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May 2008 arXiv papers — page 33

Showing 3,2013,300 of 4,900 papers

  1. Gideon Maschler

    On a 3-manifold bounding a compact 4-manifold, let a conformal structure be induced from a complete Einstein metric which conformally compactifies to a Kähler metric. Formulas are derived for the eta invariant of this conformal structure under additional assumptions. One such assumption is that the Kähler metric admits a special Kähler-Ricci potential in the

  2. Jouko Nieminen, Hsin Lin, R. S. Markiewicz, A. Bansil

    We have developed a material specific theoretical framework for modelling scanning tunneling spectroscopy (STS) of high temperature superconducting materials in the normal as well as the superconducting state. Results for $Bi_2Sr_2CaCu_2O_{8+δ}$ (Bi2212) show clearly that the tunneling process strongly modifies the STS spectrum from the local density of stat

  3. Apostolos Pilaftsis

    We study resonant leptogenesis at the electroweak phase transition in the singlet Majoron model with right-handed neutrinos. We consider a scenario, where the SM gauge group and the lepton number break down spontaneously during a second-order electroweak phase transition. We calculate the flavour- and temperature-dependent leptonic asymmetries, by including

  4. Camille Laurent-Gengoux, Eva Miranda, Pol Vanhaecke

    We prove the action-angle theorem in the general, and most natural, context of integrable systems on Poisson manifolds, thereby generalizing the classical proof, which is given in the context of symplectic manifolds. The topological part of the proof parallels the proof of the symplectic case, but the rest of the proof is quite different, since we are natura

  5. Diego A. R. Dalvit, Steve K. Lamoreaux

    We develop a new theory for Casimir-Lifshitz and Casimir-Polder interactions with semiconductor surfaces that takes into account charge drift in the bulk material. The corresponding frequency-dependent dispersion relations describe a crossover between Lifshitz results for dielectrics and for good conductors. In the quasi-static limit, our calculated reflecti

  6. Daniel M. Oberlin

    We establish a mixed norm estimate for the Radon transform in the plane when the set of directions has fractional dimension. This estimate is used to prove a result about an exceptional set of directions connected with projections of planar sets. That leads to a conjecture analogous to a well-known conjecture of Furstenberg.

  7. Kunio Hidano, Jason Metcalfe, Hart F. Smith, Christopher D. Sogge

    The purpose of this paper is to show how local energy decay estimates for certain linear wave equations involving compact perturbations of the standard Laplacian lead to optimal global existence theorems for the corresponding small amplitude nonlinear wave equations with power nonlinearities. To achieve this goal, at least for spatial dimensions $n=3$ and 4,

  8. F. C. Waldermann, B. J. Sussman, J. Nunn, V. O. Lorenz

    A technique to measure the decoherence time of optical phonons in a solid is presented. Phonons are excited with a pair of time delayed 80 fs, near infrared pulses via spontaneous, transient Raman scattering. The fringe visibility of the resulting Stokes pulse pair, as a function of time delay, is used to measure the phonon dephasing time. The method avoids

  9. H. Abuki, R. Anglani, R. Gatto, G. Nardulli

    We study the interplay between the chiral and the deconfinement transitions, both at high temperature and high quark chemical potential, by a non local Nambu-Jona Lasinio model with the Polyakov loop in the mean field approximation and requiring neutrality of the ground state. We consider three forms of the effective potential of the Polyakov loop: two of th

  10. Alexey V. Popov

    We argue that in the high energy QCD a true black disk wave function necessarily contains many quarks. This corresponds to necessity of non-vacuum reggeon loops in formation of a black disk. The result comes from decomposition of the black disk S-matrix in characters on group manifold.

  11. Massimiliano Bonamente, Douglas Swartz, Martin Weisskopf, Steven Murray

    \swift \xrt observations of the \hi line source \VV were performed on April 22 and April 26, 2008 for a total exposure time of 9.2ks. This is the first pointed X-ray observation of \VV, a putative dark galaxy in the Virgo cluster, and no photons were detected from this source. The non-detection of extended X-ray emission within the angular extent of the \hi

  12. G. Hickey, P. Carmi, A. Maheshwari, N. Zeh

    The Noah's Ark Problem (NAP) is an NP-Hard optimization problem with relevance to ecological conservation management. It asks to maximize the phylogenetic diversity (PD) of a set of taxa given a fixed budget, where each taxon is associated with a cost of conservation and a probability of extinction. NAP has received renewed interest with the rise in avai

  13. H. F. Jones

    We consider the interaction between the Hermitian world, represented by a real delta-function potential $-αδ(x)$, and the non-Hermitian world, represented by a PT-symmetric pair of delta functions with imaginary coefficients $iβ(δ(x-L)-δ(x+L))$. In the context of standard quantum mechanics, the effect of the introduction of the imaginary delta functions on t

  14. Margherita Barile, Dariush Kiani, Fatemeh Mohammadi, Siamak Yassemi

    We show that for the edge ideals of the graphs consisting of one cycle or two cycles of any length connected through a vertex or a path, the arithmetical rank equals the projective dimension.

  15. Cassio H. S. Amador, Liliana S. Zambrano

    We show that the dependence of the total energy of the atoms on their atomic number follows a q-exponential (function proposed by C. Tsallis), for almost all elements of the periodic table. The result is qualitatively explained in terms of the way the atomic configurations are arranged to minimize energy.

  16. Tanja Branz, Thomas Gutsche, Valery E. Lyubovitskij

    We discuss a possible interpretation of the f0(980) and a0(980) mesons as hadronic molecules - bound states of K and Kbar mesons. Using a phenomenological Lagrangian approach we calculate the strong f0(980) to pi pi and a0(980) to pi eta as well as the electromagnetic f0(980) to gamma gamma and a0(980) to gamma gamma decays. The covariant and gauge invariant

  17. Farhad Zamani, Ali Mostafazadeh

    We construct the most general physically admissible positive-definite inner product on the space of Proca fields. Up to a trivial scaling this defines a five-parameter family of Lorentz invariant inner products that we use to construct a genuine Hilbert space for the quantum mechanics of Proca fields. If we identify the generator of time-translations with th

  18. Jaykov Foukzon, S. A. Podosenov

    In this article, Generalized Principle of "limiting 4-dimensional symmetry": The laws of physics in non-inertial frames must display the 4-dimensional symmetry of the Generalized Lorentz-Poincare group in the limit of zero acceleration,is proposed.Classical solution of the relativistic length expansion in general accelerated system revisited.

  19. Marco G. Genoni, Matteo G. A. Paris, Konrad Banaszek

    We introduce a novel measure to quantify the non-Gaussian character of a quantum state: the quantum relative entropy between the state under examination and a reference Gaussian state. We analyze in details the properties of our measure and illustrate its relationships with relevant quantities in quantum information as the Holevo bound and the conditional en

  20. Theja N. De Silva

    We study the breathing mode frequencies of a rotating Fermi gas trapped in a harmonic plus radial quartic potential. We find that as the radial anharmonicity increases, the lowest order radial mode frequency increases while the next lowest order radial mode frequency decreases. Then at a critical anharmonicity, these two modes merge and beyond this merge the

  21. Marco G. Genoni, Matteo G. A. Paris

    We address truncated states of continuous variable systems and analyze their statistical properties numerically by generating random states in finite-dimensional Hilbert spaces. In particular, we focus to the distribution of purity and non-Gaussianity for dimension up to d=21. We found that both quantities are distributed around typical values with variances

  22. Gerasimos Dousmanis

    Let K_{f} be the finite unramified extension of Q_{p} of degree f and E any finite large enough coefficient field containing K_{f}. We construct analytic families of étale (Phi,Gamma)-modules which give rise to families of crystalline E-representations of the absolute Galois group G_{K_{f}} of K_{f}. For any irreducible effective two-dimensional crystalline

  23. Elvan Ceyhan

    Multivariate interaction between two or more classes (or species) has important consequences in many fields and causes multivariate clustering patterns such as segregation or association. The spatial segregation occurs when members of a class tend to be found near members of the same class (i.e., near conspecifics) while spatial association occurs when membe

  24. Snigdhayan Mahanta

    In this survey article we discuss a framework of noncommutative geometry with differential graded categories as models for spaces. We outline a construction of the category of noncommutative spaces and also include a discussion on noncommutative motives. We propose a motivic measure with values in a motivic ring. This enables us to introduce certain zeta fun

  25. D. S. Agafontsev, F. Dias, E. A. Kuznetsov

    We study both analytically and numerically the nonlinear stage of the instability of one-dimensional solitons in a small vicinity of the transition point from supercritical to subcritical bifurcations in the framework of the generalized nonlinear Schr\"{o}dinger equation. It is shown that near the collapsing time the pulse amplitude and its width demonstrate

  26. Yan-Rui Liu, Zong-Ye Zhang

    The bound state problem of $D^0\bar{D}^{\ast0}$ ($\bar{D}^0{D}^{\ast0}$) is relevant to the molecular interpretation of the X(3872). We investigated this problem in a chiral quark model by solving the resonating group method equation. We found the system is unbound through S-wave $π$ and $σ$ interactions. The inclusion of $ρ$ and $ω$ meson exchanges is helpf

  27. J. M. Aldaz, O. Kounchev, H. Render

    We study the existence and shape preserving properties of a generalized Bernstein operator $B_{n}$ fixing a strictly positive function $f_{0}$, and a second function $f_{1}$ such that $f_{1}/f_{0}$ is strictly increasing, within the framework of extended Chebyshev spaces $U_{n}$. The first main result gives an inductive criterion for existence: suppose there

  28. Miao Li, Yang Zhou, Shi Pu

    We consider a strings-junction holographic model of probe baryon in the finite-temperature supersymmetric Yang-Mills dual of the AdS-Schwarzschild black hole background. In particular, we investigate the screening length for high spin baryon composed of rotating N_c heavy quarks. To rotate quarks by finite force, we put hard infrared cutoff in the bulk and g

  29. F. V. Weinstein

    A partition of degree $n$ is a decomposition $n=i_1+i_2+\dots+i_q$, where ${i_1,i_2,\dots,i_q}$ are positive integers called the parts of the partition. Let $λ>0$ be an integer. The partition is said to be a $λ$--partition if $i_{a+1}-i_a\geqslant λ$ for all $a$ such that $1\leqslant a<q$. The main result of this note are combinatorial formulas, which expres

  30. Vladimir Filkov, Zachary M. Saul, Soumen Roy, Raissa M. D&#39;Souza

    Motivated by widely observed examples in nature, society and software, where groups of already related nodes arrive together and attach to an existing network, we consider network growth via sequential attachment of linked node groups, or graphlets. We analyze the simplest case, attachment of the three node V-graphlet, where, with probability alpha, we attac

  31. Shi-shyr Roan

    We establish the Bethe equation of the $τ^{(2)}$-model in the $N$-state chiral Potts model (including the degenerate selfdual cases) with alternating vertical rapidities. The eigenvalues of a finite-size transfer matrix of the chiral Potts model are computed by use of functional relations. The significance of the &#34;alternating superintegrable&#34; case of

  32. A. Lamastra, G. C. Perola, G. Matt

    The evidence of a decrease with increasing luminosity of the fraction f_{abs} of absorbed and Compton-thin among X-ray (2-10 keV) selected AGN is observationally rather well supported, while that of an increase of f_{abs} with redshift is rather controversial. In Lamastra, Perola & Matt (2006) the gravitational effect of the SMBH on the molecular interstella

  33. Haji Ahmedov, Alikram N. Aliev

    We examine the separability properties of the equation of motion for a stationary string near a rotating charged black hole with two independent angular momenta in five-dimensional minimal gauged supergravity. It is known that the separability problem for the stationary string in a general stationary spacetime is reduced to that for the usual Hamilton-Jacobi

  34. Bernd Günther

    A systematic study of the probability distribution of superimposed random codes is presented through the use of generating functions. Special attention is paid to the cases of either uniformly distributed but not necessarily independent or non uniform but independent bit structures. Recommendations for optimal coding strategies are derived.

  35. Atsushi Mori, Yoshihisa Suzuki, Shikegi Matsuo

    In the first part of this paper, a review is given on the mechanism for the disappearance of an intrinsic stacking fault in a hard-sphere (HS) crystal under gravity, which we recently discovered by Monte Carlo (MC) simulations [A. Mori et al., J. Chem. Phys., 124 (2006), 17450; Mol. Phys. 105 (2007), 1377]. We have observed, in the case of fcc (001) stacking

  36. E. B. Sonin

    The Letter analyzes stability of spin precession currents in superfluid $^3$He-B when the precession angle is very close to 104$^\circ$. In this limit a spin-precession vortex has a very large core, and a barrier blocking motion of these large-core vortices across the current streamlines (phase slip) disappears at precession-phase gradients much smaller than

  37. Yu Meiling, Xu Mingmei, Liu Lianshou

    Pair distribution function for delocalized quarks in the strongly coupled quark gluon plasma (sQGP) as well as in the states at intermediate stages of crossover from hadronic matter to sQGP are calculated using a molecule-like aggregation model. The shapes of the obtained pair distribution functions exhibit the character of liquid. The increasing correlation

  38. Zheng Xiaoping, Zhang Li, Zhou Xia, Kang Miao

    We consider the energy release associated with first-order transition by Gibbs construction and present such energy release as an accumulation of a series of tiny binding energy differences between over-compressed states and stable ones. Universal formulae for the energy release from one homogeneous phase to the other is given. We find the energy release per

  39. Alexander V. Kolesnikov

    This paper has been withdrawn by the author

  40. Taras Banakh, Volodymyr Gavrylkiv

    We prove that the minimal left ideals of the superextension $λ(Z)$ of the discrete group $Z$ of integers are metrizable topological semigroups, topologically isomorphic to minimal left ideals of the superextension $λ(Z_2)$ of the compact group $Z_2$ of integer 2-adic numbers.

  41. D. E. Juanico, A. Longjas, R. Batac, C. Monterola

    We examine avalanche statistics of rain- and vibration-driven granular slides in miniature sand mounds. A crossover from power-law to non power-law avalanche-size statistics is demonstrated as a generic driving rate $ν$ is increased. For slowly-driven mounds, the tail of the avalanche-size distribution is a power-law with exponent $-1.97\pm 0.31$, reasonably

  42. J. Y. Fu, M. W. Wu

    Using group theory and Kane-like $\mathbf{k\cdot p}$ model together with the Löwdining partition method, we derive the expressions of spin-orbit coupling of electrons and holes, including the linear-$k$ Rashba term due to the intrinsic structure inversion asymmetry and the cubic-$k$ Dresselhaus term due to the bulk inversion asymmetry in wurtzite semiconduct

  43. S. J. Curran, M. T. Whiting, T. Wiklind, J. K. Webb

    We present the results of a z>2.9 survey for HI 21-cm and molecular absorption in the hosts of radio quasars using the GMRT and the Tidbinbilla 70-m telescope. Previously published searches, which are overwhelmingly at redshifts of z<1, exhibit a 42% detection rate (31 out of 73 sources), and the inclusion of our survey yields a 17% detection rate (2 out of

  44. X. -Q. Zhou, C. -Y. Lu, W. -B. Gao, J. Zhang

    Cluster states are multi-particle entangled states with special entanglement properties particularly suitable for quantum computation. It has been shown that cluster states can exhibit Greenberger-Horne-Zeilinger (GHZ)-type non-locality even when some of their qubits have been lost. In the present work, we generated a four-photon mixed state, which is equiva

  45. S. Yu. Orevkov, Yu. P. Orevkov

    Agnihotri-Woodward-Belkale polytope $\Delta$ (resp. Klyachko cone $K$) is the set of solutions of the multiplicative (resp. additive) Horn's problem, i.e., the set of triples of spectra of special unitary (resp. traceless Hermitian) $n\times n$ matrices satisfying $AB=C$ (resp. $A+B=C$). $K$ is the tangent cone of $\Delta$ at the origin. The group $G=\Bbb Z_

  46. Shai Carmi, Zhenhua Wu, Shlomo Havlin, H. Eugene Stanley

    We investigate the electrical current and flow (number of parallel paths) between two sets of n sources and n sinks in complex networks. We derive analytical formulas for the average current and flow as a function of n. We show that for small n, increasing n improves the total transport in the network, while for large n bottlenecks begin to form. For the cas

  47. William M. Goldman

    This paper concerns the relationship between locally homogeneous geometric structures on topological surfaces and the moduli of polystable Higgs bundles on Riemann surfaces, due to Hitchin and Simpson. In particular we discuss the uniformization of Riemann surfaces by hyperbolic geometry from this viewpoint, and survey more recent developments in this theory

  48. Artur Avila, Svetlana Jitomirskaya

    We develop a quantitative version of Aubry duality and use it to obtain several sharp estimates for the dynamics of Schrödinger cocycles associated to a non-perturbatively small analytic potential and Diophantine frequency. In particular, we establish the full version of Eliasson&#39;s reducibility theory in this regime (our approach actually leads to improv

  49. Jon Feldman, S. Muthukrishnan

    Modern commercial Internet search engines display advertisements along side the search results in response to user queries. Such sponsored search relies on market mechanisms to elicit prices for these advertisements, making use of an auction among advertisers who bid in order to have their ads shown for specific keywords. We present an overview of the curren

  50. Andrea Alu, Nader Engheta

    We propose a mechanism for optical energy squeezing and anomalous light tunneling through arbitrarily-shaped plasmonic ultranarrow channels and bends connecting two larger plasmonic metal-insulator-metal waveguides. It is shown how a proper design of sub-wavelength optical channels at cut-off, patterned by plasmonic implants and connecting larger plasmonic w

  51. J. P. De Lima, L. L. Goncalves

    The isotropic XY model $(s=1/2)$ in a transverse field, with uniform long-range interactions among the transverse components of the spins, on the inhomogeneous periodic chain, is studied. The model, composed of $N$ segments with $n$ different exchange interactions and magnetic moments, is exactly solved by introducing the integral gaussian transformation and

  52. Matthew C. Johnson, Marc Kamionkowski

    Coherent oscillations of a scalar field can mimic the behavior of a perfect fluid with an equation-of-state parameter determined by the properties of the potential, possibly driving accelerated expansion in the early Universe (inflation) and/or in the Universe today (dark energy) or behaving as dark matter. We consider the growth of inhomogeneities in such a

  53. Emil Prodan, Camelia Prodan, John H. Miller

    We develop a theoretical framework to describe the dielectric response of live cells in suspensions when placed in low external electric fields. The treatment takes into account the presence of the cell&#39;s membrane and of the charge movement at the membrane&#39;s surfaces. For spherical cells suspended in aqueous solutions, we give an analytic solution fo

  54. Dejenie A. Lakew

    In this short note, we present few results on the use of the discrete Laplace transform in solving first and second order initial value problems of discrete differential equations.

  55. Matthew Bershady, Marc Verheijen, Steven Crawford

    How large disk galaxies have evolved in, and out of, the blue cloud of actively star-forming galaxies as a function of environment and time is an outstanding question. Some of the largest disks become systems like M31, M33 and the Milky Way today. In denser environments, it appears they transform onto the red sequence. Tracking disk systems since z<0.5 as a

  56. Markus Clermont, Christian Hanin, Roland T. Mittermeir

    Amongst the large number of write-and-throw-away spreadsheets developed for one-time use there is a rather neglected proportion of spreadsheets that are huge, periodically used, and submitted to regular update-cycles like any conventionally evolving valuable legacy application software. However, due to the very nature of spreadsheets, their evolution is part

  57. Yirsaw Ayalew, Markus Clermont, Roland T. Mittermeir

    The paper presents two complementary strategies for identifying errors in spreadsheet programs. The strategies presented are grounded on the assumption that spreadsheets are software, albeit of a different nature than conventional procedural software. Correspondingly, strategies for identifying errors have to take into account the inherent properties of spre

  58. A. Tappe, C. J. Lada, J. H. Black, A. A. Muench

    We present a 5-37 micron infrared spectrum obtained with the Spitzer Space Telescope toward the southeastern lobe of the young protostellar outflow HH211. The spectrum shows an extraordinary sequence of OH emission lines arising in highly excited rotational levels up to an energy E/k~28200K above the ground level. This is, to our knowledge, by far the highes

  59. Dominic C. Ford, Bojan Nikolic, Paul Alexander

    We present a semi-empirical model for the infrared emission of dust around star-forming sites in galaxies. Our approach combines a simple model of radiative transfer in dust clouds with a state-of-the-art model of the microscopic optical properties of dust grains pioneered by Draine & Li. In combination with the Starburst 99 stellar spectral synthesis packag

  60. L. D. Matthews, Y. Libert, E. Gerard, T. Le Bertre

    We report the detection of an HI counterpart to the extended, far-ultraviolet-emitting tail associated with the asymptotic giant branch star Mira (o Ceti). Using the Nancay Radio Telescope (NRT), we have detected emission as far as 88&#39; north of the star, confirming that the tail contains a significant atomic component (M_HI ~ 4x10e-3 M_sun). The NRT spec

  61. Machiel van Frankenhuijsen

    Using a `height-to-radical&#39; identity, we define the archimedean contribution to the radical, $r_\arch$, and we give a new proof of the abc theorem for the field of meromorphic functions. The first step of the proof is completely formal and yields that the height is bounded by the radical, $h\leq r$, where $r=r_\na+r_\arch$ is the radical completed with t

  62. Martyn Amos, Oliver Don

    Purpose: To present an algorithm for spatially sorting objects into an annular structure. Design/Methodology/Approach: A swarm-based model that requires only stochastic agent behaviour coupled with a pheromone-inspired &#34;attraction-repulsion&#34; mechanism. Findings: The algorithm consistently generates high-quality annular structures, and is particularly

  63. Aron J. Cohen, Paula Mori-Sánchez, Weitao Yang

    Electronic states with fractional spins arise in systems with large static correlation (strongly correlated systems). Such fractional-spin states are shown to be ensembles of degenerate ground states with normal spins. It is proven here that the energy of the exact functional for fractional-spin states is a constant, equal to the energy of the comprising deg

  64. Nicolas Vuillerme, Nicolas Pinsault, Olivier Chenu, Anthony Fleury

    We describe the architecture of an original biofeedback system for balance improvement for fall prevention and present results of a feasibility study. The underlying principle of this biofeedback consists of providing supplementary information related to foot sole pressure distribution through a wireless embedded tongue-placed tactile output device. Twelve y

  65. Andrew S. Powell

    Strategies that utilise the interference effects within $B^{\pm} \to DK^{\pm}$ decays hold great potential for improving our sensitivity to the CKM angle $γ$. However, in order to exploit fully this potential, detailed knowledge of the D meson decay structure is required. This essential information can be obtained from the quantum correlated $ψ(3770)$ datase

  66. Hume A. Feldman, Michael J. Hudson, Richard Watkins

    To study galactic motions on the largest available scales, we require bulk flow moments whose window functions have as narrow a peak as possible and having as small an amplitude as possible outside the peak. Typically the moments found using the maximum likelihood estimate weights do not meet these criteria. We present a new method for calculating weights fo

  67. C. Cameron, H. Saio, R. Kuschnig, G. A. H. Walker

    The MOST (Microvariability and Oscillations of Stars) satellite has discovered SPBe (Slowly Pulsating Be) oscillations in the stars HD 127756 (B1/B2 Vne) and HD 217543 (B3 Vpe). For HD 127756, 30 significant frequencies are identified from 31 days of nearly continuous photometry; for HD 217543, up to 40 significant frequencies from 26 days of data. In both c

  68. G. S. Denicol, T. Kodama, T. Koide, Ph. Mota

    We studied the shock propagation and its stability with the causal dissipative hydrodynamics in 1+1 dimensional systems. We show that the presence of the usual viscosity is not enough to stabilize the solution. This problem is solved by introducing an additional viscosity which is related to the coarse-graining scale of the theory.

  69. Ioannis Deretzis, Antonino La Magna

    We study dynamic nonequilibrium electron charging phenomena in ballistic molecular devices at room temperature that compromise their response to bias and whose nature is evidently distinguishable from static Schottky-type potential barriers. Using various metallic/semiconducting carbon nanotubes and alkane dithiol molecules as active parts of a molecular bri

  70. I. M. Sokolov, M. D. Kupriyanova, D. V. Kupriyanov, M. D. Havey

    The quantum optical response of high density ultracold atomic systems is critical to a wide range of fundamentally and technically important physical processes. These include quantum image storage, optically based quantum repeaters and ultracold molecule formation. We present here a microscopic analysis of the light scattering on such a system, and we compar

  71. E. M. Barboza, J. S. Alcaniz

    Determining the mechanism behind the current cosmic acceleration constitutes a major question nowadays in theoretical physics. If the dark energy route is taken, this problem may potentially bring to light new insights not only in Cosmology but also in high energy physics theories. Following this approach, we explore in this paper some cosmological consequen

  72. Keumsook Lee, Woo-Sung Jung, Jong Soo Park, M. Y. Choi

    The Metropolitan Seoul Subway system, consisting of 380 stations, provides the major transportation mode in the metropolitan Seoul area. Focusing on the network structure, we analyze statistical properties and topological consequences of the subway system. We further study the passenger flows on the system, and find that the flow weight distribution exhibits

  73. Yingdong Lu

    Stochastic knapsack problem originally was a versatile model for controls in telecommunication networks. Recently, it draws attentions of revenue management community by serving as a basic model for allocating resources over time. We develop approximation schemes for knapsack problems in this paper, a system of nonlinear but solvable partial differential equ

  74. Jesper Rasmussen, Trevor J. Ponman, Lourdes Verdes-Montenegro, Min S. Yun

    Galaxies in compact groups tend to be deficient in neutral hydrogen compared to isolated galaxies of similar optical properties. In order to investigate the role played by a hot intragroup medium (IGM) for the removal and destruction of HI in these systems, we have performed a Chandra and XMM-Newton study of eight of the most HI deficient Hickson compact gro

  75. Kenneth S. Alexander, Nikos Zygouras

    We consider a polymer with configuration modeled by the path of a Markov chain, interacting with a potential $u+V_n$ which the chain encounters when it visits a special state 0 at time $n$. The disorder $(V_n)$ is a fixed realization of an i.i.d. sequence. The polymer is pinned, i.e. the chain spends a positive fraction of its time at state 0, when $u$ excee

  76. Piotr S. Żuchowski, Jeremy M. Hutson

    We investigate the possibility of producing ultracold NH3 molecules by sympathetic cooling in a bath of ultracold atoms. We consider the interactions of NH3 with alkali-metal and alkaline-earth atoms, and with Xe, using ab initio coupled-cluster calculations. For Rb-NH3 and Xe-NH3 we develop full potential energy surfaces, while for the other systems we char

  77. A. Morozov

    Concise summary of the recent progress in the search for the world-volume action for multiple M2 branes. After a recent discovery of simplified version of BLG action, which is based on the ordinary Lie-algebra structure, does not have coupling constants and extra dynamical fields, attention should be switched to the study of M2 brane dynamics. A viable brane

  78. Konstantine Zelator

    The subject matter of this work are the linear, three variable diophantine equation ax+by+cz=d (1), and the diophantine system ax+by+cz=d (2) ex+fy+gz=h with the coefficients a,b,c,d,e,f,g,h being integers. Introductory number theory books, typically contain only a brief outline of how to solve equation (1). Even less or no material is offered on the system

  79. Wojciech Wasilewski, Czeslaw Radzewicz, Robert Frankowski, Konrad Banaszek

    We present an experimental characterization of the statistics of multiple photon pairs produced by spontaneous parametric down-conversion realized in a nonlinear medium pumped by high-energy ultrashort pulses from a regenerative amplifier. The photon number resolved measurement has been implemented with the help of a fiber loop detector. We introduce an effe

  80. Nadir Sekkal, V. R. Velasco

    We propose new confinement structures similar to heterostructures and superlattices. The new heteostructures can be obtained by applying strain to a single material in a periodic or aperiodic way. The conversion of an indirect gap into an optical active direct or quasi-direct gap problem has also been investigated together with the role of zone folding in th

  81. V. V. Klimov, D. Bloch, M. Ducloy, J. R. Rios Leite

    We show that a photon detector, sensitive to the gradients of electromagnetic fields, or to magnetic fields, should be a useful tool to characterize the quantum properties of spatially-dependent optical fields. We discuss the excitation of an atom on a magnetic dipole or electric quadrupole transitions with the spiral photons of a Laguerre-Gauss (LG) or Bess

  82. Slavek M. Rucinski, Theodor Pribulla, Stefan W. Mochnacki, Evgenij Liokumovich

    Radial-velocity measurements and sine-curve fits to the orbital radial velocity variations are presented for ten close binary systems: EG Cep,V1191 Cyg, V1003 Her, BD+7_3142, V357 Peg, V407 Peg, V1123 Tau, V1128 Tau, HH UMa, and PY Vir. While most of the studied eclipsing systems are contact binaries, EG Cep is a detached or a semi-detached double-lined bina

  83. Afshin Montakhab, Ali Asadian

    We investigate the dynamics of global entanglement, the Meyer-Wallach measure, under decoherence, analytically. We study two important class of multi-partite entangled states, the Greenberger-Horne-Zeilinger and the W state. We obtain exact results for various models of system-environment interactions (decoherence). Our results shows distinctly different sca

  84. Stéphane Colombi, Michał Chodorowski, Romain Teyssier

    We propose a simple way to estimate the parameter beta = Omega_m^(0.6)/b from three-dimensional galaxy surveys. Our method consists in measuring the relation between the cosmological velocity and gravity fields, and thus requires peculiar velocity measurements. The relation is measured *directly in redshift space*, so there is no need to reconstruct the dens

  85. M. Slawinska

    Evolution equations of YFS and DGLAP types in leading order are considered. They are compared in terms of mathematical properties and solutions. In particular, it is discussed how the properties of evolution kernels affect solutions. Finally, comparison of solutions obtained numerically are presented.

  86. Jeong San Kim, Barry C. Sanders

    We generalize the W class of states from $n$ qubits to $n$ qudits and prove that their entanglement is fully characterized by their partial entanglements even for the case of the mixture that consists of a W-class state and a product state $\ket{0}^{\otimes n}$.

  87. Marc van der Sluys, Vivien Raymond, Ilya Mandel, Christian Roever

    We present a Markov-chain Monte-Carlo (MCMC) technique to study the source parameters of gravitational-wave signals from the inspirals of stellar-mass compact binaries detected with ground-based gravitational-wave detectors such as LIGO and Virgo, for the case where spin is present in the more massive compact object in the binary. We discuss aspects of the M

  88. Andrew S. Toms

    We prove that the C*-algebra of a minimal diffeomorphism satisfies Blackadar&#39;s Fundamental Comparability Property for positive elements. This leads to the classification, in terms of K-theory and traces, of the isomorphism classes of countably generated Hilbert modules over such algebras, and to a similar classification for the closures of unitary orbits

  89. Dieter Schuch

    The time-evolution of the maximum and the width of exact analytic wave packet (WP) solutions of the time-dependent Schr\"odinger equation (SE) represents the particle and wave aspects, respectively, of the quantum system. The dynamics of the maximum, located at the mean value of position, is governed by the Newtonian equation of the corresponding classical p

  90. Andris Ambainis, Nikolajs Nahimovs

    We present a simple construction of quantum automata which achieve an exponential advantage over classical finite automata. Our automata use \frac{4}ε \log 2p + O(1) states to recognize a language that requires p states classically. The construction is both substantially simpler and achieves a better constant in the front of \log p than the previously known

  91. G. De Risi

    We present a model in which a 3-brane is embedded in a warped 5-dimensional background with a dilaton and a Kalb-Ramond 2-form. We show that it is possible to find static solutions of the form of charged dS/AdS-like black hole which could have a negative mass parameter. The motion of the 3-brane in this bulk generates an effective 4-dimensional bouncing cosm

  92. K. Itakura, O. Morimatsu, H. Otomo

    We investigate the effects of baryon chemical potential μon the shear viscosity coefficient ηand the viscosity to entropy density ratio η/s of a pion-nucleon gas mixture. We find that ηis an increasing function of T and μ, while the ratio η/s turns to a decreasing function in a wide region of T-μplane. In the kinematical region we studied, the smallest value

  93. Matthias Keller, Norbert Peyerimhoff

    In this article, we derive bounds for values of the global geometry of locally tessellating planar graphs, namely, the Cheeger constant and exponential growth, in terms of combinatorial curvatures. We also discuss spectral implications for the Laplacians.

  94. Alessandro Rossi, Giuseppe Vallone, Francesco De Martini, Paolo Mataloni

    We report on the implementation of a new interferometric scheme that allows the generation of photon pairs entangled in the time-energy degree of freedom. This scheme does not require any kind of temporal post-selection on the generated pairs and can be used even with lasers with short coherence time.

  95. Fred C. Adams, Gregory Laughlin, Anthony M. Bloch

    This paper considers the effects of turbulence on mean motion resonances in extrasolar planetary systems and predicts that systems rarely survive in a resonant configuration. A growing number of systems are reported to be in resonance, which is thought to arise from the planet migration process. If planets are brought together and moved inward through torque

  96. Luca Giomi, M. Cristina Marchetti, Tanniemola B. Liverpool

    We study the dynamical properties of active polar liquid crystalline films. Like active nematic films, active polar films undergo a dynamical transitions to spontaneously flowing steady-states. Spontaneous flow in polar fluids is, however, always accompanied by strong concentration inhomogeneities or &#34;banding&#34; not seen in nematics. In addition, a spe

  97. D. Suess, J. Lee, J. Fidler, T. Schrefl

    The potential of exchange spring bilayers and graded media is reviewed. An analytical model for the optimization of graded media gives an optimal value of the magnetic polarization of Js = 0.8 T. The optimum design allows for thermally stable grains with grain diameters in the order of 3.3 nm, which supports ultra high density up to 5 to 10 Tbit per inch2. T

  98. Britni LaBounty-Lay, Ashley Bechel, Anant P. Godbole

    A connected digraph in which the in-degree of any vertex equals its out-degree is Eulerian; this baseline result is used as the basis of existence proofs for universal cycles (also known as deBruijn cycles or $U$-cycles) of several combinatorial objects. We present new results on the existence of universal cycles of certain classes of functions. These includ

  99. Ali H. Reshak, S. Auluck, A. Majchrowski, I. V. Kityk

    Experimental measurements of the second order susceptibilities for the second harmonic generation are reported for YAl3(BO3)4 (YAB) single crystals for the two principal tensor components xyz and yyy. First principles calculation of the linear and nonlinear optical susceptibilities for Yttrium Aluminum Borate YAl3(BO3)4 (YAB) crystal have been carried out wi

  100. V. Pardo, S. Blanco-Canosa, F. Rivadulla, D. I. Khomskii

    Electronic structure calculations for spinel vanadate ZnV$_2$O$_4$ show that partial electronic delocalization in this system leads to structural instabilities. These are a consequence of the proximity to the itinerant-electron boundary, not being related to orbital ordering. We discuss how this mechanism naturally couples charge and lattice degrees of freed