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December 2006 arXiv papers — page 37

Showing 3,6013,700 of 4,461 papers

  1. Liuhua Zou, Wenjiang Pei, Tao Li, Zhenya He

    Several fundamental properties of real complex networks, such as the small-world effect, the scale-free degree distribution, and recently discovered topological fractal structure, have presented the possibility of a unique growth mechanism and allow for uncovering universal origins of collective behaviors. However, highly clustered scale-free network, with p

  2. Guillaume Weick, Dietmar Weinmann, Gert-Ludwig Ingold, Rodolfo A. Jalabert

    We propose an explanation for the anomalous behaviour observed in the relaxation dynamics of the differential optical transmission of noble-metal nanoparticles. Using the temperature dependences of the position and the width of the surface plasmon resonance, we obtain a strong frequency dependence in the time evolution of the transmission close to the resona

  3. Dušan Repovš, Boaz Tsaban, Lyubomyr Zdomskyy

    We show that even for subsets X of the real line which do not contain perfect sets, the Hurewicz property does not imply the property S1(Gamma,Gamma), asserting that for each countable family of open gamma-covers of X, there is a choice function whose image is a gamma-cover of X. This settles a problem of Just, Miller, Scheepers, and Szeptycki. Our main resu

  4. A. P. Kuznetsov, N. V. Stankevich, L. V. Turukina

    Features of synchronization picture in the system with the limit cycle embedded in a three-dimensional phase space are considered. By the example of Ressler system and Dmitriev - Kislov generator under the action of a periodic sequence of delta - function it is shown, that synchronization picture significantly depends on the direction of pulse action. Featur

  5. J. M. Nunes da Costa, F. Petalidou

    We study quasi-Jacobi and Jacobi-quasi bialgebroids and their relationships with twisted Jacobi and quasi Jacobi manifolds. We show that we can construct quasi-Lie bialgebroids from quasi-Jacobi bialgebroids, and conversely, and also that the structures induced on their base manifolds are related via a quasi Poissonization.

  6. G. Elhalel, R. Beck, G. Leibovitch, G. Deutscher

    We have probed the Landau levels of nodal quasi-particles by tunneling along a nodal direction of (110) oriented YBa$_2$Cu$_3$O$_{7-x}$ thin films with a magnetic field applied perpendicular to the $CuO_2$ planes, and parallel to the film's surface. In optimally doped films and at low temperature, finite energy nodal states are clearly observed in films

  7. J. M. Nunes da Costa, F. Petalidou

    We study the characteristic foliation of a twisted Jacobi manifold. We show that a twisted Jacobi manifold is foliated into leaves that are, according to the parity of the dimension, endowed with a twisted contact or a twisted locally conformal symplectic structure.

  8. Stefan Forste, Tatsuo Kobayashi, Hiroshi Ohki, Kei-jiro Takahashi

    We classify compactification lattices for supersymmetric Z2 times Z2 orbifolds. These lattices include factorisable as well as non-factorisable six-tori. Different models lead to different numbers of fixed points/tori. A lower bound on the number of fixed tori per twisted sector is given by four, whereas an upper bound consists of 16 fixed tori per twisted s

  9. Hong-Hao Zhang, Wen-Bin Yan, Xue-Song Li

    The contributions to $S$, $T$, and $U$ from heavy scalars in any irreducible representation of the electroweak gauge group $SU(2)_L\times U(1)_Y$ are obtained. We find that in the case of a heavy scalar doublet there is a slight difference between the $S$ parameter we have obtained and that in previous works.

  10. Jaya N. Iyer, Carlos T. Simpson

    In this paper, we obtain an explicit formula for the Chern character of a locally abelian parabolic bundle in terms of its constituent bundles. Several features and variants of parabolic structures are discussed. Parabolic bundles arising from logarithmic connections form an important class of examples. As an application, we consider the situation when the l

  11. Jinshuang Jin, Sven Welack, JunYan Luo, Xin-Qi Li

    A hierarchical equations of motion formalism for a quantum dissipation system in a grand canonical bath ensemble surrounding is constructed, on the basis of the calculus-on-path-integral algorithm, together with the parametrization of arbitrary non-Markovin bath that satisfies fluctuation-dissipation theorem. The influence functionals for both the Fermion or

  12. Eylee Jung, D. K. Park

    The Hawking radiation for massless spin-2 fields is numerically studied when the spacetime background is (4+n)-dimensional Schwarzschild black hole phase. In order to check the validity of the Emparan-Horowitz-Myers argument, {\it black holes radiate mainly on the brane}, we assume that the radial equation for the massless spin-2 fields propagating on the br

  13. Robert Skopec

    The Neurobiology Of Thinking, Identity, And Geniality Abstract: Mathematically the axioms of representation are subtle, and critical. The CNS expresses its function via its internal neuronal networks in multidimensional, intrinsic frames. CNS operation can be represented by tensor transformations within and among general frames of reference. So-called metaor

  14. Claire Amiot

    We study the problem of classifying triangulated categories with finite-dimensional morphism spaces and finitely many indecomposables over an algebraically closed field. We obtain a new proof of the following result due to Xiao and Zhu: the Auslander-Reiten quiver of such a category is of the form $\mathbb{Z}Δ/G$ where $Δ$ is a disjoint union of simply laced

  15. Jun Zhang

    We propose to measure the weak cosmic shear using the spatial derivatives of the galaxy surface brightness field. The measurement should be carried out in Fourier space, in which the point spread function (PSF) can be transformed to a desired form with multiplications, and the spatial derivatives can be easily measured. This method is mathematically well def

  16. Samuel Müller, Kaspar Rufibach

    Both parametric distribution functions appearing in extreme value theory - the generalized extreme value distribution and the generalized Pareto distribution - have log-concave densities if the extreme value index gamma is in [-1,0]. Replacing the order statistics in tail index estimators by their corresponding quantiles from the distribution function that i

  17. Victor Ginzburg

    We introduce some new algebraic structures arising naturally in the geometry of Calabi-Yau manifolds and mirror symmetry. We give a universal construction of Calabi-Yau algebras in terms of a noncommutative symplectic DG algebra resolution. In dimension 3, the resolution is determined by a noncommutative potential. Representation varieties of the Calabi-Yau

  18. Ruslan Prozorov

    High-resolution magneto-optical technique was used to analyze flux patterns in the intermediate state of bulk Pb samples of various shapes - cones, hemispheres and discs. Combined with the measurements of macroscopic magnetization these results allowed studying the effect of bulk pinning and geometric barrier on the equilibrium structure of the intermediate

  19. David Futer, Efstratia Kalfagianni, Jessica S. Purcell

    Given a hyperbolic 3-manifold with torus boundary, we bound the change in volume under a Dehn filling where all slopes have length at least 2π. This result is applied to give explicit diagrammatic bounds on the volumes of many knots and links, as well as their Dehn fillings and branched covers. Finally, we use this result to bound the volumes of knots in ter

  20. Shimul Akhanjee, Joseph Rudnick

    We explore various properties of classical one-dimensional Wigner solids in the presence of disorder at T=0 in the context of a recently discovered Anderson transition of plasma modes in the random potential system. The extent to which the Wigner lattice is really a ``crystal'' rather than an amorphous solid is discussed for two types of disorder. We

  21. Yoshio Koide

    Based on a universal seesaw mass matrix model with three scalars ϕ_i, and by assuming an S_3 flavor symmetry for the Yukawa interactions, the lepton masses and mixings are investigated systematically. In order to understand the observed neutrino mixing, the charged leptons (e, μ, τ) are regarded as the 3 elements (e_1, e_2, e_3) of S_3, while the neutrino ma

  22. Peter Lynds

    Based on the conjecture that rather than the second law of thermodynamics inevitably be breached as matter approaches a big crunch or a black hole singularity, the order of events should reverse, a model of the universe that resolves a number of longstanding problems and paradoxes in cosmology is presented. A universe that has no beginning (and no need for o

  23. Shujuan Liu, Hongwei Xiong

    In an exciting experiment by MIT's group (Science 275, 637 (1997)), clear interference fringes were observed for two initially independent Bose condensates in dilute gas. Presently, there are two different theories (measurement-induced interference theory and interaction-induced interference theory) which can both explain MIT's experimental results.

  24. Tsunehide Kuroki, Fumihiko Sugino

    We examine how nonperturbative effects in string theory are transformed under the T-duality in its nonperturbative framework by analyzing the c=1/2 noncritical string theory as a simplest example. We show that in the T-dual theory they also take the form of exp(-S_0/g_s) in the leading order and that the instanton actions S_0 of the dual ZZ-branes are exactl

  25. Avinash Khare, Sergey V. Dmitriev, Avadh Saxena

    We obtain exact moving and stationary, spatially periodic and localized solutions of a generalized discrete nonlinear Schrödinger equation. More specifically, we find two different moving periodic wave solutions and a localized moving pulse solution. We also address the problem of finding exact stationary solutions and, for a particular case of the model whe

  26. D. J. P. Ellis, R. M. Stevenson, R. J. Young, P. Atkinson

    Degeneracy of the bright single exciton spin state is a prerequisite for the production of triggered polarization-entangled photon pairs from the biexciton decay of a quantum dot. Normally, however, the exciton spin states are split due to in-plane asymmetries. Here we demonstrate that the exciton splitting of an individual dot can be tuned through zero by t

  27. D. J. P. Ellis, A. J. Bennett, P. Atkinson, D. A. Ritchie

    We report on the use of an aperture in an aluminum oxide layer to restrict current injection into a single self-assembled InAs quantum dot, from an ensemble of such dots within a large mesa. The insulating aperture is formed through the wet-oxidation of a layer of AlAs. Under photoluminescence we observe that only one quantum dot in the ensemble exhibits a S

  28. M. Paternostro, M. S. Kim, G. M. Palma

    We study the accumulation of entanglement in a memory device built out of two continuous variable (CV) systems. We address the case of a qubit mediating an indirect joint interaction between the CV systems. We show that, in striking contrast with respect to registers built out of bidimensional Hilbert spaces, entanglement superior to a single ebit can be eff

  29. Anatoly Zaitsev, Sergey Leble

    A general algebraic method of quantum corrections evaluations is presented. Quantum corrections to a few classical solutions of Landau-Ginzburg model (phi-in-quadro) are calculated in arbitrary dimensions. The Green function for heat equation with soliton potential is constructed by Darboux transformation. The generalized zeta-function is used to evaluate th

  30. Zhiguo Lü, Hang Zheng

    The decoherence of a two-state system coupled with a sub-Ohmic bath is investigated theoretically by means of the perturbation approach based on a unitary transformation. It is shown that the decoherence depends strongly and sensitively on the structure of environment. Nonadiabatic effect is treated through the introduction of a function $ξ_k$ which depends

  31. ILki Kim, Gerald J. Iafrate

    The fundamental quantum dynamics of two interacting oscillator systems are studied in two different scenarios. In one case, both oscillators are assumed to be linear, whereas in the second case, one oscillator is linear and the other is a non-linear, angular-momentum oscillator; the second case is, of course, more complex in terms of energy transfer and dyna

  32. ILki Kim, Gerald J. Iafrate

    A simple approach for understanding the quantum nature of angular momentum and its reduction to the classical limit is presented based on Schwinger's coupled-boson representation. This approach leads to a straightforward explanation of why the square of the angular momentum in quantum mechanics is given by j(j+1) instead of just j^2, where j is the angul

  33. A. Kwang-Hua Chu

    The modified Gross-Pitaevskii equation was derived and solved to obtain the 1D solution in the zero-energy limit. This stationary solution could account for the dominated contributions due to the kinetic effect as well as the chemical potential in inhomogeneous Bose gases.

  34. Dirson Jian Li

    Much information is stored in amino acid composition of protein and base composition of DNA. We simulated the evolution of amino acid frequencies and genomic GC content by a linguistic model. It is showed that the evolution of genetic code determines the evolution of amino acid frequencies and genomic GC content. We explained the relationships among amino ac

  35. L. Berge, S. Skupin, R. Nuter, J. Kasparian

    Modern laser sources nowadays deliver ultrashort light pulses reaching few cycles in duration, high energies beyond the Joule level and peak powers exceeding several terawatt (TW). When such pulses propagate through optically-transparent media, they first self-focus in space and grow in intensity, until they generate a tenuous plasma by photo-ionization. For

  36. M. Marklund, G. Brodin

    The fully nonlinear governing equations for spin 1/2 quantum plasmas are presented. Starting from the Pauli equation, the relevant plasma equations are derived, and it is shown that nontrivial quantum spin couplings arise, enabling studies of the combined collective and spin dynamics. The linear response of the quantum plasma in an electron--ion system is ob

  37. Alexander I. Kuleff, Lorenz S. Cederbaum

    Tremendous advances in laser pump-probe techniques open the door for the observation in real time of ultrafast \textit{electronic} processes. Particularly attractive is the visualization of interatomic processes where one can follow the process of energy transfer from one atom to another. The interatomic Coulombic decay (ICD) provides such a process which is

  38. Yuichi Togashi, Kunihiko Kaneko

    To study the fluctuations and dynamics in chemical reaction processes, stochastic differential equations based on the rate equation involving chemical concentrations are often adopted. When the number of molecules is very small, however, the discreteness in the number of molecules cannot be neglected since the number of molecules must be an integer. This dis

  39. Sumiyoshi Abe, Norikazu Suzuki

    The network approach plays a distinguished role in contemporary science of complex systems/phenomena. Such an approach has been introduced into seismology in a recent work [S. Abe and N. Suzuki, Europhys. Lett. 65, 581 (2004)]. Here, we discuss the dynamical property of the earthquake network constructed in California and report the discovery that the values

  40. Yuri Paskover, I. Sh. Averbukh, Yehiam Prior

    Single-shot time resolved Coherent Anti-Stokes Raman Scattering (CARS) is presented as a viable method for fast measurements of molecular spectra. The method is based on the short spatial extension of femtosecond pulses and maps time delays between pulses onto the region of intersection between broad beams. The image of the emitted CARS signal contains full

  41. V. A. Panchelyuga, V. A. Kolombet, M. S. Panchelyuga, S. E. Shnoll

    The main subject of the work is experimental investigation of local-time effect existence on laboratory scale, which means longitudinal distances between locations of measurements from tens to one meter. Also short revue of our investigations of local-time effect existence for distances from 15 km to 500 m are presented. Besides investigations of the minimal

  42. M. L. Gorelik, I. V. Safonov, M. H. Urin

    A continuum-RPA-based approach is applied to describe the decay properties of isolated dipole isobaric analog resonances in nuclei having not-too-large neutron excess. Calculated for a few resonances in 90Zr the elastic E1-radiative width and partial proton widths for decay into one-hole states of 89Y are compared with available experimental data.

  43. M. S. Bhagwat, A. Krassnigg, P. Maris, C. D. Roberts

    In this summary of the application of Dyson-Schwinger equations to the theory and phenomenology of hadrons, some deductions following from a nonperturbative, symmetry-preserving truncation are highlighted, notable amongst which are results for pseudoscalar mesons. We also describe inferences from the gap equation relating to the radius of convergence of a ch

  44. T. Melde

    We discuss electromagnetic currents in the point-form formulation of relativistic quantum mechanics. The construction is along a spectator model and implies that only one quark is explicitly coupled to the photon, but nevertheless many-body contributions are present in the current operator. Such effects are unavoidable in relativistic constructions and resul

  45. A. Leviatan

    Quantum shape-phase transitions in finite nuclei are considered in the framework of the interacting boson model. Critical-point Hamiltonians for first- and second-order transitions are identified by resolving them into intrinsic and collective parts. Suitable wave functions and finite-N estimates for observables at the critical-points are derived.

  46. A. N. Ivanov, P. Kienle, J. Marton, E. Widmann

    A phenomenological model is proposed for the analysis of the properties of the Kaonic Nuclear Cluster (KNC) Kpp in its ground state. Inside the KNC K^-pp we describe the relative motion of the protons in the pp pair and the motion of the K^- meson relative to the pp pair in terms of wave functions of 3-dimensional harmonic oscillators. The interaction streng

  47. E. Garcia, R. S. Hollis, A. Olszewski, I. C. Park

    Typical vertex finding algorithms use reconstructed tracks, registered in a multi-layer detector, which directly point to the common point of origin. A detector with a single layer of silicon sensors registers the passage of primary particles only in one place. Nevertheless, the information available from these hits can also be used to estimate the vertex po

  48. A. Rapoport, V. Rom-Kedar, D. Turaev

    This supplement to the article "Approximating multi-dimensional Hamiltonian flows by billiards" contains the proofs of C$^{0}$ and C$^{r}$ - closeness theorems stated in the article.

  49. Luca Biferale, Laurent Chevillard, Charles Meneveau, Federico Toschi

    A multi-scale model for the evolution of the velocity gradient tensor in fully developed turbulence is proposed. The model is based on a coupling between a ``Restricted Euler'' dynamics [{\it P. Vieillefosse, Physica A, {\bf 14}, 150 (1984)}] which describes gradient self-stretching, and a deterministic cascade model which allows for energy exchange

  50. Yoshinori Watanabe, Kunihiko kaneko

    Dynamics with a threshold input--output relation commonly exist in gene, signal-transduction, and neural networks. Coupled dynamical systems of such threshold elements are investigated, in an effort to find differentiation of elements induced by the interaction. Through global diffusive coupling, novel states are found to be generated that are not the origin

  51. Geoffrey Sewell

    We construct a class of quantum stochastic models of reservoir driven many-particle systems that are the natural counterparts of certain extensively studied classical ones, which have been shown to exhibit good hydrodynamical behaviour. Our treatment of these models achieves two main aims. The first is to show that they enjoy the hydrodynamical properties of

  52. Mushfiq Ahmad

    We have shown that Lorentz transformation is not necessary to present relativistic relative velocity. A modified definition of velocity together with Galilean transformation is equivalent to relativistic relative velocity. On the other hand, Galilean relative velocity can be presented as a Lorentz transformation. Again the definition of velocity requires a m

  53. O Foda, M Wheeler

    Using BKP neutral fermions, we derive a product expression for the generating function of volume-weighted plane partitions that satisfy two conditions. If we call a set of adjacent equal height-h columns, h > 0, an h-path, then 1. Every h-path can assume one of two possible colours. 2. There is a unique way to move along an h-path from any column to another.

  54. Illya M. Karabash, Aleksey S. Kostenko

    We present a new necessary condition for similarity of indefinite Sturm-Liouville operators to self-adjoint operators. This condition is formulated in terms of Weyl-Titchmarsh $m$-functions. Also we obtain necessary conditions for regularity of the critical points 0 and $\infty$ of $J$-nonnegative Sturm-Liouville operators. Using this result, we construct se

  55. Pascale Roesch

    For the study of the 2-dimensional space of cubic polynomials, J. Milnor considers the complex 1-dimensional slice S_n of the cubic polynomials which have a super-attracting orbit of period n. He gives in [M4] a detailed conjectural picture of S_n. In this article, we prove these conjectures for S_1 and generalize these results in higher degrees. In particul

  56. Nantel Bergeron, Huilan Li

    The Grothendieck group of the tower of symmetric group algebras has a self-dual graded Hopf algebra structure. Inspired by this, we introduce by way of axioms, a general notion of a tower of algebras and study two Grothendieck groups on this tower linked by a natural paring. Using representation theory, we show that our axioms give a structure of graded Hopf

  57. P. Blue, A. Soffer

    We continue our study of the decoupled wave equation in the exterior of a spherically symmetric, Schwarzschild, black hole. Because null geodesics on the photon sphere orbit the black hole, extra effort must be made to show that the high angular momentum components of a solution decay sufficiently fast, particularly for low regularity initial data. Previous

  58. Frederic Mazenc, Michael Malisoff, Patrick De Leenheer

    We study the chemostat model for one species competing for one nutrient using a Lyapunov-type analysis. We design the dilution rate function so that all solutions of the chemostat converge to a prescribed periodic solution. In terms of chemostat biology, this means that no matter what positive initial levels for the species concentration and nutrient are sel

  59. Yun-Su Kim

    We give definitions and some properties of the shift operator S_{L(H^2)} and multiplication operator on L(H^2). In addition, we obtain some properties of the commutant of the shift operator S_{L(H^2)} and characterize S_{L(H^2)}-invariant subspaces.

  60. Vigleik Angeltveit

    We set up a general framework for enriching a subcategory of the category of noncommutative sets over a category C using products of the objects of a non-Σoperad P in \C. By viewing the simplicial category as a subcategory of the category of noncommutative sets in two different ways, we obtain two generalizations of simplicial objects. For the operad given b

  61. Vigleik Angeltveit

    Let A be an A_\infty ring spectrum. We use the description from [2] of the cyclic bar and cobar construction to give a direct definition of topological Hochschild homology and cohomology of A using the Stasheff associahedra and another family of polyhedra called cyclohedra. This construction builds the maps making up the A_\infty structure into THH(A), and a

  62. Victor Goodman

    We introduce a transform on the class of stochastic exponentials for d-dimensional Brownian motions. Each stochastic exponential generates another stochastic exponential under the transform. The new exponential process is often merely a supermartingale even in cases where the original process is a martingale. We determine a necessary and sufficient condition

  63. I. A. Cheltsov, M. M. Grinenko

    We construct an example of the birationally rigid complete intersection of a quadric and a cubic in $\PA^5$ with an ordinary double point, which under a small deformation gives a non-rigid Fano variety. Thus we show that birational rigidity is not open in moduli.

  64. E B Davies, Mildred Hager

    We consider perturbations of a large Jordan matrix, either random and small in norm or of small rank. In both cases we show that most of the eigenvalues of the perturbed matrix are very close to a circle with centre at the origin. In the case of random perturbations we obtain an estimate of the number of eigenvalues that are well inside the circle in a certa

  65. Jurgen Berndt, Jose Carlos Diaz-Ramos

    We study the geometry of homogeneous hypersurfaces and their focal sets in complex hyperbolic spaces. In particular, we provide a characterization of the focal set in terms of its second fundamental form and determine the principal curvatures of the homogeneous hypersurfaces together with their multiplicities.

  66. Roger Tchangang Tambekou

    We equip the whole tangent space $TM$ to a hyperbolic manifold $M$ (of constant sectional curvature -1) with a natural metric in an intrinsic way, so that the isometries of $M$ extend to isometries of $TM$ by holomorphic continuation. The image to the tangent space to a geodesic is equivalent to a hyperbolic disk. In the case of hyperbolic space, we exhibit

  67. Zhiming Gao, Yichen Ma, Hongwei Zhuang

    This paper is concerned with the problem of shape optimization of two-dimensional flows governed by the time-dependent Navier-Stokes equations. We derive the structures of shape gradients with respect to the shape of the variable domain for time-dependent cost functionals by using the state derivative with respect to the shape of the fluid domain and its ass

  68. Andrey Tydnyuk

    We investigate the Knizhnik-Zamolodchikov linear differential system. The coefficients of this system are rational functions. We prove that the solution of the KZ system is rational when $k$ is equal to two and $n$ is equal to three. While doing so, we found the coefficients of expansion in a neighborhood of a singular point.

  69. Alan G. B. Lauder, Daqing Wan

    We present a deterministic polynomial time algorithm for computing the zeta function of an arbitrary variety of fixed dimension over a finite field of small characteristic. One consequence of this result is an efficient method for computing the order of the group of rational points on the Jacobian of a smooth geometrically connected projective curve over a f

  70. David Marin, Jean-Francois Mattei

    We consider a non-dicritic germ of foliations defined in some ball, with finite number of separatrices and satisfying some additional but generic hypothesis. We prove that there exists an open neighborhood U of the total separatice set S such that each leaf of foliaion restrict to (U-S) is incompressible in (U-S).

  71. Guillaume Carlier, Bruno Nazaret

    Among $\R^3$-valued triples of random vectors $(X,Y,Z)$ having fixed marginal probability laws, what is the best way to jointly draw $(X,Y,Z)$ in such a way that the simplex generated by $(X,Y,Z)$ has maximal average volume? Motivated by this simple question, we study optimal transportation problems with several marginals when the objective function is the d

  72. Zhiming Gao, Yichen Ma, Hongwei Zhuang

    This paper is concerned with the optimal shape design of the newtonian viscous incompressible fluids driven by the stationary nonhomogeneous Navier-Stokes equations. We use three approaches to derive the structures of shape gradients for some given cost functionals. The first one is to use the Piola transformation and derive the state derivative and its asso

  73. Shinji Tanimoto

    In order to study signed Eulerian numbers, we introduce permutations of a particular type, called parity-alternate permutations, because they take even and odd entries alternately. The objective of this paper is twofold. The first is to derive several properties of those permutations, by subdividing them into even and odd ones. The second is to discuss relat

  74. W. Mueckenheim

    The famous contradiction of a bijection between a set and its power set is a consequence of the impredicative definition involved. This is shown by the fact that a simple mapping between equivalent sets does also fail to satisfy the critical requirement.

  75. A. Alarcon, L. Ferrer, F. Martin

    The singly periodic genus-one helicoid was in the origin of the discovery of the first example of a complete minimal surface with finite topology but infinite total curvature, the celebrated Hoffman-Karcher-Wei's genus one helicoid. The objective of this paper is to give a uniqueness theorem for the singly periodic genus-one helicoid provided the existen

  76. Radu Popescu

    We define and study an equivariant $E$-theory with respect to coactions of Hopf $C^*$-algebras; we prove the Baaj-Skandalis duality in this setting. We show that the corresponding equivariant $KK$-theory of Baaj and Skandalis enjoys an universal property. In the appendix, we look at the different ways of expressing equivariant stability for a functor, and pr

  77. Carlo Marinelli, Sergei Savin

    We propose a novel approach to modeling advertising dynamics for a firm operating over distributed market domain based on controlled partial differential equations of diffusion type. Using our model, we consider a general type of finite-horizon profit maximization problem in a monopoly setting. By reformulating this profit maximization problem as an optimal

  78. P. Valtancoli

    We explore the method of entanglement entropy applied to 2d black holes. We introduce a solvable model of a real scalar field with finite volume and lattice spacing in terms of $N$ coupled mechanical oscillators and compute its entanglement entropy in many cases. The large $N$ limit of this scheme, with finite lattice spacing, should reproduce the Bekenstein

  79. V. Gayral, J. -H. Jureit, T. Krajewski, R. Wulkenhaar

    We propose a general formulation of perturbative quantum field theory on (finitely generated) projective modules over noncommutative algebras. This is the analogue of scalar field theories with non-trivial topology in the noncommutative realm. We treat in detail the case of Heisenberg modules over noncommutative tori and show how these models can be understo

  80. R. S. Ward

    We construct, numerically, a solution of the SU(2) Bogomolny equations corresponding to a sheet of BPS monopoles. It represents a domain wall between a vacuum region and a region of constant energy density, and it is the smoothed-out version of the planar sheet of Dirac monopoles obtained by linear superposition.

  81. Tapobrata Sarkar

    We study some aspects of Gauged Linear Sigma Models corresponding to orbifold singularities of the form $\BC^r/Γ$, for $r=2,3$ and $Γ= \BZ_n$ and $\BZ_n\times \BZ_m$. These orbifolds might be tachyonic in general. We compute expressions for the multi parameter sigma model Lagrangians for these orbifolds, in terms of their toric geometry data. Using this, we

  82. A. Mironov, A. Morozov

    In TeV-gravity models the gravitational coupling to particles with energies E\sim m_{Pl} \sim 10 TeV is not suppressed by powers of ultra-small ratio E/M_{Pl} with M_{Pl} \sim 10^{19} GeV. Therefore one could imagine strong synchrotron radiation of gravitons by the accelerating particles to become the most pronounced manifestation of TeV-gravity at LHC. Howe

  83. L. Frankfurt, M. Strikman, M. Zhalov

    We demonstrate that study of large t vector meson photoproduction with rapidity gaps in ultraperipheral proton-ion and ion-ion collisions at LHC would allow to investigate the energy dependence of cross section of elastic scattering of a small dipole off the parton over a wide range of energies $10^3 < s_{dipole - parton} < 10^6 GeV^2$ where this cross secti

  84. Igor N. Mishustin, Konstantin A. Lyakhov

    It is assumed that strong chromofields are generated at early stages of ultrarelativistic heavy-ion collisions which give rise to a collective deceleration of net baryons from colliding nuclei. We have solved classical equations of motion for baryonic slabs under the action of a time-dependent longitudinal chromoelectric field. It is demonstrated that the sl

  85. S. Ostapchenko

    General physics of very high energy hadronic interactions is discussed. Special attention is payed to the contribution of semihard processes to the interaction dynamics and to the role of parton shadowing and parton density saturation. In particular, the implementation of non-linear interaction effects in the QGSJET-II model is discussed in detail. The predi

  86. Marcello Ciafaloni

    I recall the main ideas about the treatment of QCD infrared physics, as developed in the late seventies, and I outline some novel applications of those ideas to Electroweak Theory.

  87. Wenna Xu, Xuelei Wang, Zhenjun Xiao

    In the framework of topcolor-assisted technicolor(TC2) model, there exist tree-level flavor-changing (FC) couplings which can result in the loop-level FC coupling $tcg$. Such $tcg$ coupling can contribute significant clues at the forthcoming Large Hadron Collider (LHC) experiments. In this paper, based on the TC2 model, we study some single t-quark productio

  88. W. M. Alberico, A. Beraudo, A. De Pace, A. Molinari

    The Schroedinger equation for the charmonium and bottomonium states at finite temperature is solved by employing an effective temperature dependent potential given by a linear combination of the color singlet free and internal energies obtained on the lattice from the Polyakov loop correlation functions. The melting temperatures and other properties of the q

  89. R. Williams, C. S. Fischer, M. R. Pennington

    We determine the ${\bar{q}}q$ condensate for quark masses from zero up to that of the strange quark within a phenomenologically successful modelling of continuum QCD by solving the quark Schwinger-Dyson equation. The existence of multiple solutions to this equation is the key to an accurate and reliable extraction of this condensate using the operator produc

  90. Koichi Hamaguchi, Mihoko M. Nojiri, Albert de Roeck

    If the scalar tau $\stau$ is the next lightest supersymmetric particle and decays into a gravitino ($\gravitino$) being the lightest supersymmetric particle, it will have generally a very long lifetime. In this paper, we investigate the possibility to study the decay of such a long lived scalar tau at the LHC. If we can add to the present LHC experiments add

  91. Markus Diefenthaler

    Azimuthal single-spin asymmetries (SSA) in semi-inclusive electroproduction of charged pions and kaons in deep-inelastic scattering of positrons on a transversely polarised hydrogen target were observed. SSA amplitudes for both the Collins and the Sivers mechanism are presented.

  92. Remo Garattini

    We consider a multigravity approach to spacetime foam. As an application we give indications on the computation of the cosmological constant, considered as an eigenvalue of a Sturm-Liouville problem. A variational approach with Gaussian trial wave functionals is used as a method to study such a problem. We approximate the equation to one loop in a Schwarzsch

  93. Linqing Wen, Yanbei Chen, Jonathan Gair

    The inspirals of stellar-mass compact objects into supermassive black holes are some of the most exciting sources of gravitational waves for LISA. Detection of these sources using fully coherent matched filtering is computationally intractable, so alternative approaches are required. In Wen & Gair (2005), we proposed a detection method based on searching for

  94. Mayeul Arminjon

    In a foregoing paper, gravity has been interpreted as the pressure force exerted on matter at the scale of elementary particles by a perfect fluid. Under the condition that Newtonian gravity must be recovered in the incompressible case, a scalar field equation has thus been proposed for gravity, giving a new theory in the compressible case. Here the theory i

  95. Stefano Ansoldi, Piero Nicolini, Anais Smailagic, Euro Spallucci

    We find a new, non-commutative geometry inspired, solution of the coupled Einstein-Maxwell field equations describing a variety of charged, self-gravitating objects, including extremal and non-extremal black holes. The metric smoothly interpolates between deSitter geometry, at short distance, and Reissner-Nordstroem geometry far away from the origin. Contrar

  96. M. Sharif, Sehar Aziz

    This paper is devoted to classify the most general plane symmetric spacetimes according to kinematic self-similar perfect fluid and dust solutions. We provide a classification of the kinematic self-similarity of the first, second, zeroth and infinite kinds with different equations of state, where the self-similar vector is not only tilted but also orthogonal

  97. Raghav Aras, Alain Dutech, François Charpillet

    We propose a formulation of a general-sum bimatrix game as a bipartite directed graph with the objective of establishing a correspondence between the set of the relevant structures of the graph (in particular elementary cycles) and the set of the Nash equilibria of the game. We show that finding the set of elementary cycles of the graph permits the computati

  98. Vladimir Anashin

    These are lecture notes of a 20-hour course at the International Summer School \emph{Mathematical Methods and Technologies in Computer Security} at Lomonosov Moscow State University, July 9--23, 2006. Loosely speaking, a $T$-function is a map of $n$-bit words into $n$-bit words such that each $i$-th bit of image depends only on low-order bits $0,..., i$ of t

  99. Jérôme Leroux

    Since 1969 \cite{C-MST69,S-SMJ77}, we know that any Presburger-definable set \cite{P-PCM29} (a set of integer vectors satisfying a formula in the first-order additive theory of the integers) can be represented by a state-based symmbolic representation, called in this paper Finite Digit Vector Automata (FDVA). Efficient algorithms for manipulating these sets

  100. Jack Dongarra, Jean-Francois Pineau, Yves Robert, Zhiao Shi

    This paper is aimed at designing efficient parallel matrix-product algorithms for heterogeneous master-worker platforms. While matrix-product is well-understood for homogeneous 2D-arrays of processors (e.g., Cannon algorithm and ScaLAPACK outer product algorithm), there are three key hypotheses that render our work original and innovative: - Centralized data