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November 2013 arXiv papers — page 22

Showing 2,1012,200 of 7,801 papers

  1. Nathan Pflueger

    Brill-Noether theory studies the existence and deformations of curves in projective spaces; its basic object of study is $\mathcal{W}^r_{d,g}$, the moduli space of smooth genus $g$ curves with a choice of degree $d$ line bundle having at least $(r+1)$ independent global sections. The Brill-Noether theorem asserts that the map $\mathcal{W}^r_{d,g} \rightarrow

  2. Giovanna Bucci, Siva P. V. Nadimpalli, Vijay A. Sethuraman, Allan F. Bower

    A combination of experimental measurements and numerical simulations are used to characterize the mechanical and electrochemical response of thin film amorphous Si electrodes during cyclic lithiation. Parameters extracted from the experiment include the variation of elastic modulus and the flow stress as functions of Li concentration; the strain rate sensiti

  3. Bartłomiej Płaczek

    Cellular automata (CA) play an important role in the development of computationally efficient microscopic traffic models and recently have gained considerable importance as a mean of optimising traffic control strategies. However, real-time application of the available CA models in traffic control systems is a difficult task due to their discrete and stochas

  4. Paul Matthews, Pedro Ribeiro, Antonio M. García-García

    Topological features of low dimensional superconductors have caused a lot of excitement recently because of their broad range of applications in quantum information and their potential to reveal novel phases of quantum matter. A potential problem for practical applications is the presence of phase-slips that break phase coherence. Dissipation in non-topologi

  5. Thomas Trogdon, Sheehan Olver

    The computation of the entries of Jacobi operators associated with orthogonal polynomials has important applications in numerical analysis. From truncating the operator to form a Jacobi matrix, one can apply the Golub--Welsh algorithm to compute the Gaussian quadrature weights and nodes. Furthermore, the entries of the Jacobi operator are the coefficients in

  6. Pooja Gupta, Nisheeth Joshi, Iti Mathur

    Since long, research on machine translation has been ongoing. Still, we do not get good translations from MT engines so developed. Manual ranking of these outputs tends to be very time consuming and expensive. Identifying which one is better or worse than the others is a very taxing task. In this paper, we show an approach which can provide automatic ranks t

  7. Pablo Echenique-Robba

    In this little non-technical piece, I argue that some of the lessons that can be learnt from the bold action carried out in 1996 by the physicist Alan Sokal and typically known as the "Sokal affair" not only apply to some sector of the humanities (which was the original target of the hoax), but also (with much less intensity, but still) to the hardes

  8. Akshay Pulipaka, Patrick Seeling, Martin Reisslein, Lina J. Karam

    The network transport of 3D video, which contains two views of a video scene, poses significant challenges due to the increased video data compared to conventional single-view video. Addressing these challenges requires a thorough understanding of the traffic and multiplexing characteristics of the different representation formats of 3D video. We examine the

  9. Michael Harder, Ulrich Stadtmüller

    We give the maximal distance between a copula and itself when the argument is permuted for arbitrary dimension, generalizing a result for dimension two by Nelsen (2007), Klement and Mesiar (2006). Furthermore, we establish a subset of $[0,1]^d$ in which this bound might be attained. For each point in this subset we present a copula and a permutation, for whi

  10. Baodong Liu, Hengyong Yu, Scott S. Verbridge, Lizhi Sun

    Electron tomography usually suffers from so called missing wedge artifacts caused by limited tilt angle range. An equally sloped tomography (EST) acquisition scheme (which should be called the linogram sampling scheme) was recently applied to achieve 2.4-angstrom resolution. On the other hand, a compressive sensing-inspired reconstruction algorithm, known as

  11. Gerard Keogh

    This paper proposes a new bootstrap method to compute predictive intervals for nonlinear autoregressive time series model forecast. This method we call the splice boobstrap as it involves splicing the last p values of a given series to a suitably simulated series. This ensures that each simulated series will have the same set of p time series values in commo

  12. Juan P. Garrahan

    A key open question in the glass transition field is whether a finite temperature thermodynamic transition to the glass state exists or not. Recent simulations of coupled replicas in atomistic models have found signatures of a static transition as a function of replica coupling. This can be viewed as evidence of an associated thermodynamic glass transition i

  13. Julian Fernandez Bonder, Graciela Giubergia, Fernando Mazzone

    In this paper, we analyze an optimization problem for the first (nonlinear) Steklov eigenvalue plus a boundary potential with respect to the potential function which is assumed to be uniformly bounded and with fixed $L^1$-norm.

  14. David Van Horn, Harry G. Mairson

    Flow analysis is a ubiquitous and much-studied component of compiler technology---and its variations abound. Amongst the most well known is Shivers' 0CFA; however, the best known algorithm for 0CFA requires time cubic in the size of the analyzed program and is unlikely to be improved. Consequently, several analyses have been designed to approximate 0CFA

  15. Jean-Paul Blaizot, Fabio Dominguez, Edmond Iancu, Yacine Mehtar-Tani

    A high energy jet that propagates in a dense medium generates a cascade of partons that can be described as a classical branching process. A simple generating functional for the probabilities to observe a given number of gluons at a given time is derived. This is used to obtain an evolution equation for the inclusive one-gluon distribution, that takes into a

  16. Ronaldo S. S. Vieira, Jan Schee, Włodek Kluźniak, Zdeněk Stuchlík

    We discuss photon and test-particle orbits in the Kehagias-Sfetsos (KS) metric. For any value of the Hořava parameter $ω$, there are values of the gravitational mass $M$ for which the metric describes a naked singularity, and this is always accompanied by a vacuum "antigravity sphere" on whose surface a test particle can remain at rest (in a zero ang

  17. Bryan Knowles, Rong Yang

    We perform social network analysis on 53 students split over three semesters and 13 groups, using conventional measures like eigenvector centrality, betweeness centrality, and degree centrality, as well as defining a variant of the Abelian Sandpile Model (ASM) with the intention of modeling stress propagation in the college classroom. We correlate the result

  18. Rupert L. Frank, Benjamin Schlein

    We study the dynamics of large polarons described by the Froehlich Hamiltonian in the limit of strong coupling. The initial conditions are (perturbations of) product states of an electron wave function and a phonon coherent state, as suggested by Pekar. We show that, to leading order on the natural time scale of the problem, the phonon field is stationary an

  19. Andrei Gruzinov

    Assuming self-similarity of the first kind, we get three possible values p=1/2, 1, 3/2 for the exponent describing the density profile, rho r^{-p}, of a non-radiative (and hence quasi-spherical) accretion flow. The high and low p cases are known as Bondi and Convection-Dominated accretion flows. The 1-law flow we tentatively identify with the so-called Magne

  20. John M. Campbell, Walter T. Giele, Ciaran Williams

    We present a general method of associating next-to-leading order weights to leading order phase space configurations at hadron colliders. The method relies on a re-organization of phase space for the real radiation contributions, defining a one-to-many map such that each point in the real phase space is associated with a distinct Born topology. As a result v

  21. David Van Horn, Harry G. Mairson

    We give an exact characterization of the computational complexity of the $k$CFA hierarchy. For any $k > 0$, we prove that the control flow decision problem is complete for deterministic exponential time. This theorem validates empirical observations that such control flow analysis is intractable. It also provides more general insight into the complexity of a

  22. Zhe Guan, Huan He, Yong-Jian Han, Chuan-Feng Li

    The ability to reach a maximally entangled state from a separable one through the use of a two-qubit unitary operator is analyzed for mixed states. This extension from the known case of pure states shows that there are at least two families of gates which are able to give maximum entangling power for all values of purity. It is notable that one of this gates

  23. Matteo Luca Ruggiero

    Gravitomagnetic effects originates from the rotation of the source of the gravitational field and from the rotational features of the observers' frame. In recent years, gravitomagnetism has been tested by means of its impact on the precession of LAGEOS orbits and on the precession of spherical gyroscopes in the GP-B experiment. What we suggest here is th

  24. V. K. Guduru, A. McCollam, A. Jost, S. Wenderich

    Magnetotransport measurements of charge carriers at the interface of a LaAlO3/SrTiO3 heterostructure with 26 unit cells of LaAlO3 show Hall resistance and magnetoresistance which at low and high temperatures is described by a single channel of electron-like charge carriers. At intermediate temperatures, we observe non-linear Hall resistance and positive magn

  25. Stéphane Ancey, Emmanuelle Bazzali, Paul Gabrielli, Michaël Mercier

    The resonant modes of two-dimensional elastic elliptical objects are studied from a modal formalism by emphasizing the role of the symmetries of the objects. More precisely, as the symmetry is broken in the transition from the circular disc to the elliptical one, the splitting up of resonances and level crossings are observed. From the mathematical point of

  26. Emil Sköldberg

    We show that the main result of algebraic Morse theory can be obtained as a consequence of the perturbation lemma of Brown and Gugenheim.

  27. Jost Fischer, Steffen Bergweiler, Markus Abel

    Wind-driven sound generation is a source of anger and pleasure, depending on the situation: airframe and car noise, or combustion noise are some of the most disturbing environmental pollutions, whereas musical instruments are sources of joy. We present an experiment on two coupled sound sources -organ pipes- together with a theoretical model which takes into

  28. Igor Gilitschenski, Gerhard Kurz, Simon J. Julier, Uwe D. Hanebeck

    Orientation estimation for 3D objects is a common problem that is usually tackled with traditional nonlinear filtering techniques such as the extended Kalman filter (EKF) or the unscented Kalman filter (UKF). Most of these techniques assume Gaussian distributions to account for system noise and uncertain measurements. This distributional assumption does not

  29. Kaspar A. Schindler, Stephan Bialonski, Marie-Therese Horstmann, Christian E. Elger

    We assess electrical brain dynamics before, during, and after one-hundred human epileptic seizures with different anatomical onset locations by statistical and spectral properties of functionally defined networks. We observe a concave-like temporal evolution of characteristic path length and cluster coefficient indicative of a movement from a more random tow

  30. Stoian I. Zlatev

    An approximation for the centrifugal term which transforms the radial equation for a particle in a Pöschl-Teller potential into an exactly solvable approximate equation is proposed. In contrast to the approximations known in the literature, the new one can be used with the most general form of the central Pöschl-Teller potential. An approximate expression fo

  31. Liang Jie Wong, Franz X. Kärtner

    We hypothesize that a charged particle in unbounded vacuum can be substantially accelerated by a force linear in the electric field of a propagating electromagnetic wave only if the accelerating field is capable of bringing the particle to a relativistic energy in its initial rest frame during the interaction. We consequently derive a general formula for the

  32. Liang Jie Wong, Franz X. Kärtner

    We study the direct acceleration of a free electron in infinite vacuum along the axis of a pulsed radially-polarized laser beam. We find that net energy transfer from laser pulse to electron is maximized with the tightest focusing. We show that the net energy gain of an electron initially moving at a relativistic velocity may exceed more than half the theore

  33. Liang Jie Wong, Franz X. Kärtner

    We propose a direct electron acceleration scheme that uses a two-color pulsed radially-polarized laser beam. The two-color scheme achieves electron acceleration exceeding 90% of the theoretical energy gain limit, over twice of what is possible with a one-color pulsed beam of equal total energy and pulse duration. The scheme succeeds by exploiting the Gouy ph

  34. Carlos Eduardo de Brito Novaes, Paulo Sergio Pereira da Silva, Pierre Rouchon

    In this paper we exploit some interesting properties of a class of bipedal robots which have an inertial disc. One of this properties is the ability to control every position and speed except for the disc position. The proposed control is designed in two hierarchic levels. The first will drive the robot geometry, while the second will control the speed and a

  35. Yu-Ting Chen, Jihyeok Choi, J. Theodore Cox

    We study voter models defined on large sets. Through a perspective emphasizing the martingale property of voter density processes, we prove that in general, their convergence to the Wright-Fisher diffusion only involves certain averages of the voter models over a small number of spatial locations. This enables us to identify suitable mixing conditions on the

  36. N. Bucciantini

    Pulsar Wind Nebulae (PWNe) are ideal astrophysical laboratories where high energy relativistic phenomena can be investigated. They are close, well resolved in our observations, and the knowledg derived in their study has a strong impact in many other fields, from AGNs to GRBs. Yet there are still unresolved issues, that prevent us from a full clear understan

  37. Michael Feischl, Thomas Führer, Dirk Praetorius, Ernst P. Stephan

    We analyze a multilevel diagonal additive Schwarz preconditioner for the adaptive coupling of FEM and BEM for a linear 2D Laplace transmission problem. We rigorously prove that the condition number of the preconditioned system stays uniformly bounded, independently of the refinement level and the local mesh-size of the underlying adaptively refined triangula

  38. Liang Jie Wong, Arya Fallahi, Franz X. Kärtner

    We numerically investigate the acceleration and bunch compression capabilities of 20 mJ, 0.6 THz-centered coherent terahertz pulses in optimized metallic dielectric-loaded cylindrical waveguides. In particular, we theoretically demonstrate the acceleration of 1.6 pC and 16 pC electron bunches from 1 MeV to 10 MeV over an interaction distance of 20mm, the com

  39. A R Bell

    Particle acceleration occurs on a range of scales from AU in the heliosphere to Mpc in clusters of galaxies and to energies ranging from MeV to EeV. A number of acceleration processes have been proposed, but diffusive shock acceleration (DSA) is widely invoked as the predominant mechanism. DSA operates on all these scales and probably to the highest energies

  40. Paul A. Jenkins

    Diffusion processes arise in many fields, and so simulating the path of a diffusion is an important problem. It is usually necessary to make some sort of approximation via model-discretization, but a recently introduced class of algorithms, known as the exact algorithm and based on retrospective rejection sampling ideas, obviate the need for such discretizat

  41. Robert Denk, Tim Seger

    We consider the situation when an elliptic problem in a subdomain $Ω_1$ of an $n$-dimensional bounded domain $Ω$ is coupled via inhomogeneous canonical transmission conditions to a parabolic problem in $Ω\setminusΩ_1$. In particular, we can treat elliptic-parabolic equations in bounded domains with discontinuous coefficients. Using Fourier multiplier techniq

  42. Shanti Venetiaan

    In this article third and fourth order efficiency are studied in the framework of translation equivariant location estimators. We assume $X_1,...,X_n$ i.i.d. $f(\cdot -θ)$. By recognizing that equality in a special form of the Cauchy-Schwarz inequality leads to a certain dependence of the cumulants of the maximum likelihood estimator (MLE) for $θ$, it is sho

  43. Markus Bach, Cheng Han Chung, Tania Robens

    In this work, we briefly report on the current status of an alternative subtraction scheme which is based on the splitting kernels of an improved parton shower prescription. Our focus is here on more recent developments as well as generic arguments on the scaling behaviour.

  44. G. V. Smirnov

    A possibility of further development of Synchrotron Mössbauer Source (SMS) of $^{57}$Fe 14.4 keV radiation is considered. The principles and detailed description of the SMS device is given in Refs. Phys. Rev. A 84, 053851 (2011) G. V. Smirnov et al, J. Synchrotron Rad., v. 19, 559 (2012) V. Potapkin et al. The perfect crystal of Iron Borate, FeBO$_{3}$, is t

  45. A. G. Biternas, G. T. P. Charnock, Ilya Kuprov

    We introduce a simple and general XML format for spin system description that is the result of extensive consultations within Magnetic Resonance community and unifies under one roof all major existing spin interaction specification conventions. The format is human-readable, easy to edit and easy to parse using standard XML libraries. We also describe a graph

  46. Roshan A, Jones PH, Greenman CD

    Biological tools such as genetic lineage tracing, three dimensional confocal microscopy and next generation DNA sequencing are providing new ways to quantify the distribution of clones of normal and mutated cells. Population-wide clone size distributions in vivo are complicated by multiple cell types, and overlapping birth and death processes. This has led t

  47. Alexander Jung

    The investigation of the effects of sparsity or sparsity constraints in signal processing problems has received considerable attention recently. Sparsity constraints refer to the a priori information that the object or signal of interest can be represented by using only few elements of a predefined dictionary. Within this thesis, sparsity refers to the fact

  48. Srikanth Bethu, G Charless Babu, J Vinoda, E Priyadarshini

    Text Categorization is traditionally done by using the term frequency and inverse document frequency.This type of method is not very good because, some words which are not so important may appear in the document .The term frequency of unimportant words may increase and document may be classified in the wrong category.For reducing the error of classifying of

  49. Maxim Pospelov, Josef Pradler

    The elastic nuclear recoil signal, being under intense scrutiny by multiple underground experiments, can be interpreted either as coming from the interaction of nuclei with WIMP dark matter or from the scattering of new species of MeV-energy neutrinos. The most promising model for the latter case is a neutrino $ν_b$ that interacts with baryon number, and wit

  50. Peter Sarlin

    This paper proposes schemes for automated and weighted Self-Organizing Time Maps (SOTMs). The SOTM provides means for a visual approach to evolutionary clustering, which aims at producing a sequence of clustering solutions. This task we denote as visual dynamic clustering. The implication of an automated SOTM is not only a data-driven parametrization of the

  51. Jonathan M. Marr, Thomas M. Perry, James Read, Gregory B. Taylor

    We obtained dual-polarization VLBI observations at six frequencies of the compact symmetric object J0029+3457 and the CSO candidate J1324+4048. By comparing the three lower-frequency maps with extrapolations of the high frequency maps we produced maps of the optical depth as a function of frequency. The morphology of the optical-depth maps of J1324+4048 is s

  52. D. L. Clements, F. G. Braglia, A. Hyde, I. Perez-Fournon

    The potential for Planck to detect clusters of dusty, star-forming galaxies at z greater than 1 is tested by examining the Herschel-SPIRE images of Planck Early Release Compact Source Catalog (ERCSC) sources lying in fields observed by the HerMES survey. Of the 16 Planck sources that lie in the roughly 90 sq. deg. examined, we find that twelve are associated

  53. Yu. Savina, A. Bludov, V. Pashchenko, S. Gnatchenko

    The angular and temperature dependences of single crystal ESR spectra at X-band frequency of quasi 1D spin 1/2 antiferromagnetic zigzag chain system β-TeVO4 are reported. Two resonance components in the ESR spectrum have been detected: a weak narrow resonance on the top of the extremely broad signal. The narrow line might be due to an impurity, the character

  54. Alastair Kay

    The partial adiabatic search algorithm was introduced in [A. Tulsi, Phys. Rev. A 80, 052328 (2009)] as a modification of the usual adiabatic algorithm for quantum search with the idea that most of the interesting computation only happens over a very short range of the adiabatic path. By focussing on that restricted range, one can potentially gain advantage b

  55. Micah W. Chrisman

    It is well-known that the monoid of long virtual knots is not commutative. This contrasts with the case of classical long knots, where $A \# B \leftrightharpoons B \# A$ for all $A,B$. In the present paper, we present a new proof that two inequivalent non-classical prime long virtual knots never commute. The original result is due to Manturov. The techniques

  56. M. V. Durnev, M. M. Glazov, E. L. Ivchenko

    We propose the 14-band $\mathbf k \cdot \mathbf p$ model to calculate spin-orbit splittings of the valence subbands in semiconductor quantum wells. The reduced symmetry of quantum well interfaces is incorporated by means of additional terms in the boundary conditions which mix the $Γ_{15}$ conduction and valence Bloch functions at the interfaces. It is demon

  57. Daniel Goetz, Christopher Schwan, Stefan Weinzierl

    In this talk, we discuss the speed-up of numerical calculations of jet observables by replacing the usual sum over all helicity amplitudes with an integral over a parametrisation for the parton polarisations called random polarisations. Random polarisations are a linear combination of helicity eigenstates multiplied by a phase factor depending on a so-called

  58. M. V. Kartsovnik, V. N. Zverev, D. Andres, W. Biberacher

    The low-temperature charge-density-wave (CDW) state in the layered organic metals $α$-(BEDT-TTF)$_2$MHg(SCN)$_4$ has been studied by means of the Shubnikov -- de Haas and de Haas -- van Alphen effects. In addition to the dominant alpha-frequency, which is also observed in the normal state, both the magnetoresistance and magnetic torque possess a slowly oscil

  59. Oliver Ungermann

    Let $B$ be a finitely generated algebra over a field $k$. Then $B$ is called a Jacobson algebra if every semiprime ideal of $B$ is semiprimitive. We will discuss several conditions, all involving the commutant of simple $B$-modules, which imply that $B$ is Jacobson. In particular, we will recover the well-known result that every finitely generated almost com

  60. Joris Borgdorff, Mariusz Mamonski, Bartosz Bosak, Krzysztof Kurowski

    We present the Multiscale Coupling Library and Environment: MUSCLE 2. This multiscale component-based execution environment has a simple to use Java, C++, C, Python and Fortran API, compatible with MPI, OpenMP and threading codes. We demonstrate its local and distributed computing capabilities and compare its performance to MUSCLE 1, file copy, MPI, MPWide,

  61. Roswitha Hofer, Harald Niederreiter

    The authors recently introduced so-called Vandermonde nets. These digital nets share properties with the well-known polynomial lattices. For example, both can be constructed via component-by-component search algorithms. A striking characteristic of the Vandermonde nets is that for fixed $m$ an explicit construction of $m \times m$ generating matrices over th

  62. M. A. Al-Wardat, Yu. Yu. Balega, V. V. Leushion, A. A. Taani

    Atmospheric modeling is used to build synthetic spectral energy distributions (SEDs) for the individual components of the speckle interferometric binary system HD375. These synthetic SEDs are combined together for the entire system and compared with its observational SED in an iterated procedure to achieve the best fit. Kurucz blanketed models with the measu

  63. Merve Avci Ardic

    In this paper, we establish some integral ineuqalities for n- times differentiable quasi-convex functions.

  64. Jose A Egea, David Henriques, Thomas Cokelaer, Alejandro F Villaverde

    Optimization is key to solve many problems in computational biology. Global optimization methods provide a robust methodology, and metaheuristics in particular have proven to be the most efficient methods for many applications. Despite their utility, there is limited availability of metaheuristic tools. We present MEIGO, an R and Matlab optimization toolbox

  65. D. D. Frederiks, K. Hurley, D. S. Svinkin, V. D. Pal'shin

    GRB 110918A is the brightest long GRB detected by Konus-WIND during its 19 years of continuous observations and the most luminous GRB ever observed since the beginning of the cosmological era in 1997. We report on the final IPN localization of this event and its detailed multiwavelength study with a number of space-based instruments. The prompt emission is c

  66. W. M. Alberico, S. Carignano, P. Czerski, A. De Pace

    We extend a previous work on the study of heavy charmonia and bottomonia in a deconfined quark-gluon plasma by considering the Bc family of mesons. With the introduction of this bound state of a charm and a beauty quark, we investigate at finite temperature the behavior of the quarkonium, in an energy region between the ψ and the Υ states.

  67. A. Ciechan, M. J. Winiarski, M. Samsel-Czekała

    The influence of hydrostatic pressure and ab-plane strain on the magnetic structure of FeTe is investigated from first principles. The results of calculations reveal a phase transition from antiferromagnetic double-stripe ordering at ambient pressure to ferromagnetic ordering at 2 GPa, or under compressive strain reducing the lattice parameter a by about 3%.

  68. Supaluck Amloy, K. Fredrik Karlsson, P. O Holtz

    Computational studies based on 6 band k$\cdot$p theory are employed on lens-shaped III-nitride quantum dots (QDs) with focus on the polarization properties of the optical interband transitions. The results predict pronounced linear polarization of the ground-state related transitions for asymmetric QDs of a material with small split-off energy. It is demonst

  69. Electra Eleftheriadou, Stephen M. Barnett, John Jeffers

    It is a fundamental principle of quantum theory that an unknown state cannot be copied or, as a consequence, an unknown optical signal cannot be amplified deterministically and perfectly. Here we describe a protocol that provides nondeterministic quantum optical amplification in the coherent state basis with high gain, high fidelity and which does not use qu

  70. Alexander Ovseevich

    We study the minimum-time damping of a physical pendulum by means of a bounded control. In the similar problem for a linear oscillator each optimal trajectory possesses a finite number of control switchings from the maximal to the minimal value. If one considers simultaneously all optimal trajectories with any initial state, the number of switchings can be a

  71. Maurice Koster, Sascha Kurz, Ines Lindner, Stefan Napel

    We introduce the prediction value (PV) as a measure of players' informational importance in probabilistic TU games. The latter combine a standard TU game and a probability distribution over the set of coalitions. Player $i$'s prediction value equals the difference between the conditional expectations of $v(S)$ when $i$ cooperates or not. We character

  72. Gianluca Frasso, Jonathan Jaeger, Philippe Lambert

    Differential equations (DEs) are commonly used to describe dynamic systems evolving in one (ordinary differential equations or ODEs) or in more than one dimensions (partial differential equations or PDEs). In real data applications the parameters involved in the DE models are usually unknown and need to be estimated from the available measurements together w

  73. Ilya D. Shkredov

    In the paper we obtain some new upper bounds for exponential sums over multiplicative subgroups G of F^*_p having sizes in the range [p^{c_1}, p^{c_2}], where c_1,c_2 are some absolute constants close to 1/2. As an application we prove that in symmetric case G is always an additive basis of order five, provided by |G| > p^{1/2} log^{1/3} p. Also the method a

  74. Chun Zhang, M. -H. Du, H. -P. Cheng, X. -G. Zhang

    We apply a first-principles computational approach to study a light-sensitive molecular switch. The molecule that comprises the switch can convert between a trans and a cis configuration upon photo-excitation. We find that the conductance of the two isomers vary dramatically, which suggests that this system has potential application as a molecular device. A

  75. Chun Zhang, R. N. Barnett, Uzi Landman

    Spin-density-functional calculations of tip-suspended gold chains, with molecular oxygen, or dissociated oxygen atoms, incorporated in them, reveal structural transitions for varying lengths. The nanowires exhibit enhanced strength for both oxygen incorporation modes, and upon stretching tip atoms join the wire. With incorporated molecular oxygen the wire co

  76. Mashhoor A. Al-Wardat, Hatem S. Widyan, Ahmed Al-thyabat

    The visually close binary system HD25811 is analyzed to estimate its physical and geometrical parameters in addition to its spectral type and luminosity class. The method depends on obtaining the best fit between the entire observational spectral energy distribution (SED) of the system and synthetic SEDs created by atmospheric modeling of the individual comp

  77. Yu. N. Pokotilovski

    The chameleon scalar field is considered as a possible cause of accelerated expansion of the Universe. The chameleon field induces an interaction potential between a particle and a massive body. Previous experiments with falling cold neutrons intended to measure the neutron coherent scattering lengths and verification of the weak equivalence principle for th

  78. Aihua Zhang, Zhenxiang Dai, Lei Shi, Yuan Ping Feng

    In this paper, we investigated the effects of periodic external potentials on properties of charge carriers in graphene using both the first-principles method based on density functional theory (DFT) and a theoretical approach based on a generalized effective spinor Hamiltonian. DFT calculations were done in a modified Kohn-Sham procedure that includes effec

  79. Bruno Winckler

    Let K be a number field, and L be a finite normal extension of K with Galois group G. It is known that the number of Frobenius automorphisms corresponding to prime ideals, whose norms are less than x, is equivalent to the logarithmic integral as x tends to infinity, and these automorphisms are well-distributed among the conjugacy classes of G : this is the C

  80. Illarion Dorofeyev

    The paper addresses the problem of relaxation of open quantum systems. Using the path integral methods we found an analytical expression for time-dependent density matrix of two coupled quantum oscillators interacting with different baths of oscillators. The expression for density matrix was found in the linear regime with respect to the coupling constant be

  81. Francisco S. N. Lobo, Jesus Martinez-Asencio, Gonzalo J. Olmo, D. Rubiera-Garcia

    We consider the collapse of a charged radiation fluid in a Planck-suppressed quadratic extension of General Relativity (GR) formulated à la Palatini. We obtain exact analytical solutions that extend the charged Vaidya-type solution of GR, which allows to explore in detail new physics at the Planck scale. Starting from Minkowski space, we find that the collap

  82. Keiichi Asada, Masanori Nakamura, Akihiro Doi, Hiroshi Nagai

    The velocity field of the M87 jet from milli-arcsecond (mas) to arcsecond scales is extensively investigated together with new radio images taken by EVN observations. We detected proper motions of components located at between 160 mas from the core and the HST-1 complex for the first time. Newly derived velocity fields exhibits a systematic increase from sub

  83. Hannes Vogt, Giuseppe Burgio, Markus Quandt, Hugo Reinhardt

    Our previous studies of Coulomb gauge Yang-Mills theory are extended to finite temperature. We investigate the SU(2) static gluon and ghost propagators and show results for the Coulomb potential, with a focus on the Gribov ambiguity. To compute these quantities at high temperatures and to solve scaling violations we use the anisotropic Wilson gauge action.

  84. Giancarlo DAgostino, Luigi Bergamaschi, Laura Giordani, Massimo Oddone

    The results of analytical measurements performed with solid-sampling techniques are affected by the distribution of the analytes within the matrix. The effect becomes significant in case of determination of trace elements in small subsamples. In this framework we propose a measurement model based on Instrumental Neutron Activation Analysis to determine the r

  85. Aihua Zhang, Hao Fatt Teoh, Zhenxiang Dai, Yuan Ping Feng

    Effects of antidot lattices on electronic structures of graphene and hexagonal BN (h-BN) are investigated using the first principles method based on density functional theory. For graphene, we find that when the antidot lattice is along the zigzag direction, the band gap opening can be related to the inter-valley scattering, and does not follow the simple sc

  86. Miao Zhou, Yongqin Cai, Minggang Zeng, Chun Zhang

    We report an \emph{ab inito} investigation on the ground-state atomic configuration, electronic structures, magnetic and spin-dependent transport properties of Mn-doped Au$_{25}$ nanoclusters protected by thiolate. It is found that the most stable dopant sites are near surfaces, rather than the center positions of the nanoparticles. Transport calculations sh

  87. Jean-Baptiste Casteras, Ilkka Holopainen, Jaime B. Ripoll

    We study the Dirichlet problem at infinity on a Cartan-Hadamard manifold for a large class of operators containing in particular the p-Laplacian and the minimal graph operator.

  88. M. F. Preston, L. S. Myers, J. R. M. Annand, K. G. Fissum

    Rate-dependent effects in the electronics used to instrument the tagger focal plane at the MAX IV Laboratory were recently investigated using the novel approach of Monte Carlo simulation to allow for normalization of high-rate experimental data acquired with single-hit time-to-digital converters (TDCs). The instrumentation of the tagger focal plane has now b

  89. Monica Bianchi, Alessandra Cornaro, José Luis Palacios, Anna Torriero

    Making use of a majorization technique for a suitable class of graphs, we derive upper and lower bounds for some topological indices depending on the degree sequence over all vertices, namely the first general Zagreb index and the first multiplicative Zagreb index. Specifically, after characterizing $c-$cyclic graphs $(0\leq c\leq 6)$ as those whose degree s

  90. Bojin Zheng, Yangqian Su, Hongrun Wu, Li Kuang

    The $3x+1$ problem, also called the Collatz conjecture, is a very interesting unsolved mathematical problem related to computer science. This paper generalized this problem by relaxing the constraints, i.e., generalizing this deterministic process to non-deterministic process, and set up three models. This paper analyzed the ergodicity of these models and pr

  91. T. I. M. van Werkhoven, M. Brogi, I. A. G. Snellen, C. U. Keller

    The Kepler object KIC 12557548 shows irregular eclipsing behaviour with a constant 15.685 hr period, but strongly varying transit depth. In this paper we fit individual eclipses, in addition to fitting binned light curves, to learn more about the process underlying the eclipse depth variation. Additionally, we put forward observational constraints that any m

  92. Zhimin Yao, Blesson Varghese, Andrew Rau-Chaplin

    Monte Carlo simulations employed for the analysis of portfolios of catastrophic risk process large volumes of data. Often times these simulations are not performed in real-time scenarios as they are slow and consume large data. Such simulations can benefit from a framework that exploits parallelism for addressing the computational challenge and facilitates a

  93. Blesson Varghese, Andrew Rau-Chaplin

    Risk Analytics is important to quantify, manage and analyse risks from the manufacturing to the financial setting. In this paper, the data challenges in the three stages of the high-performance risk analytics pipeline, namely risk modelling, portfolio risk management and dynamic financial analysis is presented.

  94. Won Sang Chung, Mahouton Norbert Hounkonnou, Sama Arjika

    This work addresses a full characterization of three new q-polynomials derived from the $q-$oscillator algebra. Related matrix elements and generating functions are deduced. Further, a connection between Hahn factorial and q-Gaussian polynomials is established.

  95. Shuanglong Liu, Argo Nurbawono, Na Guo, Chun Zhang

    By solving two-component spinor equation for massless Dirac Fermions, we show that graphene under a periodic external magnetic field exhibits a unique energy spectrum: At low energies, Dirac Fermions are localized inside the magnetic region with discrete Landau energy levels, while at higher energies, Dirac Fermions are mainly found in non-magnetic regions w

  96. Argo Nurbawono, Chun Zhang

    By first principles calculations, we demonstrate that when decorated with photochromic molecules, it is possible to use light to reversibly control the magnetic properties of a nanoscale magnetic system. The combination of a graphene-based magnetic system and a photochromic azobenzene molecule is chosen as a model system. The {\it trans} and {\it cis} isomer

  97. Jiachen Li, Feifei Gao, Tao Jiang, Wen Chen

    In this paper, we present a new cognitive radio (CR) scenario when the primary user (PU) operates under more than one transmit power levels. Different from the existing studies where PU is assumed to have only one constant transmit power, the new consideration well matches the practical standards, i.e., IEEE 802.11 Series, GSM, LTE, LTE-A, etc., as well as t

  98. Chun Zhang

    The uniform electron gas placed between two reservoirs is used as a model system for molecular junctions under an external bias. The energetics of the electron gas are calculated by generalizing the Thomas-Fermi-Dirac (TFD) model to nonequilibrium cases. We show that when the bias voltage is not zero, the first Hohenberg-Kohn (HK) theorem breaks down, and en

  99. Takashi Suzuki

    We study Smoluchowski-Poisson equation in two space dimensions provided with Dirichlet boundary condition for the Poisson part. For this equation several profiles of blowup solution have been noticed. Here we show collapse mass quantization with possible vanishing term.

  100. Shuanglong Liu, Yuan Ping Feng, Chun Zhang

    We show that when a molecular junction is under an external bias, its properties can not be uniquely determined by the total electron density in the same manner as the density functional theory (DFT) for ground state (GS) properties. In order to correctly incorporate bias-induced nonequilibrium effects, we present a dual mean field (DMF) approach. The key id