables that, when continuously monitored, maximize the instantaneous reduction in the von Neumann entropy. This allows us to obtain all locally optimal feedback protocols with strong feedback, and explicit expressions for the best such protocols for systems of size N <= 4. We also show that for a qutrit

  32. J. Quintanilla, S. T. Carr, J. J. Betouras

    It has been suggested that some strongly correlated matter might be understood qualitatively in terms of liquid crystalline phases intervening between the Fermi gas and the Wigner crystal or Mott insulator. We propose a tunable realisation of this soft quantum matter physics in an ultra-cold gas. It uses optical lattices and dipolar interactions to realise a

  33. M. N. Kiselev, K. Kikoin, J. Richert

    We show how the charge input signal applied to the gate electrode in double quantum dot may be converted to a pulse in the Kondo cotunneling current as a spin response of a nano-device in a strong Coulomb blockade regime. The stochastic component of the input signal comes as the infrared cutoff of Kondo transmission.

  34. Peter Ronhovde, Zohar Nussinov

    We report on an exceptionally accurate spin-glass-type Potts model for community detection. With a simple algorithm, we find that our approach is at least as accurate as the best currently available algorithms and robust to the effects of noise. It is also competitive with the best currently available algorithms in terms of speed and size of solvable systems

  35. Jeremy S. Heyl

    Recent observations of white dwarfs in globular clusters indicate that these stars may get a velocity kick during their time as giants. This velocity kick could originate naturally if the mass loss while on the asymptotic giant branch is slightly asymmetric. The kicks may be large enough to dramatically change the radial distribution of young white dwarfs, g

  36. L. Miller, T. J. Turner, J. N. Reeves

    The Seyfert I galaxy MCG-6-30-15 shows one of the best examples of a broad &#34;red wing&#34; of emission in its X-ray spectrum at energies 2 < E < 6.4 keV, commonly interpreted as being caused by relativistically-blurred reflection close to the event horizon of the black hole. We aim to test an alternative model in which absorption creates the observed spec

  37. Tobias Fritz

    The theory of categories of fractions as originally developed by Gabriel and Zisman is reviewed in a pedagogical manner giving detailed proofs of all statements. A weakening of the category of fractions axioms used by Higson is discussed and shown to be equivalent to the original axioms.

  38. Richard J. Cook, M. Shane Burns

    The cosmological Robertson-Walker metric of general relativity is often said to have the consequences that (1) the recessional velocity $v$ of a galaxy at proper distance $\ell$ obeys the Hubble law $v=H\ell$, and therefore galaxies at sufficiently great distance $\ell$ are receding faster than the speed of light $c$; (2) faster than light recession does not

  39. P. Pin, M. Marsili, S. Franz

    Our societies are heterogeneous in many dimensions such as census, education, religion, ethnic and cultural composition. The links between individuals - e.g. by friendship, marriage or collaboration - are not evenly distributed, but rather tend to be concentrated within the same group. This phenomenon, called `imbreeding homophily&#39;, has been related to e

  40. H. Sedaghat, M. A. Wood, J. W. Cain, C-K. Cheng

    A two-component model is developed that consists of a discrete loop of cardiac cells that circulates action potentials together with a cardiac pacing mechanism. Physiological properties of cells such as restitutions of refractoriness and of conduction velocity are given via experimentally measured functions. The dynamics of circulating pulses and their inter

  41. F. Colomo, A. G. Pronko

    The problem of the limit shape of large alternating sign matrices (ASMs) is addressed by studying the emptiness formation probability (EFP) in the domain-wall six-vertex model. Assuming that the limit shape arises in correspondence to the `condensation&#39; of almost all solutions of the saddle-point equations for certain multiple integral representation for

  42. Matthew van Adelsberg, Kevin Heng, Richard McCray, John C. Raymond

    Balmer-dominated shocks in supernova remnants (SNRs) produce strong hydrogen lines with a two-component profile composed of a narrow contribution from cold upstream hydrogen atoms, and a broad contribution from hydrogen atoms that have undergone charge transfer reactions with hot protons. Observations of emission lines from edge-wise shocks in SNRs can const

  43. Stefan Forcey

    We describe a new sequence of polytopes which characterize A_infinity maps from a topological monoid to an A_infinity space. Therefore each of these polytopes is a quotient of the corresponding multiplihedron. Later term(s) in our sequence of polytopes are demonstrated not to be combinatorially equivalent to the associahedron, as was previously assumed. They

  44. L. P. Gamberg, A. Mukherjee, P. J. Mulders

    The non-vanishing of gluonic pole matrix elements can explain the appearance of single spin asymmetries in high-energy scattering processes. We use a spectator framework approach to investigate the spectral properties of quark-quark-gluon correlators and use this to study gluonic pole matrix elements. Such matrix elements appear in principle both for distrib

  45. S. Bhattacharya, A. Milchev, V. G. Rostiashvili, A. Y. Grosberg

    We study analytically and by means of an off-lattice bead-spring dynamic Monte Carlo simulation model the adsorption kinetics of a single macromolecule on a structureless flat substrate in the regime of strong physisorption. The underlying notion of a ``stem-flower&#39;&#39; polymer conformation, and the related mechanism of ``zipping&#39;&#39; during the ad

  46. S. G. Magalhaes, C. V. Morais, F. M. Zimmer

    We investigate the inverse freezing in the fermionic Ising spin-glass (FISG) model in a transverse field $Γ$. The grand canonical potential is calculated in the static approximation, replica symmetry and one-step replica symmetry breaking Parisi scheme. It is argued that the average occupation per site $n$ is strongly affected by $Γ$. As consequence, the bou

  47. Hyun Min Lee

    We construct a consistent supersymmetric action for brane chiral and vector multiplets in a six-dimensional chiral gauged supergravity. A nonzero brane tension can be accommodated by allowing for a brane-localized Fayet-Iliopoulos term proportional to the brane tension. When the brane chiral multiplet is charged under the bulk U(1)_R, we obtain a nontrivial

  48. Giacomo Aletti, Enea G. Bongiorno, Vincenzo Capasso

    The paper considers a particular family of set--valued stochastic processes modeling birth--and--growth processes. The proposed setting allows us to investigate the nucleation and the growth processes. A decomposition theorem is established to characterize the nucleation and the growth. As a consequence, different consistent set--valued estimators are studie

  49. R. Casana, B. M. Pimentel, G. E. R. Zambrano

    We studied the scalar electrodynamics ($SQED_{4}$) and the spinor electrodynamics ($QED_{4}$) in the null-plane formalism. We followed the Dirac&#39;s technique for constrained systems to perform a detailed analysis of the constraint structure in both theories. We imposed the appropriated boundary conditions on the fields to fix the hidden subset first class

  50. Gerard Briscoe, Philippe De Wilde

    A primary motivation for our research in Digital Ecosystems is the desire to exploit the self-organising properties of biological ecosystems. Ecosystems are thought to be robust, scalable architectures that can automatically solve complex, dynamic problems. Self-organisation is perhaps one of the most desirable features in the systems that we engineer, and i

  51. Alessandro Pesci

    The Bousso entropy bound, in its generalized form, is investigated for the case of perfect fluids at local thermodynamic equilibrium and evidence is found that the bound is satisfied if and only if a certain local thermodynamic property holds, emerging when the attempt is made to apply the bound to thin layers of matter. This property consists in the existen

  52. Florian Bauer, Durmus A. Demir

    We analyze non-minimally coupled scalar field theories in metric (second-order) and Palatini (first-order) formalisms in a comparative fashion. After contrasting them in a general setup, we specialize to inflation and find that the two formalisms differ in their predictions for various cosmological parameters. The main reason is that dependencies on the non-

  53. Sheng-Li Qin, Jun-Jie Wang, Gang Zhao, Martin Miller

    Aims: We searched for the molecular outflows from fifteen molecular clouds associated with ultra-compact and compact HII (UCHII/HII) regions and discussed possible gas heating mechanism. Methods: Mapping observations of CO $J=3-2$ and $J=2-1$ lines were carried out with the KOSMA 3m-Telescope towards the 15 HII regions/molecular cloud complexes. Results: Ten

  54. Frederick R. Cohen, David J. Hemmer, Daniel K. Nakano

    The main result of this paper is an application of the topology of the space $Q(X)$ to obtain results for the cohomology of the symmetric group on $d$ letters, $Σ_d$, with `twisted&#39; coefficients in various choices of Young modules and to show that these computations reduce to certain natural questions in representation theory. The authors extend classica

  55. Kingman Cheung, Cheng-Wei Chiang, Tzu-Chiang Yuan

    What if only a light Higgs boson is discovered at the CERN LHC? Conventional wisdom tells us that the scattering of longitudinal weak gauge bosons would not grow strong at high energies. We show that this is not always true. In some composite models, two-Higgs-doublet models, or even supersymmetric models, the presence of a light Higgs boson does not guarant

  56. I. Jack, R. Purdy

    We discuss the structure of the non-anticommutative N=2 non-linear sigma-model in two dimensions, constructing differential operators which implement the deformed supersymmetry generators and using them to reproduce the classical action. We then compute the one-loop quantum corrections and express them in a more compact form using the differential operators.

  57. Viktor Eisler, Ingo Peschel

    We consider a chain of free electrons with periodically switched dimerization and study the entanglement entropy of a segment with the remainder of the system. We show that it evolves in a stepwise manner towards a value proportional to the length of the segment and displays in general slow oscillations. For particular quench periods and full dimerization an

  58. J. Terradas, I. Arregui, R. Oliver, J. L. Ballester

    Recent observations with the Hinode Solar Optical Telescope display an active region prominence whose fine threads oscillate in the vertical direction as they move along a path parallel to the photosphere. A seismological analysis of this event is carried out by taking advantage of the small radius of these structures compared to the total length of magnetic

  59. Daniel Massart

    We study autonomous Tonelli Lagrangians on closed surfaces. We aim to clarify the relationship between the Aubry set and the Mather set, when the latter consists of periodic orbits which are not fixed points. Our main result says that in that case the Aubry set and the Mather set almost always coincide.

  60. Clement Pellegrini

    &#34;Quantum trajectories&#34; are solutions of stochastic differential equations of non-usual type. Such equations are called &#34;Belavkin&#34; or &#34;Stochastic Schrödinger Equations&#34; and describe random phenomena in continuous measurement theory of Open Quantum System. Many recent investigations deal with the control theory in such model. In this ar

  61. Gunnar Bjork, Jonas Almlof, Isabel Sainz

    The paper has been withdrawn by the autors. The proposed code is not working because orthogonality.

  62. Alexandre Souto Martinez, Rodrigo Silva Gonzalez, Cesar Augusto Sangaletti Tercariol

    Consider the one-parameter generalizations of the logarithmic and exponential functions which are obtained from the integration of non-symmetrical hyperboles. These generalizations coincide to the one obtained in the context of non-extensive thermostatistics. We show that these functions are suitable to describe and unify the great majority of continuous gro

  63. Fa Wang, Li Li, Jianming Hu, Yan Ji

    To provide a more accurate description of the driving behaviors in vehicle queues, a namely Markov-Gap cellular automata model is proposed in this paper. It views the variation of the gap between two consequent vehicles as a Markov process whose stationary distribution corresponds to the observed distribution of practical gaps. The multiformity of this Marko

  64. Indrajit Mitra

    We consider the evaluation of D-dimensional conformal invariant integrals which involve spin one-half and spin-one particles. The star-triangle relation for the massless Yukawa theory is derived, and the longitudinal part of the three-point Green function of massless QED is determined to the lowest order in position space. The operator algebraic method of ca

  65. François-Xavier Dupé, Jalal Fadili, Jean Luc Starck

    We propose an image deconvolution algorithm when the data is contaminated by Poisson noise. The image to restore is assumed to be sparsely represented in a dictionary of waveforms such as the wavelet or curvelet transforms. Our key contributions are: First, we handle the Poisson noise properly by using the Anscombe variance stabilizing transform leading to a

  66. François-Xavier Dupé, Jalal Fadili, Jean Luc Starck

    We propose a deconvolution algorithm for images blurred and degraded by a Poisson noise. The algorithm uses a fast proximal backward-forward splitting iteration. This iteration minimizes an energy which combines a \textit{non-linear} data fidelity term, adapted to Poisson noise, and a non-smooth sparsity-promoting regularization (e.g $\ell_1$-norm) over the

  67. Marie-Amélie Lawn, Julien Roth

    We give a spinorial characterization of isometrically immersed hypersurfaces into 4-dimensional space forms and product spaces $\M^3(κ)\times\R$, in terms of the existence of particular spinor fields, called generalized Killing spinors or equivalently solutions of a Dirac equation. This generalizes to higher dimensions several recent results for surfaces by

  68. S. Jhingan, S. Nojiri, S. D. Odintsov, M. Sami

    In this paper we have investigated the cosmological dynamics of non-locally corrected gravity involving a function of the inverse d&#39;Alembertian of the Ricci scalar, $f(\Box^{-1} R))$. Casting the dynamical equations into local form, we derive the fixed points of the dynamics and demonstrate the existence and stability of a one parameter family of dark en

  69. Yves Grandati, Alain Berard, Herve Mohrbach

    Bohlin-Arnold-Vassiliev&#39;s duality transformation establishes a correspondence between motions in different central potentials. It offers a very direct way to construct the dynamical conserved quantities associated to the isotropic harmonic oscillator (Fradkin-Jauch-Hill tensor) and to the Kepler&#39;s problem (Laplace-Runge-Lenz vector).

  70. Erik Sjöqvist

    The concept of relative state is used to introduce geometric phases that originate from correlations in states of composite quantum systems. In particular, we identify an entanglement-induced geometric phase in terms of a weighted average of geometric phase factors associated with a decomposition that define the entanglement of formation. An explicit procedu

  71. Ho-Meoyng Choi, Chueng-Ryong Ji

    We extend a recent analysis of the pion electromagnetic form factor constrained by the conformal symmetry to explore the time-like region. We show explicitly that the time-like form factor obtained by the analytic continuation of the space-like form factor correctly satisfies the dispersion relation. Our results indicate that the quark spin and dynamical mas

  72. Andrey Grozin

    In this lecture, the early history of asymptotic freedom is discussed. The first completely correct derivation of β_0 in non-abelian gauge theory (Khriplovich, 1969) was done in the Coulomb gauge; this derivation is reproduced (in modernized terms) in Sect. 2. A qualitative physical explanation of asymptotic freedom via chromomagnetic properties of vacuum (N

  73. R. Soler, R. Oliver, J. L. Ballester

    High-resolution observations show that oscillations and waves in prominence threads are common and that they are attenuated in a few periods. In addition, observers have also reported the presence of material flows in such prominence fine-structures. Here we investigate the time damping of non-leaky oscillations supported by a homogeneous cylindrical promine

  74. Fabio Biancalana

    We theoretically investigate the possibility of realizing a nonlinear all-optical diode by using the unique features of quasiperiodic 1D photonic crystals. The interplay between the intrinsic spatial asymmetry in odd-order Thue-Morse lattices and Kerr nonlinearity, combined with the unconventional field localization properties of this class of quasiperiodic

  75. Yves Stalder

    We explain, following Gromov, how to produce uniform isometric actions of groups starting from isometric actions without fixed point, using common ultralimits techniques. This gives in particular a simple proof of a result by Shalom: Kazhdan&#39;s property (T) defines an open subset in the space of marked finitely generated groups.

  76. Vicente Garzo

    A new segregation criterion based on the inelastic Enskog kinetic equation is derived to show the transition between the Brazil-nut effect (BNE) and the reverse Brazil-nut effect (RBNE) by varying the different parameters of the system. In contrast to previous theoretical attempts the approach is not limited to the near-elastic case, takes into account the i

  77. Elodie Brunel, Fabienne Comte

    We consider projection methods for the estimation of the cumulative distribution function under interval censoring, case 1. Such censored data also known as current status data, arise when the only information available on the variable of interest is whether it is greater or less than an observed random time. Two types of adaptive estimators are investigated

  78. Huayi Chen

    We establish, for a generically big Hermitian line bundle, the convergence of truncated Harder-Narasimhan polygons and the uniform continuity of the limit. As applications, we prove a conjecture of Moriwaki asserting that the arithmetic volume function is actually a limit instead of a sup-limit, and we show how to compute the asymptotic polygon of a Hermitia

  79. A. S. Sanz, F. Borondo

    Here we analyze the relationship between quantum contextuality and decoherence in interference experiments with matter particles by means of a simple reduced quantum-trajectory model, which attempts to simulate the behavior of the projections of multi-dimensional, system-plus-environment Bohmian trajectories onto the subspace of the reduced system. This mode

  80. Noga Alon, Shmuel Friedland

    We show that the number of perfect matching in a simple graph $G$ with an even number of vertices and degree sequence $d_1,d_2, ..., d_n$ is at most $\prod_{i=1}^n (d_i !)^{\frac{1}{2d_i}}$. This bound is sharp if and only if $G$ is a union of complete balanced bipartite graphs.

  81. T. P. Simula, T. Mizushima, K. Machida

    We have theoretically investigated Kelvin waves of quantized vortex lines in trapped Bose-Einstein condensates. Counterrotating perturbation induces an elliptical instability to the initially straight vortex line, driven by a parametric resonance between a quadrupole mode and a pair of Kelvin modes of opposite momenta. Subsequently, Kelvin waves rapidly deca

  82. Z. Li, G. F. Chen, J. Dong, G. Li

    A series of layered nickel-based LaO$_{1-x}$F$_x$NiAs compounds with x=0 to 0.15 are synthesized by solid state reactions. The pure LaONiAs exhibits bulk superconductivity with Tc $\sim$ 2.75 K. Partial substitution of oxygen by fluorine increases the transition temperature to $\sim 3.8$ K. The LaO$_{0.9}$F$_{0.1}$NiAs sample shows a sharp superconducting tr

  83. Shashi Borade, Baris Nakiboglu, Lizhong Zheng

    An information theoretic framework for unequal error protection is developed in terms of the exponential error bounds. The fundamental difference between the bit-wise and message-wise unequal error protection (UEP) is demonstrated, for fixed length block codes on DMCs without feedback. Effect of feedback is investigated via variable length block codes. It is

  84. Yousuke Nakamura, Sinya Aoki, Yusuke Taniguchi, Tomoteru Yoshié

    We calculate non-perturbative renormalization factors at hadronic scale for $\Delta S=2$ four-quark operators in quenched domain-wall QCD using the Schr\"{o}dinger functional method. Combining them with the non-perturbative renormalization group running by the Alpha collaboration, our result yields the fully non-perturbative renormalization factor, which con

  85. D. Li, X. Li, H. Huang, X. Li

    Grover presented the fixed-point search by replacing the selective inversions by selective phase shifts of $π/3$. In this paper, we investigate the convergence behavior of the fixed-point search algorithm with general but equal phase shifts for any iterations.

  86. Rodolfo A. Diaz, William J. Herrera, Diego A. Manjarres

    It is usual in introductory courses of mechanics to develop the work and energy formalism from Newton&#39;s laws. On the other hand, literature analyzes the way in which forces transform under a change of reference frame. Notwithstanding, no analogous study is done for the way in which work and energy transform under those changes of reference frames. We ana

  87. Sang Pyo Kim, Don N. Page

    We study Schwinger pair production in scalar QED from a uniform electric field in dS_2 with scalar curvature R_{dS} = 2 H^2 and in AdS_2 with R_{AdS} = - 2 K^2. With suitable boundary conditions, we find that the pair-production rate is the same analytic function of the scalar curvature in both cases.

  88. Marina Chugunova, Illya M. Karabash, Sergei G. Pyatkov

    We study the Cauchy problem with periodic initial data for the forward-backward heat equation defined by the J-self-adjoint linear operator L depending on a small parameter. The problem has been originated from the lubrication approximation of a viscous fluid film on the inner surface of the rotating cylinder. For a certain range of the parameter we rigorous

  89. Denis Auroux

    The first part of this paper is a review of the Strominger-Yau-Zaslow conjecture in various settings. In particular, we summarize how, given a pair (X,D) consisting of a Kahler manifold and an anticanonical divisor, families of special Lagrangian tori in X-D and weighted counts of holomorphic discs in X can be used to build a Landau-Ginzburg model mirror to

  90. T. C. Li, H. Kelkar, D. Medellin, M. G. Raizen

    We report an experimental method to create optical lattices with real-time control of their periodicity. We demonstrate a continuous change of the lattice periodicity from 0.96 $μ$m to 11.2 $μ$m in one second, while the center fringe only moves less than 2.7 $μ$m during the whole process. This provides a powerful tool for controlling ultracold atoms in optic

  91. Daniel Gomes Lichtenthaler, Carla Goldman

    The collective behavior of molecular motor proteins have been investigated in the literature using models to describe the long-time dynamics of a unidimensional continuum motor distribution. Here, we consider the phenomena related to the transport of particles (vesicles, organelles, virus, etc) in the realm of these continuum motor systems. We argue that car

  92. M. Cecilia Gimenez, Ezequiel P. M. Leiva

    The adsorption of a metal monolayer or submonolayer for the systems Ag/Au(100), Au/Ag(100), Ag/Pt(100), Pt/Ag(100), Au/Pt(100), Pt/Au(100), Au/Pd(100) and Pd/Au(100) was studied by means of lattice Monte Carlo simulations, in the presence of surface defects.

  93. M. W. C. Dharma-wardana, Marek Z. Zgierski

    The electronic structure, bonding and magnetism in graphene containing vacancies are studied using density-functional methods. The single-vacancy graphene ground state is spin polarized and structurally flat. The unpolarized state is non planar only for finite segments. Systems containing periodic arrays of vacancies displays magnetic transitions and metal-i

  94. William Detmold, Martin J. Savage, Aaron Torok, Silas R. Beane

    The ground-state energies of systems containing up to twelve $π^+$&#39;s in a spatial volume V ~ (2.5 fm)^3 are computed in dynamical, mixed-action lattice QCD at a lattice spacing of ~ 0.125 fm for four different values of the light quark masses. Clean signals are seen for each ground state, allowing for a precise extraction of both the $π^+π^+$ scattering

  95. G. Vignale

    I show that the so-called causality paradox of time-dependent density functional theory arises from an incorrect formulation of the variational principle for the time evolution of the density. The correct formulation not only resolves the paradox in real time, but also leads to a new expression for the causal exchange-correlation kernel in terms of Berry cur

  96. J. H. Muñoz, N. Quintero

    We present a brief discussion about expressions of decay widths of exclusive nonleptonic and semileptonic B decays at tree level including $l=0$ and $l=1$ mesons in final state. Our analysis is carried out assuming factorization hypothesis and using parametrizations of hadronic matrix elements given in WSB and ISGW quark models. Special interest is focused o

  97. Sulakshana Thanvanthri, Kishore T. Kapale, Jonathan P. Dowling

    We recently proposed a scheme for the creation of coherent superpositions of vortex states in Bose-Einstein condensates (BEC) using orbital angular momentum (OAM) states of light [Phys. Rev. Lett. 95, 173601 (2005)]. Here we discuss further technical details of the proposal, provide alternative, time-reversal-symmetric scheme for transfer of a superposition

  98. C. P. Opeil, B. Mihaila, R. K. Schulze, L. Manosa

    Ultraviolet-photoemission (UPS) measurements and supporting specific-heat, thermal-expansion, resistivity and magnetic-moment measurements are reported for the magnetic shape-memory alloy Ni$_2$MnGa over the temperature range $100K < T < 250K$. All measurements detect clear signatures of the premartensitic transition ($T_\mathrm{PM}\sim 247K$) and the marten

  99. Marco Zoli

    The semiclassical Euclidean path integral method is applied to compute the low temperature quantum decay rate for a particle placed in the metastable minimum of a cubic potential in a {\it finite} time theory. The classical path, which makes a saddle for the action, is derived in terms of Jacobian elliptic functions whose periodicity establishes the one-to-o

  100. Reba M. Bandyopadhyay, Stephen S. Eikenberry, Curtis Dewitt, Andrew J. Gosling

    I describe the IR and X-ray campaign we have undertaken to determine the nature of the faint discrete X-ray source population discovered by Chandra in the Galactic Center. These results will provide the input to the FLAMINGOS-2 Galactic Center Survey (F2GCS). With FLAMINGOS-2's multi-object IR spectrograph we will obtain 1000s of IR spectra of candidate X-ra