April 2010 arXiv papers — page 38

Ameet Talwalkar, Afshin Rostamizadeh

The Nystrom method is an efficient technique to speed up large-scale learning applications by generating low-rank approximations. Crucial to the performance of this technique is the assumption that a matrix can be well approximated by working exclusively with a subset of its columns. In this work we relate this assumption to the concept of matrix coherence a

V. Ksenofontov, G. Wortmann, A. I. Chumakov, T. Gasi

The temperature and pressure dependence of the partial density of phonon states of iron atoms in superconducting Fe1.01Se was studied by 57Fe nuclear inelastic scattering (NIS). The high energy resolution allows for a detailed observation of spectral properties. A sharpening of the optical phonon modes and shift of all spectral features towards higher energi

Beixiang Fang, Li Liu, Hairong Yuan

We prove that for the two-dimensional steady complete compressible Euler system, with given uniform upcoming supersonic flows, the following three fundamental flow patterns (special solutions) in gas dynamics involving transonic shocks are all unique in the class of piecewise $C^1$ smooth functions, under appropriate conditions on the downstream subsonic flo

S. De Santis, A. Gabrielli, M. Bozzali, B. Maraviglia

A new method to investigate anomalous diffusion in human brain is proposed. The method has been inspired by both the stretched-exponential model proposed by Hall and Barrick (HB) and DTI. Quantities extracted using HB method were able to discriminate different cerebral tissues on the basis of their complexity, expressed by the stretching exponent gamma and o

Van Vu

Computing the first few singular vectors of a large matrix is a problem that frequently comes up in statistics and numerical analysis. Given the presence of noise, exact calculation is hard to achieve, and the following problem is of importance: \vskip2mm \centerline {\it How much a small perturbation to the matrix changes the singular vectors ?} \vskip2mm A

Daohang Sha, Vladimir B. Bajic

Back-propagation with gradient method is the most popular learning algorithm for feed-forward neural networks. However, it is critical to determine a proper fixed learning rate for the algorithm. In this paper, an optimized recursive algorithm is presented for online learning based on matrix operation and optimization methods analytically, which can avoid th

Magdalena Boos, Markus Reineke

The orbits of the group B of upper-triangular matrices acting on 2-nilpotent complex matrices via conjugation are classified via oriented link patterns, generalizing A. Melnikov's classification of the B-orbits on upper-triangular such matrices. The orbit closures as well as the "building blocks" of minimal degenerations of orbits are described.

Bernhard Mieck

A coherent state path integral of anti-commuting fields is considered for a two-band, semiconductor-related solid which is driven by a ultrashort, classical laser field. We describe the generation of exciton quasi-particles from the driving laser field as anomalous pairings of the fundamental, fermionic fields. This gives rise to Hubbard-Stratonovich transfo

B. Enoch, A. Collier Cameron, N. R. Parley, L. Hebb

To determine the physical parameters of a transiting planet and its host star from photometric and spectroscopic analysis, it is essential to independently measure the stellar mass. This is often achieved by the use of evolutionary tracks and isochrones, but the mass result is only as reliable as the models used. The recent paper by Torres et al (2009) showe

Antonio Arico', Giuseppe Rodriguez

We describe a fast solver for linear systems with reconstructable Cauchy-like structure, which requires O(rn^2) floating point operations and O(rn) memory locations, where n is the size of the matrix and r its displacement rank. The solver is based on the application of the generalized Schur algorithm to a suitable augmented matrix, under some assumptions on

L. M. Camacho, J. R. Gómez, B. A. Omirov, R. M. Turdibaev

The paper is devoted to the study of finite dimensional complex evolution algebras. The class of evolution algebras isomorphic to evolution algebras with Jordan form matrices is described. For finite dimensional complex evolution algebras the criteria of nilpotency is established in terms of the properties of corresponding matrices. Moreover, it is proved th

C M Rohwer, K G Zloshchastiev, L Gouba, F G Scholtz

We explore the notion of spatial extent and structure, already alluded to in earlier literature, within the formulation of quantum mechanics on the noncommutative plane. Introducing the notion of average position and its measurement, we find two equivalent pictures: a constrained local description in position containing additional degrees of freedom, and an

Pavel Exner, Jiri Lipovsky

The subject of the paper are Schrödinger operators on tree graphs which are radial having the branching number $b_n$ at all the vertices at the distance $t_n$ from the root. We consider a family of coupling conditions at the vertices characterized by $(b_n-1)^2+4$ real parameters. We prove that if the graph is sparse so that there is a subsequence of $\{t_{n

Hansjörg Geiges, Jesús Gonzalo

Generalised spin structures, or r-spin structures, on a 2-dimensional orbifold Σare r-fold fibrewise connected coverings (also called r-th roots) of its unit tangent bundle STΣ. We investigate such structures on hyperbolic orbifolds. The conditions on r for such structures to exist are given. The action of the diffeomorphism group of Σon the set of r-spin st

M. Tropeano, M. R. Cimberle, C. Ferdeghini, G. Lamura

In this work we present a systematic experimental and theoretical study of the structural, transport and superconducting properties of Sm(Fe1-xRux)As(O0.85F0.15) polycrystalline samples as a function of Ru content (x) ranging from 0 to 1. The choice of Ru as isoelectronic substitution at Fe site of F-doped compounds allows to better clarify the role of struc

A. Grigahcene, A. Moya, J. -C. Suarez, S. Martin-Ruiz

The present work performs an asteroseismic study of a gamma Doradus star member of the open cluster NGC 2506. This work conjugates the observational information of the star and the strong constraints imposed by the cluster membership, with the latest developed theoretical asteroseismic tools for the modelling of this type of objects, in particular the Freque

Armand Niederberger, Marek M. Rams, Jacek Dziarmaga, Fernando M. Cucchietti

We observe signatures of disorder-induced order in 1D XY spin chains with an external, site-dependent uni-axial random field within the XY plane. We numerically investigate signatures of a quantum phase transition at T=0, in particular an upsurge of the magnetization in the direction orthogonal to the external magnetic field, and the scaling of the block-ent

S. W. Ham, Seong-A Shim, C. M. Kim, S. K. Oh

We study the Higgs sector of the minimal supersymmetric standard model extended with vector-like quarks, at the one-loop level. The radiative corrections to the tree-level masses of the scalar Higgs bosons are calculated by including the contributions from the loops of top quark, vector-like quarks, and their scalar superpartners, for a reasonable parameter

Willem A. de Graaf

Algorithms are described that help with obtaining a classification of the semisimple subalgebras of a given semisimple Lie algebra, up to linear equivalence. The algorithms have been used to obtain classifications of the semisimple subalgebras of the simple Lie algebras of ranks <= 8. These have been made available as a database inside the SLA package of GAP

Yuhei Takagi, Yoichi Itoh, Yumiko Oasa

We present a new method for determining the age of late-K type pre-main sequence (PMS) stars by deriving their surface gravity from high-resolution I-band spectroscopy. Since PMS stars contract as they evolve, age can be estimated from surface gravity. We used the equivalent width ratio (EWR) of nearby absorption lines to create a surface gravity diagnostic

Péter Dusán Ispánovity, István Groma, Géza Györgyi, Ferenc F. Csikor

The existence of a well defined yield stress, where a macroscopic piece of crystal begins to plastically flow, has been one of the basic observations of materials science. In contrast to macroscopic samples, in micro- and nanocrystals the strain accumulates in distinct, unpredictable bursts, which makes controlled plastic forming rather difficult. Here we st

M. D. Lumsden, A. D. Christianson

In this review, we present a summary of experimental studies of magnetism in Fe-based superconductors. The doping dependent phase diagram shows strong similarities to the generic phase diagram of the cuprates. Parent compounds exhibit magnetic order together with a structural phase transition both of which are progressively suppressed with doping allowing su

K. Smolders, B. Acke, T. Verhoelst, J. A. D. L. Blommaert

Polycyclic aromatic hydrocarbons (PAHs) produce characteristic infrared emission bands that have been observed in a wide range of astrophysical environments, where carbonaceous material is subjected to ultraviolet (UV) radiation. Although PAHs are expected to form in carbon-rich AGB stars, they have up to now only been observed in binary systems where a hot

Bojan Nikolic, Branislav Sazdovic

We consider type IIB superstring theory with embedded $D5$-brane and choose boundary conditions which preserve half of the initial supersymmetry. In the canonical approach that we use, boundary conditions are treated as canonical constraints. The effective theory, obtained from the initial one on the solution of boundary conditions, has the form of the type

S. Messina, S. Desidera, M. Turatto, A. C. Lanzafame

Our goal is to determine the rotational and magnetic-related activity properties of stars at different stages of evolution. We have focussed our attention on 6 young loose stellar associations within 100 pc and ages in the range 8-70 Myr: TW Hydrae (~8 Myr), beta Pictoris (~10 Myr), Tucana/Horologium, Columba, Carina (~30 Myr), and AB Doradus (~70 Myr). Addi

Daniel Valesin

We consider a two-type contact process on $\Z$ in which both types have equal finite range and supercritical infection rate. We show that a given type becomes extinct with probability 1 if and only if, in the initial configuration, it is confined to a finite interval $[-L,L]$ and the other type occupies infinitely many sites both in $(-\infty, L)$ and $(L, \

Veronika Junk, Stefanie Walch, Fabian Heitsch, Andreas Burkert

Given the importance of shear flows for astrophysical gas dynamics, we study the evolution of the Kelvin-Helmholtz instability (KHI) analytically and numerically. We derive the dispersion relation for the two-dimensional KHI including viscous dissipation. The resulting expression for the growth rate is then used to estimate the intrinsic viscosity of four nu

Alexander Szameit, Felix Dreisow, Matthias Heinrich, Robert Keil

We report on the experimental realization of an optical analogue of a quantum geometric potential for light wave packets constrained on thin dielectric guiding layers fabricated in silica by the femtosecond laser writing technology. We further demonstrate the optical version of a topological crystal, with the observation of Bloch oscillations and Zener tunne

Udayan B. Darji, Steve W. Seif

A regular language L is said to be cellular if there exists a 1-dimensional cellular automaton CA such that L is the language consisting of the finite blocks associated with CA. It is shown that cellularity of a regular language is decidable using a new characterization of cellular languages formulated by Freiling, Goldstein and Moews and implied by a deep r

Lilia Boeri, Matteo Calandra, Igor I. Mazin, Oleg V. Dolgov

We calculate the effect of local magnetic moments on the electron-phonon coupling in BaFe$_{2}$As$_{2}+δ$ using the density functional perturbation theory. We show that the magnetism enhances the total electron-phonon coupling by $\sim 50%$, up to $λ\lesssim 0.35$, still not enough to explain the high critical temperature, but strong enough to have a non-neg

A. J. Berrick, I. Chatterji And G. Mislin

We prove that the Bost Conjecture on the $\ell^1$-assembly map for countable discrete groups implies the Bass Conjecture. It follows that all amenable groups satisfy the Bass Conjecture.

Michel Gros, Masaharu Kaneda

Let G be a simply connected semisimple algebraic group over an algebraically closed field k of positive characteristic. We will untwist the structure of G-modules by a newly found splitting of the Frobenius endomorphism on the algebra of distributions of G, which, for example, explains the subsumed G-equivariant nature of the Frobenius splitting of the flag

L. M. Camacho, J. R. Gómez, B. A. Omirov, R. M. Turdibaev

In this work we investigate the derivations of $n-$dimensional complex evolution algebras, depending on the rank of the appropriate matrices. For evolution algebra with non-singular matrices we prove that the space of derivations is zero. The spaces of derivations for evolution algebras with matrices of rank $n-1$ are described.

Sriram Ramaswamy

Active particles contain internal degrees of freedom with the ability to take in and dissipate energy and, in the process, execute systematic movement. Examples include all living organisms and their motile constituents such as molecular motors. This article reviews recent progress in applying the principles of nonequilibrium statistical mechanics and hydrod

Victor Putz, Jorn Dunkel, Julia M. Yeomans

We describe and analyze CUDA simulations of hydrodynamic interactions in active dumbbell suspensions. GPU-based parallel computing enables us not only to study the time-resolved collective dynamics of up to a several hundred active dumbbell swimmers but also to test the accuracy of effective time-averaged models. Our numerical results suggest that the stroke

Tom G. Mackay, Akhlesh Lakhtakia

Biomimetic nanoengineered metamaterials called chiral sculptured thin films (CSTFs) are attractive platforms for optical sensing because their porosity, morphology and optical properties can be tailored to order. Furthermore, their ability to support more than one surface-plasmon-polariton (SPP) wave at a planar interface with a metal offers functionality be

Neelesh Sharma, R. C. Verma

In this paper, we investigate phenomenologically two-body weak decays of the bottom mesons emitting pseudoscalar and tensor mesons. Decay amplitudes are obtained using the factorization scheme in the improved ISGW II model. Branching ratios for the CKM-favored and CKM-suppressed decays are calculated.

Moumita Das, Subhendra Mohanty

We study the generation of magnetic field in Higgs-inflation models where the Standard Model Higgs boson has a large coupling to the Ricci scalar. We couple the Higgs field to the Electromagnetic fields via a non- renormalizable dimension six operator suppressed by the Planck scale in the Jordan frame. We show that during Higgs inflation magnetic fields with

V. Koerting, P. Fritsch, S. Kehrein

Since the experimental realization of Kondo physics in quantum dots, its far-from-equilibrium properties have generated considerable theoretical interest. This is due to the interesting interplay of non-equilibrium physics and correlation effects in this model, which has by now been analyzed using several new theoretical methods that generalize renormalizati

Tiago P. Peixoto, Katharina Doblhoff-Dier, Jörn Davidsen

Aftershock sequences are of particular interest in seismic research since they may condition seismic activity in a given region over long time spans. While they are typically identified with periods of enhanced seismic activity after a large earthquake as characterized by the Omori law, our knowledge of the spatiotemporal correlations between events in an af

Jonathan R. Gair, Christopher Tang, Marta Volonteri

One of the sources of gravitational waves for the proposed space-based gravitational wave detector, the Laser Interferometer Space Antenna (LISA), are the inspirals of compact objects into supermassive black holes in the centres of galaxies - extreme-mass-ratio inspirals (EMRIs). Using LISA observations, we will be able to measure the parameters of each EMRI

K. V. Storozhuk

Let T be a C_0-semigroup on X with generator A. We prove that if the abscissa of uniform boundedness of the resolvent A is non-negative then for each a non-decreasing function h:[0,\infty] -> [0,\infty], there are x&#39; in X&#39; and x in X such that integral from 0 to \infty of h(|< x&#39;,T(t)x)>| is equal to \infty. If Sp(A) contained a number from iR th

Kaifu Luo, Ralf Metzler

Using Langevin dynamics simulations in three dimensions (3D), we investigate the dynamics of polymer translocation into the regions between two parallel plane walls with separation $R$ under a driving force $F$, respectively. Compared with an unconfined environment, the translocation dynamics is greatly changed due to the crowding effect of the partially tra

L. Decin, E. De Beck, S. Brunken, H. S. P. Muller

Aims: Little information exists on the circumstellar molecular abundance stratifications of many molecules. The aim is to study the circumstellar chemical abundance pattern of 11 molecules and isotopologs ($^{12}$CO, $^{13}$CO, SiS, $^{28}$SiO, $^{29}$SiO, $^{30}$SiO, HCN, CN, CS, SO, SO$_2$) in the oxygen-rich evolved star IK~Tau. Methods: We have performed

J. P. Fernandez-Garcia, M. Rodriguez-Gallardo, M. A. G. Alvarez, A. M. Moro

We present an optical model (OM) analysis of the elastic scattering data of the reactions 6He+27Al and 6He+208Pb at incident energies around the Coulomb barrier. The bare part of the optical potential is constructed microscopically by means of a double folding procedure, using the Sao Paulo prescription without any renormalization. This bare interaction is s

Antonio Capella, Juan Dávila, Louis Dupaigne, Yannick Sire

We investigate stable solutions of elliptic equations of the type \begin{equation*} \left \{ \begin{aligned} (-Δ)^s u&=λf(u) \qquad {\mbox{ in $B_1 \subset \R^{n}$}} \\ u&= 0 \qquad{\mbox{ on $\partial B_1$,}}\end{aligned}\right . \end{equation*} where $n\ge2$, $s \in (0,1)$, $λ\geq 0$ and $f$ is any smooth positive superlinear function. The operator $(-Δ)^s

J. V. Clausen, S. Frandsen, H. Bruntt, E. H. Olsen

We present a detailed study of the F-type detached eclipsing binary BK Peg, based on new photometric and spectroscopic observations. The two components, which have evolved to the upper half of the main-sequence band, are quite different with masses and radii of (1.414 +/- 0.007 Msun, 1.988 +/- 0.008 Rsun) and (1.257 +/- 0.005 Msun, 1.474 +/- 0.017 Rsun), res

V. Wakelam, E. Herbst, J. Le Bourlot, F. Hersant

Because of new telescopes that will dramatically improve our knowledge of the interstellar medium, chemical models will have to be used to simulate the chemistry of many regions with diverse properties. To make these models more robust, it is important to understand their sensitivity to a variety of parameters. In this article, we report a study of the sensi

Frederic Bourdarot, Elena Hassinger, Stephane Raymond, Dai Aoki

New inelastic neutron scattering experiments have been performed on URu2Si2 with special focus on the response at Q0=(1,0,0), which is a clear signature of the hidden order (HO) phase of the compound. With polarized inelastic neutron experiments, it is clearly shown that below the HO temperature (T0 = 17.8 K) a collective excitation (the magnetic resonance a

G. Q. Huang, Z. W. Xing, D. Y. Xing

The lattice dynamics and the effect of pressure on superconducting LiFeAs in both nonmagnetic (NM) and striped antiferromagnetic (SAF) phases are investigated using the plane-wave pseudopotential, density-functional-based method. While the obtained electron-phonon coupling $λ$ is very small for the NM calculation, the softening of phonon in the SAF phase may

L. Ducci, L. Sidoli, A. Paizis, S. Mereghetti

Supergiant Fast X-ray Transients (SFXTs) are a new class of High Mass X-ray Binaries, discovered by the INTEGRAL satellite, which display flares lasting from minutes to hours, with peak luminosity of 1E36-1E37 erg/s. Outside the bright outbursts, they show a frequent long-term flaring activity reaching an X-ray luminosity level of 1E33-1E34 erg/s, as recentl

L. Chirolli, E. Strambini, V. Giovannetti, F. Taddei

Three different implementations of interaction-free measurements (IFMs) in solid-state nanodevices are discussed. The first one is based on a series of concatenated Mach-Zehnder interferometers, in analogy to optical-IFM setups. The second one consists of a single interferometer and concatenation is achieved in the time domain making use of a quantized elect

Yu. D. Fomin V. N. Ryzhov

We analyze the applicability of the Rosenfeld entropy scaling relations to the systems with the core-softened potentials demonstrating the water-like anomalies. It is shown that the validity of the of Rosenfeld scaling relation for the diffusion coefficient depends on the thermodynamic path which is used for the calculations of the kinetic coefficients and t

Hiromi Kashiwaya, Tetsuro Matsumoto, Hajime Shibata, Hiroshi Eisaki

We study the dynamics of multi-junction switching (MJS): several intrinsic Josephson junctions (IJJs) in an array switch to the finite voltage state simultaneously. The number of multi-switching junctions ($N$) was successfully tuned by changing the load resistance serially connected to an Bi$_2$Sr$_{1.6}$La$_{0.4}$CuO$_{6+δ}$ IJJ array. The independence of

O. Chaix-Pluchery, D. Sauer, J. Kreisel

We report a temperature-dependent Raman scattering investigation of DyScO3 and GdScO3 single crystals from room temperature up to 1200 °C. With increasing temperature, all modes decrease monotonously in wavenumber without anomaly, which attests the absence of a structural phase transition. The high temperature spectral signature and extrapolation of band pos

Geneviève Paquin, Christophe Reutenauer

Initially stated in terms of Beatty sequences, the Fraenkel conjecture can be reformulated as follows: for a $k$-letter alphabet A, with a fixed $k \geq 3$, there exists a unique balanced infinite word, up to letter permutations and shifts, that has mutually distinct letter frequencies. Motivated by the Fraenkel conjecture, we study in this paper whether two

The NA49 Collaboration, T. Anticic, B. Baatar, J. Bartke

New data on the production of charged kaons in p+p interactions are presented. The data come from a sample of 4.8 million inelastic events obtained with the NA49 detector at the CERN SPS at 158 GeV/c beam momentum. The kaons are identified by energy loss in a large TPC tracking system. Inclusive invariant cross sections are obtained in intervals from 0 to 1.

Stephen Gustafson, Tuoc Van Phan

We consider nonlinear Schrödinger equations, $i\partial_t ψ= H_0 ψ+ λ|ψ|^2ψ$ in $\mathbb{R}^3 \times [0,\infty)$, where $H_0 = -Δ+ V$, $λ=\pm 1$, the potential $V$ is radial and spatially decaying, and the linear Hamiltonian $H_0$ has only two eigenvalues $e_0 < e_1 <0$, where $e_0$ is simple, and $e_1$ has multiplicity three. We show that there exist two br

Phalguni Gupta, Dakshina Ranjan Kisku, Jamuna Kanta Sing, Massimo Tistarelli

This paper presents a robust and dynamic face recognition technique based on the extraction and matching of devised probabilistic graphs drawn on SIFT features related to independent face areas. The face matching strategy is based on matching individual salient facial graph characterized by SIFT features as connected to facial landmarks such as the eyes and

Dakshina Ranjan Kisku, Phalguni Gupta, Jamuna Kanta Sing

This paper presents a feature level fusion approach which uses the improved K-medoids clustering algorithm and isomorphic graph for face and palmprint biometrics. Partitioning around medoids (PAM) algorithm is used to partition the set of n invariant feature points of the face and palmprint images into k clusters. By partitioning the face and palmprint image

J. Sanchez Almeida, J. A. Bonet, B. Viticchie, D. Del Moro

We present a visual determination of the number of bright points (BPs) existing in the quiet Sun, which are structures though to trace intense kG magnetic concentrations. The measurement is based on a 0.1 arcsec angular resolution G-band movie obtained with the Swedish Solar Telescope at the solar disk center. We find 0.97 BPs/Mm^2, which is a factor three l

K. Behrend, I. Ciocan-Fontanine, J. Hwang, M. Rose

We construct the derived scheme of stable sheaves on a smooth projective variety via derived moduli of finite graded modules over a graded ring. We do this by dividing the derived scheme of actions of Ciocan-Fontanine and Kapranov by a suitable algebraic gauge group. We show that the natural notion of GIT-stability for graded modules reproduces stability for

Markus Kuba

In this short note we discuss recent results on hook length formulas of trees unifying some earlier results, and explain hook length formulas naturally associated to families of increasingly labelled trees.

G. Gubbiotti, S. Tacchi, M. Madami, G. Carlotti

The application of Brillouin light scattering to the study of the spin-wave spectrum of one- and two-dimensional planar magnonic crystals consisting of arrays of interacting stripes, dots and antidots is reviewed. It is shown that the discrete set of allowed frequencies of an isolated nanoelement becomes a finite-width frequency band for an array of identica

Song He, Mei Huang, Qi-Shu Yan

We stude the \textit{holographic} QCD model which contains a quadratic term $ -σz^2$ and a logarithmic term $-c_0\log[(z_{IR}-z)/z_{IR}]$ with an explicit infrared cut-off $z_{IR}$ in the deformed ${\rm AdS}_5$ warp factor. We investigate the heavy quark potential for three cases, i.e, with only quadratic correction, with both quadratic and logarithmic corre

Á. Sódor

We developed an Inverse Photometric method (IPM) to determine global physical parameters of RR Lyrae stars exclusively from multicolor light curves (Sódor, Jurcsik & Szeidl, 2009, MNRAS, 394, 261). We showed that for good quality photometric observations of unmodulated RRab stars, the IPM gives similarly good results as direct Baade-Wesselink analyses do, bu

Satoshi Aoki, Akimichi Takemura

We give an expository review of applications of computational algebraic statistics to design and analysis of fractional factorial experiments based on our recent works. For the purpose of design, the techniques of Gröbner bases and indicator functions allow us to treat fractional factorial designs without distinction between regular designs and non-regular d

Arieh Königl, Raquel Salmeron

This is a draft chapter for a book, entitled Physical Processes in Circumstellar Disks around Young Stars, which is scheduled for publication by the University of Chicago Press as one of its Theoretical Astrophysics Series volumes. Sect. 1 presents the motivation for considering the effects of a large-scale, ordered magnetic field on the formation and evolut

J. A. Sheikh, G. H. Bhat, Y. Sun, R. Palit

Inspired by the recent experimental data (Phys. Lett. B {\bf 675} (2009) 420), we extend the triaxial projected shell model approach to study the $γ$-band structure in odd-mass nuclei. As a first application of the new development, the $γ$-vibrational structure of $^{103}$Nb is investigated. It is demonstrated that the model describes the ground-state band a

A. Rusydi, W. Ku, B. Schulz, R. Rauer

A new excitation is observed at 201 meV in the doped-hole ladder cuprate Sr$_{14}$Cu$_{24}$O$_{41}$, using ultraviolet resonance Raman scattering with incident light at 3.7 eV polarized along the direction of the rungs. The excitation is found to be of charge nature, with a temperature independent excitation energy, and can be understood via an intra-ladder

Yu-ichi Takamizu, Shinji Mukohyama, Misao Sasaki, Yoshiharu Tanaka

We develop a theory of nonlinear cosmological perturbations on superhorizon scales for a single scalar field with a general kinetic term and a general form of the potential. We employ the ADM formalism and the spatial gradient expansion approach, characterised by $O(ε^m)$, where $ε=1/(HL)$ is a small parameter representing the ratio of the Hubble radius to t

Anatoly Vershik, Dmitry Pavlov

The article presents the results of experiments in computation of statistical values related to Young diagrams, including the estimates on maximum and average (by Plancherel distribution) dimension of irreducible representation of symmetric group $S_n$. The computed limit shapes of two-dimensional and three-dimensional diagrams distributed by Richardson stat

Yang Xiang, Yueping Niu, Yihong Qi, Shangqing Gong

With the development of laser technology, pulse length enters the optical cycle regime and hence the interaction time between laser pulse and atoms becomes prominent. We investigate this problem in this Letter through the photoelectron spectrum of hydrogen atom in few-cycle xuv laser pulses. By solving one-dimensional time-dependent Schrödinger equation, we

Shantia Yarahmadian, Blake Barker, Kevin Zumbrun, Sidney L. Shaw

We generalize the Dogterom-Leibler model for microtubule dynamics [DL] to the case where the rates of elongation as well as the lifetimes of the elongating and shortening phases are a function of GTP-tubulin concentration. We study also the effect of nucleation rate in the form of a damping term which leads to new steady-states. For this model, we study exis

Vladimir Nikulin

We consider upper exponential bounds for the probability of the event that an absolute deviation of sample mean from mathematical expectation p is bigger comparing with some ordered level epsilon. These bounds include 2 coefficients {alpha, beta}. In order to optimize the bound we are interested to minimize linear coefficient alpha and to maximize exponentia

Dusty Grundmeier

We study the signature pair for certain group-invariant Hermitian polynomials arising in CR geometry. In particular, we determine the signature pair for the finite subgroups of $SU(2)$. We introduce the asymptotic positivity ratio and compute it for cyclic subgroups of $U(2)$. We calculate the signature pair for dihedral subgroups of $U(2)$.

M. Eselevich, V. Eselevich

Analysis of SOHO/LASCO C3 data reveals a discontinuity, interpreted as a shock wave, in plasma density radial profiles in a restricted region ahead of each of ten selected coronal mass ejections (CME) along their travel directions. In various events, shock wave velocity $V\approx$ 800-2500 km s$^{-1}$. Comparing the dependence of Alfvén Mach number $M_A$ on

Nam-Hoon Lee

Most of Calabi-Yau manifolds that have been considered by physicists are complete intersection Calabi-Yau manifolds of toric varieties or some quotients of product types. Purpose of this paper is to introduce a different and rather new kind of construction method of Calabi-Yau manifolds by pasting two non-compact Calabi-Yau manifolds. We will also in some de

Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz

Numerical algorithms have two kinds of costs: arithmetic and communication, by which we mean either moving data between levels of a memory hierarchy (in the sequential case) or over a network connecting processors (in the parallel case). Communication costs often dominate arithmetic costs, so it is of interest to design algorithms minimizing communication. I

Elliot Anshelevich, Martin Hoefer

We consider network contribution games, where each agent in a social network has a budget of effort that he can contribute to different collaborative projects or relationships. Depending on the contribution of the involved agents a relationship will flourish or drown, and to measure the success we use a reward function for each relationship. Every agent is t

Dan Solomon

We find three exact solutions to the Klein-Gordon equation in 1-1 dimensional space-time for different time dependent potentials. In two cases we consider a time dependent scalar potential and in one case a time dependent electric potential.

Yohan Dubois, Julien Devriendt, Adrianne Slyz, Romain Teyssier

We present the first implementation of Active Galactic Nuclei (AGN) feedback in the form of momentum driven jets in an Adaptive Mesh Refinement (AMR) cosmological resimulation of a galaxy cluster. The jets are powered by gas accretion onto Super Massive Black Holes (SMBHs) which also grow by mergers. Throughout its formation, the cluster experiences differen

Vyacheslav M. Abramov

Let $X_1$, $X_2$, $...$ be a sequence of independently and identically distributed random variables with $\mathsf{E}X_1=0$, and let $S_0=0$ and $S_t=S_{t-1}+X_t$, $t=1,2,...$, be a random walk. Denote $τ={cases}\inf\{t>1: S_t\leq0\}, &\text{if} \ X_1>0, 1, &\text{otherwise}. {cases}$ Let $α$ denote a positive number, and let $L_α$ denote the number of level-

R. G. Hamish Robertson

An improved treatment of neutrino oscillations follows when neutrino mass eigenstates and their associated recoiling particle states are entangled. When the neutrino and its recoil partner are treated as a single entangled quantum state the conservation of energy and momentum in neutrino oscillations can be assured, even in a plane-wave treatment. The oscill

Sylvain E. Cappell, Laurentiu Maxim, Joerg Schuermann, Julius L. Shaneson

Homology Hirzebruch characteristic classes for singular varieties have been recently defined by Brasselet-Schuermann-Yokura as an attempt to unify previously known characteristic class theories for singular spaces (e.g., MacPherson-Chern classes, Baum-Fulton-MacPherson Todd classes, and Goresky-MacPherson L-classes, respectively). In this note we define equi

Madalin Guta, Peter Bowles, Gerardo Adesso

A successful state transfer (or teleportation) experiment must perform better than the benchmark set by the `best&#39; measure and prepare procedure. We consider the benchmark problem for the following families of states: (i) displaced thermal equilibrium states of given temperature; (ii) independent identically prepared qubits with completely unknown state.

Leszek Hadasz, Zbigniew Jaskolski, Paulina Suchanek

Using recursive relations satisfied by Nekrasov partition functions and by irregular conformal blocks we prove the AGT correspondence in the case of N=2 superconformal SU(2) quiver gauge theories with N_f = 0,1,2 antifundamental hypermultiplets

H. Bombin

Anyon models can be symmetric under some permutations of their topological charges. One can then conceive topological defects that, under monodromy, transform anyons according to a symmetry. We study the realization of such defects in the toric code model, showing that a process where defects are braided and fused has the same outcome as if they were Ising a

Yejun Feng, R. Jaramillo, A. Banerjee, J. M. Honig

We use synchrotron x-ray diffraction and electrical transport under pressure to probe both the magnetism and the structure of single crystal NiS2 across its Mott-Hubbard transition. In the insulator, the low-temperature antiferromagnetic order results from superexchange among correlated electrons and couples to a (1/2, 1/2, 1/2) superlattice distortion. Appl

Prasad Chebolu, Leslie Ann Goldberg, Russell Martin

We investigate the complexity of approximately counting stable matchings in the $k$-attribute model, where the preference lists are determined by dot products of &#34;preference vectors&#34; with &#34;attribute vectors&#34;, or by Euclidean distances between &#34;preference points&#34; and &#34;attribute points&#34;. Irving and Leather proved that counting t

K. Sinha, N. Cummings, B. L. Hu

We analyze the time evolution of quantum entanglement in a model consisting of two two-level atoms interacting with a two-mode electromagnetic field for a variety of initial states. We study two different coupling schemes motivated by the forms that can arise due to atomic separation. We observe a variety of qualitative features such as entanglement sudden d

Marco Bertola, Alexander Tovbis

The semiclassical (zero-dispersion) limit of the one-dimensional focusing Nonlinear Schroedinger equation (NLS) with decaying potentials is studied in a full scaling neighborhood D of the point of gradient catastrophe (x_0,t_0). This neighborhood contains the region of modulated plane wave (with rapid phase oscillations), as well as the region of fast amplit

Gadi Fibich

We show that the subcritical $d$-dimensional nonlinear Schrödinger equation $i ψ_t + Δψ+ |ψ|^{2 σ} ψ= 0$, where $1<σd<2$, admits smooth solutions that become singular in~$L^p$ for $p^*<p \le \infty$, where $p^*:=\frac{σd}{σd -1}$. Since $\lim_{σd \to 2-} p^* = 2$, these solutions can collapse at any $2<p \le \infty$, and in particular for $p = 2 σ+2$.

The D0 Collaboration, V. Abazov

Using 5.4 fb-1 of integrated luminosity from ppbar collisions at sqrt(s)=1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider, we search for decays of the lightest Kaluza-Klein mode of the graviton in the Randall-Sundrum model to ee and gammagamma. We set 95% C.L. lower limits on the mass of the lightest graviton between 560 GeV and 1050 G

Till Barmeier, Christoph Schweigert

Let G be a finite group. Given a finite G-set X and a modular tensor category C, we construct a weak G-equivariant fusion category, called the permutation equivariant tensor category. The construction is geometric and uses the formalism of modular functors. As an application, we concretely work out a complete set of structure morphisms for Z/2-permutation eq

Steven Kenneth Kauffmann

It was pointed out in a previous paper that although neither the Klein-Gordon equation nor the Dirac Hamiltonian produces sound solitary free-particle relativistic quantum mechanics, the natural square-root relativistic Hamiltonian for a nonzero-mass free particle does achieve this. Failures of the Klein-Gordon and Dirac theories are reviewed: the solitary D

Piotr Trocha

Electronic transport through a two-level system driven by external electric field and coupled to (magnetic or non-magnetic) electron reservoirs is considered theoretically. The basic transport characteristics such as current and tunnel magnetoresistance (TMR) are calculated in the weak coupling approximation by the use of rate equation connected with Green f

Prasanta Mahato

Starting from the multiplicative torsion approach of gravity and assuming a Killing vector to be proportional to the axial-vector matter current, here we derive Newton&#39;s law of gravity where the logarithm of the proportionality factor has been found to be the potential function.

Sahin Buyukdagli, Manoel Manghi, John Palmeri

Using a variational field theory, we show that an electrolyte confined to a neutral cylindrical nanopore traversing a low dielectric membrane exhibits a first-order ionic liquid-vapor pseudo-phase-transition from an ionic-penetration &#34;liquid&#34; phase to an ionic-exclusion &#34;vapor&#34; phase, controlled by nanopore-modified ionic correlations and die

Prabhu Manyem

We show that the maximum clique problem (decision version) can be expressed in existential second order (ESO) logic, where the first order part is a Horn formula in second-order quantified predicates. Without ordering, the first order part is $Π_2$ Horn; if ordering is used, then it is universal Horn (in which case, the second order variables can be determin