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April 2014 arXiv papers — page 7

Showing 601–700 of 7,863 papers

  1. Krunoslav Prsa, Mark Laver, Martin Mansson, Sebastian Guerrero

    Frustrated systems exhibit remarkable properties due to the high degeneracy of their ground states. Stabilised by competing interactions, a rich diversity of typically nanometre-sized phase structures appear in polymer and colloidal systems, while the surface of ice pre-melts due to geometrically frustrated interactions. Atomic spin systems where magnetic in

  2. Sujay K. Ashok, Eleonora Dell'Aquila, Jan Troost

    We demonstrate that Appell-Lerch sums with higher order poles as well as their modular covariant completions arise as partition functions in the cigar conformal field theory with worldsheet supersymmetry. The modular covariant derivatives of the elliptic genus of the cigar give rise to operator insertions corresponding to (powers of) right-moving momentum, l

  3. Louis Lyons

    We consider the relative merits of two different approaches to discovery or exclusion of new phenomena, a raster scan or a 2-dimensional approach.

  4. Z. Vörös, G. Weihs

    In this paper we theoretically study how structural disorder in coupled semiconductor heterostructures influences single-particle scattering events that would otherwise be forbidden by symmetry. We extend the model of V. Savona to describe Rayleigh scattering in coupled planar microcavity structures, and answer the question, whether effective filter theories

  5. G. Bilalbegovic, A. Maksimovic, V. Mohacek-Grosev

    The calcium-silicate-hydrate is used to model properties of cement on Earth. We study cementitious nanoparticles and propose these structures as components of cosmic dust grains. Quantum density functional theory methods are applied for the calculation of infrared spectra of Ca4Si4O14H4, Ca6Si3O13H2, and Ca12Si6O26H4 clusters. We find bands distributed over

  6. Shenghao Wang, Augusto Marcelli, Daniele Di Gioacchino, Ziyu Wu

    The AC magnetic susceptibility is a fundamental method in materials science, which allows to probe the dynamic magnetic response of magnetic materials and superconductors. The LAMPS laboratory at the Laboratori Nazionali di Frascati of the INFN hosts an AC multi-harmonic magnetometer that allows performing experiments with an AC magnetic field ranging from 0

  7. Sergey Galkin

    Consider a Laurent polynomial with real positive coefficients such that the origin is strictly inside its Newton polytope. Then it is strongly convex as a function of real positive argument. So it has a distinguished Morse critical point --- the unique critical point with real positive coordinates. As a consequence we obtain a positive answer to a question o

  8. Cheng Ma, Xiao Xu, Yan Liu, Lihong V. Wang

    The ability to steer light propagation inside scattering media has long been sought-after due to its potential widespread applications. To form optical foci inside scattering media, the only feasible strategy is to guide photons by using either implanted or virtual guide stars. However, all of these guide stars must be introduced extrinsically, either invasi

  9. Denis Benois

    The first part of the paper is a survey of recent results about the cohomology of $(ϕ,Γ)$-modules and its applications to the theory of Selmer complexes. In the second part we formulate a version of the Main Conjecture for $p$-adic representations which are semistable at $p$ and discuss some related topics.

  10. B. Arroyo-Torres, I. Martí-Vidal, J. M. Marcaide, M. Wittkowski

    The main goal of this research is to determine the angular size and the atmospheric structures of cool giant stars and to compare them with hydrostatic stellar model atmospheres, to estimate the fundamental parameters, and to obtain a better understanding of the circumstellar environment. We conducted spectro-interferometric observations of epsilon Oct, beta

  11. Peter R Hague, Mark I Wilkinson

    The disparity between the density profiles of galactic dark matter haloes predicted by dark matter only cosmological simulations and those inferred from rotation curve decomposition, the so-called cusp-core problem, suggests that baryonic physics has an impact on dark matter density in the central regions of galaxies. Feedback from black holes, supernovae an

  12. Aritra Sen, Ambedkar Dukkipati

    A motivation to study Gröbner theory for fields with valuations comes from tropical geometry, for example, they can be used to compute tropicalization of varieties \citep{maclagan2009introduction}. The computational aspect of this theory was first studied in (Chen \& Maclagan, 2013). In this paper, we generalize this Gröbner basis theory to free modules over

  13. Amir-Kian Kashani-Poor, Jan Troost

    We continue our study of the semi-classical (large central charge) expansion of the toroidal one-point conformal block in the context of the 2d/4d correspondence. We demonstrate that the Seiberg-Witten curve and (epsilon1-deformed) differential emerge naturally in conformal field theory when computing the block via null vector decoupling equations. This fram

  14. Adrián Andrada, Marcos Origlia

    We study left-invariant locally conformally Kähler structures on Lie groups, or equivalently, on Lie algebras. We give some properties of these structures in general, and then we consider the special cases when its complex structure is bi-invariant or abelian. In the former case, we show that no such Lie algebra is unimodular, while in the latter, we prove t

  15. David Stotz, Helmut Bölcskei

    It is well known that in K-user constant single-antenna interference channels K/2 degrees of freedom (DoF) can be achieved for almost all channel matrices. Explicit conditions on the channel matrix to admit K/2 DoF are, however, not available. The purpose of this paper is to identify such explicit conditions, which are satisfied for almost all channel matric

  16. X. Davoine, F. Fiúza, R. A. Fonseca, W. B. Mori

    In this paper, we determine the electron beam quality requirements to obtain exponential radiation amplification in the ion-channel laser, where a relativistic electron beam wiggles in a focusing ion-channel that can be created in a wakefield accelerator. The beam energy and wiggler parameter spreads should be limited. Those spread limits are functions of th

  17. Gianluca Frasso, Jonathan Jaeger, Philippe Lambert

    Nonlinear (systems of) ordinary differential equations (ODEs) are common tools in the analysis of complex one-dimensional dynamic systems. In this paper we propose a smoothing approach regularized by a quasilinearized ODE-based penalty in order to approximate the state functions and estimate the parameters defining nonlinear differential systems from noisy d

  18. A. C. Fabian, S. A. Walker, A. Celotti, G. Ghisellini

    Double-lobed radio galaxies a few 100s of kpc in extent, like Cygnus A, are common at redshifts of 1 to 2, arising from some 10 per cent of the most powerful Active Galactic Nuclei (AGN). At higher redshifts they are rare, with none larger than a few 10s of kpc known above redshift z~4. Recent studies of the redshift evolution of powerful-jetted objects indi

  19. Mickaël Melzani, Rolf Walder, Doris Folini, Christophe Winisdoerffer

    Magnetic reconnection is a leading mechanism for magnetic energy conversion and high-energy non-thermal particle production in a variety of high-energy astrophysical objects, including ones with relativistic ion-electron plasmas (e.g., microquasars or AGNs) - a regime where first principle studies are scarce. We present 2D particle-in-cell (PIC) simulations

  20. A. Idini, G. Potel, F. Barranco, E. Vigezzi

    An essentially "complete" description of the low-energy nuclear structure of the superfluid nucleus $^{120}$Sn and of its odd-$A$ neighbors is provided by the observations carried out with the help of Coulomb excitation and of one-- and of two-- particle transfer reactions, specific probes of vibrations, quasiparticle and pairing degrees of freedom r

  21. Jinzhu Jia, Luke Miratrix, Bin Yu, Brian Gawalt

    In this paper we propose a general framework for topic-specific summarization of large text corpora and illustrate how it can be used for the analysis of news databases. Our framework, concise comparative summarization (CCS), is built on sparse classification methods. CCS is a lightweight and flexible tool that offers a compromise between simple word frequen

  22. Jinguo Zhang

    In this paper, we deal with the existence and multiplicity of solutions for the fractional elliptic problems involving critical and supercritical Sobolev exponent via variational arguments. By means of the truncation combining with the Moser iteration, we prove that the problems has at least three solutions.

  23. Daniel C. Wagner, Thilo A. Schmitt, Rudi Schäfer, Thomas Guhr

    An agent-based model for financial markets has to incorporate two aspects: decision making and price formation. We introduce a simple decision model and consider its implications in two different pricing schemes. First, we study its parameter dependence within a supply-demand balance setting. We find realistic behavior in a wide parameter range. Second, we e

  24. E. Berchio, F. Gazzola

    We consider a mathematical model for the study of the dynamical behavior of suspension bridges. We show that internal resonances, which depend on the bridge structure only, are the origin of torsional instability. We obtain both theoretical and numerical estimates of the thresholds of instability. Our method is based on a finite dimensional projection of the

  25. Ido Ben-Dayan, Shenglin Jing, Mahdi Torabian, Alexander Westphal

    We study a model of inflation with terms quadratic and logarithmic in the Ricci scalar, where the gravitational action is $f(R)=R+αR^2+βR^2 \ln R$. These terms are expected to arise from one loop corrections involving matter fields in curved space-time. The spectral index $n_s$ and the tensor to scalar ratio yield $10^{-4}\lesssim r\lesssim0.03$ and $0.94\le

  26. Mano Vikash Janardhanan

    Ramsey theory is the study of conditions under which mathematical objects show order when partitioned. Ramsey theory on the integers concerns itself with partitions of $[1,n]$ into $r$ subsets and asks the question whether one (or more) of these $r$ subsets contains a $k$-term member of $\mathcal{F}$, where $[1,n]=\{1,2,3,\ldots,n\}$ and $\mathcal{F}$ is a c

  27. Eliran Subag, Ofer Zeitouni

    The limiting extremal processes of the branching Brownian motion (BBM), the two-speed BBM, and the branching random walk are known to be randomly shifted decorated Poisson point processes (SDPPP). In the proofs of those results, the Laplace functional of the limiting extremal process is shown to satisfy $L[θ_y f]=g(y-τ_f)$ for any nonzero, nonnegative, compa

  28. Assaf Manor, Leopoldo L. Martin, Carmel Rotschild

    Improving the conversion efficiency of solar energy to electricity is most important to mankind. For single-junction photovoltaic solar-cells, the Shockley-Queisser thermodynamic efficiency limit is extensively due to the heat dissipation, inherently accompanying the quantum process of electro-chemical potential generation. Concepts such as solar thermo-phot

  29. Chaowen Zhang

    The simplicity of the Kac modules for the quantum superalgebra U_q(gl(m,n)) is studied, and the relation between the representation of U_q(gl(m,n)) and that of U_q(g_{\0}) is investigated.

  30. Mats Boij, Gregory G. Smith

    We study the closed convex hull of various collections of Hilbert functions. Working over a standard graded polynomial ring with modules that are generated in degree zero, we describe the supporting hyperplanes and extreme rays for the cones generated by the Hilbert functions of all modules, all modules with bounded a-invariant, and all modules with bounded

  31. Doyo G. Enki, Angela Noufaily, C. Paddy Farrington

    We propose a new parametric time-varying shared frailty model to represent changes over time in population heterogeneity, for use with bivariate current status data. The model uses a power transformation of a time-invariant frailty $U$, and is particularly convenient when $U$ is a member of the generalized gamma family. This model avoids some shortcomings of

  32. A. Kievsky, M. Gattobigio, N. K. Timofeyuk

    It is well-known that three-boson systems show the Efimov effect when the two-body scattering length $a$ is large with respect to the range of the two-body interaction. This effect is a manifestation of a discrete scaling invariance (DSI). In this work we study DSI in the $N$-body system by analysing the spectrum of $N$ identical bosons obtained with a pairw

  33. Francesca Chittaro, Gianna Stefani

    We consider the minimum-time problem for a multi-input control-affine system, where we assume that the controlled vector fields generate a non-involutive distribution of constant dimension, and where we do not assume a-priori bounds for the controls. We use Hamiltonian methods to prove that the coercivity of a suitable second variation associated to a Pontry

  34. Florent Jacquemard, Clément Poncelet Sanchez

    We describe an intermediate language designed as a medium-level internal representation of programs of the interactive music system Antescofo. This representation is independent both of the Antescofo source language and of the architecture of the execution platform. It is used in tasks such as verification of timings, model-based conformance testing, static

  35. W. Zimdahl

    Interactions inside the cosmological dark sector influence the cosmological dynamics. As a consequence, the future evolution of the Universe may be different from that predicted by the $Λ$CDM model. We review main features of several recently studied models with nongravitational couplings between dark matter and dark energy.

  36. Massimo Giovannini

    If we posit the validity of the consistency relations, the tensor spectral index and the relative amplitude of the scalar and tensor power spectra are both fixed by a single slow roll parameter. The physics of the protoinflationary transition can break explicitly the consistency relations causing a reduction of the inflationary curvature scale in comparison

  37. Cesar Hernandez-Velez, Jesus Leanos, Gelasio Salazar

    A drawing of a graph is {\em pseudolinear} if there is a pseudoline arrangement such that each pseudoline contains exactly one edge of the drawing. The {\em pseudolinear crossing number} of a graph $G$ is the minimum number of pairwise crossings of edges in a pseudolinear drawing of $G$. We establish several facts on the pseudolinear crossing number, includi

  38. Akshay Uttama Nambi S. N., Prabhakar T., R Venkatesha Prasad, Jamadagni H. S

    We present our ``Zero Energy Network'' (ZEN) protocol stack for energy harvesting wireless sensor networks applications. The novelty in our work is $4$ fold: (1) Energy harvesting aware fully featured MAC layer. Carrier sensing, Backoff algorithms, ARQ, RTS/CTS mechanisms, Adaptive Duty Cycling are either auto configurable or available as tunable par

  39. H. Niemi, G. S. Denicol

    We investigate the applicability of fluid dynamics in ultrarelativistic heavy ion (AA) collisions and high multiplicity proton nucleus (pA) collisions. In order for fluid dynamics to be applicable the microscopic and macroscopic distance/time scales of the system have to be sufficiently separated. The degree of separation is quantified by the ratio between t

  40. Jean-Philippe Argaud, Bertrand Bouriquet, Aimery Assire, Stéphane Gervais

    The detailed knowledge of the inner skin temperature behavior is very important to evaluate and manage the aging of large pipes in cooling systems. We describe here a method to obtain this information as a function of outer skin temperature measurements, in space and time. This goal is achieved by mixing fine simulations and numerical methods such as impulse

  41. Johannes Roth, Armin Krauß, Jan Lotze, Hans-Rainer Trebin

    Lasers are becoming a more and more important tool in cutting and shaping materials. Improving precision and effectivity is an ongoing demand in science and industry. One possibility are double pulses. Here we study laser ablation of aluminum by the two-temperature model. There the laser is modeled as a source in a continuum heat conduction equation for the

  42. Matan Zehavi, Gilad Yossifon

    We study here the curious particle dynamics resulting from electro-osmotic flow around a microchannel junction corner whose dielectric walls are weakly polarizable. The hydrodynamic velocity field is obtained via superposition of a linear irrotational term associated with the equilibrium zeta potentials of both the microchannel and particle surfaces and the

  43. Bo Qu, Qian Li, Shlomo Havlin, H. Eugene Stanley

    Dynamic social opinion models have been widely studied on undirected networks, and most of them are based on spin interaction models that produce a consensus. In reality, however, many networks such as Twitter and the World Wide Web are directed and are composed of both unidirectional and bidirectional links. Moreover, from choosing a coffee brand to decidin

  44. Yusuf Kucukakca

    In this paper, in the framework of teleparallel gravity we consider scalar tensor theories of gravity in which scalar fields are nonminimal coupled to torsion scalar. Noether symmetry of the Lagrangian of such a theory for the Friedman-Robertson-Walker spacetime is used to determine the explicit forms for the coupling function and for the potential, and it i

  45. Damiano Brigo, Qing Liu, Andrea Pallavicini, David Sloth

    We develop an arbitrage-free framework for consistent valuation of derivative trades with collateralization, counterparty credit gap risk, and funding costs, following the approach first proposed by Pallavicini and co-authors in 2011. Based on the risk-neutral pricing principle, we derive a general pricing equation where Credit, Debit, Liquidity and Funding

  46. Hamid Ramezani, Raj Thilak Rajan, Geert Leus

    In this paper, the Cramer Rao bound (CRB) for range estimation between two underwater nodes is calculated under a Gaussian noise assumption on the measurements. The nodes can measure their depths, their mutual time of flight, and they have access to noisy sound speed samples at different depths. The effect of each measurement on the CRB will be analyzed, and

  47. Jochen Wambach, Ralf-Arno Tripolt, Nils Strodthoff, Lorenz von Smekal

    In this article we wish to present a new method to obtain spectral functions at finite temperature and density from the Functional Renormalization Group (FRG). The FRG offers a powerful non-perturbative tool to deal with phase transitions in strong-interaction matter under extreme conditions and their fluctuation properties. Based on a thermodynamically cons

  48. Daniel Teyssier

    We present the results and prospects for searches beyond the Standard Model (SM) at the LHC by the ATLAS and CMS collaborations. The minimal supersymmetric extension of the SM has been investigated in various configurations and lower limits are set on the s-particle masses. The searches for other scenarios of physics beyond the SM are also presented and lowe

  49. Aleksandr Pikalev, Lidia Luizova

    Ordered dusty structures influence plasma conditions. This influence can be revealed, when plasma spectral characteristics change, as dusty particles are injected. For example, a variation in the atomic temperature leads to a variation in the profiles of spectral lines. We studied the profile of a 585 nm neon spectral line in the dusty structures. The struct

  50. Yoichi Iwata, Keigo Oka

    Fully dynamic graph is a data structure that (1) supports edge insertions and deletions and (2) answers problem specific queries. The time complexity of (1) and (2) are referred to as the update time and the query time respectively. There are many researches on dynamic graphs whose update time and query time are $o(|G|)$, that is, sublinear in the graph size

  51. Canyi Lu, Jinhui Tang, Shuicheng Yan, Zhouchen Lin

    As surrogate functions of $L_0$-norm, many nonconvex penalty functions have been proposed to enhance the sparse vector recovery. It is easy to extend these nonconvex penalty functions on singular values of a matrix to enhance low-rank matrix recovery. However, different from convex optimization, solving the nonconvex low-rank minimization problem is much mor

  52. Vincenzo Di Gennaro, Davide Franco, Giambattista Marini

    Let $ Y \subseteq \Bbb P^N $ be a possibly singular projective variety, defined over the field of complex numbers. Let $X$ be the intersection of $Y$ with $h$ general hypersurfaces of sufficiently large degrees. Let $d>0$ be an integer, and assume that $\dim Y=n+h$ and $ \dim Y_{sing} \le \min\{ d+h-1 , n-1 \} $. Let $Z$ be an algebraic cycle on $Y$ of dimen

  53. Dionysios Mylonas, Richard J. Szabo

    We describe quasi-Hopf twist deformations of flat closed string compactifications with non-geometric R-flux using a suitable cochain twist, and construct nonassociative deformations of fields and differential calculus. We report on our new findings in using this formalism to construct perturbative nonassociative field theories on these backgrounds. We descri

  54. Ben Fairbairn, Emilio Pierro

    We generalise a construction of mixed Beauville groups first given by Bauer, Catanese and Grunewald. We go on to give several examples of infinite families of characteristically simple groups that satisfy the hypotheses of our theorem and thus provide a wealth of new examples of mixed Beauville groups.

  55. Matthew Reimherr, Dan Nicolae

    We present a new method based on Functional Data Analysis (FDA) for detecting associations between one or more scalar covariates and a longitudinal response, while correcting for other variables. Our methods exploit the temporal structure of longitudinal data in ways that are otherwise difficult with a multivariate approach. Our procedure, from an FDA perspe

  56. Christian Bräuer-Burchardt, Peter Kühmstedt, Gunther Notni

    Code minimization provides a speed-up of the processing time of fringe projection based stereo sensors and possibly makes them real-time applicable. This paper reports a methodology which enables such sensors to completely omit Gray code or other additional code. Only a sequence of sinusoidal images is necessary. The code reduction is achieved by involvement

  57. M. Messineo, K. M. Menten, D. Figer, B. Davies

    An overview of a spectroscopic survey for massive stars in the direction of the Galactic giant molecular complex G23.3-0.3 is presented (Messineo et al. 2010, and 2014 A&A submitted). This region is interesting because it is rich in HII regions and supernova remnants (SNRs). A number of 38 early-type stars, a new luminous blue variable, and a dozen of red su

  58. Edward Grefenstette, Phil Blunsom, Nando de Freitas, Karl Moritz Hermann

    Many successful approaches to semantic parsing build on top of the syntactic analysis of text, and make use of distributional representations or statistical models to match parses to ontology-specific queries. This paper presents a novel deep learning architecture which provides a semantic parsing system through the union of two neural models of language sem

  59. E. G. Hill, E. H. Slate

    Periodontal probing depth is a measure of periodontitis severity. We develop a Bayesian hierarchical model linking true pocket depth to both observed and recorded values of periodontal probing depth, while permitting correlation among measures obtained from the same mouth and between duplicate examiners' measures obtained at the same periodontal site. Pe

  60. M. Komarov, A. Pikovsky

    We study synchronization in a Kuramoto model of globally coupled phase oscillators with a bi-harmonic coupling function, in the thermodynamic limit of large populations. We develop a method for an analytic solution of self-consistent equations describing uniformly rotating complex order parameters, both for single-branch (one possible state of locked oscilla

  61. Ruxandra Cojocaru, Santiago Torres, Jordi Isern, Enrique García-Berro

    It has been known for a long time that stellar metallicity plays a significant role in the determination of the ages of the different Galactic stellar populations, when main sequence evolutionary tracks are employed. Here we analyze the role that metallicity plays on the white dwarf luminosity function of the Galactic disk, which is often used to determine i

  62. Song-Jin Im, Gum-Song Ho

    We theoretically study on non-perturbative effective nonlinear responses of metal nanocomposites based on the intrinsic third-order nonlinear response of metal nanoparticles. The large intrinsic third-order nonlinear susceptibility of metal nanoparticles and an irradiation by ultrashort control pulse of light with a sufficiently high peak intensity and moder

  63. Christian Blanchet, Francesco Costantino, Nathan Geer, Bertrand Patureau-Mirand

    We construct and study a new family of TQFTs based on nilpotent highest weight representations of quantum sl(2) at a root of unity indexed by generic complex numbers. This extends to cobordisms the non-semi-simple invariants defined in (arXiv:1202.3553) including the Kashaev invariant of links. Here the modular category framework does not apply and we use th

  64. Yi-Zheng Fan, Long Wang

    The square of a connected graph $G$ is obtained from $G$ by adding an edge between every pair of vertices at distance $2$. In this paper we give some upper or lower bounds for the spectral radius of the square of connected graphs, trees and unicyclic graphs respectively.We also investigate the spectral radius of the square of unicyclic graphs with given girt

  65. Andra Stroe, Reinout J. van Weeren, David Sobral, Clare Rumsey

    The CIZA J2242.8+5301 cluster hosts an extraordinary, narrow, Mpc-wide, diffuse patch of radio emission tracing travelling shock waves, called a relic. We perform a multi-wavelength of observations of the cluster. We discover radio spectral steepening and increasing spectral curvature in the shock downstream area, indicative of emission produced by spectrall

  66. Sylvie Huet, Guillaume Deffuant

    We propose a new opinion dynamic model based on the experiments and results of Wood et al (1996). We consider pairs of individuals discussing on two attitudinal dimensions, and we suppose that one dimension is important, the other secondary. The dynamics are mainly ruled by the level of agreement on the main dimension. If two individuals are close on the mai

  67. Sofie Demeyer, Tom Michoel

    Transcriptional regulation of gene expression is one of the main processes that affect cell diversification from a single set of genes. Regulatory proteins often interact with DNA regions located distally from the transcription start sites (TSS) of the genes. We developed a computational method that combines open chromatin and gene expression information for

  68. Ji Chen, Xin-Zheng Li, Qianfan Zhang, Angelos Michaelides

    Proton transport (PT) in bulk liquid water and within a thin water-filled carbon nanotube has been examined with ab initio pathintegral molecular dynamics (PIMD). Barrierless proton transfer is observed in each case when quantum nuclear effects (QNEs) are accounted for. The key difference between the two systems is that in the nanotube facile PT is facilitat

  69. Michael Gr. Voskoglou

    Contract bridge occupies nowadays a position of great prestige being, together with chess, the only mind games officially recognized by the International Olympic Committee. In the present paper an innovative method for assessing the total performance of bridge- players' belonging to groups of special interest(e.g. different bridge clubs during a tourname

  70. Mikołaj Bojańczyk

    This paper shows that over infinite trees, satisfiability is decidable for weak monadic second-order logic extended by the unbounding quantifier U and quantification over infinite paths. The proof is by reduction to emptiness for a certain automaton model, while emptiness for the automaton model is decided using profinite trees.

  71. Shai Keren, Amir Levinson

    We compute the time integrated, thermal emission produced by a series of radiation mediated shocks that emerge from the photosphere of a GRB outflow. We show that for a sufficiently broad distribution of shock strengths, the overall shape of the time integrated spectral energy distribution below the peak is a power law, $νE_ν\propto ν^α$, with a slope $1<α<2

  72. J. M. Torrelles, S. Curiel, R. Estalella, G. Anglada

    We report multi-epoch VLBI H$_2$O maser observations towards the compact cluster of YSOs close to the Herbig Be star LkH$α$ 234. This cluster includes LkH$α$ 234 and at least nine more YSOs that are formed within projected distances of $\sim$10 arcsec ($\sim$9,000 au). We detect H$_2$O maser emission towards four of these YSOs. In particular, our VLBI observ

  73. Daniele Binosi, David Ibañez

    We report on a recently unveiled connection at the nonperturbative level between the masslessness of the ghost, the precise form of the gluon propagator in the deep infrared, and the divergences observed in certain kinematic limits of the three-gluon vertex.

  74. Sylvie Huet, Guillaume Deffuant, Wander Jager

    We add a rejection mechanism (negative influence) into a two-dimensions bounded confidence model. The principle is that one shifts aways from a close attitude of one&#39;s interlocutor, when there is a strong disagreement on the other attitude. The model shows metastable clusters, which maintain themselves through opposite influences of competitor clusters.

  75. J. Grineviciute, B. A. Brown, H. Schatz

    We investigate the importance of proton capture on low-lying excited states that are thermally excited in hot stellar environments. In addition to the previously known case of $^{32}$Cl$(p,γ)^{33}$Ar we find several other sd-shell nuclei with large stellar enhancement factors. We discuss the uncertainty this introduces into rp-process nucleosynthesis.

  76. Tamara M. Davis

    It has been only ~15 years since the discovery of dark energy (although some may argue there were strong indications even earlier). In the short time since measurements of type Ia supernovae indicated an accelerating universe, many other techniques have now confirmed the acceleration is real. The variety of ways in which dark energy has been confirmed is one

  77. Maria Spichkova, Xiuna Zhu, Dongyue Mou

    One of the common problems of system development projects is that the system documentation is often outdated and does not describe the latest version of the system. The situation is even more complicated if we are speaking not about a natural language description of the system, but about its formal specification. In this paper we discuss how the problem coul

  78. Eliza M. McIntosh, K. Thor Wikfeldt, John Ellis, Angelos Michaelides

    An understanding of hydrogen diffusion on metal surfaces is important, not just for its role in heterogeneous catalysis and hydrogen fuel cell technology, but also because it provides model systems where tunneling can be studied under well-defined conditions. Here we report helium spin-echo measurements of the atomic-scale motion of hydrogen on the Ru(0001)

  79. L. Sunil Chandran, Rogers Mathew, Deepak Rajendraprasad

    The boxicity (respectively cubicity) of a graph $G$ is the minimum non-negative integer $k$, such that $G$ can be represented as an intersection graph of axis-parallel $k$-dimensional boxes (respectively $k$-dimensional unit cubes) and is denoted by $box(G)$ (respectively $cub(G)$). It was shown by Adiga and Chandran (Journal of Graph Theory, 65(4), 2010) th

  80. Maria Spichkova

    This paper presents the methodology for the system requirements and architecture w.r.t. their decomposition and refinement. It also introduces ideas of refinement layers and of refinement-based verification.

  81. Cyril Voyant, Marie Laure Nivet, Christophe Paoli, Marc Muselli

    In this paper, we propose to study four meteorological and seasonal time series coupled with a multi-layer perceptron (MLP) modeling. We chose to combine two transfer functions for the nodes of the hidden layer, and to use a temporal indicator (time index as input) in order to take into account the seasonal aspect of the studied time series. The results of t

  82. Liu Long, Huang Yang, Ma Bo, Xu Qing

    X-ray Fluorescence Computed Tomography(XFCT) is a prevalent experimental technique which is utilized to investigate the spatial distribution of elements in sample. The sensitivity of L-shell XFCT of some elements is lower than that of K-shell XFCT. However, the image reconstruction for this technique has much more problems than that of transmission tomograph

  83. E. Massaro, A. Ardito, P. Ricciardi, F. Massa

    The microquasar GRS 1915+105, exhibits a large variety of characteristic states, according to its luminosity, spectral state, and variability. The most interesting one is the so-called rho-state, whose light curve shows recurrent bursts. This paper presents a model based on Fitzhugh-Nagumo equations containing two variables: x, linked to the source photon lu

  84. Longwen Zhou, Hailong Wang, Derek Y. H. Ho, Jiangbin Gong

    Recently the creation of novel topological states of matter by a periodic driving field has attracted great attention. To motivate further experimental and theoretical studies, we investigate interesting aspects of Floquet bands and topological phase transitions in a continuously driven Harper model. In such a continuously driven system with an odd number of

  85. Maria Spichkova

    This paper provides a brief introduction to the work that aims to apply the achievements within the area of engineering psychology to the area of formal methods, focusing on the specification phase of a system development process.

  86. S Sabari, R Vasantha Jayakantha Raja, K Porsezian, P Muruganandam

    We study the stabilization of a trapless Bose-Einstein condensate by analysing the mean-field Gross-Pitaevskii equation with attractive two- and three-body interactions through both analytical and numerical methods. Using the variational method we show that there is an enhancement of the condensate stability due to the inclusion of a three-body interaction i

  87. Jang-il Sohn

    In statistical physics, entropy is generally logarithm of probability. Therefore, if dynamics is decomposed by log, entropy production should be decomposed properly. In the present work, log-decomposition of dynamics is introduced. By which time evolution operator is logarithmically decomposed into a symmetric operator and an asymmetric factor. Path probabil

  88. Rolf-Peter Kudritzki, Miguel A. Urbaneja, Fabio Bresolin, Matthew. W. Hosek

    Low resolution ESO VLT/FORS spectra of blue supergiant stars are analyzed to determine stellar metallicities (based on elements such as Fe, Ti, Mg) in the extended disk of the spiral galaxy NGC3621. Mildly subsolar metallicity (-0.30 dex) is found for the outer objects beyond 7 kpc independent of galactocentric radius and compatible with the absence of a met

  89. Federico García, Deborah N. Aguilera, Gustavo E. Romero

    In the magneto-centrifugal mechanism for jet formation, accreting neutron stars are assumed to produce relativistic jets only if their surface magnetic field is weak enough ($B \sim 10^8$ G). However, the most common manifestation of neutron stars are pulsars, whose magnetic field distribution peaks at $B \sim 10^{12}$ G. If the neutron star magnetic field h

  90. David Maxwell

    The Kasner metrics are among the simplest solutions of the vacuum Einstein equations, and we use them here to examine the conformal method of finding solutions of the Einstein constraint equations. After describing the conformal method&#39;s construction of constant mean curvature (CMC) slices of Kasner spacetimes, we turn our attention to non-CMC slices of

  91. Ralph Brinks

    Background: A common modelling approach in public health and epidemiology divides the population under study into compartments containing persons that share the same status. Here we consider a three-state model with the compartments: A, B and Dead. States A and B may be the states of any dichotomous variable, for example, Healthy and Ill, respectively. The t

  92. Mark Braverman, Gal Oshri

    We investigate the problem of a principal looking to contract an expert to provide a probability forecast for a categorical event. We assume all experts have a common public prior on the event&#39;s probability, but can form more accurate opinions by engaging in research. Various experts&#39; research costs are unknown to the principal. We present a truthful

  93. T. Srinivasa Rao, Rajasekhar R. Kurra

    Video Watermarking serves as a new technology mainly used to provide security to the illegal distribution of digital video over the web. The purpose of any video watermarking scheme is to embed extra information into video in such a way that must be perceptually undetectable while still holding enough information in order to extract the watermark beginning w

  94. Jianqing Fan, Han Liu, Yang Ning, Hui Zou

    Graphical models are commonly used tools for modeling multivariate random variables. While there exist many convenient multivariate distributions such as Gaussian distribution for continuous data, mixed data with the presence of discrete variables or a combination of both continuous and discrete variables poses new challenges in statistical modeling. In this

  95. S. J. Moon, Y. S. Lee, A. A. Schafgans, A. V. Chubukov

    We investigate infrared manifestations of the pseudogap in the prototypical cuprate and pnictide superconductors: YBa2Cu3Oy and BaFe2As2 (Ba122) systems. We find remarkable similarities between the spectroscopic features attributable to the pseudogap in these two classes of superconductors. The hallmarks of the pseudogap state in both systems include a weak

  96. Jia-ju Zhang

    In this note we investigate the first law of thermodynamics of the two-dimensional conformal field theory (CFT) that is dual to black holes. We start from the Cardy formula and get the CFT thermodynamics with minimal reasonable assumptions. We use both the microcanonical ensemble and canonical ensemble versions of the Cardy formula. In the black hole/CFT cor

  97. Xueliang Li, Guihai Yu

    An oriented graph $G^σ$ is a digraph without loops and multiple arcs, where $G$ is called the underlying graph of $G^σ$. Let $S(G^σ)$ denote the skew-adjacency matrix of $G^σ$. The rank of the skew-adjacency matrix of $G^σ$ is called the {\it skew-rank} of $G^σ$, denoted by $sr(G^σ)$. The skew-adjacency matrix of an oriented graph is skew symmetric and the s

  98. A. Bacigalupo, L. Morini, A. Piccolroaz

    The focus of the article is on the analysis of effective elastic properties of planar Solid Oxide Fuell Cell (SOFC) devices. An ideal periodic multi-layered composite (SOFC-like) reproducing the overall properties of multi-layer SOFC devices is defined. Adopting a non-local dynamic homogenization method, explicit expressions for overall elastic moduli and in

  99. Quan Cheng, Yun-Wei Yu

    In a newly born (high-temperature and Keplerian rotating) neutron star, r-mode instability can lead to stellar differential rotation, which winds the seed poloidal magnetic field ($\sim 10^{11}$ G) to generate an ultra-high ($\sim 10^{17}$ G) toroidal field component. Subsequently, by succumbing to the Tayler instability, the toroidal field could be partiall

  100. Abdulqader Mustafa, Siraj Uddin, B. R. Wong

    In this paper, we study warped product submanifolds of nearly trans-Sasakian manifolds. The non-existence of the warped product semi-slant submanifolds of the type $N_θ\times{_{f}N_T}$ is shown, whereas some characterization and new geometric obstructions are obtained for the warped products of the type $N_T\times{_{f}N_θ}$. We establish two general inequali