January 2011 arXiv papers — page 2

H. A. Gururaja, Soma Maity, Harish Seshadri

B Wilking has recently shown that one can associate a Ricci flow invariant cone of curvature operators $C(S)$, which are nonnegative in a suitable sense, to every $Ad_{SO(n,\C)}$ invariant subset $S \subset {\bf so}(n,\C)$. For curvature operators of a Kähler manifold of complex dimension $n$, one considers $Ad_{GL(n,\C)}$ invariant subsets $S \subset {\bf g

A. V. Berezhnoy, A. K. Likhoded, A. V. Luchinsky, A. A. Novoselov

The article is devoted to double J/psi-meson production at LHC. Theoretical predictions for pp -> 2J/psi+X cross section at sqrt{s}=7 TeV for different kinematical restrictions are presented. Special attention is payed to possible contribution of novel particles -- tetraquarks build from four c-quarks. According to presented in our article estimates, it is q

J. Kluson

We consider RFDiff invariant Horava-Lifshitz gravity action with additional Lagrange multiplier term that is a function of scalar curvature. We find its Hamiltonian formulation and we show that the constraint structure implies the same number of physical degrees of freedom as in General Relativity.

Ning Xu, Daan Frenkel, Andrea J. Liu

We propose a free-energy based Monte-Carlo method to measure the volume of potential-energy basins in configuration space. Using this approach we can estimate the number of distinct potential-energy minima, even when this number is much too large to be sampled directly. We validate our approach by comparing our results with the direct enumeration of distinct

Jiwei Ke, Mingxing Luo, Liucheng Wang, Guohuai Zhu

Recently, the Fermi-LAT collaboration reported upper limits on the GeV gamma-ray flux from nearby clusters of galaxies. Motivated by these limits, we study corresponding constraints on gamma-ray emissions from two specific decaying dark matter models, one via grand unification scale suppressed operators and the other via R-parity violating operators. Both ca

Kitty Meeks, Alexander Scott

We consider the complexity of problems related to the combinatorial game Free-Flood-It, in which players aim to make a coloured graph monochromatic with the minimum possible number of flooding operations. Although computing the minimum number of moves required to flood an arbitrary graph is known to be NP-hard, we demonstrate a polynomial time algorithm to c

Noa Lavi

The purpose of this paper is to give a characterization for polynomials and rational functions which admit only non-negative values on definable sets in real closed valued fields. That is, generalizing the relative positivstellensätze for sets defined also by valuation terms. For this, we use model theoretic tools, together with existence of canonical valuat

Peter Csermely, Kuljeet Singh Sandhu, Eszter Hazai, Zsolt Hoksza

During the last decade, network approaches became a powerful tool to describe protein structure and dynamics. Here we review the links between disordered proteins and the associated networks, and describe the consequences of local, mesoscopic and global network disorder on changes in protein structure and dynamics. We introduce a new classification of protei

Ting Zhang, Daoyuan Fang

We investigate global strong solutions for the incompressible viscoelastic system of Oldroyd--B type with the initial data close to a stable equilibrium. We obtain the existence and uniqueness of the global solution in a functional setting invariant by the scaling of the associated equations, where the initial velocity has the same critical regularity index

Charles Baker, Tao Jia, Rahul V. Kulkarni

A wealth of new research has highlighted the critical roles of small RNAs (sRNAs) in diverse processes such as quorum sensing and cellular responses to stress. The pathways controlling these processes often have a central motif comprising of a master regulator protein whose expression is controlled by multiple sRNAs. However, the regulation of stochastic gen

Mahatsab Mandal, Lusaka Bhattacharya, Pradip Roy

We calculate the nuclear modification factor ($R_{AA}$) of light hadrons by taking into account the initial state momentum anisotropy of the quark gluon plasma (QGP) expected to be formed in relativistic heavy ion collisions. Such an anisotropy can result from the initial rapid longitudinal expansion of the matter. A phenomenological model for the space time

Michael Bateman, Nets Hawk Katz

We provide an improvement over Meshulam's bound on cap sets in $F_3^N$. We show that there exist universal $ε>0$ and $C>0$ so that any cap set in $F_3^N$ has size at most $C {3^N \over N^{1+ε}}$. We do this by obtaining quite strong information about the additive combinatorial properties of the large spectrum.

Shuji Nakamura, Yoshiaki Yamauchi, Masayuki Hashisaka, Kensaku Chida

Mesoscopic systems provide us a unique experimental stage to address non-equilibrium quantum statistical physics. By using a simple tunneling model, we describe the electron exchange process via a quantum coherent conductor between two reservoirs, which yields the fluctuation theorem (FT) in mesoscopic transport. We experimentally show that such a treatment

Masaaki Fujii, Akihiko Takahashi

The importance of collateralization through the change of funding cost is now well recognized among practitioners. In this article, we have extended the previous studies of collateralized derivative pricing to more generic situation, that is asymmetric and imperfect collateralization with the associated counter party credit risk. By introducing the collatera

Toshiyuki Tanisaki

We formulate a Beilinson-Bernstein type derived equivalence for a quantized enveloping algebra at a root of 1 as a conjecture. It says that there exists a derived equivalence between the category of modules over a quantized enveloping algebra at a root of 1 with fixed regular Harish-Chandra central character and the category of certain twisted $D$-modules on

Kevin H. Lin, Daniel Pomerleano

We study matrix factorization and curved module categories for Landau-Ginzburg models (X,W) with X a smooth variety, extending parts of the work of Dyckerhoff. Following Positselski, we equip these categories with model category structures. Using results of Rouquier and Orlov, we identify compact generators. Via Toën's derived Morita theory, we identify

Prakash Belkale

We prove that the vector bundles of conformal blocks, on suitable moduli spaces of genus zero curves with marked points, for arbitrary simple Lie algebras and arbitrary integral levels, carry unitary metrics of geometric origin which are preserved by the Knizhnik-Zamolodchikov/Hitchin connection (as conjectured by Gawedzki). Our proof builds upon the work of

S. Clemmen, A. Perret, J. Saffioui, W. Bogaerts

When a pump beam is propagating through a silicon nanophotonic waveguide, a very small fraction of the light is scattered to other frequencies. At very low intensity, the amount of scattered light is proportional to the power of the pump beam. We show that the scattering intensity increases linearly within the temperature range 300-575 K and that the photon

Krzysztof Łatuszyński, Gareth O. Roberts, Jeffrey S. Rosenthal

We consider various versions of adaptive Gibbs and Metropolis-within-Gibbs samplers, which update their selection probabilities (and perhaps also their proposal distributions) on the fly during a run by learning as they go in an attempt to optimize the algorithm. We present a cautionary example of how even a simple-seeming adaptive Gibbs sampler may fail to

Krzysztof Latuszynski, Blazej Miasojedow, Wojciech Niemiro

The Nummellin's split chain construction allows to decompose a Markov chain Monte Carlo (MCMC) trajectory into i.i.d. "excursions". RegenerativeMCMC algorithms based on this technique use a random number of samples. They have been proposed as a promising alternative to usual fixed length simulation [25, 33, 14]. In this note we derive nonasymptot

Radhakrishnamurty Padyala

Lord Kelvin's postulate is a standard form of statement of the second law of thermodynamics. Caratheodory's principle is also considered as a different form of this law. Landsberg deduced Caratheodory's principle from Kelvin's postulate and Dunning-Davies deduced its converse to show the equivalence of the two principles, and these deductions

Alexei V. Nesteruk

The paper discusses the problem of demarcation between the dimensions of natural and the human sciences in contemporary cosmology. In spite of a common presumption that cosmology is a natural science, the specificity of its alleged subject matter, that is the universe as a whole, makes cosmology fundamentally different from other natural sciences. The reason

Ye Tian, Aylin Yener

We consider the Gaussian interference channel with an intermediate relay as a main building block for cooperative interference networks. On the achievability side, we consider compress-and-forward based strategies. Specifically, a generalized compress-and-forward strategy, where the destinations jointly decode the compression indices and the source messages,

Ian A. Kash, Michael Mitzenmacher, Justin Thaler, Jonathan Ullman

We consider the zero-error capacity of deletion channels. Specifically, we consider the setting where we choose a codebook ${\cal C}$ consisting of strings of $n$ bits, and our model of the channel corresponds to an adversary who may delete up to $pn$ of these bits for a constant $p$. Our goal is to decode correctly without error regardless of the actions of

V. A. Slipko, I. Savran, Y. V. Pershin

We demonstrate that a homogeneous spin polarization in one-dimensional structures of finite length in the presence of Bychkov-Rashba spin-orbit coupling decays spontaneously toward a persistent spin helix. The analysis of formation of spin helical state is presented within a novel approach based on a mapping of spin drift-diffusion equations into a heat equa

Ricardo Salinas, Tom Richtler, Michael J. West, Aaron J. Romanowsky

We study the structure and internal kinematics of the "star pile" in Abell 545 - a low surface brightness structure lying in the center of the cluster.We have obtained deep long-slit spectroscopy of the star pile using VLT/FORS2 and Gemini/GMOS, which is analyzed in conjunction with deep multiband CFHT/MEGACAM imaging. As presented in a previous stud

Khaoula Ben Abdeljelil

We define the periodic Full Kostant-Toda on every simple Lie algebra, and show its Liouville integrability. More precisely we show that this lattice is given by a Hamiltonian vector field, associated to a Poisson bracket which results from an R-matrix. We construct a large family of constant of motion which we use to prove the Liouville integrability of the

Anand Sharma, Pawel Hawrylak

We present a microscopic theory of a lateral quantum dot molecule in a radial magnetic field with a Greenberger- Horne- Zeilinger (GHZ) maximally entangled three particle groundstate. The quantum dot molecule consists of three quantum dots with one electron spin each forming a central equilateral triangle. The anti-ferromagnetic spin-spin interaction is chan

Huang Huang, Changbin Yu, Qinghe Wu

This paper considers a novel problem of how to choose an appropriate geometry for a group of agents with only shape constraints but with a flexible scale. Instead of assigning the formation system with a specific geometry, here the only requirement on the desired geometry is a shape without any location, rotation and, most importantly, scale constraints. Opt

Khaoula Ben Abdeljelil

We define the 2-Toda lattice on every simple Lie algebra g, and we show its Liouville integrability. We show that this lattice is given by a pair of Hamiltonian vector fields, associated with a Poisson bracket which results from an R-matrix of the underlying Lie algebra. We construct a big family of constants of motion which we use to prove the Liouville int

Torsten Rendler, Marc Renz, Eva Hammann, Stefan Ernst

FoF1-ATP synthase is the essential membrane enzyme maintaining the cellular level of adenosine triphosphate (ATP) and comprises two rotary motors. We measure subunit rotation in FoF1-ATP synthase by intramolecular Foerster resonance energy transfer (FRET) between two fluorophores at the rotor and at the stator of the enzyme. Confocal FRET measurements of fre

Usman A. Gillani, Mudassar Rehman, K. Saifullah

Hawking radiation of uncharged and charged scalars from accelerating and rotating black holes is studied. We calculate the tunneling probabilities of these particles from the rotation and acceleration horizons of these black holes. Using the tunneling method we recover the correct Hawking temperature as well.

Ignacio Negueruela, Carlos Gonzalez-Fernandez, Amparo Marco, J. Simon Clark

Four clusters of red supergiants have been discovered in a region of the Milky Way close to base of the Scutum-Crux Arm and the tip of the Long Bar. Population synthesis models indicate that they must be very massive to harbour so many supergiants. The spatial extent of one of these clusters, RSGC3, has not been investigated. We utilised 2MASS JHK photometry

Rolf Dahm

We start from a noncompact Lie algebra isomorphic to the Dirac algebra and relate this Lie algebra in a brief review to low energy hadron physics described by the compact group SU(4). This step permits an overall physical identification of the operator actions. Then we discuss the geometrical origin of this noncompact Lie algebra and 'reduce' the geo

Parasaran Raman, Jeff M. Phillips, Suresh Venkatasubramanian

This paper proposes a new distance metric between clusterings that incorporates information about the spatial distribution of points and clusters. Our approach builds on the idea of a Hilbert space-based representation of clusters as a combination of the representations of their constituent points. We use this representation and the underlying metric to desi

Wojciech Mazurczyk, Jozef Lubacz, Krzysztof Szczypiorski

The paper presents a new hidden data insertion procedure based on estimated probability of the remaining time of the call for steganographic method called LACK (Lost Audio PaCKets steganography). LACK provides hidden communication for real-time services like Voice over IP. The analytical results presented in this paper concern the influence of LACK's hid

Jacek Jakubowski, Maciej Wisniewolski

The aim of this paper is to present the new results concerning some functionals of Brownian motion with drift and present their applications in financial mathematics. We find a probabilistic representation of the Laplace transform of special functional of geometric Brownian motion using the squared Bessel and radial Ornstein-Uhlenbeck processes. Knowing the

Moira I. Gresham, Ian-Woo Kim, Kathryn M. Zurek

We study new top flavor violating resonances that are singly produced in association with a top at the LHC. Such top flavor violating states could be responsible for the Tevatron top forward-backward asymmetry. Since top flavor violating states can directly decay to a top (or anti-top) and jet, and are produced in conjunction with another (oppositely charged

Egang Lu, Guy D. Moore

We compute the bulk viscosity of a gas of pions at temperatures below the QCD crossover temperature, for the physical value of pion mass, to lowest order in chiral perturbation theory. Bulk viscosity is controlled by number-changing processes which become exponentially slow at low temperatures when the pions become exponentially dilute, leading to an exponen

John Davey, Amihay Hanany, Rak-Kyeong Seong

We review three methods of counting abelian orbifolds of the form C^3/Gamma which are toric Calabi-Yau (CY). The methods include the use of 3-tuples to define the action of Gamma on C^3, the counting of triangular toric diagrams and the construction of hexagonal brane tilings. A formula for the partition function that counts these orbifolds is given. Extensi

Steven Abel, Mark Goodsell

A simple and natural model is presented that gives Dirac gauginos. The configuration is related to "deconstructed gaugino mediation". A high energy completion is provided based on existing ISS-like models of deconstructed gaugino mediation. This provides a complete picture of Dirac gauginos that includes the necessary extra adjoint fermions (generate

A. G. Bedregal, L. Colina, R. Azzollini, S. Arribas

By observing the local luminous infrared galaxy NGC5135 with the near-IR IFU spectrograph SINFONI (ESO-VLT), we report an approx. 600 pc (in projection) AGN outflow traced by [SiVI]1.96mum emission. This is the largest outflow traced by a coronal line ever reported. Its large spatial scale suggests that shocks, in addition to AGN continuum emission, are need

Lara B. Anderson, James Gray, Andre Lukas, Burt Ovrut

We propose a scenario to stabilize all geometric moduli - that is, the complex structure, Kahler moduli and the dilaton - in smooth heterotic Calabi-Yau compactifications without Neveu-Schwarz three-form flux. This is accomplished using the gauge bundle required in any heterotic compactification, whose perturbative effects on the moduli are combined with non

Alex Ely Kossovsky

Nash's solution in his celebrated article on the bargaining problem calling for maximization of product of marginal utilities is revisited; a different line of argument supporting such a solution is suggested by straightforward or more direct reasoning, and a conjecture is raised which purports uniqueness of algorithm, namely his solution. Other alternat

M. Glenn Sterenborg, Ofer Cohen, Jeremy J. Drake, Tamas I. Gombosi

We present a focused parameter study of solar wind - magnetosphere interaction for the young Sun and Earth, $~3.5$ Ga ago, that relies on magnetohydrodynamic (MHD) simulations for both the solar wind and the magnetosphere. By simulating the quiescent young Sun and its wind we are able to propagate the MHD simulations up to Earth's magnetosphere and obtai

Aaron D. Ludlow, Julio F. Navarro, Michael Boylan-Kolchin, Volker Springel

Cosmological N-body simulations indicate that the spherically-averaged density profiles of cold dark matter halos are accurately described by Einasto profiles, where the logarithmic slope is a power-law of adjustable exponent, γ=dlnρ/dlnr ~ r^α$. The pseudo-phase-space density (PPSD) profiles of CDM halos also show remarkable regularity, and are well approxi

Peter Sorensen, Carl Eric Dahl

We show for the first time that the quenching of electronic excitation from nuclear recoils in liquid xenon is well-described by Lindhard theory, if the nuclear recoil energy is reconstructed using the combined (scintillation and ionization) energy scale proposed by Shutt {\it et al.}. We argue for the adoption of this perspective in favor of the existing pr

J. A. Formaggio

The shape of the beta decay energy distribution is sensitive to the mass of the electron neutrino. Attempts to measure the endpoint shape of tritium decay have so far seen no distortion from the zero-mass form. Here we show that a new type of electron energy spectroscopy could improve future measurements of this spectrum and therefore of the neutrino mass. W

Hans Vernaeve

Someone knowledgeable in nonstandard analysis may get the feeling that in the nonlinear theory of generalized functions, too often one works directly on the nets and spends effort to obtain results that should be clear from general principles. We want to show that such principles can indeed be introduced and to illustrate their role to solve problems. This t

Rashida Jahangir, K. Saifullah

Thermodynamics of the BTZ black hole in noncommutative geometry is studied. We work out the Hawking temperature and entropy which reduce to their commutative limits when the noncommutativity parameter tends to zero. We also discuss the range of validity of the Hawking area law in the noncommutative case and provide graphical analysis. We see that the law is

Matthew Kerr

The sensitivity of the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope allows detection of thousands of new gamma-ray sources and detailed characterization of the spectra and variability of bright sources. Unsurprisingly, this increased capability leads to increased complexity in data analysis. Likelihood methods are ideal for connectin

Byung Chan Eu

In this paper, we make use of the exact hydrodynamic solution for the Stokes equation for the velocity of a binary ionic solution that we have recently obtained, and show that the nonequilibrium pressure in an electrolyte solution subjected to an external electric field can be not only compressive, but also divergent in the region containing the coordinate o

Diego Guarin, Edilson Delgado, Alvaro Orozco

Testing for nonlinearity is one of the most important preprocessing steps in nonlinear time series analysis. Typically, this is done by means of the linear surrogate data methods. But it is a known fact that the validity of the results heavily depends on the stationarity of the time series. Since most physiological signals are non-stationary, it is easy to f

The CDF Collaboration

The observation of the $Y(4140)$ structure in $B^\pm\rightarrow J/ψ\,ϕK^\pm$ decays produced in $\bar{p} p $ collisions at $\sqrt{s}=1.96~\TeV$ is reported with a statistical significance greater than 5 standard deviations. A fit to the $J/ψ\,ϕ$ mass spectrum is performed assuming the presence of a Breit-Wigner resonance. The fit yields a signal of $19^{+6}_

J. A. Kennea, P. Romano, V. Mangano, A. P. Beardmore

We describe the results of the first year of a program to localize new Galactic Transient sources discovered by MAXI with NASA's Swift mission. Swift is ideally suited for follow-up of MAXI discovered transients as its X-ray Telescope (XRT) field of view (~0.2 degrees radius) is closely matched to the typical MAXI error circle. The XRT is capable of loca

Fernando Rozenblit, Mauro Copelli

We study the effects of a probabilistic refractory period in the collective behavior of coupled discrete-time excitable cells (SIRS-like cellular automata). Using mean-field analysis and simulations, we show that a synchronized phase with stable collective oscillations exists even with non-deterministic refractory periods. Moreover, further increasing the co

Boryana V. Efremova, Luciana Bianchi, David A. Thilker, James D. Neill

We characterize the star formation in the low-metallicity galaxy NGC 6822 over the past few hundred million years, using GALEX far-UV (FUV, 1344-1786 A) and near-UV (NUV, 1771-2831 A) imaging, and ground-based Ha imaging. From GALEX FUV image, we define 77 star-forming (SF) regions with area >860 pc^2, and surface brightness <=26.8 mag(AB)arcsec^-2, within 0

Leonard Susskind

This paper is an addendum to [arXiv:0808.2096] in which I point out that both de Sitter space and Rindler space are fast scramblers. This fact naturally suggests that the holographic description of a causal patch of de Sitter space may be a matrix quantum mechanics at finite temperature. The same can be said of Rindler space. Some qualitative features of the

Alex Levchenko, M. R. Norman

We develop a theory of the rectification effect in a double-layer system where both layers are superconductors, or one of the layers is a normal metal. The Coulomb interaction is assumed to provide the dominant coupling between the layers. We find that superconducting fluctuations strongly enhance the drag conductivity, with rectification most pronounced whe

Edi Halyo

We describe supersymmetry breaking by the F-term of a heavy right-handed tau neutrino with a VEV. Due to the the tau neutrino Yukawa coupling, the neutralino, chargino and scalar mass matrices and the weak currents are modified. In addition, there are new cubic and quartic scalar and trilinear R parity violating interactions. For large $\tan β$ these effects

M. Larouche, J. Patera

The orbits of Weyl groups W(B(n)), W(C(n)) and W(D(n)) of the simple Lie algebras B(n), C(n) and D(n) are reduced to the union of the orbits of Weyl groups of the maximal reductive subalgebras of B(n), C(n) and D(n). Matrices transforming points of W(B(n)), W(C(n)) and W(D(n)) orbits into points of subalgebra orbits are listed for all cases n<=8 and for the

Murat M. Kaskulov, Ulrich Mosel

An interpretation of the beam spin azimuthal asymmetries measured at JLAB in deep exclusive electroproduction of charged and neutral pions is presented. The model combines a Regge pole approach with the effect of nucleon resonances. The $s$- and $u$-channel contributions are described using a dual Bloom-Gilman connection between the exclusive form factors an

John Stephen Marsland

An alternative definition for the non local impact ionization coefficient is given and its relationship to the ionization pathlength probability distribution function (PDF) is determined. A model for the ionization pathlength PDF is proposed and the resultant non local ionization coefficient is derived. An expression for the avalanche multiplication is deriv

M. A. Jafarizadeh, R. Sufiani, F. Eghbalifam, M. Azimi

We consider a pure 2m-qubit initial state to evolve under a particular quantum me- chanical spin Hamiltonian, which can be written in terms of the adjacency matrix of the Johnson network J(2m;m). Then, by using some techniques such as spectral dis- tribution and stratification associated with the graphs, employed in [1, 2], a maximally entangled GHZ state is

Jose Antonio Martin H

In this paper, an algorithm for determining 3-colorability, i.e. the decision problem (YES/NO), in planar graphs is presented. The algorithm, although not exact (it could produce false positives) has two very important features: (i) it has polynomial complexity and (ii) for every &#34;NO&#34; answer, a &#34;short&#34; proof is generated, which is of much int

Daniel Beltita, Karl-Hermann Neeb

To each irreducible infinite dimensional representation $(π,\cH)$ of a $C^*$-algebra $\cA$, we associate a collection of irreducible norm-continuous unitary representations $π_λ^\cA$ of its unitary group $\U(\cA)$, whose equivalence classes are parameterized by highest weights in the same way as the irreducible bounded unitary representations of the group $\

François Rodier

We prove a necessary condition for some polynomials of Kasami degree to be APN over F_{q^n} for large n.

Enrico Camporeale, David Burgess

We present two-dimensional fully-kinetic Particle-in-Cell simulations of decaying electromagnetic fluctuations. The computational box is such that wavelengths ranging from electron to ion gyroradii are resolved. The parameters used are realistic for the solar wind, and the ion to electron mass ratio is physical. The understanding of the dissipation of turbul

Sourabh Bhattacharya, Ali Khanafer, Tamer Başar

In this work, we study the problem of power allocation in teams. Each team consists of two agents who try to split their available power between the tasks of communication and jamming the nodes of the other team. The agents have constraints on their total energy and instantaneous power usage. The cost function is the difference between the rates of erroneous

U. Welp, C. Chaparro, A. E. Koshelev, W. K. Kwok

We report on the specific heat determination of the anisotropic phase diagram of single crystals of optimally doped SmFeAsO1-xFx. In zero-field, the optimally doped compound displays a clear cusp-like anomaly in C/T with ΔC/Tc = 24 mJ/molK2 at Tc = 49.5 K. In magnetic fields applied along the c-axis, we find pronounced superconducting fluctuations induced br

M. B. Mickaliger, M. A. McLaughlin, D. R. Lorimer, G. I. Langston

The 43m telescope at the NRAO site in Green Bank, WV has recently been outfitted with a clone of the Green Bank Ultimate Pulsar Processing Instrument (GUPPI \cite{Ransom:2009}) backend, making it very useful for a number of pulsar related studies in frequency ranges 800-1600 MHz and 220-440 MHz. Some of the recent science being done with it include: monitori

R. Sekhar Chivukula, Baradhwaj Coleppa, Heather E. Logan, Adam Martin

We discuss the deconstructed version of a topcolor-assisted technicolor model wherein the mechanism of top quark mass generation is separated from the rest of electroweak symmetry breaking. The minimal deconstructed version of this scenario is a &#34;triangle moose&#34; model, where the top quark gets its mass from coupling to a top-Higgs field, while the ga

E. S. Roberts, A. C. C. Coolen, T. Schlitt

We generate new mathematical tools with which to quantify the macroscopic topological structure of large directed networks. This is achieved via a statistical mechanical analysis of constrained maximum entropy ensembles of directed random graphs with prescribed joint distributions for in- and outdegrees and prescribed degree-degree correlation functions. We

D. B. Blaschke, G. Roepke, V. V. Dmitriev, S. A. Smolyansky

It is well known that in the presence of strong external electromagnetic fields many processes forbidden in standard QED become possible. One example is the one-photon annihilation process considered recently by the present authors in the framework of a kinetic approach to the quasiparticle e-e+ gamma plasma created from vacuum in the focal spot of two count

Kristopher Yirak, Ed Schroeder, Adam Frank, Andrew J. Cunningham

We investigate the role discrete clumps embedded in an astrophysical jet play on the jet&#39;s morphology and line emission characteristics. By varying clumps&#39; size, density, position, and velocity, we cover a range of parameter space motivated by observations of objects such as the Herbig Haro object HH~34. We here extend the results presented in Yirak

C. Skordis, T. G. Zlosnik

Modified Newtonian Dynamics is an empirical modification to Poisson&#39;s equation which has had success in accounting for the `gravitational field&#39; $Φ$ in a variety of astrophysical systems. The field $Φ$ may be interpreted in terms of the weak field limit of a variety of spacetime geometries. Here we consider three of these geometries in a more compreh

Andrea Roli, Cristian Arcaroli, Marco Lazzarini, Stefano Benedettini

We present and discuss the results of an experimental analysis in the design of Boolean networks by means of genetic algorithms. A population of networks is evolved with the aim of finding a network such that the attractor it reaches is of required length $l$. In general, any target can be defined, provided that it is possible to model the task as an optimis

Stefano Iellamo, Lin Chen, Marceau Coupechoux

In this paper, we tackle the problem of opportunistic spectrum access in large-scale cognitive radio networks, where the unlicensed Secondary Users (SU) access the frequency channels partially occupied by the licensed Primary Users (PU). Each channel is characterized by an availability probability unknown to the SUs. We apply evolutionary game theory to mode

Bo Thidé, Fabrizio Tamburini, Elettra Mari, Filippo Romanato

It has been known for a century that electromagnetic fields can transport not only energy and linear momentum but also angular momentum. However, it was not until twenty years ago, with the discovery in laser optics of experimental techniques for the generation, detection and manipulation of photons in well-defined, pure orbital angular momentum (OAM) states

Samuel Lara-Avila, Kasper Moth-Poulsen, Rositza Yakimova, Thomas Bjørnholm

Electronic devices using epitaxial graphene on Silicon Carbide require encapsulation to avoid uncontrolled doping by impurities deposited in ambient conditions. Additionally, interaction of the graphene monolayer with the substrate causes relatively high level of electron doping in this material, which is rather difficult to change by electrostatic gating al

Guoliang Lu, Chunhua Zhu, Zhaojun Wang, Wensheng Huo

Using a simple accelerating model and an assumption that $γ$-rays originate from $p-p$ collisions for a $π^0$ model, we investigate $γ$-ray sources like V407 Cygni in symbiotic stars. The upper limit of their occurrence rate in the Galaxy is between 0.5 and 5 yr$^{-1}$, indicating that they may be an important source of the high-energy $γ$-rays. The maximum

Chao Chen, Chunjing Xie

In this paper, we study the global existence of steady subsonic Euler flows through infinitely long nozzles which are periodic in $x_1$ direction with the period $L$. It is shown that when the variation of Bernoulli function at some given section is small and mass flux is in a suitable regime, there exists a unique global subsonic flow in the nozzle. Further

Andrea Roli, Michela Milano

In this paper we present a new approach to solve the satisfiability problem (SAT), based on boolean networks (BN). We define a mapping between a SAT instance and a BN, and we solve SAT problem by simulating the BN dynamics. We prove that BN fixed points correspond to the SAT solutions. The mapping presented allows to develop a new class of algorithms to solv

Ulrich Harst, Martin Reuter

We discuss the non-perturbative renormalization group flow of Quantum Electrodynamics (QED) coupled to Quantum Einstein Gravity (QEG) and explore the possibilities for defining its continuum limit at a fixed point that would lead to a non-trivial, i.e. interacting field theory. We find two fixed points suitable for the Asymptotic Safety construction. In the

Pavel Sekatski, Nicolas Sangouard, Nicolas Gisin, Hugues de Riedmatten

Spontaneous Raman emission in atomic gases provides an attractive source of photon pairs with a controllable delay. We show how this technique can be implemented in solid state systems by appropriately shaping the inhomogeneous broadening. Our proposal is eminently feasible with current technology and provides a realistic solution to entangle remote rare-ear

J. W. Johnson

Certain weight-based orders on the free associative algebra $R = k<x_1, ..., x_t >$ can be specified by $t \times \infty$ arrays whose entries come from the subring of nonnegative elements in a totally ordered field. Such an array $A$ satisfying certain additional conditions produces a partial order on $R$ which is an admissible order on the quotient $R/I_A$

Kevin Dusling

In this work we study how quantum fluctuations modify the quantum evolution of an initially classical field theory. We consider a scalar $ϕ^4$ theory coupled to an external source as a toy model for the Color Glass Condensate description of the early time dynamics of heavy-ion collisions. We demonstrate that quantum fluctuations considerably modify the time

Andrea Roli, Mattia Manfroni, Carlo Pinciroli, Mauro Birattari

Dynamical systems theory and complexity science provide powerful tools for analysing artificial agents and robots. Furthermore, they have been recently proposed also as a source of design principles and guidelines. Boolean networks are a prominent example of complex dynamical systems and they have been shown to effectively capture important phenomena in gene

Beatriz Mingo, Martin J. Hardcastle, Judith H. Croston, Daniel A. Evans

Markarian 6 is a nearby (D~78 Mpc) Seyfert 1.5, early-type galaxy, with a double set of radio bubbles. The outer set spans ~7.5 kpc and is expanding into the halo regions of the host galaxy. We present an analysis of our new Chandra observation, together with archival XMM-Newton data, to look for evidence of emission from shocked gas around the external radi

D. Kobyakov, V. Bychkov, E. Lundh, A. Bezett

The dynamics of an interface in a two-component Bose-Einstein condensate driven by a spatially uniform time-dependent force is studied. Starting from the Gross-Pitaevskii Lagrangian, the dispersion relation for linear waves and instabilities at the interface is derived by means of a variational approach. A number of diverse dynamical effects for different ty

Bojin Zheng, Yuanxiang Li

Multi-Objective Evolutionary Algorithms (MOEAs) have been proved efficient to deal with Multi-objective Optimization Problems (MOPs). Until now tens of MOEAs have been proposed. The unified mode would provide a more systematic approach to build new MOEAs. Here a new model is proposed which includes two sub-models based on two classes of different schemas of

Markus Meinert, Jan-Michael Schmalhorst, Günter Reiss, Elke Arenholz

The quaternary full Heusler compound Mn(2-x)Co(x)VAl with x = 1 is predicted to be a half-metallic antiferromagnet. Thin films of the quaternary compounds with x = 0...2 were prepared by DC and RF magnetron co-sputtering on heated MgO (001) substrates. The magnetic structure was examined by x-ray magnetic circular dichroism and the chemical disorder was char

Lars Bonnes, Stefan Wessel

We examine the equilibrium properties of lattice bosons with attractive on-site interactions in the presence of a three-body hard-core constraint that stabilizes the system against collapse and gives rise to a dimer superfluid phase formed by virtual hopping processes of boson pairs. Employing quantum Monte Carlo simulations, the ground state phase diagram o

Yoshitaka Hatta

Recently, X. Chen et al. proposed a new approach to the gauge invariant decomposition of the nucleon spin into helicity and orbital parts. The key ingredient in their construction is the separation of the gauge field into `physical&#39; and `pure gauge&#39; parts. We suggest a simple separation scheme and show that the resulting gluon helicity coincides with

Christian Saemann, Richard J. Szabo

We propose generalized quantization axioms for Nambu-Poisson manifolds, which allow for a geometric interpretation of n-Lie algebras and their enveloping algebras. We illustrate these axioms by describing extensions of Berezin-Toeplitz quantization to produce various examples of quantum spaces of relevance to the dynamics of M-branes, such as fuzzy spheres i

Wolfgang Lucha, Dmitri Melikhov, Silvano Simula

We present a sum-rule extraction of the decay constants of the charmed mesons D and D_s from the two-point correlator of pseudoscalar currents. First, we compare the perturbative expansion for the correlator and the decay constant performed in terms of the pole and the running MSbar masses of the charm quark. The perturbative expansion in terms of the pole m

H. V. Beltrao Neto, W. Henkel, V. C. da Rocha

Irregular low-density parity check (LDPC) codes are particularly well-suited for transmission schemes that require unequal error protection (UEP) of the transmitted data due to the different connection degrees of its variable nodes. However, this UEP capability is strongly dependent on the connection profile among the protection classes. This paper applies a

Md. Saifur Rahman, Aaron B. Wagner

We study a hypothesis testing problem in which data is compressed distributively and sent to a detector that seeks to decide between two possible distributions for the data. The aim is to characterize all achievable encoding rates and exponents of the type 2 error probability when the type 1 error probability is at most a fixed value. For related problems in

O. Oliveira, P. J. Silva, P. Bicudo

The calculation of the Landau gauge gluon propagator performed in Coimbra using lattice QCD simulations is reviewed. Particular attention is given to the behavior of the gluon propagator in the infrared region and the value of $D(0)$. In the second part of the article, the modeling of the lattice data using massive type propagators and Gribov type propagator

J. Levinsen, D. S. Petrov

We develop a diagrammatic approach for solving few-body problems in heteronuclear fermionic mixtures near a narrow interspecies Feshbach resonance. We calculate s-, p-, and d-wave phaseshifts for the scattering of an atom by a weakly-bound dimer. The fermionic statistics of atoms and the composite nature of the dimer lead to a strong angular momentum depende