April 2010 arXiv papers — page 50

Joana Terra, Noemi Wolanski

We study the large time behavior of nonnegative solutions of the Cauchy problem $u_t=\int J(x-y)(u(y,t)-u(x,t))\,dy-u^p$, $u(x,0)=u_0(x)\in L^\infty$, where $|x|^αu_0(x)\to A>0$ as $|x|\to\infty$. One of our main goals is the study of the critical case $p=1+2/α$ for $0<α<N$, left open in previous articles, for which we prove that $t^{α/2}|u(x,t)-U(x,t)|\to 0

Israel Perez

From the customary view the Michelson-Morley experiment is used to expose the failure of the aether theory. The key point in this experiment is the \emph{fringe shift} of the interference pattern. Regularly, the fringe shift calculations are only presented from the perspective of the inertial frame where the one-way speed of light is anisotropic which gives

Anton Dochtermann, Alexander Engstrom

Minimal cellular resolutions of the edge ideals of cointerval hypergraphs are constructed. This class of d-uniform hypergraphs coincides with the complements of interval graphs (for the case d=2), and strictly contains the class of `strongly stable&#39; hypergraphs corresponding to pure shifted simplicial complexes. The polyhedral complexes supporting the re

Sergio Ferrara, Renata Kallosh, Andrei Linde, Alessio Marrani

We present a complete explicit N=1, d=4 supergravity action in an arbitrary Jordan frame with non-minimal scalar-curvature coupling of the form $Φ(z, \bar z)\, R$. The action is derived by suitably gauge-fixing the superconformal action. The theory has a modified Kaehler geometry, and it exhibits a significant dependence on the frame function $Φ(z, \bar z)$

R. G. Bower, I. Vernon, M. Goldstein, A. J. Benson

Semi-analytic models are a powerful tool for studying the formation of galaxies. However, these models inevitably involve a significant number of poorly constrained parameters that must be adjusted to provide an acceptable match to the observed universe. In this paper, we set out to quantify the degree to which observational data-sets can constrain the model

Ran Li, Frank Gaitan

Twisted rapid passage is a type of non-adiabatic rapid passage that generates controllable quantum interference effects that were first observed experimentally in 2003. It is shown that twisted rapid passage sweeps can be used to implement a universal set of quantum gates that operate with high-fidelity. The gate set consists of the Hadamard and NOT gates, t

Dmitry Green, Luiz Santos, Claudio Chamon

Dispersionless bands, such as Landau levels, serve as a good starting point for obtaining interesting correlated states when interactions are added. With this motivation in mind, we study a variety of dispersionless (&#34;flat&#34;) band structures that arise in tight-binding Hamiltonians defined on hexagonal and kagome lattices with staggered fluxes. The fl

Emily J. King

Transmitted data may be corrupted by both noise and data loss. Grassmannian frames are in some sense optimal representations of data transmitted over a noisy channel that may lose some of the transmitted coefficients. Fusion frame (or frame of subspaces) theory is a new area that has potential to be applied to problems in such fields as distributed sensing a

Roman V. Shcherbakov, Frederick K. Baganoff

We propose a two-temperature radial inflow-outflow model near Sgr A* with self-consistent feeding and conduction. Stellar winds from individual stars are considered to find the rates of mass injection and energy injection. These source terms help to partially eliminate the boundary conditions on the inflow. Electron thermal conduction is crucial for inhibiti

Stephen Powell, Ryan Barnett, Rajdeep Sensarma, Sankar Das Sarma

Motivated by experimental advances in the synthesis of gauge potentials for ultracold atoms, we consider the superfluid phase of interacting bosons on a square lattice in the presence of a magnetic field. We show that superfluid order implies spatial symmetry breaking, and predict clear signatures of many-body effects in time-of-flight measurements. By devel

Xinyu Dai, Francesco Shankar, Gregory R. Sivakoff

Low-ionization (MgII, FeII, FeIII) broad absorption line quasars (LoBALs) probe a relatively obscured quasar population, and could be at an early evolutionary stage for quasars. We study the intrinsic fractions of LoBALs using the SDSS, 2MASS, and FIRST surveys. We find that the LoBAL fractions of the near infra-red (NIR) and radio samples are approximately

Spencer Chang, Jia Liu, Aaron Pierce, Neal Weiner

Recently, the CoGeNT experiment has reported events in excess of expected background. We analyze dark matter scenarios which can potentially explain this signal. Under the standard case of spin independent scattering with equal couplings to protons and neutrons, we find significant tensions with existing constraints. Consistency with these limits is possible

Ruobing Dong, Yan Wang, D. N. C. Lin, X. -W. Liu

A significant fraction of the mature FGK stars have cool dusty disks at least an orders of magnitudes brighter than the solar system&#39;s outer zodiacal light. Since such dusts must be continually replenished, they are generally assumed to be the collisional fragments of residual planetesimals analogous to the Kuiper Belt objects. At least 10% of solar type

Steen Hannestad, Alessandro Mirizzi, Georg G. Raffelt, Yvonne Y. Y. Wong

We update cosmological hot dark matter constraints on neutrinos and hadronic axions. Our most restrictive limits use 7-year data from the Wilkinson Microwave Anisotropy Probe for the cosmic microwave background anisotropies, the halo power spectrum (HPS) from the 7th data release of the Sloan Digital Sky Survey, and the Hubble constant from Hubble Space Tele

Anjali Tripathi, Joshua N. Winn, John Asher Johnson, Andrew W. Howard

We present new spectroscopic and photometric observations of the transiting exoplanetary system WASP-3. Spectra obtained during two separate transits exhibit the Rossiter-McLaughlin (RM) effect and allow us to estimate the sky-projected angle between the planetary orbital axis and the stellar rotation axis, lambda = 3.3^{+2.5}_{-4.4} degrees. This alignment

Rouven Essig, Jared Kaplan, Philip Schuster, Natalia Toro

TeV-mass dark matter charged under a new GeV-scale gauge force can explain electronic cosmic-ray anomalies. We propose that the CoGeNT and DAMA direct detection experiments are observing scattering of light stable states -- &#34;GeV-Matter&#34; -- that are charged under this force and constitute a small fraction of the dark matter halo. Dark higgsinos in a s

A. R. Draper, D. R. Ballantyne

Previous studies of the active galactic nuclei (AGN) contribution to the cosmic X-ray background (CXB) consider only observable parameters such as luminosity and absorbing column. Here, for the first time, we extend the study of the CXB to physical parameters including the Eddington ratio of the sources and the black hole mass. In order to calculate the cont

Itzhak Bars

Position and momentum enter at the same level of importance in the formulation of classical or quantum mechanics. This is reflected in the invariance of Poisson brackets or quantum commutators under canonical transformations, which I regard as a global symmetry. A gauge symmetry can be defined in phase space (X,P) that imposes equivalence of momentum and pos

Tobias Dyckerhoff, Daniel Murfet

We provide a new perspective on the Kapustin-Li formula for the duality pairing on the morphism complexes in the matrix factorization category of an isolated hypersurface singularity. In our context, the formula arises as an explicit description of a local duality isomorphism, obtained by using the basic perturbation lemma and Grothendieck residues. The non-

Sergey Ivliev

The model is aimed to discriminate the &#39;good&#39; and the &#39;bad&#39; companies in Russian corporate sector based on their financial statements data based on Russian Accounting Standards. The data sample consists of 126 Russian public companies- issuers of Ruble bonds which represent about 36% of total number of corporate bonds issuers. 25 companies ha

Preethi B. Nair, Roberto G. Abraham

We investigate the stellar masses of strongly barred spiral galaxies. Our analysis is based on a sample of ~14000 visually-classified nearby galaxies given in Nair & Abraham 2010(a). The fraction of barred spiral galaxies is found to be a strong function of stellar mass and star formation history, with a minimum near the characteristic mass at which bimodali

I. Talukdar, R. Shrestha, G. S. Summy

We experimentally investigate the sub-Fourier behavior of a $δ$-kicked rotor resonance by performing a measurement of the fidelity or overlap of a Bose-Einstein condensate (BEC) exposed to a periodically pulsed standing wave. The temporal width of the fidelity resonance peak centered at the Talbot time and zero initial momentum exhibits an inverse cube pulse

Samuel E. Gralla, Abraham I. Harte, Robert M. Wald

We study systems analogous to binary black holes with spin in order to gain some insight into the origin and nature of &#34;bobbing&#34; motion and &#34;kicks&#34; that occur in this system. Our basic tool is a general formalism for describing the motion of extended test bodies in an external electromagnetic field in curved spacetime and possibly subject to

Christopher P. Saunders, Linda J. Davis, Andrea C. Lamas, John J. Miller

In this study we illustrate a statistical approach to questioned document examination. Specifically, we consider the construction of three classifiers that predict the writer of a sample document based on categorical data. To evaluate these classifiers, we use a data set with a large number of writers and a small number of writing samples per writer. Since t

Jochen Rau

I show that in tomographic experiments measurement of a small set of observables suffices to confirm or incrementally amend prior expectations with a high degree of confidence. To this end I adapt the evidence procedure, an estimation technique used in classical image reconstruction, to use in quantum state tomography.

Jong Soo Lim, Mircea Crisan, David Sanchez, Rosa Lopez

We consider a flux-threaded Aharonov-Bohm ring with an embedded quantum dot coupled to two normal leads. The local Rashba spin-orbit interaction acting on the dot electrons leads to a spin-dependent phase factor in addition to the Aharonov-Bohm phase caused by the external flux. Using the numerical renormalization group method, we find a splitting of the Kon

Narayan Ganesan, Tzyh-Jong Tarn

In this article, we study the problem of designing a Decoherence Control for quantum systems with the help of a scalable ancillary quantum control and techniques from geometric control theory, in order to successfully and completely decouple an open quantum system from its environment. We re-formulate the problem of decoherence control as a disturbance rejec

Lee Smolin

In deformed or doubly special relativity (DSR) the action of the lorentz group on momentum eigenstates is deformed to preserve a maximal momenta or minimal length, supposed equal to the Planck length. The classical and quantum dynamics of a particle propagating in kappa-Minkowski spacetime is discussed in order to examine an apparent paradox of locality whic

M. Heydari-Malayeri, R. Selier

We present a study of the compact H II region N66A in the SMC pre-eminent starburst region N66/NGC346. Despite extensive research on various components of the N66/NGC346 complex, few studies have so far focused on N66A, which is a special object in the whole complex and therefore deserves scrutiny. The study of this compact H II region and its fellow objects

Julie Déserti, Julien Grivaux

A complex compact surface which carries an automorphism of positive topological entropy has been proved by Cantat to be either a torus, a K3 surface, an Enriques surface or a rational surface. Automorphisms of rational surfaces are quite mysterious and have been recently the object of intensive studies. In this paper, we construct several new examples of aut

Pierre de la Harpe

This paper, in French, is a celebration of Max Dehn, and an essay of describing some of his results published in the beginning of the 1910&#39;s, and their offspring. It has been written up for a winter school in Les Diablerets, March 7-12, 2010: Geometry, topology and computation in groups, 100 years since Dehn&#39;s Decision Problems.

Chiaki Yamaguchi

The conjectured exact percolation thresholds of the Fortuin-Kasteleyn cluster for the +-J Ising spin glass model are theoretically shown based on a conjecture. It is pointed out that the percolation transition of the Fortuin-Kasteleyn cluster for the spin glass model is related to a dynamical transition for the freezing of spins. The present results are obta

Oliver Kullmann

We consider the links between Ramsey theory in the integers, based on van der Waerden&#39;s theorem, and (boolean, CNF) SAT solving. We aim at using the problems from exact Ramsey theory, concerned with computing Ramsey-type numbers, as a rich source of test problems, where especially methods for solving hard problems can be developed. In order to control th

Hans Christian Öttinger

The quantum master equation obtained from two different thermodynamic arguments is seriously nonlinear. We argue that, for quantum systems, nonlinearity occurs naturally in the step from reversible to irreversible equations and we analyze the nature and consequences of the nonlinear contribution. The thermodynamic nonlinearity naturally leads to canonical eq

Danko Radic, Anatoly M. Kadigrobov, Leonid Y. Gorelik, Robert I. Shekhter

We theoretically study electronic transport through a layer of quantum dots connecting two metallic leads. By the inclusion of an inductor in series with the junction, we show that steady electronic transport in such a system may be unstable with respect to temporal oscillations caused by an interplay between the Coulomb blockade of tunneling and spin accumu

Daniel Feldman, Zuowei Liu, Pran Nath, Gregory Peim

Most analyses of dark matter within supersymmetry assume the entire cold dark matter arising only from weakly interacting neutralinos. We study a new class of models consisting of $U(1)^n$ hidden sector extensions of the MSSM that includes several stable particles, both fermionic and bosonic, which can be interpreted as constituents of dark matter. In one su

Chiara Arina, Francois-Xavier Josse-Michaux, Narendra Sahu

In a large class of models we show that the light scalar field responsible for the Sommerfeld enhancement in the annihilation of dark matter leads to observable direct detection rates, due to its mixing with the standard model Higgs. As a result the large annihilation cross-section of dark matter at present epoch, required to explain the observed cosmic ray

Mario Bessa, Cesar Silva

We give a new definition for a Lyapunov exponent (called new Lyapunov exponent) associated to a continuous map. Our first result states that these new exponents coincide with the usual Lyapunov exponents if the map is differentiable. Then, we apply this concept to prove that there exists a C0-dense subset of the set of the area-preserving homeomorphisms defi

Y. Zhou, M. W. Wu

Electron spin relaxation in graphene on a substrate is investigated from the fully microscopic kinetic spin Bloch equation approach. All the relevant scatterings, such as the electron-impurity, electron--acoustic-phonon, electron--optical-phonon, electron--remote-interfacial-phonon, as well as electron-electron Coulomb scatterings, are explicitly included. O

Ryohei Hisano, Takayuki Mizuno

Using the uniform most powerful unbiased test, we observed the sales distribution of consumer electronics in Japan on a daily basis and report that it follows both a lognormal distribution and a power-law distribution and depends on the state of the market. We show that these switches occur quite often. The underlying sales dynamics found between both period

Angel R. Lopez-Sanchez, Cesar Esteban

(Abridged) We performed a multiwavelength analysis of a sample of starburst galaxies that show the presence of a substantial population of very young massive (WR) stars. Here we present the global analysis of the derived photometric and chemical properties. We compare optical/NIR colours and the physical properties (reddening coefficient, equivalent widths o

I. V. Tokatly

It is shown that an electric field applied to p-doped graphane generates a dissipationless orbital momentum Hall current. In the clean limit the corresponding Hall conductivity is independent of the concentration of holes. The Hall effect is related to the $2π$-Berry phase accumulated when heavy and light holes are transported around the degeneracy point in

T. Hikihara, T. Momoi, A. Furusaki, H. Kawamura

We study the one-dimensional spin-1/2 Heisenberg model with antiferromagnetic nearest-neighbor J_1 and next-nearest-neighbor J_2 exchange couplings in magnetic field h. With varying dimensionless parameters J_2/J_1 and h/J_1, the ground state of the model exhibits several phases including three gapped phases (dimer, 1/3-magnetization plateau, and fully polar

Changhyun Ahn, Kyungsung Woo

The M-theory lift of N=2 SU(3) x U(1)_R-invariant RG flow via a combinatorical use of the 4-dimensional flow and 11-dimensional Einstein-Maxwell equations was found previously. By taking the three internal coordinates differently and preserving only SU(3) symmetry from the CP^2 space, we find a new 11-dimensional solution of N=1 SU(3)-invariant RG flow inter

Bartomeu Fiol

We investigate some aspects of a recent proposal for a holographic description of the multiverse. Specifically, we focus on the implications on the suggested duality of the fluctuations of a bubble separating two universes with different cosmological constants. We do so by considering a similar problem in a 2+1 CFT with a codimension one defect, obtained by

Iair Arcavi, Avishay Gal-Yam, Mansi M. Kasliwal, Robert M. Quimby

We use the first compilation of 72 core-collapse supernovae (SNe) from the Palomar Transient Factory (PTF) to study their observed subtype distribution in dwarf galaxies compared to giant galaxies. Our sample is the largest single-survey, untargeted, spectroscopically classified, homogeneous collection of core-collapse events ever assembled, spanning a wide

Bernhard Keller, Sarah Scherotzke

We prove that the frieze sequences of cluster variables associated with the vertices of an affine quiver satisfy linear recurrence relations. In particular, we obtain a proof of a recent conjecture by Assem-Reutenauer-Smith.

Ibrahim Gullu, Tahsin Cagri Sisman, Bayram Tekin

We define various Born-Infeld gravity theories in 3+1 dimensions which reduce to Horava&#39;s model at the quadratic level in small curvature expansion. In their exact forms, our actions provide z->(infinity) extensions of Horava&#39;s gravity, but when small curvature expansion is used, they reproduce finite z models, including some half-integer ones.

Rikizo Ikuta, Toshiyuki Tashima, Takashi Yamamoto, Masato Koashi

We derive the maximum success probability of the circuits with passive linear optics for expanding an N-photon W state to an (N + n)-photon W state, by accessing only one photon of the initial W state and adding n photons in a Fock state. We show that the maximum success probability is achieved by a polarization-dependent beamsplitter and n-1 polarization-in

Noriaki Ikeda, Kyousuke Uchino

A A BV algebra and a QP-structure of degree 3 is formulated. A QP-structure of degree 3 gives rise to Lie algebroids up to homotopy and its algebraic and geometric structure is analyzed. A new algebroid is constructed, which derives a new topological field theory in 4 dimensions by the AKSZ construction.

Daisuke Yamauchi, Yuuiti Sendouda, Chul-Moon Yoo, Keitaro Takahashi

We compute the one-point probability distribution function of small-angle cosmic microwave background temperature fluctuations due to curved cosmic (super-)strings with a simple model of string network by performing Monte Carlo simulations. Taking into account of the correlation between the curvature and the velocity of string segments, there appear non-Gaus

G. E. Volovik

We discuss phenomenology of quantum vacuum. Phenomenology of macroscopic systems has three sources: thermodynamics, topology and symmetry. Thermodynamics of the self-sustained vacuum allows us to treat the problems related to the vacuum energy: the cosmological constant problems. The natural value of the energy density of the equilibrium the self-sustained v

Masahiko Egami, Kazutoshi Yamazaki

Sustaining efficiency and stability by properly controlling the equity to asset ratio is one of the most important and difficult challenges in bank management. Due to unexpected and abrupt decline of asset values, a bank must closely monitor its net worth as well as market conditions, and one of its important concerns is when to raise more capital so as not

M. R. Setare, D. Momeni

If the uncertainty principle applies to the Verlinde entropic idea, it leads to a new term in the Newton&#39;s second law of mechanics in the Planck&#39;s scale. This curious velocity dependence term inspires a frictional feature of the gravity. In this short letter we address that this new term modifies the effective mass and the Newtonian constant as the t

Hajime Yoshino, Tomoaki Nogawa, Bongsoo Kim

A vortex solid with self-generated randomness is found theoretically in a frustrated Josephson junction array (JJA) under external magnetic field with anisotropic couplings. Vorticies induced by external magnetic field develop stripes parallel to the direction of weaker coupling. It is shown analytically that there is a continuous, gapless band of metastable

Frédéric Campana, Vincent Koziarz, Mihai Paun

In this note we show that given a lc pair $(X, Δ)$, a large enough multiple of the bundle $K_X+ Δ$ is effective provided that its Chern class contains an effective $\bQ$-divisor.

Thorranin Thansri

For a pair $(H_1,H_2)$ of graphs, Lovász introduced a polytopal complex called the Hom complex $\text{Hom}(H_1,H_2)$, in order to estimate topological lower bounds for chromatic numbers of graphs. The definition is generalized to hypergraphs. Denoted by $K_r^r$ the complete $r$-graph on $r$ vertices. Given an $r$-graph $H$, we compare $\text{Hom}(K_r^r,H)$ w

Shigeru Furuichi

In this paper, we show that the $ν$-weighted arithmetic mean is greater than the product of the $ν$-weighted geometric mean and Specht&#39;s ratio. As a corollary, we also show that the $ν$-weighted geometric mean is greater than the product of the $ν$-weighted harmonic mean and Specht&#39;s ratio. These results give the improvements for the classical Young

Yoshio Koide

Stimulated by a recent work by Sumino, on the basis of a model in which effective Yukawa coupling constants are described by vacuum expectation values of a scalar $Φ$ with $3\times 3$ components, a possible form of the scalar potential $V(Φ)$ which can well describe the observed charged lepton mass spectrum is investigated without referring to a specific fla

Clément de Seguins Pazzis

Let V be a linear subspace of M_{n,p}(K) with codimension lesser than n, where K is an arbitrary field and n >=p. In a recent work of the author, it was proven that V is always spanned by its rank p matrices unless n=p=2 and K is isomorphic to F_2. Here, we give a sufficient condition on codim V for V to be spanned by its rank r matrices for a given r betwee

Uri Jacob, Flavio Mercati, Giovanni Amelino-Camelia, Tsvi Piran

We investigate the implications of energy-dependence of the speed of photons, one of the candidate effects of quantum-gravity theories that has been most studied recently, from the perspective of observations in different reference frames. We examine how a simultaneous burst of photons would be measured by two observers with a relative velocity, establishing

Sergei I. Doronin, Anna V. Fedorova, Edward B. Fel&#39;dman, Alexander I. Zenchuk

This paper is devoted to the multiple-quantum (MQ) NMR spectroscopy in nanopores filled by a gas of spin-carrying molecules (s=1/2) in a strong external magnetic field. It turned out that the high symmetry of the spin system in nanopores yields a possibility to overcome the problem of the exponential growth of the Hilbert space dimension with an increase in

Kevin K. Lin, Lai-Sang Young

We review some recent results surrounding a general mechanism for producing chaotic behavior in periodically-kicked oscillators. The key geometric ideas are illustrated via a simple linear shear model.

John Augustine, Sandip Das, Anil Maheshwari, Subhas Nandy

We study new types of geometric query problems defined as follows: given a geometric set $P$, preprocess it such that given a query point $q$, the location of the largest circle that does not contain any member of $P$, but contains $q$ can be reported efficiently. The geometric sets we consider for $P$ are boundaries of convex and simple polygons, and point

Satish Babu Korada, Andrea Montanari

We use a generalization of the Lindeberg principle developed by Sourav Chatterjee to prove universality properties for various problems in communications, statistical learning and random matrix theory. We also show that these systems can be viewed as the limiting case of a properly defined sparse system. The latter result is useful when the sparse systems ar

Ricky Fok, Graham D. Kribs

We demonstrate that mu/e slepton mixing is significantly more restricted than previously thought within the already remarkably flavor-safe R-symmetric supersymmetric standard model. We calculate bounds from mu to e gamma, mu to 3e and, most importantly, mu to e conversion. The process mu to e conversion is significantly more restrictive in R-symmetric models

Finny Oktariani, Atsuo T. Okazaki, Shoji Kato

In order to study the origin of high-frequency quasi-periodic oscillations observed in X-ray binaries, Kato (2004) suggested a resonant excitation mechanism of disk oscillations in deformed disks. In this paper, we study numerically, following his formulation, whether trapped g-mode oscillations in a warped disk, where the warp amplitude varies with radius,

Jinshu Huang, Gongru Lu, Wei Xu, Shuaiwei Wang

We have studied the associated production processes of a neutral top-Higgs in the topcolor assisted technicolor model with a pair of heavy quarks in γγcollisions at the International Linear Collider (ILC). We find that the cross section for t\bar{t}h_t in γγcollisions is at the level of a few fb with the c.m. energy \sqrt{s}=1000 GeV, which is consistent wit

M. Chen, Z. Shi, S. M. Zhou, J. Li

For L1(0) FePt films, the anomalous Hall resistivity is found to be proportional to spontaneous magnetization $M_{\mathrm{S}}$. After the $M_{\mathrm{S}}$ temperature effect is eliminated, $ρ_{\mathrm{xyo}}$ can be fitted by $ρ_{\mathrm{xyo}}=a_{\mathrm{o}}ρ_{\mathrm{xx}}+ b_{\mathrm{o}}ρ_{\mathrm{xx}}^{\mathrm{2}}$. $a_{\mathrm{o}}$ and $b_{\mathrm{o}}$ cha

Satoru Odake, Ryu Sasaki

An alternative derivation is presented of the infinitely many exceptional Wilson and Askey-Wilson polynomials, which were introduced by the present authors in 2009. Darboux-Crum transformations intertwining the discrete quantum mechanical systems of the original and the exceptional polynomials play an important role. Infinitely many continuous Hahn polynomia

L. I. Petrova

Skew-symmetric forms possess unique capabilities. The properties of closed exterior and dual forms, namely, invariance, covariance, conjugacy and duality, either explicitly or implicitly appear in all invariant mathematical formalisms. This enables one to see an internal connection between various branches of mathematics. However, the theory of closed exteri

W. Zima, T. Arentoft, J. De Ridder, S. Salmon

The PLATO satellite mission project is a next generation ESA Cosmic Vision satellite project dedicated to the detection of exo-planets and to asteroseismology of their host-stars using ultra-high precision photometry. The main goal of the PLATO mission is to provide a full statistical analysis of exo-planetary systems around stars that are bright and close e

Efrain J. Ferrer

In this talk I will discuss how the in-medium magnetic field can influence the gluon dynamics in a three-flavor color superconductor. It will be shown how at field strengths comparable to the charged gluon Meissner mass a new phase can be realized, giving rise to Abrikosov&#39;s vortices of charged gluons. In that phase, the inhomogeneous gluon condensate an

Alexandra Shlapentokh, Xavier Vidaux

Büchi&#39;s $n$ Squares Problem asks for an integer $M$ such that any sequence $(x_0,...,x_{M-1})$, whose second difference of squares is the constant sequence $(2)$ (i.e. $x^2_n-2x^2_{n-1}+x_{n-2}^2=2$ for all $n$), satisfies $x_n^2=(x+n)^2$ for some integer $x$. Hensley&#39;s problem for $r$-th powers (where $r$ is an integer $\geq2$) is a generalization o

Sudip Chakravarty

Extensive body of work has shown that for the model of a non-interacting electron in a random potential there is a quantum critical point for dimensions greater than two---a metal-insulator transition. This model also plays an important role in the plateau-to-plateu transition in the integer quantum Hall effect, which is also correctly captured by a scaling

A. Tsiatmas, R. Buckingham, V. A. Fedotov, S. Wang

Negative dielectric constant and dominant kinetic resistance make superconductors an intriguing plasmonic media. Here we report on the first study of one of the most important and disputed manifestations of plasmonics, the effect of extraordinary transmission through an array of sub-wavelength holes, using a perforated film of high-temperature superconductor

Ilango Sriram, Dave Cliff

Modern large-scale date centres, such as those used for cloud computing service provision, are becoming ever-larger as the operators of those data centres seek to maximise the benefits from economies of scale. With these increases in size comes a growth in system complexity, which is usually problematic. There is an increased desire for automated &#34;self-s

Anthony Kim, Muriel Medard

We study matroidal networks introduced by Dougherty et al. We prove the converse of the following theorem: If a network is scalar-linearly solvable over some finite field, then the network is a matroidal network associated with a representable matroid over a finite field. It follows that a network is scalar-linearly solvable if and only if the network is a m

C. A. Giuppone, C. Beaugé, T. A. Michtchenko, S. Ferraz-Mello

We study the stability regions and families of periodic orbits of two planets locked in a co-orbital configuration. We consider different ratios of planetary masses and orbital eccentricities, also we assume that both planets share the same orbital plane. Initially we perform numerical simulations over a grid of osculating initial conditions to map the regio

Brian Reville, John G. Kirk

(abbrev.) Linear acceleration emission occurs when a charged particle is accelerated parallel to its velocity. We evaluate the spectral and angular distribution of this radiation for several special cases, including constant acceleration (hyperbolic motion) of finite duration. Based on these results, we find the following general properties of the emission f

Orr Shalit

This note records some dilation theorems about contraction semigroups on a Hilbert space - all of which fall into the categories &#34;known&#34; or &#34;probably known&#34; - that I proved while working on my PhD in mathematics (under the supervision of Baruch Solel). It is convenient to have them recorded for reference.

B. Coutinho dos Santos, C. Tsallis

We consider a class of single-particle one-dimensional stochastic equations which include external field, additive and multiplicative noises. We use a parameter $θ\in [0,1]$ which enables the unification of the traditional Itô and Stratonovich approaches, now recovered respectively as the $θ=0$ and $θ=1/2$ particular cases to derive the associated Fokker-Pla

Jeongsu Lee, William Falls, Rafal Oszwaldowski, Igor Zutic

We provide an analytic study of the dynamics of semiconductor lasers with injection (pump) of spin-polarized electrons, previously considered in the steady-state regime. Using complementary approaches of quasi-static and small signal analyses, we elucidate how the spin modulation in semiconductor lasers can improve performance, as compared to the conventiona

J. Ambjorn, R. Loll, W. Westra, S. Zohren

In this short note we review a recently found formulation of two-dimensional causal quantum gravity defined through Causal Dynamical Triangulations and stochastic quantization. This procedure enables one to extract the nonperturbative quantum Hamiltonian of the random surface model including the sum over topologies. Interestingly, the generally fictitious st

Igor Shparlinski

We estimate the deviation of the number of solutions of the congruence $$ m^2-n^2 \equiv c \pmod q, \qquad 1 \le m \le M, \ 1\le n \le N, $$ from its expected value on average over $c=1, ..., q$. This estimate is motivated by the recently established by D. R. Heath-Brown connection between the distibution of solution to this congruence and the pair correlati

Darrell E. Haile, Ilseop Han, Adrian R. Wadsworth

Let k be a field with char(k) not 2 or 3. Let C_f be the projective curve of a binary cubic form f, and k(C_f) the function field of C_f. In this paper we explicitly describe the relative Brauer group Br(k(C_f)/k) of k(C_f) over k. When f is diagonalizable we show that every algebra in Br(k(C_f)/k) is a cyclic algebra obtainable using the y-coordinate of a k

W. de Paula, T. Frederico

We show that a Dynamical AdS/QCD model is able to reproduce the linear Regge trajectories for the light-flavor sector of mesons with high spin and also for the scalar and pseudoscalar ones. In addition the model has confinement by the Wilson loop criteria and a mass gap. We also calculate the decay amplitude of scalars into two pion in good agreement to the

L. Gan, A. Gasparian, S. Gevorkyan, R. Miskimen

In a recent article by Rodrigues et al. [1] eta photo-nuclear data taken by Browman et al. [2] in 1974 were refit as a means to extract the eta->gamma gamma decay width. The key assertion in the author&#39;s analysis is attributing backgrounds in the eta angular distribution to nuclear incoherent production only. We disagree with this assertion and question

Luca Giomi, Mark Bowick

The interplay between order and geometry in soft condensed matter systems is an active field with many striking results and even more open problems. Ordered structures on curved surfaces appear in multi-electron helium bubbles, viral and bacteriophage protein capsids, colloidal self-assembly at interfaces and in physical membranes. Spatial curvature can lead

Hsiao-Wen Chen, Jennifer E. Helsby, Jean-Rene Gauthier, Stephen A. Shectman

We report results from a survey of MgII absorbers in the spectra of background QSOs that are within close angular distances to a foreground galaxy at z<0.5, using the Magellan Echellette Spectrograph. We have established a spectroscopic sample of 94 galaxies at a median redshift of <z> = 0.24 in fields around 70 distant background QSOs (z_QSO>0.6), 71 of whi

Nicholas P. Butch, M. Brian Maple

Substitution of Re for Ru in the heavy fermion compound URu2Si2 suppresses the hidden order transition and gives rise to ferromagnetism at higher concentrations. The hidden order transition of URu(2-x)Re(x)Si2, tracked via specific heat and electrical resistivity measurements, decreases in temperature and broadens, and is no longer observed for x>0.1. A crit

Heng-Yu Chen, Nick Dorey, Kirill Petunin

We calculate the leading weak-coupling instanton contribution to the moduli-space metric of N=2 supersymmetric Yang-Mills theory with gauge group SU(2) compactified on R^3 x S^1. The results are in precise agreement with the semiclassical expansion of the exact metric recently conjectured by Gaiotto, Moore and Neitzke based on considerations related to wall-

Karun Thanjavur, David Crampton, Jon Willis

Using a combined analysis of strong lensing and galaxy dynamics, we characterize the mass distributions and M/L ratios of galaxy groups, which form an important transition regime in Lambda-CDM cosmology. By mapping the underlying mass distribution, we test whether groups are dark matter dominated as hypothesized by the standard cosmogony, or isothermal as ob

Jaime de la Cruz Rodríguez, Hector Socas-Navarro, Michiel van Noort, Luc Rouppe van der Voort

The solar chromosphere is a vigorously dynamic region of the sun, where waves and magnetic fields play an important role. To improve chromospheric diagnostics, we present new observations in Ca II 8542 carried out with the SST/CRISP on La Palma, working in full-Stokes mode. We measured Stokes line profiles in active regions. The line profiles observed close

Julia M. Comerford, Leonidas A. Moustakas, Priyamvada Natarajan

Scaling relations of observed galaxy cluster properties are useful tools for constraining cosmological parameters as well as cluster formation histories. One of the key cosmological parameters, sigma8, is constrained using observed clusters of galaxies, although current estimates of sigma8 from the scaling relations of dynamically relaxed galaxy clusters are

Zvi Bern, Tristan Dennen, Yu-tin Huang, Michael Kiermaier

We explore consequences of the recently discovered duality between color and kinematics, which states that kinematic numerators in a diagrammatic expansion of gauge-theory amplitudes can be arranged to satisfy Jacobi-like identities in one-to-one correspondence to the associated color factors. Using on-shell recursion relations, we give a field-theory proof

M. Rheinhardt, A. Brandenburg

Aims: The test-field method for computing turbulent transport coefficients from simulations of hydromagnetic flows is extended to the regime with a magnetohydrodynamic (MHD) background. Methods: A generalized set of test equations is derived using both the induction equation and a modified momentum equation. By employing an additional set of auxiliary equati

Péter E. Frenkel, Mihály Weiner

Let $v_1$,..., $v_n$ be $n$ vectors in an inner product space. Can we find a natural number $d$ and positive (semidefinite) complex matrices $A_1$,..., $A_n$ of size $d \times d$ such that ${\rm Tr}(A_kA_l)= <v_k, v_l>$ for all $k,l=1,..., n$? For such matrices to exist, one must have $<v_k, v_l> \geq 0$ for all $k,l=1,..., n$. We prove that if $n<5$ then th

Jean-Claude Juhel

The effect of leverage on liquidity is a tool for analysing the level of liquidity for a given production process. It measures the sensitivity of the level of liquidity that results from changes in the volume of production and unit operating margin. A commercial activity is liquid at the moment when all costs are covered by revenues. However, not all of the

M. Paramasivam, S. Valarmathi, J. J. H. Miller

A singularly perturbed linear system of second order ordinary differential equations of reaction-diffusion type with given boundary conditions is considered. The leading term of each equation is multiplied by a small positive parameter. These singular perturbation parameters are assumed to be distinct. The components of the solution exhibit overlapping layer