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November 2007 arXiv papers — page 25

Showing 2,4012,500 of 5,016 papers

  1. Frank Aurzada

    We obtain some new results concerning the small deviation problem for $S=\sum_n q^n X_n$ and $M=\sup_n q^n X_n$, where $0<q<1$ and $(X_n)$ are i.i.d. non-negative random variables. In particular, the asymptotics is shown to be the same for $S$ and $M$ in some cases.

  2. MAGIC Collaboration, J. Albert

    The nearby dwarf spheroidal galaxy Draco with its high mass to light ratio is one of the most auspicious targets for indirect dark matter searches. Annihilation of hypothetical DM particles can result in high-energy gamma-rays, e.g. from neutralino annihilation in the supersymmetric framework. With the MAGIC telescope a search for a possible DM signal origin

  3. Xiaofeng Wang, Weidong Li, Alexei V. Filippenko, Ryan J. Foley

    We report the discovery of a light echo (LE) from the Type Ia supernova (SN) 2006X in the nearby galaxy M100. The presence of the LE is supported by analysis of both the Advanced Camera for Surveys (ACS) images taken with the {\it Hubble Space Telescope (HST)} at $\sim$300 d after maximum brightness and the Keck optical spectrum obtained at a similar phase.

  4. Miguel Ballesteros, Ricardo Weder

    We obtain high-velocity estimates with error bounds for the scattering operator of the Schr\"odinger equation in three dimensions with electromagnetic potentials in the exterior of bounded obstacles that are handlebodies. A particular case is a finite number of tori. We prove our results with time-dependent methods. We consider high-velocity estimates where

  5. Alex L. Castro, Richard Montgomery

    We compute the chains associated to the left-invariant CR structures on the three-sphere. These structures are characterized by a single real modulus $a$. For the standard structure $a=1$, the chains are well-known and are closed curves. We show that for almost all other values of the modulus $a$ either two or three types of chains are simultaneously present

  6. Ashraf Ibrahim, J. Maurice Rojas, Korben Rusek

    Withdrawn by the authors due to an error in the proof of the finite field result (Thm. 1.5): The random primes used in the proof need NOT avoid the exceptional primes from Lemma 2.7, thus leaving Thm. 1.5 unproved.

  7. Shun&#39;ya Mizoguchi

    We construct spacetime supersymmetric, modular invariant partition functions of strings on the conifold-type singularities which include contributions from the discrete-series representations of SL(2, R). The discrete spectrum is automatically consistent with the GSO projection in the continuous sector, and contains massless matter fields localized on a four

  8. Jaume Garriga, Alexander Vilenkin

    Probabilities in the multiverse can be calculated by assuming that we are typical representatives in a given reference class. But is this class well defined? What should be included in the ensemble in which we are supposed to be typical? There is a widespread belief that this question is inherently vague, and that there are various possible choices for the t

  9. Roman Orus

    Under successive Renormalization Group transformations applied to a quantum state $\ketΨ$ of finite correlation length $ξ$, there is typically a loss of entanglement after each iteration. How good it is then to replace $\ketΨ$ by a product state at every step of the process? In this paper we give a quantitative answer to this question by providing first anal

  10. H. I. Nurdin, M. R. James, I. R. Petersen

    Based on a recently developed notion of physical realizability for quantum linear stochastic systems, we formulate a quantum LQG optimal control problem for quantum linear stochastic systems where the controller itself may also be a quantum system and the plant output signal can be fully quantum. Such a control scheme is often referred to in the quantum cont

  11. L. Del Riego, Phillip. E. Parker

    The main purpose of this article is to introduce a comprehensive, unified theory of the geometry of all connections. We show that one can study a connection via a certain, closely associated second-order differential equation. One of the most important results is our extended Ambrose-Palais-Singer correspondence. We extend the theory of geodesic sprays to ce

  12. S. P. Knurenko, A. A. Ivanov, A. V. Sabourov

    The differential energy spectrum of cosmic rays from Cherenkov radiation measurements in EAS in the energy range of 10^15-10^20eV has been compared with an anomalous diffusion model for the particles in interstellar space having fractal properties (Lagutin et al, 2001). The close association between experimental data and calculated "all particle" spectra in

  13. Wojciech Moczydlowski

    ZF is a well investigated impredicative constructive version of Zermelo-Fraenkel set theory. Using set terms, we axiomatize IZF with Replacement, which we call \izfr, along with its intensional counterpart \iizfr. We define a typed lambda calculus $\li$ corresponding to proofs in \iizfr according to the Curry-Howard isomorphism principle. Using realizability

  14. Jae-Hun Jung, Gaurav Khanna, Ian Nagle

    The inhomogeneous Zerilli equation is solved in time-domain numerically with the Chebyshev spectral collocation method to investigate a radial-infall of the point particle towards a Schwarzschild black hole. Singular source terms due to the point particle appear in the equation in the form of the Dirac $\delta$-function and its derivative. For the approximat

  15. David Tytler, Pascal Paschos, David Kirkman, Michael L. Norman

    We study the effects of box size on ENZO simulations of the intergalactic medium (IGM) at z = 2. We follow statistics of the cold dark matter (CDM) and the Lya absorption. We find that the larger boxes have fewer pixels with significant absorption (flux < 0.96) and more pixels in longer stretches with little or no absorption, and they have wider Lya lines. W

  16. Haibao Duan, Xuezhi Zhao

    Let $G$ be a compact and $1$--connected Lie group with a maximal torus $T$. Based on Schubert calculus on the flag manifold $G/T$ [15] we construct the integral cohomology ring $H^{\ast}(G)$ uniformly for all $G$.

  17. Jeremy D. Schmit, Ercan Kamber, Jané Kondev

    We study the effect of confinement on diffusion limited bimolecular reactions within a lattice model where a small number of reactants diffuse amongst a much larger number of inert particles. When the number of inert particles is held constant the rate of the reaction is slow for small reaction volumes due to limited mobility from crowding, and for large rea

  18. Yury Kreimer, Yoram Last, Barry Simon

    We relate asymptotics of Jacobi parameters to asymptotics of the spectral weights near the edges. Typical of our results is that for $a_n\equiv 1$, $b_n =-C n^{-β}$ ($0<β< \frac23)$, one has $dμ(x)= w(x) dx$ on $(-2,2)$, and near $x=2$, $w(x)=e^{-2Q(x)}$ where \[ Q(x)=β^{-1} C^{\frac{1}β} \frac{Γ(\frac32)Γ(\frac{1}β}-\frac12)(2-x)^{\frac12 -\frac{1}β}}{Γ(\fr

  19. Barry Simon

    This is a comprehensive review of the uses of potential theory in studying the spectral theory of orthogonal polynomials. Much of the article focuses on the Stahl-Totik theory of regular measures, especially the case of OPRL and OPUC. Links are made to the study of ergodic Schrodinger operators where one of our new results implies that, in complete generalit

  20. Kevin P. Costello, Van Vu

    We investigate the rank of random (symmetric) sparse matrices. Our main finding is that with high probability, any dependency that occurs in such a matrix is formed by a set of few rows that contains an overwhelming number of zeros. This allows us to obtain an exact estimate for the co-rank.

  21. Barry Simon

    We consider OPRL and OPUC with measures regular in the sense of Ullman-Stahl-Totik and prove consequences on the Jacobi parameters or Verblunsky coefficients. For example, regularity on $[-2,2]$ implies $\lim_{N\to\infty} N^{-1} [\sum_{n=1}^N (a_n-1)^2 + b_n^2] =0$.

  22. Dmitry Pelinovsky, Guido Schneider

    We justify the validity of the discrete nonlinear Schrodinger equation for the tight-binding approximation in the context of the Gross-Pitaevskii equation with a periodic potential. Our construction of the periodic potential and the associated Wannier functions is based on the previous work, while our analysis involving energy estimates and Gronwall&#39;s in

  23. Anyi Li, Andrei Alexandru, Keh-Fei Liu

    We present some new results regarding simulations of finite density QCD based on a canonical approach. A previous study has shown that such simulations are feasible, at least on small lattices. In the current study, we investigate some of the issues left open: we study the errors introduced by our approximation of the action and we show how to tune it to red

  24. I. Romero, T. V. Teperik, F. J. Garcia de Abajo

    Coupled and shape-tailored metallic nanoparticles are known to exhibit hybridized plasmon resonances. This Letter discuss the optical properties of a complementary system formed by overlapped nanovoid dimers buried in gold and filled with silica. This is an alternative route for plasmon engineering that benefits from vanishing radiation losses. Our analysis

  25. Henry A. Kobulnicky, Evan. D. Skillman

    VLA and Parkes 64 m radiotelescope 21-cm observations of the starburst dwarf galaxy NGC 5253 reveal a multi-component non-axisymmetric HI distribution. The component associated with the stellar body shows evidence for a small amount of rotational support aligned with the major axis, in agreement with optically measured kinematics and consistent with the smal

  26. Steffen Waldherr, Frank Allgower

    Feedback circuits in biochemical networks which underly cellular signaling pathways are important elements in creating complex behavior. A specific aspect thereof is how stability of equilibrium points depends on model parameters. For biochemical networks, which are modelled using many parameters, it is typically very difficult to estimate the influence of p

  27. Duilia F. de Mello, L. J. Smith, E. Sabbi, J. S. Gallagher

    We present multi-wavelength observations of stellar features in the HI tidal bridge connecting M81 and M82 in the region called Arp&#39;s Loop. We identify eight young star-forming regions from Galaxy Evolution Explorer ultraviolet observations. Four of these objects are also detected at Hα. We determine the basic star formation history of Arp&#39;s Loop usi

  28. David Callan

    There are (at least) three bijections from Dyck paths to 321-avoiding permutations in the literature, due to Billey-Jockusch-Stanley, Krattenthaler, and Mansour-Deng-Du. How different are they? Denoting them B,K,M respectively, we show that M = B \circ L = K \circ L&#39; where L is the classical Kreweras-Lalanne involution on Dyck paths and L&#39;, also an i

  29. The ANTARES Collaboration

    Contributions to ICRC 2007, Merida, Mexico. Contents pages for the Contribution on behalf of the ANTARES Collaboration to the 30th ICRC that took place in July 2007 in Merida, Mexico. The contents are in html form with clickable links to the papers that exist on the Astrophysics archive.

  30. K. Fu, R. Zannoni, C. Chan, S. Adams

    It is reported that terahertz radiation from 0.69 THz to 2.54 THz has been sensitively detected in a device consisting of bundles of metallic carbon nanotubes, quasi-optically coupled through a lithographically fabricated antenna, and a silicon lens. The measured data are consistent with a bolometric process and show promise for operation above 4.2 K.

  31. Andrei Alexandru, Anyi Li, Keh-Fei Liu

    Previous investigations have shown that the canonical approach to simulating QCD at finite density is promising. The algorithm we used in our earlier work employs an exact calculation of the fermionic determinant which limits the size of the lattices we can simulate. Interesting questions can only be answered if we simulate at larger volume. In this paper we

  32. Stanislav Volkov, Timothy Wong

    We study a simple random walk on an n-dimensional hypercube. For any starting position we find the probability of hitting vertex a before hitting vertex b, whenever a and b share the same edge. This generalizes the model in Doyle, P., and Snell, J., &#34;Random Walks and Electric Networks&#34;, Mathematical Association of America, 1984 (see Exercise 1.3.7 th

  33. Himanshu Thapliyal, Hamid R. Arabnia, Rajnish Bajpai, Kamal K. Sharma

    IEEE 754r is the ongoing revision to the IEEE 754 floating point standard and a major enhancement to the standard is the addition of decimal format. Furthermore, in the recent years reversible logic has emerged as a promising computing paradigm having its applications in low power CMOS, quantum computing, nanotechnology, and optical computing. The major goal

  34. Patrick M. Gilmer

    We give two proofs that the 3-torus is not weakly d-congruent to the connected sum of three S^1xS^2&#39;s, if d>2. We study how cohomology ring structure relates to weak congruence. We give an example of three 3--manifolds which are weakly 5-congruent but are not 5-congruent.

  35. Krzysztof Barański, Bogusława Karpińska, Anna Zdunik

    We prove that for meromorphic maps with logarithmic tracts (e.g. entire or meromorphic maps with a finite number of poles from class $\mathcal B$), the Julia set contains a compact invariant hyperbolic Cantor set of Hausdorff dimension greater than 1. Hence, the hyperbolic dimension of the Julia set is greater than 1.

  36. Himanshu Thapliyal, Hamid R. Arabnia, Rajnish Bajpai, Kamal K. Sharma

    In this paper, we propose an architecture/methodology for making FPGAs suitable for integer as well as variable precision floating point multiplication. The proposed work will of great importance in applications which requires variable precision floating point multiplication such as multi-media processing applications. In the proposed architecture/methodolog

  37. Peter Schneider, Otmar Venjakob

    This paper is a natural continuation of the study of skew power series rings A initiated in [P. Schneider and O. Venjakob, On the codimension of modules over skew power series rings with applications to Iwasawa algebras, J. Pure Appl. Algebra 204 (2005), 349 - 367.]. We construct skew Laurent series rings B and show the existence of some canonical Ore sets S

  38. Stanislav Babak, John G. Baker, Matthew J. Benacquista, Neil J. Cornish

    The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of several data sets containing simulated instrument noise and gravitational-wave sources of undisclosed parameters. Participants are asked to analyze the data sets and report the maximum information

  39. Matthew T. Harrison

    Suppose a string $X_1^n=(X_1,X_2,...,X_n)$ generated by a memoryless source $(X_n)_{n\geq 1}$ with distribution $P$ is to be compressed with distortion no greater than $D\geq 0$, using a memoryless random codebook with distribution $Q$. The compression performance is determined by the ``generalized asymptotic equipartition property&#39;&#39; (AEP), which sta

  40. Maria Fyta, Jayanta Sircar, Efthimios Kaxiras, Simone Melchionna

    We employ a multiscale approach to model the translocation of biopolymers through nanometer size pores. Our computational scheme combines microscopic Molecular Dynamics (MD) with a mesoscopic Lattice Boltzmann (LB) method for the solvent dynamics, explicitly taking into account the interactions of the molecule with the surrounding fluid. We describe an effic

  41. Thomas D. Cohen

    This is a response to the comment, arXiv:0709.4651. It is noted that while the comment raises an extremely interesting and subtle point, the original conclusion that theoretically consistent exceptions exist for the proposed general bound for the ratio of shear viscosity to entropy density, appears to remain unaffected by the issue raised.

  42. Steven R. Blusk

    We present recent results from the CLEO Collaboration on leptonic decay rates of $D$ and $D_s$ near $c\bar{c}$ production threshold. From these decay rates, we extract the decay constants, f_D = (222.6+-16.7^{+2.8}_{-3.4}) MeV, f_Ds = (274+-10+-5) MeV, and the ratio f_Ds/f_D = 1.23+-0.11+-0.03.

  43. Paolo Castorina, Dario Zappalà

    The spontaneous breaking of of translational invariance in non-commutative self-interacting scalar field theory in two dimensions is investigated by effective action techniques. The analysis confirms the existence of the stripe phase, already observed in lattice simulations, due to the non-local nature of the non-commutative dynamics.

  44. Anisa T. Bajkova, Aleksandr B. Pushkarev

    Maps of the radio source 3C 120 obtained from VLBA+ observations at 8.4 GHz at five epochs in January - September 2002 are presented. The images were reconstructed using the maximum entropy method and the Pulkovo VLBImager software package for VLBI mapping. Apparent superluminal motions of the brightest jet knots have been estimated. The speeds of jet knots

  45. Maksim Kouza, Chin-Kun Hu, Mai Suan Li

    We have developed a new extended replica exchange method to study thermodynamics of a system in the presence of external force. Our idea is based on the exchange between different force replicas to accelerate the equilibrium process. We have shown that the refolding pathways of single ubiquitin depend on which terminus is fixed. If the N-end is fixed then th

  46. Hans Westman

    We discuss quantum non-locality and contextuality using the notion of transition sets. This approach provides a way to obtain a direct logical contradiction with locality/non-contextuality in the EPRB gedanken experiment as well as a clear graphical illustration of what violations of Bell inequalities quantify. In particular, we show graphically how these vi

  47. Brockway McMillan

    Each compact manifold M of finite dimension k is differentiable and supports an intrinsic probability measure. There then exists a measurable transformation of M to the k-dimensional &#34;surface&#34; of the (k+1)-dimensional ball.

  48. G. C. Branco, M. N. Rebelo

    We review some aspects of neutrino physics and CP violation both in the quark and lepton sectors.

  49. A. Drezet, A. Hohenau, J. R. Krenn, M. Brun

    We present an overview of recent progress in plasmonics. We focus our study on the observation and excitation of surface plasmon polaritons (SPPs) with optical near-field microscopy. We discuss in particular recent applications of photon scanning tunnelling microscope (PSTM) for imaging of SPP propagating in metal and dielectric wave guides. We show how near

  50. K. Zwintz

    A comparison of the hot and cool boundaries of the classical instability strip with observations has been an important test for stellar structure and evolution models of post- and main sequence stars. Over the last few years, the number of pulsating pre-main sequence (PMS) stars has increased significantly: 36 PMS pulsators and candidates are known as of Jun

  51. Pedro D. Alvarez, Joaquim Gomis, Kiyoshi Kamimura, Mikhail S. Plyushchay

    We investigate the planar anisotropic harmonic oscillator with explicit rotational symmetry as a particle model with non-commutative coordinates. It includes the exotic Newton-Hooke particle and the non-commutative Landau problem as special, isotropic and maximally anisotropic, cases. The system is described by the same (2+1)-dimensional exotic Newton-Hooke

  52. Filippo Caruso, Constantino Tsallis

    We present details on a physical realization, in a many-body Hamiltonian system, of the abstract probabilistic structure recently exhibited by Gell-Mann, Sato and one of us (C.T.), that the nonadditive entropy $S_q=k [1- Tr \hatρ^q]/[q-1]$ ($\hatρ\equiv$ density matrix; $S_1=-k Tr \hatρ \ln \hatρ$) can conform, for an anomalous value of q (i.e., q not equal

  53. Michael Creutz

    In 1976 &#39;t Hooft introduced an elegant approach towards understanding the physical consequences of the topological structures that appear in non-Abelian gauge theories. These effects are concisely summarized in terms of an effective multi-fermion interaction. These old arguments provide a link between a variety of recent and sometimes controversial ideas

  54. Jurgen Schaffner-Bielich, Stefan Schramm, Horst Stocker

    In these lecture notes, the role of strangeness in relativistic astrophysics of compact stars is addressed. The appearance of strange particles, as hyperons, kaons, and strange quarks, in the core of compact stars is examined and common features as well as differences are presented. Impacts on the global properties of compact stars and signals of the presenc

  55. Cedric M. Campos, Marcelo Epstein, Manuel de Leon

    The notions of uniformity and homogeneity of elastic materials are reviewed in terms of Lie groupoids and frame bundles. This framework is also extended to consider the case Functionally Graded Media, which allows us to obtain some homogeneity conditions.

  56. Yu. M. Gavriljuk, V. N. Gavrin, A. M. Gangapshev, V. V. Kazalov

    The results of the experiment searching for 2K-capture with large low-background proportional counter are presented. The comparison of spectra of the background of the proportional counter filled with Kr enriched in $^{78}$Kr (8400 hr) and with natural Kr (3039 hr) is given. A new limit on the half-life of $^{78}$Kr with regard to 2K-capture, T$_{1/2}\geq2.0

  57. A. Maier, P. Maierhoefer, P. Marquard

    We present the first 30 moments of the low energy expansions of the vector, axial-vector, scalar and pseudo-scalar heavy quark correlation functions at three-loop order, including the singlet contribution which appears for the first time at three loops. In addition we compare the behavior of the moments for large n with the prediction from threshold calculat

  58. Elizabeth S. Werbos

    We examine the shift in the chiral condensate due to a constant electromagnetic field at ${\cal O}(p^6)$ using SU(2) chiral perturbation theory and a realistic $M_π= 140 \textrm{MeV}$. We find that this value differs significantly from the value calculated using $M_π= 0$, while the magnitude of the two-loop correction is unclear due to the uncertainty in the

  59. Kenji Fukushima

    We correct a mistake in the analytical expression for the energy density given in Phys. Rev. C76, 021902 (2007) [arXiv:0704.3625 [hep-ph]]. The expression should be multiplied by 16. One question then arises; how could it be possible to explain this difference between the analytical and numerical results in the same model if both are correct? We find a subtl

  60. Andreas Neuenkirch, Ivan Nourdin, Samy Tindel

    In this article, we illustrate the flexibility of the algebraic integration formalism introduced by M. Gubinelli (2004), by establishing an existence and uniqueness result for delay equations driven by rough paths. We then apply our results to the case where the driving path is a fractional Brownian motion with Hurst parameter H>1/3.

  61. J. González-Nuevo, M. Massardi, F. Argüeso, D. Herranz

    We present results on spectral index distributions, number counts, redshift distribution and other general statistical properties of extragalactic point sources in the NEWPS5 sample López-Caniego et al. (2007). The flux calibrations at all the WMAP channels have been reassessed both by comparison with ground based observations and through estimates of the ef

  62. John Eldridge

    We first discuss the mass range of type IIP SN progenitors and how the upper and lower limits impose interesting constraints on stellar evolution. Then we discuss the possible implications of two SNe, 2002ap and 2006jc, for Wolf-Rayet star mass-loss rates and long Gamma-ray bursts.

  63. Carlos Rodrigo, Raul Gutierrez, Enrique Solano, Miguel Cervino

    Although full interoperativity between theoretical and observational data in the framework of the Virtual Observatory would be a very desirable achievement, the current status of VO offers few approaches to handle theoretical models. TSAP (Theoretical Spectra Access Protocol) has been proposed as a tool to fill this void, providing a simple scheme to easily

  64. Kazuhide Ichikawa

    We show that the cosmic microwave background (CMB) data of WMAP can give subelectronvolt limit on the neutrino mass: m_nu < 0.63 eV (95% CL). We also investigate its degeneracy with other cosmological parameters. In particular, we show the Hubble constant derived from the WMAP data decreases considerably when the neutrino mass is a few times 0.1 eV.

  65. D. C. Heggie, M. Giersz

    Astronomers have constructed models of globular clusters for over 100 years. These models mainly fall into two categories: (i) static models, such as King&#39;s model and its variants, and (ii) evolutionary models. Most attention has been given to static models, which are used to estimate mass-to-light ratios and mass segregation, and to combine data from pr

  66. Kateryna Mishchenko, Sverker Holmgren, Lars Ronnegard

    Robust and efficient optimization methods for variance component estimation using Restricted Maximum Likelihood (REML) models for genetic mapping of quantitative traits are considered. We show that the standard Newton-AI scheme may fail when the optimum is located at one of the constraint boundaries, and we introduce different approaches to remedy this by ta

  67. Walid K. Abou Salem

    The mean-field limit for the dynamics of bosons with random interactions is rigorously studied. It is shown that, for interactions that are almost-surely bounded, the many-body quantum evolution can be replaced in the mean-field limit by a single particle nonlinear evolution that is described by the Hartree equation. This is an Egorov-type theorem for many-b

  68. Ganesh Bagler

    Proteins are an important class of biomolecules that serve as essential building blocks of the cells. Their three-dimensional structures are responsible for their functions. In this thesis we have investigated the protein structures using a network theoretical approach. While doing so we used a coarse-grained method, viz., complex network analysis. We model

  69. Franco Bagnoli, Francesca Di Patti

    We present a method for measuring the distance among records based on the correlations of data stored in the corresponding database entries. The original method (F. Bagnoli, A. Berrones and F. Franci. Physica A 332 (2004) 509-518) was formulated in the context of opinion formation. The opinions expressed over a set of topic originate a ``knowledge network&#3

  70. Yu. M. Gavriljuk, V. N. Gavrin, A. M. Gangapshev, V. V. Kazalov

    The construction of an ion pulse ionization chamber aimed at measuring ultra-low levels of surface alpha-activity of different samples is described. The results of measurement carried out with alpha-source and copper samples and light-reflecting film VM2000 are presented.

  71. Vasily E. Tarasov

    Continuous limits of discrete systems with long-range interactions are considered. The map of discrete models into continuous medium models is defined. A wide class of long-range interactions that give the fractional equations in the continuous limit is discussed. The one-dimensional systems of coupled oscillators for this type of long-range interactions are

  72. D. V. Senthilkumar, M. Lakshmanan

    In this paper, we report the nature of transition to generalized synchronization (GS) in a system of two coupled scalar piecewise linear time-delay systems using the auxiliary system approach. We demonstrate that the transition to GS occurs via on-off intermittency route and also it exhibits characteristically distinct behaviors for different coupling config

  73. L. Rosales, P. Orellana, Z. Barticevic, M. Pacheco

    We study the electronic and transport properties of heterostructures formed by armchair graphene nanoribbons with intersections of finite length. We describe the system by a tight-binding model and calculate the density of states and the conductance within the Green&#39;s function formalism based on real-space renormalization techniques. We show the appariti

  74. Tom Claeys

    We study unitary random matrix ensembles in the critical regime where a new cut arises away from the original spectrum. We perform a double scaling limit where the size of the matrices tends to infinity, but in such a way that only a bounded number of eigenvalues is expected in the newborn cut. It turns out that limits of the eigenvalue correlation kernel ar

  75. H. Arp

    If active galaxies are defined as extragalactic objects with appreciably non thermal spectra then a continuity exists in redshift from the highest redshift quasars to low redshift Seyferts, AGNs and allied galaxies. Evidence is discussed for this sequence to be an evolutionary track with objects evolving from high to low intrinsic redshift with time. At the

  76. H1-Collaboration

    Three- and four-jet production is measured in deep-inelastic $ep$ scattering at low $x$ and $Q^2$ with the H1 detector using an integrated luminosity of $44{.}2 {\rm pb}^{-1}$. Several phase space regions are selected for the three-jet analysis in order to study the underlying parton dynamics from global topologies to the more restrictive regions of forward

  77. D. M. Harrington, J. R. Kuhn

    The near-star environment around young stars is very dynamic with winds, disks, and outflows. These processes are involved in star and planet formation, and influence the formation and habitability of planets around host stars. Even for the closest young stars, this will not be imaged even after the completion of the next generation of telescopes decades fro

  78. J. Hasper, S. Müller, D. Savran, L. Schnorrenberger

    We have investigated the photoneutron cross section of the isotopes $^{148,150}$Nd, $^{154}$Sm, and $^{154,160}$Gd close to the neutron emission threshold in photoactivation experiments at the Darmstadt superconducting electron linear accelerator S-DALINAC. Naturally composed targets were activated with a high-intensity bremsstrahlung beam at various energie

  79. S. Chanyawadee, P. G. Lagoudakis, R. T. Harley, D. G. Lidzey

    Non-radiative optical energy transfer from a GaAs quantum well to a thin overlayer of an infrared organic semiconductor dye is unambiguously demonstrated. The dynamics of exciton transfer are studied in the time-domain using pump-probe spectroscopy at the donor site and fluorescence spectroscopy at the acceptor site. The effect is observed as simultaneous in

  80. Patrick Achenbach

    Spectroscopy of Lambda hypernuclei has recently become one of the most valuable tools for the experimental investigation of strangeness nuclear physics. Several new approached are being pursued currently: In Mainz, the Microtron MAMI has been upgraded to 1.5 GeV electron beam energy and will be used to produce strange hadronic systems in the near future. The

  81. Shigeki Matsumoto, Joe Sato, Masato Senami, Masato Yamanaka

    Relic abundance of dark matter is investigated in the framework of universal extra dimension models with right-handed neutrinos. These models are free from the serious Kaluza-Klein (KK) graviton problem that the original universal extra dimension model possesses. The first KK particle of the right-handed neutrino is a candidate for dark matter in this framew

  82. N. S. Chernikov

    We give a new proof of the known Shunkov&#39;s Theorem on locally finite groups with the minimal condition for nonabelian subgroups and also an extension of the known Suchkova-Shunkov Theorem on Shunkov groups with the minimal condition for abelian subgroups.

  83. L. Podio, P. J. V. Garcia, F. Bacciotti, S. Antoniucci

    Most of the observed emission lines and continuum excess from young accreting low mass stars (Classical T Tauri stars -- CTTSs) take place in the star-disk or inner disk region. These regions have a complex emission topology still largely unknown. In this paper the magnetospheric accretion and inner wind contributions to the observed permitted He and H near

  84. Fabian Herrmann, Alexander V. Krivov

    Although known for almost a century, the photophoretic force has only recently been considered in astrophysical context for the first time. In our work, we have examined the effect of photophoresis, acting together with stellar gravity, radiation pressure, and gas drag, on the evolution of solids in transitional circumstellar disks. We have applied our calcu

  85. Edgar A. Osorio, Kevin O&#39;Neill, Maarten Wegewijs, Nicolai Stuhr-Hansen

    Low-temperature three-terminal transport measurements through a thiol end-capped Pi -conjugated molecule have been carried out. Electronic excitations, including zero and finite-bias Kondo-effects have been observed and studied as a function of magnetic field. Using a simplified two-orbital model we have accounted for the spin and the electronic configuratio

  86. Andrew D. Brooke-Taylor

    We use a reverse Easton forcing iteration to obtain a universe with a definable well-ordering, while preserving the GCH and proper classes of a variety of very large cardinals. This is achieved by coding using the principle diamond star at a proper class of successor cardinals.

  87. A. Moya, R. Garrido

    Granada oscillation code (GraCo) is a software constructed to compute adiabatic and non-adiabatic oscillation eigenfunctions and eigenvalues. The adiabatic version gives the standard numerical resolution, and also the Richardson extrapolation, different sets of eigenfunctions, different outer mechanical boundary conditions or different integration variables.

  88. Joakim Arnlind, Martin Bordemann, Laurent Hofer, Jens Hoppe

    We introduce C-Algebras of compact Riemann surfaces $Σ$ as non-commutative analogues of the Poisson algebra of smooth functions on $Σ$. Representations of these algebras give rise to sequences of matrix-algebras for which matrix-commutators converge to Poisson-brackets as $N\to\infty$. For a particular class of surfaces, nicely interpolating between spheres

  89. A. Moya, J. Christensen-Dalsgaard, S. Charpinet, Y. Lebreton

    In order to make astroseismology a powerful tool to explore stellar interiors, different numerical codes should give the same oscillation frequencies for the same input physics. This work is devoted to test, compare and, if needed, optimize the seismic codes used to calculate the eigenfrequencies to be finally compared with observations. The oscillation code

  90. J. Trujillo Bueno, R. Manso Sainz

    The only way to obtain reliable empirical information on the intensity and topology of the weak magnetic fields of the quiet solar chromosphere is via the measurement and rigorous physical interpretation of polarization signals in chromospheric spectral lines. The observed Stokes profiles reported here are due to the Hanle and Zeeman effects operating in a w

  91. Kazuo Fujikawa

    All the geometric phases, adiabatic and non-adiabatic, are formulated in a unified manner in the second quantized path integral formulation. The exact hidden local symmetry inherent in the Schrödinger equation defines the holonomy. All the geometric phases are shown to be topologically trivial. The geometric phases are briefly compared to the chiral anomaly

  92. P. J. Rippon, G. M. Stallard

    We describe conditions under which a multiply connected wandering domain of a transcendental meromorphic function with a finite number of poles must be a Baker wandering domain, and we discuss the possible eventual connectivity of Fatou components of transcendental meromorphic functions. We also show that if $f$ is meromorphic, $U$ is a bounded component of

  93. S. R. Kane, W. I. Clarkson, R. G. West, D. M. Wilson

    The Wide Angle Search for Planets (WASP) survey currently operates two installations, designated SuperWASP-N and SuperWASP-S, located in the northern and southern hemispheres respectively. These installations are designed to provide high time-resolution photometry for the purpose of detecting transiting extra-solar planets, asteroids, and transient events. H

  94. P. G. Jonker

    Chandra or XMM-Newton observations of quiescent low-mass X-ray binaries can provide important constraints on the equation of state of neutron stars. The mass and radius of the neutron star can potentially be determined from fitting a neutron star atmosphere model to the observed X-ray spectrum. For a radius measurement it is of critical importance that the d

  95. Hasi Ray

    A proposal is made by the University College of London Group [1] for measuring the target-ionization cross sections in Ps and atom scattering. We calculate the corresponding theoretical data for Ps-H and Ps-He systems including the effect of exchange on Coulomb-Born approximation for the projectile-elastic and projectile-inelastic processes and report the to

  96. S. Rodrigues, B. Tome, M. C. Abreu, N. Santos

    The GEANT4 Monte Carlo simulation and experimental characterization of the Siemens E.Cam Dual Head gamma camera hosted in the Particular Hospital of Algarve have been done. Imaging tests of thyroid and other phantoms have been made &#34;in situ&#34; and compared with the results obtained with the Monte Carlo simulation.

  97. I. Nagy, A. Zawadowski

    An effective Hamiltonian which could model the interaction between a tunneling proton and the conduction electrons of a metal is investigated. A remarkably simple correlation between the motion of the $TLS$-atom and an angular-momentum change of scattering electron is deduced, at the first-order Born level, by using a momentum-space representation with plane

  98. P. G. Jonker, J. Kaastra, M. Mendez, J. J. M. In &#39;t Zand

    We have identified three possible ways in which future XMM-Newton observations can provide significant constraints on the equation of state of neutron stars. First, using a long observation of the neutron star X-ray transient CenX-4 in quiescence one can use the RGS spectrum to constrain the interstellar extinction to the source. This removes this parameter

  99. Kashif Ali, Edy Tri Baskoro

    For given graphs $G$ and $H,$ the \emph{Ramsey number} $R(G,H)$ is the least natural number $n$ such that for every graph $F$ of order $n$ the following condition holds: either $F$ contains $G$ or the complement of $F$ contains $H.$ In this paper, we improve the Surahmat and Tomescu&#39;s result \cite{ST:06} on the Ramsey number of paths versus Jahangirs. We

  100. Vasily E. Tarasov

    Definitions of fractional derivatives as fractional powers of derivative operators are suggested. The Taylor series and Fourier series are used to define fractional power of self-adjoint derivative operator. The Fourier integrals and Weyl quantization procedure are applied to derive the definition of fractional derivative operator. Fractional generalization