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February 2014 arXiv papers — page 12

Showing 1,101–1,200 of 7,390 papers

  1. Bo Huang, Leonid A. Sidorenkov, Rudolf Grimm, Jeremy M. Hutson

    We report the observation of a three-body recombination resonance in an ultracold gas of cesium atoms at a very large negative value of the $s$-wave scattering length. The resonance is identified as the second triatomic Efimov resonance, which corresponds to the situation where the first excited Efimov state appears at the threshold of three free atoms. This

  2. V. V. Kassandrov, I. Sh. Khasanov, N. V. Markova

    In development of the old conjecture of Stuckelberg, Wheeler and Feynman on the so-called "one electron Universe", we elaborate a purely algebraic construction of an ensemble of identical pointlike particles occupying the same worldline and moving in concordance with each other. In the proposed construction one does not make use of any differential e

  3. Sunandan Gangopadhyay, Frederik G Scholtz

    In this paper, the connection between the path integral representation of propagators in the coherent state basis with additional degrees of freedom \cite{rohwer} and the one without any such degrees of freedom \cite{sgfgs} is established. We further demonstrate that the path integral formalism developed in the noncommutative plane using the coherent state b

  4. Vladimir Sokolovsky, Daniel Rohrlich, Baruch Horovitz

    Atom chips made of superconducting material can generate magnetic traps with significantly reduced noise. Recently, several designs for superconducting chips have been theoretically analyzed and experimentally tested, for cases with many vortices considered as an average vortex density. Here we show theoretically, for the first time, how the magnetic field o

  5. Alexander P. Kuznetsov, Yuliya V. Sedova

    A dynamics of a low-dimensional ensemble consisting of connected in a network five discrete phase oscillators is considered. A two-parameter synchronization picture which appears instead of the Arnold tongues with an increase of the system dimension is discussed. An appearance of the Arnol'd resonance web is detected on the "frequency - coupling"

  6. Io Kawaguchi, Takuya Matsumoto, Kentaroh Yoshida

    We consider a Jordanian deformation of the AdS_5xS^5 superstring action by taking a simple R-operator which satisfies the classical Yang-Baxter equation. The metric and NS-NS two-form are explicitly derived with a coordinate system. Only the AdS part is deformed and the resulting geometry contains the 3D Schrodinger spacetime as a subspace. Then we present t

  7. Himadri Mukherjee

    In a finite distributive lattice $Ł$ we define two functions $s(α)=|\{δ\in \mathcal{L} | δ\leq α\}|$ and $l(α)=|\{δ\in \mathcal{L} | δ\geq α\}|$. In this present article we prove that the sum of these two functions over a finite distributive lattice are equal. Using this identity we give a formula for the number of non-comparable pairs of elements in a finit

  8. Oliver Baer, Ben Horz

    The chiral Lagrangian describing the low-energy behavior of N_f=2+1+1 twisted mass lattice QCD is constructed through O(a^2). In contrast to existing results the effects of a heavy charm quark are consistently removed, leaving behind a charmless 3-flavor Lagrangian. This Lagrangian is used to compute the pion and kaon masses to one loop in a regime where the

  9. Michael J. W. Hall, D. -A. Deckert, Howard M. Wiseman

    We investigate whether quantum theory can be understood as the continuum limit of a mechanical theory, in which there is a huge, but finite, number of classical 'worlds', and quantum effects arise solely from a universal interaction between these worlds, without reference to any wave function. Here a `world' means an entire universe with well-def

  10. F. Lenz, K. Ohta, K. Yazaki

    Within the framework of the "brick wall model", a novel method is developed to compute the contributions of a scalar field to the thermodynamic quantities of black holes. The relations between (transverse) momenta and frequencies in Rindler space are determined numerically with high accuracy and analytically with an accuracy of better than 10 % and a

  11. Md. Wali Hossain, R. Myrzakulov, M. Sami, Emmanuel N. Saridakis

    In this paper, we investigate a scenario of variable gravity and apply it to the unified description of inflation and late time cosmic acceleration dubbed quintessential inflation. The scalar field called "cosmon" which in this model unifies both the concepts reduces to inflaton at early epochs. We calculate the slow-roll parameters, the Hubble param

  12. Sanjay Chawla, Kiran Garimella, Aristides Gionis, Dominic Tsang

    We introduce a new computational problem, the BackboneDiscovery problem, which encapsulates both functional and structural aspects of network analysis. While the topology of a typical road network has been available for a long time (e.g., through maps), it is only recently that fine-granularity functional (activity and usage) information about the network (l

  13. K. Srivastava, S. K. Srivastava

    The purpose of this paper is to classify paracontact metric $3$-manifolds $M^3$ such that the Ricci operator $S$ commutes with the endomorhism $ϕ$ of its tangent bundle $Γ(TM^3)$.

  14. Juha Lehrbäck

    We establish both sufficient and necessary conditions for weighted Hardy inequalities in metric spaces in terms of Assouad (co)dimensions. Our sufficient conditions in the case where the complement is thin are new even in Euclidean spaces, while in the case of a thick complement we give new formulations for previously known sufficient conditions which reveal

  15. Henning Bostelmann, Daniela Cadamuro

    Integrable quantum field theories in 1+1 dimensions have recently become amenable to a rigorous construction, but many questions about the structure of their local observables remain open. Our goal is to characterize these local observables in terms of their expansion coefficients in a series expansion by interacting annihilators and creators, similar to for

  16. Arkadiusz Jadczyk

    Time of arrival in quantum mechanics is discussed in two versions: the classical axiomatic "time of arrival operator" introduced by J. Kijowski and the EEQT method. It is suggested that for free particles the two methods may lead to the same result. On the other hand the EEQT method can be easily geometrized within the framework of Galilei-Newton gen

  17. James Watson, Chris Holmes

    Decisions based partly or solely on predictions from probabilistic models may be sensitive to model misspecification. Statisticians are taught from an early stage that "all models are wrong", but little formal guidance exists on how to assess the impact of model approximation on decision making, or how to proceed when optimal actions appear sensitive

  18. Bruce W. Westbury

    In this paper we study the Frobenius characters of the invariant subspaces of the tensor powers of a representation V. The main result is a formula for these characters for a polynomial functor of V involving the characters for V. The main application is to representations V for which these characters are known. The best understood case is for V the vector r

  19. Chandrachur Chakraborty, Kamakshya Prasad Modak, Debades Bandyopadhyay

    We derive the exact frame-dragging rate inside rotating neutron stars. This formula is applied to show that the frame-dragging rate monotonically decreases from the centre to the surface of the neutron star along the pole. In case of frame-dragging rate along the equatorial distance, it decreases initially away from the centre, becomes negligibly small well

  20. Dezső Horváth

    The 40 years old Standard Model, the theory of particle physics, seems to describe all experimental data very well. All of its elementary particles were identified and studied apart from the Higgs boson until 2012. For decades many experiments were built and operated searching for it, and finally, the two main experiments of the Large Hadron Collider at CERN

  21. Wei Du, Zuhui Fan

    With the halo catalog from the {\it Millennium Simulation}, we analyze the weak-lensing measured density profiles for clusters of galaxies, paying attention to the determination of the concentration-mass ($c$-$M$) relation which can be biased by the center offset, selection effect, and shape noise from intrinsic ellipticities of background galaxies. Several

  22. J. E. Garcia-Ramos, K. Heyde, L. M. Robledo, R. Rodriguez-Guzman

    The evolution of the total energy surface and the nuclear shape in the isotopic chain $^{172-194}$Pt are studied in the framework of the interacting boson model, including configuration mixing. The results are compared with a self-consistent Hartree-Fock-Bogoliubov calculation using the Gogny-D1S interaction and a good agreement between both approaches shows

  23. Graeme Boore

    It has been shown that certain 2-vertex directed graph iterated function systems (IFSs), defined on the unit interval and satisfying the convex strong separation condition (CSSC), have attractors whose components are not standard IFS attractors where the standard IFSs may be with or without separation conditions. The proof required the multiplicative rationa

  24. Yuri I. Fujii, Satoshi Okuzumi, Takayuki Tanigawa, Shu-ichiro Inutsuka

    We examine whether the magnetorotational instability (MRI) can serve as a mechanism of angular momentum transport in circumplanetary disks. For the MRI to operate the ionization degree must be sufficiently high and the magnetic pressure must be sufficiently lower than the gas pressure. We calculate the spatial distribution of the ionization degree and search

  25. David Degras, Martin A. Lindquist

    In this paper we introduce a new hierarchical model for the simultaneous detection of brain activation and estimation of the shape of the hemodynamic response in multi-subject fMRI studies. The proposed approach circumvents a major stumbling block in standard multi-subject fMRI data analysis, in that it both allows the shape of the hemodynamic response funct

  26. Hao-Wen Dong, Yue-Sheng Wang, Tian-Xue Ma, Xiao-Xing Su

    By using the non-dominated sorting-based genetic algorithm II, we study the topology optimization of the two-dimensional phoxonic crystals (PxCs) with simultaneously maximal and complete photonic and phononic bandgaps. Our results show that the optimized structures are composed of the solid lumps with narrow connections, and their Pareto-optimal solution set

  27. J. Smyrnakis, M. Magiropoulos, Nikolaos K. Efremidis, G. M. Kavoulakis

    We present variational and numerical solutions for the problem of stability of persistent currents in a two-component Bose-Einstein condensate of distinguishable atoms which rotate in a ring potential. We consider the general class of solutions of constant density in the two components separately, thus providing an alternative approach of the solution of the

  28. Nalini Joshi, Nobutaka Nakazono, Yang Shi

    In this paper, we show how to relate $n$-dimensional cubes on which ABS equations hold to the symmetry groups of discrete Painlevé equations. We here focus on the reduction from the 4-dimensional cube to the $q$-discrete third Painlevé equation, which is a dynamical system on a rational surface of type $A_5^{(1)}$ with the extended affine Weyl group $\wideti

  29. Dani Korpi, Lauri Anttila, Ville Syrjälä, Mikko Valkama

    This article addresses the modeling and cancellation of self-interference in full-duplex direct-conversion radio transceivers, operating under practical imperfect radio frequency (RF) components. Firstly, detailed self-interference signal modeling is carried out, taking into account the most important RF imperfections, namely transmitter power amplifier nonl

  30. Jianguo Hong, Xiangjun Wang

    In this paper we prove that $β_{p^2/p^2-1}$ survives to $E_\infty$ in the Adams-Novikov spectral sequence for $p\geqslant 5$. As an easy consequence we prove that $β_{sp^2/j}$ are perminent cycles for all $s\geqslant 1$, $j\leqslant p^2-1$. From the Thom map $Φ: Ext^{s,t}_{BP_*BP}(BP_*, BP_*)\longrightarrow Ext^{s,t}_A(\mathbb{Z}/p, \mathbb{Z}/p)$, we also s

  31. CUORE Collaboration, D. R. Artusa, F. T. Avignone, O. Azzolini

    Neutrinoless double-beta ($0νββ$) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for $0νββ$ decay of $^{130}$Te using an array of 988 TeO$_2$ crystal b

  32. Hong-Jian Feng, Bi Duan, Jinshou Tian, Xiaohui Guo

    The absorption performance in the BiFeO$_3$/TiO$_2$ bilayer film prepared by simple sol-gel method has been significantly improved in the ultraviolet and visible-light region, comparing with BiFeO$_3$ and TiO$_2$ films. Terahertz-radiation emission presents a direct evidence of photon-induced electrons and holes transport in the heterostructures. First-princ

  33. Ming-Xia Li, Zhi-Qiang Jiang, Wen-Jie Xie, Salvatore Miccichè

    Mobile phone calling is one of the most widely used communication methods in modern society. The records of calls among mobile phone users provide us a valuable proxy for the understanding of human communication patterns embedded in social networks. Mobile phone users call each other forming a directed calling network. If only reciprocal calls are considered

  34. S. Toth, B. Lake

    Linear spin wave theory provides the leading term in the calculation of the excitation spectra of long-range ordered magnetic systems as a function of $1/\sqrt{S}$. This term is acquired using the Holstein-Primakoff approximation of the spin operator and valid for small $δS$ fluctuations of the ordered moment. We propose an algorithm that allows magnetic gro

  35. Micha Berkooz, Ran Yacoby, Amir Zait

    Recently, the conformal-bootstrap has been successfully used to obtain generic bounds on the spectrum and OPE coefficients of unitary conformal field theories. In practice, these bounds are obtained by assuming the existence of a scalar operator in the theory and analyzing the crossing-symmetry constraints of its 4-point function. In $\mathcal{N}=1$ supercon

  36. Christina Sormani

    One of the most powerful theorems in metric geometry is the Arzela-Ascoli Theorem which provides a continuous limit for sequences of equicontinuous functions between two compact spaces. This theorem has been extended by Gromov and Grove-Petersen to sequences of functions with varying domains and ranges where the domains and the ranges respectively converge i

  37. Qinwen Wang, Zhonggen Su, Jianfeng Yao

    In this paper, we derive a joint central limit theorem for random vector whose components are function of random sesquilinear forms. This result is a natural extension of the existing central limit theory on random quadratic forms. We also provide applications in random matrix theory related to large-dimensional spiked population models. For the first applic

  38. Jesús Rubio, Alfredo Luis

    We address the propagation of the spin along classical trajectories for a 1/2-spin particle obeying the Dirac equation with scalar potentials. Focusing on classical trajectories as the exact propagation of wave-function discontinuities we find an explicit spin-transport law for the case of the Dirac oscillator. In the general case we examine the spin propaga

  39. Bum-Hoon Lee, Shahin Mamedov, Chanyong Park

    Using the AdS/CFT correspondence, we investigate a nucleon mass splitting and nucleon-pion coupling in the isospin medium. We find that there exists a nucleon mass splitting which is exactly given by the half of the meson mass splitting because nucleon has the half isospin charge of the charged mesons. In addition, we also investigate the nucleon-pion coupli

  40. Pierre Bérard, Bernard Helffer

    In this paper, we revisit Courant's nodal domain theorem for the Dirichlet eigenfunctions of a square membrane, and the analyses of A. Stern and Å. Pleijel.

  41. Ying Li

    Using the factorization approach, we investigate the $\overline B^0 \to \overline K^0K^+π^-$ and $\overline B^0 \to K^0K^-π^+$ decays individually including the resonant and nonresonant contributions. Under the flavor SU(3) symmetry, we obtain the total branching fraction $BR [\overline B^0 \to (\overline K^0K^+π^-+K^0K^-π^+)]=(7.17^{+0.50+1.97+0.08}_{-0.53-

  42. Zhiyuan Li, Zhiyu Tian

    We discuss the space of sections and certain bisections on a quadric surfaces bundle $X$ over a smooth curve. The Abel-Jacobi from these spaces to the intermediate Jacobian will be shown to be dominant with rationally connected fibers. As an application, we prove that the integral Hodge conjecture holds for degree four integral Hodge classes of fourfolds fib

  43. Edward S. T. Fan, Tony W. H. Wong

    Given an ordered triple of positive integers $(n,r,b)$, where $1\leq b\leq\binom{n}{r}$, does there exist a matrix of size $r\times n$ with exactly $b$ invertible submatrices of size $r\times r$? Such a matrix is called an $(n,r,b)$-matrix. This question is a stronger version of an open problem in matroid theory raised by Dominic Welsh. In this paper, we pro

  44. Jan M. Pawlowski, Ion-Olimpiu Stamatescu, Christian Zielinski

    In this paper we discuss one-dimensional models reproducing some features of quantum electrodynamics and quantum chromodynamics at nonzero density and temperature. Since a severe sign problem makes a numerical treatment of QED and QCD at high density difficult, such models help to explore various effects peculiar to the full theory. Studying them gives insig

  45. Jiao Gu, Bobo Hua, Shiping Liu

    By assigning a probability measure via the spectrum of the normalized Laplacian to each graph and using L^p Wasserstein distances between probability measures, we define the corresponding spectral distances d_p on the set of all graphs. This approach can even be extended to measuring the distances between infinite graphs. We prove that the diameter of the se

  46. Daniel Junghans, Daniel Schmidt, Marco Zagermann

    We study AdS$_7$ vacua of massive type IIA string theory compactified on a 3-sphere with $H_3$ flux and anti-D6-branes. In such backgrounds, the anti-brane backreaction is known to generate a singularity in the $H_3$ energy density, whose interpretation has not been understood so far. We first consider supersymmetric solutions of this setup and give an analy

  47. Clark Barwick, Tyler Lawson

    We identify a regularity property for structured ring spectra, and with it we prove a natural analogue of Quillen's localization theorem for algebraic K-theory in this setting.

  48. Satoshi Nozawa, Yasuharu Kohyama

    We study the Sunyaev-Zeldovich effect for clusters of galaxies. We explore the relativistic corrections to the Kompaneets equation in terms of two different expansion approximation schemes, namely, the Fokker-Planck expansion approximation and delta function expansion approximation. We show that two expansion approximation formalisms are equivalent under the

  49. Gustavo Jasso

    Let $\mathbb{X}$ be a weighted projective line and $\operatorname{coh}\mathbb{X}$ the associated categoy of coherent sheaves. We classify the tilting complexes $T$ in $D^b(\operatorname{coh}\mathbb{X})$ such that $τ^2 T\cong T$, where $τ$ is the Auslander-Reiten translation in $D^b(\operatorname{coh}\mathbb{X})$. As an application of this result, we classify

  50. Yuri Berest, Peter Samuelson

    In this paper, we propose and discuss implications of a general conjecture that there is a canonical action of a rank 1 double affine Hecke algebra on the Kauffman bracket skein module of the complement of a knot $K \subset S^3$. We prove this in a number of nontrivial cases, including all $(2,2p+1)$ torus knots, the figure eight knot, and all 2-bridge knots

  51. D. A. Carranza, S. Mendoza

    Under natural assumptions on the thermodynamic properties of space and time with the holographic principle we reproduce a MOND-like behaviour of gravity on particular scales of mass and length, where Newtonian gravity requires a modification or extension if no dark matter component is introduced in the description of gravitational phenomena. The result is di

  52. David Y Gao

    This paper presents a pure complementary energy variational method for solving anti-plane shear problem in finite elasticity. Based on the canonical duality-triality theory developed by the author, the nonlinear/nonconex partial differential equation for the large deformation problem is converted into an algebraic equation in dual space, which can, in princi

  53. Jiarui Fei

    Let $G$ be a reductive group acting on a path algebra $kQ$ as automorphisms. We assume that $G$ admits a graded polynomial representation theory, and the action is polynomial. We describe the quiver $Q_G$ of the smash product algebra $kQ\# k[M_G]^*$, where $M_G$ is the associated algebraic monoid of $G$. We use $Q_G$-representations to construct $G$-invarian

  54. Gene Abrams, Mark Tomforde

    We describe primitive and prime ideals in the C*-algebra C*(E) of a graph E satisfying Condition (K), together with the topologies on each of these spaces. In particular, we find that primitive ideals correspond to the set of maximal tails disjoint union the set of finite-return vertices, and that prime ideals correspond to the set of clusters of maximal tai

  55. Pengfei Wan, Gene Cheung, Philip A. Chou, Dinei Florencio

    In texture-plus-depth representation of a 3D scene, depth maps from different camera viewpoints are typically lossily compressed via the classical transform coding / coefficient quantization paradigm. In this paper we propose to reduce distortion of the decoded depth maps due to quantization. The key observation is that depth maps from different viewpoints c

  56. Lei Wang, Jing Liu

    Conventional 3D printings are generally time-consuming and printable metal inks are rather limited. From an alternative way, we proposed a liquid phase 3D printing for quickly making metal objects. Through introducing metal alloys whose melting point is slightly above room temperature as printing inks, several representative structures spanning from one, two

  57. G. Rajasekaran

    The history of weak interactions starting with Fermi's creation of the beta decay theory and culminating in its modern avatar in the form of the electroweak gauge theory is described. Discoveries of parity violation, matter-antimatter asymmetry, W and Z bosons and neutrino mass are highlighted.

  58. Tiancheng Han, Huapeng Ye, Yu Luo, Swee Ping Yeo

    The principle of transformation optics has been applied to various wave phenomena (e.g., optics, electromagnetics, acoustics and thermodynamics). Recently, metamaterial devices manipulating dc currents have received increasing attention which usually adopted the analogue of transformation optics using complicated resistor networks to mimic the inhomogeneous

  59. C. Huang, Y. Y. Yan, G. Li, Y. Y. Deng

    It is of great importance to track the solar wind back to its photospheric source region and identify the related current sheets; this will provide key information for investigating the origin and predictions of the solar wind. We report a statistical study relating the photospheric footpoint motion and in-situ observation of current sheets in the solar wind

  60. A. Drezet

    Protective measurements which were defined by Aharonov and Vaidman in 1993 played an important role in the discussion about the interpretation of quantum mechanics. In 1999, following an early work by Englert et al., Aharonov et al. wrote an article in which they showed that protective measurements can be used to demonstrate the `surrealism' of Bohmian m

  61. Yan Qi, An Du

    A spin model of LiCu2O2 compound with ground state of ellipsoidal helical structure has been adopted. Taking into account the interchain coupling and exchange anisotropy, we focus on the magnetoelectric properties in a rotating magnetic field and perform the Monte Carlo simulation on a two-dimensional lattice. A prominent anisotropic response is observed in

  62. Marie Pahlmeyer, Andrew Hankins, Sam Tuppan, Woo-Joong Kim

    We have performed scanning capacitance microscopy using a relaxation oscillator. Precision calibrations indicate a sensitivity on the order of 0.05 pF. Surface topography of metallic structures, such as machined grooves and coins, can be readily obtained either in the constant-height (non-contact) or tapping (contact) mode. Spatial resolution of sub-50 $μ$m

  63. Richard O. Moore

    We demonstrate a trade-off between linewidth and loss-of-lock frequency in a mode-locked laser employing active feedback to control the carrier-envelope offset phase difference. In frequency metrology applications, the linewidth translates directly to uncertainty in the measured frequency, while the impact of lock loss and recovery on the measured frequency

  64. Polnop Samutpraphoot, Sophie Weber, Qian Lin, Dorian Gangloff

    We present a simple method for narrowing the intrinsic Lorentzian linewidth of a commercial ultraviolet grating extended-cavity diode laser (TOPTICA DL Pro) using weak optical feedback from a long external cavity. We achieve a suppression in frequency noise spectral density of 20 dB measured at frequencies around 1 MHz, corresponding to the narrowing of the

  65. Samir D. Mathur

    It has been conjectured that the dual of the eternal black hole in AdS is two entangled but disconnected CFTs. We show that the entanglement created by the process of Hawking radiation creates several challenges for this conjecture. The nature of fuzzball states suggests a different picture, where the dual to two entangled CFTs is two entangled but disconnec

  66. Jernej Azarija, Sandi Klavžar, Jaehun Lee, Jay Pantone

    The generalized Fibonacci cube $Q_d(f)$ is the subgraph of the $d$-cube $Q_d$ induced on the set of all strings of length $d$ that do not contain $f$ as a substring. It is proved that if $Q_d(f) \cong Q_d(f')$ then $|f|=|f'|$. The key tool to prove this result is a result of Guibas and Odlyzko about the autocorrelation polynomial associated to a bina

  67. Gloria Delgado-Inglada, Mónica Rodríguez

    We study the dust present in 56 Galactic planetary nebulae (PNe) through their iron depletion factors, their C/O abundance ratios (in 51 objects), and the dust features that appear in their infrared spectra (for 33 objects). Our sample objects have deep optical spectra of good quality, and most of them also have ultraviolet observations. We use these observa

  68. Xiaohu Li, Carina Arasa, Marc C. van Hemert, Ewine F. van Dishoeck

    The dynamics of the reaction H + OH $\to$ O (3P) + H2 have been studied in a series of quasi-classical trajectory (QCT) calculations and transition state theory (TST) methods using high quality 3A' and 3A'' potential energy surfaces (PESs). Accurate OH (v, j) state resolved cross sections and rate constants on both potential energy surfaces are p

  69. Satoru Morita, Jin Yoshimura

    It has not been known whether preferential dispersal is adaptive in fluctuating environments. We investigate the effect of preferential and random dispersals in bet-hedging systems by using a discrete stochastic metapopulation model, where each site fluctuates between good and bad environments with temporal correlation. To explore the optimal migration patte

  70. D. Ray, C. Reichhardt, C. J. Olson Reichhardt

    We numerically examine run-and-tumble active matter particles in Casimir geometries composed of two finite parallel walls. We find that there is an attractive force between the two walls of a magnitude that increases with increasing run length. The attraction exhibits an unusual exponential dependence on the wall separation, and it arises due to a depletion

  71. Luis P. Chimento, Martín G. Richarte

    We investigate the interacting dark sector composed of dark matter, dark energy, and dark radiation for a spatially flat Friedmann-Robertson-Walker (FRW) background by introducing a three-dimensional internal space spanned by the interaction vector $\mathbf{Q}$ and solve the source equation for a linear transversal interaction. Then, we explore a realistic m

  72. Steven A. Frank

    Microbes require several complex organic molecules for growth. A species may obtain a required factor by taking up molecules released by other species or by synthesizing the molecule. The patterns of uptake and synthesis set a flow of resources through the multiple species that create a microbial community. This article analyzes a simple mathematical model o

  73. Osman Hegazy, Omar S. Soliman, Mustafa Abdul Salam

    In this paper, Artificial Bee Colony (ABC) algorithm which inspired from the behavior of honey bees swarm is presented. ABC is a stochastic population-based evolutionary algorithm for problem solving. ABC algorithm, which is considered one of the most recently swarm intelligent techniques, is proposed to optimize least square support vector machine (LSSVM) t

  74. Martin Barbie, Abhishek Gupta

    We study here the topology of information on the space of probability measures over Polish spaces that was defined in Hellwig (1996). We show that under this topology, a convergent sequence of probability measures satisfying a conditional independence property converges to a measure that also satisfies the same conditional independence property. This also co

  75. Aharon Ben-Tal, Elad Hazan, Tomer Koren, Shie Mannor

    Robust optimization is a common framework in optimization under uncertainty when the problem parameters are not known, but it is rather known that the parameters belong to some given uncertainty set. In the robust optimization framework the problem solved is a min-max problem where a solution is judged according to its performance on the worst possible reali

  76. P. Garcia, L. Bronfman, L. Nyman, T. M. Dame

    The Columbia - U. de Chile CO Survey of the Southern Milky Way is used for separating the CO(1-0) emission of the fourth Galactic quadrant within the solar circle into its dominant components, giant molecular clouds (GMCs). After the subtraction of an axisymmetric model of the CO background emission in the inner Southern Galaxy, 92 GMCs are identified, and f

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

    We present a quantitative analysis of the low-resolution (4.5 A) spectra of 12 late-B and early-A blue supergiants (BSGs) in the metal-poor dwarf galaxy NGC 3109. A modified method of analysis is presented which does not require use of the Balmer jump as an independent temperature indicator, as used in previous studies. We determine stellar effective tempera

  78. Andrea Causin, Margarida Mendes Lopes, Gian Pietro Pirola

    We prove a new inequality for the Hodge number h^1,1 of irregular complex smooth projective surfaces of general type without irregular pencils of genus >1. More specifically we show that if the irregularity q satisfies q=2^k+1 then h^1,1>4q-4.

  79. Rutger H. Boels, Tobias Hansen

    It is argued that the complete S-matrix of string theory at tree level in a flat background can be obtained from a small set of target space properties, without recourse to the worldsheet description. The main non-standard inputs are (generalised) Britto-Cachazo-Feng-Witten shifts, as well as the monodromy relations for open string theory and the Kawai-Lewel

  80. Christopher McFarland, Leonid Mirny, Kirill S. Korolev

    Cancer progression is an example of a rapid adaptive process where evolving new traits is essential for survival and requires a high mutation rate. Precancerous cells acquire a few key mutations that drive rapid population growth and carcinogenesis. Cancer genomics demonstrates that these few 'driver' mutations occur alongside thousands of random &#3

  81. Jack J. Lissauer, Geoffrey W. Marcy, Stephen T. Bryson, Jason F. Rowe

    We extend the statistical analysis of Lissauer et al. (2012, ApJ 750, 112), which demonstrates that the overwhelming majority of Kepler candidate multiple transiting systems (multis) represent true transiting planets, and develop therefrom a procedure to validate large numbers of planet candidates in multis as bona fide exoplanets. We show that this statisti

  82. Fabrizio Margaroli

    Almost two decades after its discovery at Fermilab's Tevatron collider experiments, the top quark is still under the spotlight due to its connections to some of the most interesting puzzles in the Standard Model. The Tevatron has been shut down two years ago, yet some interesting results are coming out of the CDF and D0 collaborations. The LHC collider a

  83. Constantinos Constantinou, Brian Muccioli, Madappa Prakash, James M. Lattimer

    We investigate the thermal properties of the potential model equation of state of Akmal, Pandharipande and Ravenhall. This equation of state approximates the microscopic model calculations of Akmal and Pandharipande, which feature a neutral pion condensate. We treat the bulk homogeneous phase for isospin asymmetries ranging from symmetric nuclear matter to p

  84. T. V. Smirnova, V. I. Shishov, M. V. Popov, C. R. Gwinn

    RadioAstron space-ground VLBI observations of the pulsar B0950+08, conducted with the 10-m space radio telescope in conjunction with the Arecibo 300-m telescope and Westerbork Synthesis Radio Telescope at a frequency of 324 MHz, were analyzed in order to investigate plasma inhomogeneities in the direction of this nearby pulsar. The observations were conducte

  85. Andrew C. Potter, Itamar Kimchi, Ashvin Vishwanath

    The surface states of Weyl semi-metals (SM's) consist of disjointed Fermi-arcs. This unusual surface-Fermiology provides a fingerprint of the topological features of the bulk Weyl-phase. Using a combination of semiclassical and numerical methods, we show that, in contrast to naive expectation, there are closed magnetic orbits involving the open- surface

  86. Kevin France, Rebecca Schindhelm, Edwin Bergin, Evelyne Roueff

    The far-ultraviolet (FUV; 912--1700 Å) radiation field from accreting central stars in Classical T Tauri systems influences the disk chemistry during the period of giant planet formation. Previous efforts to measure the true stellar+accretion-generated FUV luminosity (both hot gas emission lines and continua) have been complicated by a combination of low-sen

  87. V. Silva Aguirre, G. R. Ruchti, S. Hekker, S. Cassisi

    About 1% of giant stars have been shown to have large surface Li abundances, which is unexpected according to standard stellar evolution models. Several scenarios for lithium production have been proposed, but it is still unclear why these Li-rich giants exist. A missing piece in this puzzle is the knowledge of the exact stage of evolution of these stars. Us

  88. G. Ghirlanda, D. Burlon, G. Ghisellini, R. Salvaterra

    Orphan Afterglows (OA) are slow transients produced by Gamma Ray Bursts seen off-axis that become visible on timescales of days/years at optical/NIR and radio frequencies, when the prompt emission at high energies (X and gamma rays) has already ceased. Given the typically estimated jet opening angle of GRBs theta_jet ~ 3 deg, for each burst pointing to the E

  89. J. Parrent, B. Friesen, M. Parthasarathy

    SN 2011fe was the nearest and best-observed type Ia supernova in a generation, and brought previous incomplete datasets into sharp contrast with the detailed new data. In retrospect, documenting spectroscopic behaviors of type Ia supernovae has been more often limited by sparse and incomplete temporal sampling than by consequences of signal-to-noise ratios,

  90. Garrett Somers, Marc Pinsonneault

    We investigate lithium depletion in standard stellar models (SSMs) and main sequence (MS) open clusters, and explore the origin of the Li dispersion in young, cool stars of equal mass, age and composition. We first demonstrate that SSMs accurately predict the Li abundances of solar analogs at the zero-age main sequence (ZAMS) within theoretical uncertainties

  91. Hannah Broekhoven-Fiene, Brenda C. Matthews, Paul M. Harvey, Robert A. Gutermuth

    We present observations of the Auriga-California Molecular Cloud (AMC) at 3.6, 4.5, 5.8, 8.0, 24, 70 and 160 micron observed with the IRAC and MIPS detectors as part of the Spitzer Gould Belt Legacy Survey. The total mapped areas are 2.5 sq-deg with IRAC and 10.47 sq-deg with MIPS. This giant molecular cloud is one of two in the nearby Gould Belt of star-for

  92. Benjamin Hendricks, Andreas Koch, Gustavo A. Lanfranchi, Corrado Boeche

    We present alpha-element abundances of Mg, Si, and Ti for a large sample of field stars in two outer fields of the Fornax dwarf spheroidal galaxy (dSph), obtained with VLT/GIRAFFE (R~16,000). Due to the large fraction of metal-poor stars in our sample, we are able to follow the alpha-element evolution from [Fe/H]=-2.5 continuously to [Fe/H]=-0.7 dex. For the

  93. K. Decker French, Kenneth C. Wong, Ann I. Zabludoff, S. Mark Ammons

    Certain configurations of massive structures projected along the line of sight maximize the number of detections of gravitationally lensed $z\sim10$ galaxies. We characterize such lines of sight with the étendue $σ_μ$, the area in the source plane magnified over some threshold $μ$. We use the Millennium I and Millennium XXL cosmological simulations to determ

  94. A. Alexandradinata, Chen Fang, Matthew J. Gilbert, B. Andrei Bernevig

    We explore the 32 crystallographic point groups and identify topological phases of matter with robust surface modes. For n =3,4 and 6 of the C_{nv} groups, we find the first-known 3D topological insulators without spin-orbit coupling, and with surface modes that are protected only by point groups, i.e., not needing time-reversal symmetry. To describe these C

  95. Anatoly Dymarsky, Kara Farnsworth, Zohar Komargodski, Markus A. Luty

    This paper addresses the question of whether there are 4D Lorentz invariant unitary quantum field theories with scale invariance but not conformal invariance. An important loophole in the arguments of Luty-Polchinski-Rattazzi and Dymarsky-Komargodski-Schwimmer-Theisen is that trace of the energy-momentum tensor $T$ could be a generalized free field. In this

  96. M. Chara, R Toledano

    In this paper we study general conditions to prove the infiniteness of the genus of certain towers of function fields over a perfect field. We show that many known examples of towers with infinite genus are particular cases of these conditions.

  97. Pablo Dorta-Gonzalez, Maria Isabel Dorta-Gonzalez, Dolores Rosa Santos-Penate, Rafael Suarez-Vega

    The journal impact factor is not comparable among fields of science and social science because of systematic differences in publication and citation behaviour across disciplines. In this work, a source normalization of the journal impact factor is proposed. We use the aggregate impact factor of the citing journals as a measure of the citation potential in th

  98. L. M. W. Leggett, D. A. Ball

    Understanding current global climate requires an understanding of trends both in Earth's atmospheric temperature and the El Nino-Southern Oscillation (ENSO), a characteristic large-scale distribution of warm water in the tropical Pacific Ocean and the dominant mode of year-to-year climate variability (Holbrook et al. 2009. However, despite much effort, t

  99. G. Muhrer

    In this paper the theoretical concept of a cold crystal reflector filter will be presented. The aim of this concept is to balance the shortcoming of the traditional cold polycrystalline reflector filter, which lies in the significant reduction of the neutron flux right above (in energy space) or right below (wavelength space) the first Bragg edge.

  100. Abdelali Gabih, Hakam Kondakji, Jörn Sass, Ralf Wunderlich

    This paper investigates optimal portfolio strategies in a financial market where the drift of the stock returns is driven by an unobserved Gaussian mean reverting process. Information on this process is obtained from observing stock returns and expert opinions. The latter provide at discrete time points an unbiased estimate of the current state of the drift.