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January 2006 arXiv papers — page 20

Showing 1,9012,000 of 3,943 papers

  1. Chien Y. Peng, Chris D. Impey, Hans-Walter Rix, Charles R. Keeton

    Gravitational lensing assists in the detection of quasar hosts by amplifying and distorting the host light away from the unresolved quasar core images. We present the results of HST observations of 30 quasar hosts at redshifts 1 < z < 4.5. The hosts are small in size (r_e <~ 6 kpc), and span a range of morphologies consistent with early-types (though smaller

  2. P. Shalima, N. V. Sujatha, Jayant Murthy, Richard Conn Henry

    We have modelled diffuse far-ultraviolet spectrum observed by FUSE near M42 as scattering of starlight from the Trapezium stars by dust in front of the nebula. The dust grains are known to be anomalous in Orion with Rv = 5.5 and these are the first measurements of the FUV optical properties of the grains outside of ``normal&#39;&#39; Milky Way dust. We find

  3. Giovanni Covone, Jean-Paul Kneib, Genevieve Soucail, Eric Jullo

    We present the on-going observational program of a VIMOS Integral Field Unit survey of the central regions of massive, gravitational lensing galaxy clusters at redshift z~0.2. We have observed six clusters using the low-resolution blue grism (R about 200), and the spectroscopic survey is complemented by a wealth of photometric data, including Hubble Space Te

  4. S. S. Larsen, L. Origlia, J. P. Brodie, J. S. Gallagher

    Using the NIRSPEC spectrograph at Keck II, we have obtained H and K-band echelle spectra for a young (10-15 Myr), luminous (MV=-13.2) super-star cluster in the nearby spiral galaxy NGC 6946. From spectral synthesis and equivalent width measurements we obtain for the first time accurate abundances and abundance patterns in an extragalactic super-star cluster.

  5. M. Wernli, P. Valiron, A. Faure, L. Wiesenfeld

    Cross sections for the rotational (de)excitation of CO by ground state para- and ortho-H_2 are obtained using quantum scattering calculations for collision energies between 1 and 520 cm^{-1}. A new CO-H_2 potential energy surface is employed and its quality is assessed by comparison with explicitly correlated CCSD(T)-R12 calculations. Rate constants for rota

  6. M. J. Ireland, M. Scholz

    The formation of dust with temperature-dependent non-grey opacity is considered in a series of self-consistent model atmospheres at different phases of an O-rich Mira variable of mass 1.2 $M_\odot$. Photometric and interferometric properties of these models are predicted under different physical assumptions regarding the dust formation. The iron content of t

  7. Irini Sakelliou, Trevor J. Ponman

    It has been known that Abell 2255 is not a relaxed cluster, but it is undergoing a merger. Here, we report on the analysis of the XMM-Newton observations of this cluster. The X-ray data give us the opportunity to reveal the complexity of the cluster, especially its temperature distribution. The integrated spectrum is well fitted by a single temperature therm

  8. Piyabut Burikham

    We investigate the TeV-scale stringy signals of the four-fermion scattering at the electron-positron collider with the center of mass energy 500-1000 GeV. The nature of the stringy couplings leads to distinguishable asymmetries comparing to the other new physics models. Specifically, the stringy states in the four-fermion scattering at the leading-order corr

  9. Rudolf Gati, Boerge Hemmerling, Jonas Foelling, Michael Albiez

    Here we report on the experimental investigation of thermally induced fluctuations of the relative phase between two Bose-Einstein condensates which are coupled via tunneling. The experimental control over the coupling strength and the temperature of the thermal background allows for the quantitative analysis of the phase fluctuations. Furthermore, we demons

  10. Chi-Hang Fred Fung, Bing Qi, Kiyoshi Tamaki, Hoi-Kwong Lo

    Quantum key distribution (QKD) can be used to generate secret keys between two distant parties. Even though QKD has been proven unconditionally secure against eavesdroppers with unlimited computation power, practical implementations of QKD may contain loopholes that may lead to the generated secret keys being compromised. In this paper, we propose a phase-re

  11. R. Enberg, B. Pire, L. Szymanowski

    The chiral-odd generalized parton distribution (GPD), or transversity GPD, of the nucleon can be accessed experimentally through the photo- or electroproduction of two vector mesons on a polarized nucleon target, γ^(*) N --> ρ_1 ρ_2 N&#39;, where ρ_1 is produced at large transverse momentum, ρ_2 is transversely polarized, and the mesons are separated by a la

  12. Charles J. Lada

    In this short communication I compare recent findings suggesting a low binary star fraction for late type stars with knowledge concerning the forms of the stellar initial and present day mass functions for masses down to the hydrogen burning limit. This comparison indicates that most stellar systems formed in the galaxy are likely single and not binary as ha

  13. Guoqiang Cui, M. G. Raymer

    We derive analytical formulas for the forward emission and side emission spectra of cavity-modified single-photon sources, as well as the corresponding normal-mode oscillations in the cavity quantum electrodynamics (QED) strong-coupling regime. We investigate the effects of pure dephasing, treated in the phase-diffusion model based on a Wiener-Levy process,

  14. C. K. Shalem, R. Chechik, A. Breskin, K. Michaeli

    We present results on THGEM operation at low gas pressures, in the range 0.5-50 Torr. Gaseous gain up to 100000 was recorded at 10 Torr of Isobutane in a single multiplier element, with pulses rise-time in the few ns range. Cascaded operation of two THGEMs is reported, with similar total gain but at lower voltages on each element. The present work encompasse

  15. Claudio Furtado, Fernando Moraes, A. M. de M. Carvalho

    In this article we use a geometric approach to study geometric phases in graphitic cones. The spinor that describes the low energy states near the Fermi energy acquires a phase when transported around the apex of the cone, as found by a holonomy transformation. This topological result can be viewed as an analogue of the Aharonov-Bohm effect. The topological

  16. Song Guo, Zhi-Wei Sun

    For positive integers $a_1,a_2,...,a_m$, we determine the least positive integer $R(a_1,...,a_m)$ such that for every 2-coloring of the set $[1,n]={1,...,n}$ with $n\ge R(a_1,...,a_m)$ there exists a monochromatic solution to the equation $a_1x_1+...+a_mx_m=x_0$ with $x_0,...,x_m\in[1,n]$. The precise value of $R(a_1,...,a_m)$ is shown to be $av^2+v-a$, wher

  17. Sema Salur

    In an earlier paper, we proved that given an asymptotically cylindrical G_2-manifold M with a Calabi-Yau boundary X, the moduli space of coassociative deformations of an asymptotically cylindrical coassociative 4-fold C in M with a fixed special Lagrangian boundary L in X is a smooth manifold of dimension dim(V_+), where V_+ is the positive subspace of the i

  18. Jozef J. Dudek, Robert G. Edwards, David G. Richards

    Radiative transitions between charmonium states offer an insight into the internal structure of heavy-quark bound states within QCD. We compute, for the first time within lattice QCD, the transition form-factors of various multipolarities between the lightest few charmonium states. In addition, we compute the experimentally unobservable, but physically inter

  19. Oktay Aydogdu

    This paper has inappropriate amounts of overlap with the following papers also written by the authors or their collaborators: gr-qc/0608050, gr-qc/0509047, gr-qc/0505078, gr-qc/0603108, gr-qc/0512080, gr-qc/0511030, gr-qc/0606022, gr-qc/0603027, gr-qc/0603063, gr-qc/0607116, and others.

  20. Michael Gronau, Yuval Grossman, Jonathan L. Rosner

    Methods are proposed for measuring the ratio $R^{+/0} = Γ(Υ(4S) \to B^+ B^-)/$ $Γ(Υ(4S) \to \bo \ob)$ without assuming isospin invariance in exclusive hadronic decays such as $B \to J/ψK$. The validity of isospin invariance in various B decays is discussed. Isospin violations are expected to be especially small in inclusive semileptonic decays, so that $Γ(B^

  21. Ting Gao, Feng-Li Yan, You-Cheng Li

    We propose a quantum secret sharing scheme between $m$-party and $n$-party using three conjugate bases, i.e. six states. A sequence of single photons, each of which is prepared in one of the six states, is used directly to encode classical information in the quantum secret sharing process. In this scheme, each of all $m$ members in group 1 choose randomly th

  22. Oliver Rinne

    This thesis is concerned with formulations of the Einstein equations in axisymmetric spacetimes which are suitable for numerical evolutions. We develop two evolution systems based on the (2+1)+1 formalism. The first is a (partially) constrained scheme with elliptic gauge conditions arising from maximal slicing and conformal flatness. The second is a strongly

  23. G. Degrassi, P. Gambino, P. Slavich

    We compute the complete supersymmetric QCD corrections to the Wilson coefficients of the magnetic and chromomagnetic operators, relevant in the calculation of b -> s gamma decays, in the MSSM with Minimal Flavor Violation. We investigate the numerical impact of the new results for different choices of the MSSM parameters and of the scale where the quark and

  24. G. Ballesteros, J. A. Casas, J. R. Espinosa

    The WMAP results on the scalar spectral index n and its running with scale, though preliminary, open a very interesting window to physics at very high energies. We address the problem of finding inflaton potentials well motivated by particle physics which can accomodate WMAP data. We make a model independent analysis of a large class of models: those with fl

  25. V. Braude

    Excitation of spin waves is considered in a superconducting ferromagnetic slab with the equilibrium magnetization both perpendicular and parallel to the surface. The surface impedance is calculated and its behavior near propagation thresholds is analyzed. Influence of non-zero magnetic induction at the surface is considered in various cases. The results prov

  26. Maciej Dunajski, Simon West

    Using twistor methods, we explicitly construct all local forms of four--dimensional real analytic neutral signature anti--self--dual conformal structures $(M,[g])$ with a null conformal Killing vector. We show that $M$ is foliated by anti-self-dual null surfaces, and the two-dimensional leaf space inherits a natural projective structure. The twistor space of

  27. Luciano da Fontoura Costa

    This article describes an approach to modeling knowledge acquisition in terms of walks along complex networks. Each subset of knowledge is represented as a node, and relations between such knowledge are expressed as edges. Two types of edges are considered, corresponding to free and conditional transitions. The latter case implies that a node can only be rea

  28. Kamil Walczak

    Here we present the calculations of incoherent current flowing through the two-site molecular device as well as the DNA-based junction within the rate-equation approach. Few interesting phenomena are discussed in detail. Structural asymmetry of two-site molecule results in rectification effect, which can be neutralized by asymmetric voltage drop at the molec

  29. Emel Gulez, Alan Gray, Matthew Wingate, Christine T. H. Davies

    The semileptonic process, B --> πl ν, is studied via full QCD Lattice simulations. We use unquenched gauge configurations generated by the MILC collaboration. These include the effect of vacuum polarization from three quark flavors: the $s$ quark and two very light flavors ($u/d$) of variable mass allowing extrapolations to the physical chiral limit. We empl

  30. K. Goeke, S. Meissner, A. Metz, M. Schlegel

    The Sivers mechanism gives rise to a non-zero average transverse momentum of partons inside a transversely polarized target. According to a sum rule of Burkardt this transverse momentum vanishes when summing over all partons. We explicitly check the Burkardt sum rule by means of one-loop calculations for a quark target in perturbative QCD and for a diquark s

  31. M. Ioannou, H. Panagopoulos

    We calculate the 1-loop renormalization of the fermion self-energy, all local fermion bilinears, as well as a set of extended bilinears which form a basis corresponding to moments of the parton distribution functions. We use the overlap action for fermions and Symanzik improved action for gluons. Our results are presented as a function of the overlap paramet

  32. Laura La Porta, Carlo Burigana

    The Galactic synchrotron emission is expected to be the most relevant source of astrophysical contamination in cosmic microwave background polarization measurements, at least at frequencies < 100 GHz and at angular scales > 30&#39;. We present a multifrequency analysis of the Leiden surveys, linear polarization surveys covering essentially the Northern Celes

  33. N. Armesto, J. G. Milhano

    We consider modifications of the standard non-linear QCD evolution in an attempt to account for some of the missing ingredients discussed recently, such as correlations, discreteness in gluon emission and Pomeron loops. The evolution is numerically performed using the Balitsky-Kovchegov equation on individual configurations defined by a given initial value o

  34. Alexander A. Reshetnyak

    A Lagrangian BRST quantization for generic gauge theories in general irreducible non-Abelian hypergauges is proposed on a basis of the multilevel Batalin--Tyutin formalism and a special BV--BFV dual description for a reducible gauge model in a symplectic supermanifold $\mathcal{M}_0$ locally parameterized by antifields for Lagrangian multipliers and by the f

  35. Nuno D. Antunes, Pedro Gandra, Ray J. Rivers, A. Swarup

    Defects in superfluid 3He, high-Tc superconductors, QCD colour superfluids and cosmic vortons can possess (anti)ferromagnetic cores, and their generalisations. In each case there is a second order parameter whose value is zero in the bulk which does not vanish in the core. We examine the production of defects in the simplest 1+1 dimensional scalar theory in

  36. Dariusz Chruscinski, Andrzej Kossakowski

    We construct a new class of multipartite states possessing orthogonal symmetry. This new class defines a convex hull of multipartite states which are invariant under the action of local unitary operations introduced in our previous paper &#34;On multipartite invariant states I. Unitary symmetry&#34;. We study basic properties of multipartite symmetric states

  37. E. Vanzella, S. Cristiani, M. Dickinson, H. Kuntschner

    We present the second campaign of the ESO/GOODS program of spectroscopy of faint galaxies in the GOODS-South field. Objects were selected as candidates for VLT/FORS2 observations primarily based on the expectation that the detection and measurement of their spectral features would benefit from the high throughput and spectral resolution of FORS2. The reliabi

  38. Mark D. Roberts

    It is shown that four dimensional vacuum Einstein solutions simply embedded in five dimensions obey the Gauss-Bonnet-Einstein field equations: $G_{ab}+αGB_{ab}+δ^{55}_{ab}α\exp(-2χ/\sqrtα)GB_4=0$ and the Pauli-Einstein equations $G_{ab}-3αP_{ab}/5=0$, and the Bach-Einstein equations $B_{ab}=0$. General equations are calculated for which these and similar res

  39. G. E. Volovik

    Many quantum condensed matter systems are strongly correlated and strongly interacting fermionic systems, which cannot be treated perturbatively. However, physics which emerges in the low-energy corner does not depend on the complicated details of the system and is relatively simple. It is determined by the nodes in the fermionic spectrum, which are protecte

  40. K. Grove-Rasmussen, H. Ingerslev Jørgensen, P. E. Lindelof

    We have contacted single wall carbon nanotubes grown by chemical vapor deposition to superconducting Ti/Al/Ti electrodes. The device, we here report on is in the Kondo regime exhibiting a four-fold shell structure, where a clear signature of the superconducting electrodes is observed below the critical temperature. Multiple Andreev reflections are revealed b

  41. Gregor Diezemann

    Aging effects in the two-time correlation function and the response function after a quench from a high temperature to some low temperature are considered for a simple kinetic random energy model exhibiting stretched exponential relaxation. Because the system reaches thermal equilibrium for long times after the quench, all aging effect are of a transient nat

  42. Michael Gronau, Yuval Grossman, Guy Raz, Jonathan L. Rosner

    While flavor symmetries are useful for studying hadronic B decays, symmetry relations for amplitudes and decay rates are usually violated by first order symmetry breaking corrections. We point out two cases in which first order symmetry breaking is suppressed by a small ratio of amplitudes: (1) An isospin sum rule for four $B\to Kπ$ decays, where isospin bre

  43. P. X. Xu, K. Xia, M. Zwierzycki, M. Talanana

    As devices are reduced in size, interfaces start to dominate electrical transport making it essential to be able to describe reliably how they transmit and reflect electrons. For a number of nearly perfectly lattice-matched materials, we calculate from first-principles the dependence of the interface transparency on the crystal orientation. Quite remarkably,

  44. Hao Fang, Zhiqin Lu, Ken-Ichi Yoshikawa

    After Bershadsky-Cecotti-Ooguri-Vafa, we introduce an invariant of Calabi-Yau threefolds, which we call the BCOV invariant and which we obtain using analytic torsion. We give an explicit formula for the BCOV invariant as a function on the compactified moduli space, when it is isomorphic to a projective line. As a corollary, we prove the formula for the BCOV

  45. N. Khosravi, S. Jalalzadeh, H. R. Sepangi

    A non-commutative multi-dimensional cosmological model is introduced and used to address the issues of compactification and stabilization of extra dimensions and the cosmological constant problem. We show that in such a scenario these problems find natural solutions in a universe described by an increasing time parameter.

  46. Oyvind Hammer, Dag K. Dysthe, Bjorn Jamtveit

    This paper has been withdrawn by the author because of publication in the journal Earth and Planetary Science Letters (Elsevier), which does not permit preprints at arxiv.org

  47. Nick Evans, Tim R. Morris, Oliver J. Rosten

    A field theoretic understanding of how the radial direction in the AdS/CFT Correspondence plays the role of a gauge invariant measure of energy scale has long been missing. In SU(N) Yang-Mills, a realization of a gauge invariant cutoff has been achieved by embedding the theory in spontaneously broken SU(N|N) gauge theory. With the recent discovery of ghost D

  48. M. Fujisawa, T. Ono, H. Fujiwara, H. Tanaka

    TlCuCl$_3$ is a coupled spin dimer system, which has a singlet ground state with an excitation gap of $Δ/gμ_{\mathrm B}$ = 5.5 T. TlCu$_{1-x}$Mg$_x$Cl$_3$ doped with nonmagnetic Mg$^{2+}$ ions undergoes impurity-induced magnetic ordering. Because triplet excitation with a finite gap still remains, this doped system can also undergo magnetic-field-induced mag

  49. Mariya Vlasenko

    For quantum torus generated by unitaries $UV = e(θ)VU$ there exist nontrivial strong Morita autoequivalences in case when $θ$ is real quadratic irrationality. A.Polishchuk introduced and studied the graded ring of holomorphic sections of powers of the respective bimodule (depending on the choice of a complex structure). We consider a Segre square of this rin

  50. L. M. Zhang, Z. P. Zhang, J. Li

    We report the results of a search for D0-D0bar mixing in D0 -> K+ pi- decays based on 400 fb^{-1} of data accumulated by the Belle detector at KEKB. Both assuming CP conservation and allowing for CP violation, we fit the decay-time distribution for the mixing parameters x' and y', as well as for the parameter R_D, the ratio of doubly-Cabibbo-suppressed decay

  51. R. Toivonen, J. -P. Onnela, J. Saramäki, J. Hyvönen

    Social networks are organized into communities with dense internal connections, giving rise to high values of the clustering coefficient. In addition, these networks have been observed to be assortative, i.e. highly connected vertices tend to connect to other highly connected vertices, and have broad degree distributions. We present a model for an undirected

  52. R Inanc Baykur

    In this article we show that every closed oriented smooth 4-manifold can be decomposed into two codimension zero submanifolds (one with reversed orientation) so that both pieces are exact Kahler manifolds with strictly pseudoconvex boundaries and that induced contact structures on the common boundary are isotopic. Meanwhile, matching pairs of Lefschetz fibra

  53. Liang Sun

    In this paper, we studied the long-wave instability of the shear flows. When the wavenumber of perturbation is larger than the critical value, the flow is always neutrally stable. First, we obtain a new upper bound for the neutral wavenumber $k_1\leq (p^2-1)μ_1$, where $p>1$ and $μ_1$ is the smallest eigenvalue of Poincaré&#39;s problem. Second, we find a ne

  54. N. B. Manson, J. P. Harrison, M. J. Sellars

    Symmetry considerations are used in presenting a model of the electronic structure and the associated dynamics of the nitrogen-vacancy center in diamond. The model accounts for the occurrence of optically induced spin polarization, for the change of emission level with spin polarization and for new measurements of transient emission. The rate constants given

  55. H. Furuhashi, Y. Nambu, H. Saida

    A numerical simulation of fluid flows in a Laval nozzle is performed to observe formations of acoustic black holes and the classical counterpart to Hawking radiation under a realistic setting of the laboratory experiment. We determined the Hawking temperature of the acoustic black hole from obtained numerical data. Some noteworthy points in analyzing the exp

  56. Hiromitsu Nishikori, Mami Machida, Ryoji Matsumoto

    We carried out global three-dimensional resistive magnetohydrodynamic simulations of galactic gaseous disks to investigate how the galactic magnetic fields are amplified and maintained. We adopt a steady axisymmetric gravitational potential given by \cite*{Miy80}. As the initial condition, we assume a warm ($T\sim10^{5} \mathrm{K}$) rotating gas torus center

  57. Koji Nagata, Wieslaw Laskowski, Tomasz Paterek

    Based on a geometrical argument introduced by Zukowski, a new multisetting Bell inequality is derived, for the scenario in which many parties make measurements on two-level systems. This generalizes and unifies some previous results. Moreover, a necessary and sufficient condition for the violation of this inequality is presented. It turns out that the class

  58. Nemanja Kaloper, Derrick Kiley

    We derive exact gravitational fields of a black hole and a relativistic particle stuck on a codimension-2 brane in $D$ dimensions when gravity is ruled by the bulk $D$-dimensional Einstein-Hilbert action. The black hole is locally the higher-dimensional Schwarzschild solution, which is threaded by a tensional brane yielding a deficit angle and includes the f

  59. Pascal O. Vontobel, Ashwin Ganesan

    The notion of universally decodable matrices (UDMs) was recently introduced by Tavildar and Viswanath while studying slow fading channels. It turns out that the problem of constructing UDMs is tightly connected to the problem of constructing maximum distance separable (MDS) codes. In this paper, we first study the properties of UDMs in general and then we di

  60. Maxim Raginsky

    The problem of joint universal source coding and modeling, addressed by Rissanen in the context of lossless codes, is generalized to fixed-rate lossy coding of continuous-alphabet memoryless sources. We show that, for bounded distortion measures, any compactly parametrized family of i.i.d. real vector sources with absolutely continuous marginals (satisfying

  61. Frank Gaitan

    Results are presented of a large-scale simulation of the quantum adiabatic search (QuAdS) algorithm in the presence of noise. The algorithm is applied to the NP-Complete problem Exact Cover 3 (EC3). The noise is assumed to Zeeman-couple to the qubits and its effects on the algorithm&#39;s performance is studied for various levels of noise power, and for 4 di

  62. Linda E. Reichl, Michael G. Snyder

    We present a calculation of the shot noise in a ballistic electron waveguide square root of NOT gate. A general expression for the shot noise in the leads connected to these types of gates is shown. We then parameterize an S-matrix which qualitatively describes the action of a square root of NOT gate previously found through numerical methods for GaAs/Al_xGa

  63. L. H. Ford

    This paper discusses two distinct, but related issues in quantum fluctuation effects. The first is the frequency spectrum which can be assigned to one loop quantum processes. The formal spectrum is a flat one, but the finite quantum effects can be associated with a rapidly oscillating spectrum, as in the case of the Casimir effect. The leads to the speculati

  64. Dorje C. Brody, Daniel W. Hook

    For a prescribed pair of quantum states |psi_I> and |psi_F> we establish an elementary derivation of the optimum Hamiltonian, under constraints on its eigenvalues, that generates the unitary transformation |psi_I> --> |psi_F> in the shortest duration. The derivation is geometric in character and does not rely on variational calculus.

  65. David W. Kribs, Raymond Laflamme, David Poulin, Maia Lesosky

    This paper is an expanded and more detailed version of our recent work in which the Operator Quantum Error Correction formalism was introduced. This is a new scheme for the error correction of quantum operations that incorporates the known techniques - i.e. the standard error correction model, the method of decoherence-free subspaces, and the noiseless subsy

  66. Jaewook Joo, Eric Harvill, Reka Albert

    Pathogen-mediated competition, through which an invasive species carrying and transmitting a pathogen can be a superior competitor to a more vulnerable resident species, is one of the principle driving forces influencing biodiversity in nature. Using an experimental system of bacteriophage-mediated competition in bacterial populations and a deterministic mod

  67. Cheng Zhu, James F. Babb, Alex Dalgarno

    We perform fully quantum mechanical calculations in the binary approximation of the emission and absorption profiles of the sodium $3s$-$3p$ and potassium $4s$-$4p$ resonance lines under the influence of a helium perturbing gas. We use carefully constructed potential energy surfaces and transition dipole moments to compute the emission and absorption coeffic

  68. F. D. Amaro, J. F. C. A. Veloso, A. Breskin, R. Chechik

    We report on the performance of a Micro-Hole & Strip Plate (MHSP) electron multiplier operating in pure Xe, Kr, Ar and Ne at the pressure range of 1 to 6 bar. The maximal gains at 1 bar Xe and Kr are 50000 and 100000, respectively; they drop by about one order of magnitude at 2 bar and by almost another order of magnitude at 5-6 bar; they reach gains of 500

  69. Valerio Lucarini, Sandro Calmanti, Alessandro Dell&#39;Aquila, Paolo M. Ruti

    We compare, for the overlapping time frame 1962-2000, the estimate of the northern hemisphere (NH) mid-latitude winter atmospheric variability within the XX century simulations of 17 global climate models (GCMs) included in the IPCC-4AR with the NCEP and ECMWF reanalyses. We compute the Hayashi spectra of the 500hPa geopotential height fields and introduce a

  70. C. Shalem, R. Chechik, A. Breskin, K. Michaeli

    Thick GEM-like (THGEM) gaseous electron multipliers are made of standard printed-circuit board perforated with sub-millimeter diameter holes, etched at their rims. Effective gas multiplication factors of 100000 and 10000000 and fast pulses in the few nanosecond rise-time scale were reached in single- and cascaded double-THGEM elements, in atmospheric-pressur

  71. C. M. Queiroz, S. Agathopoulos

    The European quest for the hard paste porcelain lasted until about 1710, when the first production unit was built at Meissen in Saxony. Although, it is generally believed that Bottger discovered the European porcelain technology, this work shows that the German porcelain quest was a State affair; a collective project directed by Tschirnhaus and supported by

  72. Jose N. Pecina-Cruz

    This article proves that elementary particles can violate the second postulate of the Special Theory of Relativity. According to Heisenberg&#39;s principle, superluminal particles are allowed in the theoretical framework of Quantum Mechanics. In this paper the tachyons, are identified with the unitary irreducible representations of the &#34;full&#34; Poincar

  73. N. Cufaro Petroni, S. De Martino, S. De Siena, F. Illuminati

    We describe the transverse beam distribution in particle accelerators within the controlled, stochastic dynamical scheme of the Stochastic Mechanics (SM) which produces time reversal invariant diffusion processes. This leads to a linearized theory summarized in a Shchrödinger--like (\Sl) equation. The space charge effects have been introduced in a recent pap

  74. Rodrigo Medina

    The problem of the self-interaction of a quasi-rigid classical particle with an arbitrary spherically symmetric charge distribution is completely solved up to the first order in the acceleration. No ad hoc assumptions are made. It is shown that most of the puzzles that this problem has aroused are due to the inertia of the negative pressure that equilibrates

  75. Xianglei Zhu, Marcus Bleicher, Horst Stoecker

    The Lee-Yang zeroes method is applied to study elliptic flow ($v_2$) in Au+Au collisions at $\sqrt{s}=200A$~GeV, with the UrQMD model. In this transport approach, the true event plane is known and both the nonflow effects and event-by-event $v_2$ fluctuations exist. Although the low resolutions prohibit the application of the method for most central and peri

  76. Qingfeng Li, Zhuxia Li, Sven Soff, Marcus Bleicher

    Several observables of unbound nucleons which are to some extent sensitive to the medium modifications of nucleon-nucleon elastic cross sections in neutron-rich intermediate energy heavy ion collisions are investigated. The splitting effect of neutron and proton effective masses on cross sections is discussed. It is found that the transverse flow as a functi

  77. M. Sohani

    At the Kernfysisch Vensneller Institiutr (KVI) in Groningen, NL, a new facility (TRImP) is under development. It aims for producing, slowing down, and trapping of radioactive isotopes in order to perform accurate measurements on fundamental symmetries and interactions. A production target station and a dual magnetic separator installed and commissioned. We w

  78. L. N. Bogdanova, M. G. Gavrilov, V. N. Kornoukhov, A. S. Starostin

    We consider the cosmic muon background for the installations located at shallow depths. We suggest a relatively simple formula for the sea-level muon spectrum, which allows calculate dependencies of the vertical muon intensity and integral muon flux density on overburden. Muon flux dependency on the zenith angle at overburden of 10 to 100 meters of standard

  79. Alexey V. Shchepetilov

    The quantum mechanical two-body problem with a central interaction on the sphere ${\bf S}^{n}$ is considered. Using recent results in representation theory an ordinary differential equation for some energy levels is found. For several interactive potentials these energy levels are calculated in explicit form.

  80. A. V. Shchepetilov, I. E. Stepanova

    The two-body problem with a central interaction on simply connected constant curvature spaces of an arbitrary dimension is considered. The explicit expression for the quantum two-body Hamiltonian via a radial differential operator and generators of the isometry group is found. We construct a self-adjoint extension of this Hamiltonian. Some its exact spectral

  81. Hirotachi Abo, Chris Peterson

    In 1997, N.M. Kumar published a paper which introduced a new tool of use in the construction of algebraic vector bundles. Given a vector bundle on projective n-space, a well known theorem of Quillen-Suslin guarantees the existence of sections which generate the bundle on the complement of a hyperplane in projective n-space. Kumar used this fact to give a cor

  82. Peter Bubenik

    The cell-attachment problem, perhaps first studied by J.H.C. Whitehead around 1940, asks one to describe the effect of attaching one or more cells, on the algebraic invariants of a topological space. This thesis studies the effect of cell attachments on loop space homology. It generalizes previous work by D. Anick on spherical 2-cones, and S. Halperin, J.-M.

  83. Laurent Bartholdi, Markus Neuhauser, Wolfgang Woess

    Let T_1,..., T_d be homogeneous trees with degrees q_1+1,..., q_d+1>=3, respectively. For each tree, let h:T_j->Z be the Busemann function with respect to a fixed boundary point (end). Its level sets are the horocycles. The horocyclic product of T_1,...,T_d is the graph DL(q_1,...,q_d) consisting of all d-tuples x_1...x_d in T_1x...xT_d with h(x_1)+...+h(x_d

  84. Peter Jorgensen

    Differential Graded Algebras can be studied through their Differential Graded modules. Among these, the compact ones attract particular attention. This paper proves that over a suitable chain Differential Graded Algebra R, each compact Differential Graded module M satisfies amp M >= amp R, where amp denotes amplitude which is defined in a straightforward way

  85. Richard Hamilton, Natasa Sesum

    In this paper we consider the class $\mathcal{A}$ of those solutions $u(x,t)$ to the conjugate heat equation $\frac{d}{dt}u = -Δu + Ru$ on compact Kähler manifolds $M$ with $c_1 > 0$ (where $g(t)$ changes by the unnormalized Kähler Ricci flow, blowing up at $T < \infty$), which satisfy Perelman&#39;s differential Harnack inequality on $[0,T)$. We show $\math

  86. Melody Chan

    Let G be a group acting faithfully on a set X. The distinguishing number of the action of G on X is the smallest number of colors such that there exists a coloring of X where no nontrivial group element induces a color-preserving permutation of X. In this paper, we consider the distinguishing number of two important product actions, the wreath product and th

  87. Helmut Strade

    We present a list of all isomorphism classes of nonsolvable Lie algebras of dimension less than 7 over a finite field.

  88. Antonio Azzollini, Alessio Pomponio

    In this paper we present some compactness results, showing how they can be applied in dealing with &#34;zero mass&#34; problems by a variational approach. In particular we use our results in two different situations: we look for complex valued solutions of a very classical elliptic equation, and we study an elliptic problem on an axially symmetric unbounded

  89. Giovanni Alessandrini, Luca Rondi

    In the paper, G. Alessandrini and L. Rondi, ``Determining a sound-soft polyhedral scatterer by a single far-field measurement&#39;&#39;, Proc. Amer. Math. Soc. 133 (2005), pp. 1685-1691, on the determination of a sound-soft polyhedral scatterer by a single far-field measurement, the proof of Proposition 3.2 is incomplete. In this corrigendum we provide a new

  90. P. Amengual, P. Meurs, B. Cleuren, R. Toral

    We present two collective games with new paradoxical features when they are combined. Besides reproducing the so--called Parrondo effect, where a winning game is obtained from the alternation of two fair games, a new effect appears, i.e., there exists a current inversion when varying the mixing probability between the games. We present a detailed study by me

  91. Nafaa Chbili

    We use the topological invariant of spatial graphs introduced by S. Yamada to find necessary conditions for a spatial graph to be periodic with a prime period. The proof of the main result is based on computing the Yamada skein algebra of the solid torus then proving that this algebra injects into the Kauffman bracket skein algebra of the solid torus.

  92. Youngook Choi, Seonja Kim, Young Rock Kim

    Let $C$ be a smooth curve of genus $g\ge 4$ and Clifford index $c$. In this paper, we prove that if $C$ is neither hyperelliptic nor bielliptic with $g\ge 2c+5$ and $\mathcal M$ computes the Clifford index of $C$, then either $°\mathcal M\le \frac{3c}{2}+3$ or $|\mathcal M|=|g^1_{c+2}+h^1_{c+2}|$ and $g=2c+5$. This strengthens the Coppens and Martens&#39; th

  93. Wayne Raskind, Xavier Xarles

    For an algebraic variety $X$ of dimension $d$ with totally degenerate reduction over a $p$-adic field (definition recalled below) and an integer $i$ with $1\leq i\leq d$, we define a rigid analytic torus $J^i(X)$ together with an Abel-Jacobi mapping to it from the Chow group $CH^i(X)_{hom}$ of codimension $i$ algebraic cycles that are homologically equivalen

  94. Tanush Shaska

    We introduce a new approach of computing the automorphism group and the field of moduli of points $\p=[C]$ in the moduli space of hyperelliptic curves $\H_g$. Further, we show that for every moduli point $\p \in \H_g(L)$ such that the reduced automorphism group of $\p$ has at least two involutions, there exists a representative $C$ of the isomorphism class $

  95. Tanush Shaska

    The development of computational techniques in the last decade has made possible to attack some classical problems of algebraic geometry. In this survey, we briefly describe some open problems related to algebraic curves which can be approached from a computational viewpoint.

  96. Arie Bialostocki, Tanush Shaska

    In the process of computing the Galois group of a prime degree polynomial $f(x)$ over $\mathbb Q$ we suggest a preliminary checking for the existence of non-real roots. If $f(x)$ has non-real roots, then combining a 1871 result of Jordan and the classification of transitive groups of prime degree which follows from CFSG we get that the Galois group of $f(x)$

  97. D. Maulik, R. Pandharipande

    We use a topological framework to study descendent Gromov-Witten theory in higher genus, non-toric settings. Two geometries are considered: surfaces of general type and the Enriques Calabi-Yau threefold. We conjecture closed formulas for surfaces of general type in classes K and 2K. For the Enriques Calabi-Yau, Gromov-Witten invariants are calculated in genu

  98. Stavros Garoufalidis, Marcos Marino

    The contribution of reducible connections to the U(N) Chern-Simons invariant of a Seifert manifold $M$ can be expressed in some cases in terms of matrix integrals. We show that the U(N) evaluation of the LMO invariant of any rational homology sphere admits a matrix model representation which agrees with the Chern-Simons matrix integral for Seifert spheres an

  99. Alberto Calabri, Ciro Ciliberto, Flaminio Flamini, Rick Miranda

    In this paper we study degenerations of scrolls to union of planes, a problem already considered by G. Zappa in 1940-50. We prove, using techniques different from the ones of Zappa, a degeneration result to union of planes with the mildest possible singularities, for linearly normal scrolls of genus $g$ and of degree $d$ larger than $2g+4$ in $\Pp^{d-2g+1}$.

  100. Xiao-Song Lin, Hao Zheng

    This paper has been withdrawn since it is identical to the paper math.QA/0601267. It was posted by mistake.