June 2009 arXiv papers — page 55

I. Firmansyah, Z. Akbar, L. T. Handoko

We present the architecture and application of the distributed control in public cluster, a parallel machine which is open for public access. Following the nature of public cluster, the integrated distributed control system is fully accessible through network using a user-friendly web interface. The system is intended mainly to control the power of each node

A. M. Hillas

The correlation between the directions of optically-detected AGNs within 75 Mpc and the arrival directions of cosmic rays above 57 EeV detected by the Auger collaboration up to August 2007 is examined using uniform-exposure plots and a form of right ascension resonance which does not require choice of an association window radius. Using the latter, the chanc

Wang-Chang Su

Within the framework of supersymmetric quantum mechanics, we study the simplified version of potential algebra of shape invariance condition in k steps, where k is an arbitrary positive integer. The associated potential algebra is found to be equivalent to the generalized deformed oscillator algebra that has a built-in Z_k-grading structure. The algebraic re

Donal F. Connon

The Stieltjes constants are the coefficients of the Laurent expansion of the Hurwitz zeta function and surprisingly little is known about them. In this paper we derive some relations for the difference between two Stieltjes constants together with various other relationships.

Alexander K. Popov, Sergey A. Myslivets, Vladimir M. Shalaev

The extraordinary properties of laser-induced transparency of a negative-index slab and parametric amplification for a backward-wave signal are investigated. The effects of the idler absorption and phase mismatch on the amplification of the signal are studied, and the feasibility of ensuring robust transparency for a broad range of control field intensities

G. R. Honarasa, M. K. Tavassoly, M. Hatami

In this paper we study the quantum phase properties of {\it "nonlinear coherent states"} and {\it "solvable quantum systems with discrete spectra"} using the Pegg-Barnett formalism in a unified approach. The presented procedure will then be applied to few special solvable quantum systems with known discrete spectrum as well as to some new cla

Andrea Rocco

We study the effect of extrinsic noise in metabolic networks. We introduce external random fluctuations at the kinetic level, and show how these lead to a stochastic generalization of standard Metabolic Control Analysis. While Summation and Connectivity Theorems hold true in presence of extrinsic noise, control coefficients incorporate its effect through an

Adam Van Tuyl

Let G be a bipartite graph with edge ideal I(G) whose quotient ring R/I(G) is sequentially Cohen-Macaulay. We prove: (1) the independence complex of G must be vertex decomposable, and (2) the Castelnuovo-Mumford regularity of R/I(G) can be determined from the invariants of G.

Murad Banaji, David Angeli

In this paper we generalise a useful result due to J. Mierczynski which states that for a strictly cooperative system on the positive orthant, with increasing first integral, all bounded orbits are convergent. Moreover any equilibrium attracts its entire level set, and there can be no more than one equilibrium on any level set. Here, more general state space

Dipankar Home, A. K. Pan, S. Adhikari, A. S. Majumdar

By sending a classical two-level system, one can transfer information about only \emph{two} distinguishable outcomes. Here we show that in quantum mechanics, using both the spin and path degrees of freedom of a spin-1/2 particle, and a Mach-Zehnder type interferometric arrangement with two suitable Stern-Gerlach detectors, it is possible to transfer informat

A. La Magna, I. Deretzis, V. Privitera

A method for the study of the electronic transport in strongly coupled electron-phonon systems is formalized and applied to a model of polyyne chains biased through metallic Au leads. We derive a stationary non equilibrium polaronic theory in the general framework of a variational formulation. The numerical procedure we propose can be readily applied if the

Vincent Nelis, Joel Goossens

In this paper, we address the global and preemptive energy-aware scheduling problem of sporadic constrained-deadline tasks on DVFS-identical multiprocessor platforms. We propose an online slack reclamation scheme which profits from the discrepancy between the worst- and actual-case execution time of the tasks by slowing down the speed of the processors in or

Pierre Le Doussal

We study the Sinai model for the diffusion of a particle in a one dimension random potential in presence of a small concentration $ρ$ of perfect absorbers using the asymptotically exact real space renormalization method. We compute the survival probability, the averaged diffusion front and return probability, the two particle meeting probability, the distrib

O. D. Dalkarov, P. A. Khakhulin, A. Yu. Voronin

Hadron electromagnetic form factor in the time-like region at the boundary of the physical region is considered. The energy behavior of the form factor is shown to be determined by the strong hadron-antihadron interaction. Imaginary parts of the scattering lengths for $p\bar{p}$, $\Lambda\bar{\Lambda}$, $\Lambda\bar{\Sigma}^0 (\bar{\Lambda}{\Sigma}^0)$ and $

R. Yanes, R. Rozada, F. Garcia-Sanchez, O. Chubykalo-Fesenko

The microwave assisted magnetisation reversal is modelled in a permalloy micron-sized magnetic ellipsoid. Our simulations confirm that this process requires less field than magnetisation reversal under a static field. This is due to a different reversal mode which in case of the microwave-assisted process is always a ripple structure. During the magnetisatio

D. V. Senthilkumar, J. Kurths, M. Lakshmanan

Stability of synchronization in unidirectionally coupled time-delay systems is studied using the Krasovskii-Lyapunov theory. We have shown that the same general stability condition is valid for different cases, even for the general situation (but with a constraint) where all the coefficients of the error equation corresponding to the synchronization manifold

Ian D. Morris

We use ergodic theory to prove a quantitative version of a theorem of M. A. Berger and Y. Wang, which relates the joint spectral radius of a set of matrices to the spectral radii of finite products of those matrices. The proof rests on a theorem asserting the existence of a continuous invariant splitting for certain matrix cocycles defined over a minimal hom

Rakesh Kumar, Dushyant Kumar, Brijesh Kumar

We present an antiferromagnetic quantum spin-1/2 model on honeycomb lattice. It has two parts, one of which is the usual nearest-neighbor Heisenberg model. The other part is a certain multiple spin interaction term, introduced by us, which is exactly solvable for the ground state. Without the Heisenberg part, the model has an exact threefold degenerate dimer

A. V. Derbin, A. I. Egorov, I. A. Mitropol'sky, V. N. Muratova

A search for resonant absorbtion of 14.4 keV solar axions by $^{57}$Fe target was performed. The Si(Li) detector placed inside the low-background setup was used to detect the $γ$-quanta appearing in the deexcitation of 14.4 keV nuclear level: $A+\rm{^{57}Fe} \to \rm{^{57}Fe^{*}} \to \rm{^{57}Fe} + γ$. The new upper limit for the hadronic axion mass have been

T. Spadaro

Recent Kaon decay studies seeking lepton-flavor violating (LFV) new-physics effects are briefly discussed. The main focus is set on precise measurements of rare or not-so-rare decays aiming at finding evidence of deviations from the SM prediction rather than on the results from direct searches of LFV transitions forbidden or ultra-rare in the SM.

Salla Jaakkola, Vivek Sharma, Arto Annila

Biological macromolecules, proteins and nucleic acids are composed exclusively of chirally pure monomers. The chirality consensus appears vital for life and it has even been considered as a prerequisite of life. However the primary cause for the ubiquitous handedness has remained obscure. We propose that the chirality consensus is a kinetic consequence that

Jeong-Hoon Lee, Kyu-Young Whang, Hyo-Sang Lim, Byung-Suk Lee

In this paper, we study the problem of processing continuous range queries in a hierarchical wireless sensor network. Contrasted with the traditional approach of building networks in a "flat" structure using sensor devices of the same capability, the hierarchical approach deploys devices of higher capability in a higher tier, i.e., a tier closer to t

Peter Wurtz, Arto Annila

The species-area relationship is one of the central generalizations in ecology however its origin has remained a puzzle. Since ecosystems are understood as energy transduction systems, the regularities in species richness are considered to result from ubiquitous imperatives in energy transduction. From a thermodynamic point of view, organisms are transductio

Wei Zhang, L. -M. Duan

We propose to utilize density distributions from a series of time-of-flight images of an expanding cloud to reconstruct single-particle correlation functions of trapped ultra-cold atoms. In particular, we show how this technique can be used to detect off-diagonal correlations of atoms in a quasi-one-dimensional trap, where both real- and momentum- space corr

D. Ward-Thompson, A. K. Sen, J. M. Kirk, D. Nutter

We present optical and submillimetre polarimetry data of the Bok globule CB3 and optical polarimetry data of the Bok globule CB246. We use each set of polarimetry data to infer the B-field orientation in each of the clouds. The optical data can only be used in the low density, low extinction edge regions of clouds. The submillimetre data can only be used in

Tung T. Kim, Albert Guillen i Fabregas

Reliable communication over delay-constrained block-fading channels with discrete inputs and mismatched (imperfect) channel state information at the transmitter (CSIT) is studied. The CSIT mismatch is modeled as Gaussian random variables, whose variances decay as a power of the signal-to-noise ratio (SNR). A special focus is placed on the large-SNR decay of

D. V. Khomitsky

The steady current-voltage characteristics of ferromagnet-silicon-ferromagnet channels with tunable emitter and collector polarizations are investigated in the presence of spin blockade generalizing the model developed by Pershin Yu V and Di Ventra M (2008 {\it Phys. Rev.} B {\bf 77} 073301). The dependence of the critical current on both collector and emitt

A. M. Mathai, H. J. Haubold

In reaction rate theory, in production-destruction type models and in reaction-diffusion problems when the total derivatives are replaced by fractional derivatives the solutions are obtained in terms of Mittag-Leffler functions and their generalizations. When fractional calculus enters into the picture the solutions of these problems, usually available in te

C. Aruta, G. Ghiringhelli, V. Bisogni, L. Braicovich

We have performed x-ray linear and circular magnetic dichroism experiments at the Mn L2,3-edge of the La0.7Sr0.3MnO3 ultra thin films. Our measurements show that the antiferromagnetic (AF) insulating phase is stabilized by the interfacial rearrangement of the Mn 3d orbitals, despite the relevant magnetostriction anisotropic effect on the double-exchange ferr

Miroslav Pardy

We determine the impact force generated by the projectile penetrating the body of the harmonic oscillator. We discuss the ballistic effect in connection with the Compton effect. Key words: Mathematical pendulum, physical pendulum, ballistic pendulum, harmonic oscillator.

B. C. Hiesmayr, M. Huber

We introduce systematically with the help of Weyl operators novel classes of multipartite and multidimensional states which are all bound entangled for arbitrary dimension. We find that the entanglement is bound due to different reasons: unlockable due to the multi--particle nature and some states are in addition bound due the fact being positive under parti

Thomas Roche, Cédric Tavernier

Power analysis attacks against embedded secret key cryptosystems are widely studied since the seminal paper of Paul Kocher, Joshua Ja, and Benjamin Jun in 1998 where has been introduced the powerful Differential Power Analysis. The strength of DPA is such that it became necessary to develop sound and efficient countermeasures. Nowadays embedded cryptographic

Richard Lieu, Bizhu Jiang

The spatial and temporal noise properties of diffuse radiation is investigated in the context of the cosmic microwave background (CMB), although generic formulae that enable application to any other forms of incoherent light of a prescribed energy spectrum are also provided. It is shown that the variance of fluctuations in the density and flux consists of tw

Hiromi Seta, Naoki Isobe, Makoto S. Tashiro, Yuichi Yaji

Suzaku observations of the blazar OJ 287 were performed in 2007 April 10--13 and November 7--9. They correspond to a quiescent and a flaring state, respectively. The X-ray spectra can be well described with single power-law models in both exposures. The derived X-ray photon index and the flux density at 1 keV were found to be Gamma = 1.65 +- 0.02 and S_{1 ke

DaeKil Park, Jin-Woo Son, Seong-Keuck Cha, Eun Deock Seo

We have examined the effect of the decoherence in the Ekert91 quantum cryptographic protocol. In order to explore this issue we have introduced two major decoherences, the depolarizing channel and the generalized amplitude damping, between the singlet source and one of the legitimate users. It is shown that the depolarizing channel disentangles the quantum c

Emiliano Sefusatti, Michele Liguori, Amit P. S. Yadav, Mark G. Jackson

The primordial non-Gaussian parameter fNL has been shown to be scale-dependent in several models of inflation with a variable speed of sound. Starting from a simple ansatz for a scale-dependent amplitude of the primordial curvature bispectrum for two common phenomenological models of primordial non-Gaussianity, we perform a Fisher matrix analysis of the bisp

Henrik Nilsen

The associated production of jets and vector bosons is an important process at hadron colliders. An overview over recent Tevatron vector boson+jets measurements is given with an emphasis on comparisons between data and the predictions of various theory models.

B. C. Joshi, M. A. McLaughlin, A. G. Lyne, D. A. Ludovici

We report on the discovery of three new pulsars in the first blind survey of the north Galactic plane (45 degrees < l < 135 degrees; |b| < 1 degrees with the Giant Meterwave Radio telescope (GMRT) at an intermediate frequency of 610 MHz. The survey covered 106 square degrees with a sensitivity of roughly 1 mJy to long-period pulsars (pulsars with period long

Takumi Nagayama, Toshihiro Omodaka, Toshihiro Handa, Hideyuki Toujima

It is an open question why the temperature of molecular gas in the Galactic center region is higher than that of dust. To address this problem, we made simultaneous observations in the NH_3 (J,K) = (1,1), (2,2), and (3,3) lines of the central molecular zone (CMZ) using the Kagoshima 6 m telescope. The ortho-to-para ratio of NH_3 molecules in the CMZ is 1.5--

Petr Siegl

Spectra of the second derivative operators corresponding to the special PT-symmetric point interactions are studied. The results are partly the completion of those obtained in [1]. The particular PT-symmetric point interactions causing unusual spectral effects are investigated for the systems defined on a finite interval as well. The spectrum of this type of

Daichi Yanagisawa, Ayako Kimura, Akiyasu Tomoeda, Ryosuke Nishi

In this paper, two important factors which affect the pedestrian outflow at a bottleneck significantly are studied in detail to analyze the effect of an obstacle set up in front of an exit. One is a conflict at an exit when pedestrians evacuate from a room. We use floor field model for simulating such behavior, which is a well-studied pedestrian model using

K. S. Dwarakanath, Ruta Kale

We have formed a new sample which consists of extended extragalactic radio sources without obvious active galactic nuclei (AGN) in them. Most of these sources appear to be dead double radio sources. These sources with steep spectra ($α< $ -1.8; S $\propto ν^α$) were identified using the 74 (VLSS) and the 1400 MHz (NVSS) surveys and further imaged using the V

L. Alvarez-Ruso, J. A. Oller, J. M. Alarcon

We have studied the ϕ(1020)f_0(980) S-wave scattering at energies around threshold employing chiral Lagrangians coupled to vector mesons through minimal coupling. The interaction kernel is obtained by considering the f_0(980) as a K\bar{K} bound state. The Y(2175) resonance is generated in this approach by the self-interactions between the ϕ(1020) and the f_

Denny H. Leung

Let $X, Y$ be complete metric spaces and $E, F$ be Banach spaces. A bijective linear operator from a space of $E$-valued functions on $X$ to a space of $F$-valued functions on $Y$ is said to be biseparating if $f$ and $g$ are disjoint if and only if $Tf$ and $Tg$ are disjoint. We introduce the class of generalized Lipschitz spaces, which includes as special

Denny H. Leung, Wee-Kee Tang

Let $X$ and $Y$ be completely regular spaces and $E$ and $F$ be Hausdorff topological vector spaces. We call a linear map $T$ from a subspace of $C(X,E)$ into $C(Y,F)$ a \emph{Banach-Stone map} if it has the form $Tf(y) = S_{y}(f(h(y))$ for a family of linear operators $S_{y} : E \to F$, $y \in Y$, and a function $h: Y \to X$. In this paper, we consider maps

Arunima Banerjee, Lynn D. Matthews, Chanda J. Jog

We model the shape and density profile of the dark matter halo of the low surface brightness, superthin galaxy UGC 7321, using the observed rotation curve and the HI scale height data as simultaneous constraints. We treat the galaxy as a gravitationally coupled system of stars and gas, responding to the gravitational potential of the dark matter halo. An iso

Junko S. Hiraga, Y. Kobayashi, T. Tamagawa, A. Hayato

We searched for evidence of line emission around 4keV from the northwestern rim of the supernova remnant RX J0852.0-4622 using Suzaku XIS data. Several papers have reported the detection of an emission line around 4.1keV from this region of the sky. This line would arise from K-band fluorescence by Sc, the immediate decay product of 44Ti. We performed spectr

Miju Kang, John H. Bieging, Craig A. Kulesa, Youngung Lee

We present Heinrich Hertz Telescope CO observations of the shell structure near the active star-forming complex W51A to investigate the process of star formation triggered by the expansion of an HII region. The CO observations confirm that dense molecular material has been collected along the shell detected in Spitzer IRAC images. The CO distribution shows t

Toshihiro Nakanishi, Hirokazu Kobayashi, Kazuhiko Sugiyama, Masao Kitano

For dissipation-free photon-photon interaction at the single photon level, we analyze one-photon transition and two-photon transition induced by photon pairs in three-level atoms using two-photon wavefunctions. We show that the two-photon absorption can be substantially enhanced by adjusting the time correlation of photon pairs. We study two typical cases: G

Lixin Xu, Jianbo Lu, Wenbo Li

In this paper, we consider generalized holographic and Ricci dark energy models where the energy densities are given as $ρ_{R}=3c^2M^{2}_{pl}Rf(H^2/R)$ and $ρ_{h}=3c^2M^{2}_{pl}H^2g(R/H^2)$ respectively, here $f(x),g(y)$ are positive defined functions of dimensionless variables $H^2/R$ or $R/H^2$. It is interesting that holographic and Ricci dark energy dens

Francisco Colomer

High resolution maps of maser emission provide very detailed information on processes occurring in circumstellar envelopes of late-type stars. A particularly detailed picture of the innermost shells around AGB stars is provided by SiO masers. Considerable progress is being made to provide astrometrically aligned multi-transition simultaneous observations of

Vincent E. Sacksteder

This paper shows how to obtain non-rigorous mathematical control over models of loosely coupled disordered grains; it provides new information about saddle point structure and perturbative corrections. Both the Wegner model and a variant due to Disertori are transformed to matrix models which are similar to the supersymmetric model of disorder, having two ma

Vincent E. Sacksteder

It is shown that the Wegner model of disorder contains a system of constraints which is important whenever the disorder is not weak and which is responsible for localization in D > 2 dimensions. When the disorder is strong the constraints divide the phase space into an exponentially large number of domains; the localized phase is a glass. This work is based

Yuanlin Zhang, Forrest Sheng Bao

Tree convex sets refer to a collection of sets such that each set in the collection is a subtree of a tree whose nodes are the elements of these sets. They extend the concept of row convex sets each of which is an interval over a total ordering of the elements of those sets. They have been applied to identify tractable Constraint Satisfaction Problems and Co

Abedelaziz Mohaisen, Dowon Hong

The rotation based transformation (RBT) for privacy preserving data mining (PPDM) is vulnerable to the independent component analysis (ICA) attack. This paper introduces a modified multiple rotation based transformation (MRBT) technique for special mining applications mitigating the ICA attack while maintaining the advantages of the RBT.

R. A. Gutermuth, S. T. Megeath, P. C. Myers, L. E. Allen

We present a uniform mid-infrared imaging and photometric survey of 36 young, nearby, star-forming clusters and groups using {\it Spitzer} IRAC and MIPS. We have confidently identified and classified 2548 young stellar objects using recently established mid-infrared color-based methods. We have devised and applied a new algorithm for the isolation of local s

Vartan Choulakian

The aim of this paper is the introduction of a new method for the numerical computation of the rank of a three-way array. We show that the rank of a three-way array over R is intimately related to the real solution set of a system of polynomial equations. Using this, we present some numerical results based on the computation of Grobner bases. Key words: Tens

Y. Chen, X. Li, H. Q. Song, Q. Q. Shi

Plasma blobs are observed to be weak density enhancements as radially stretched structures emerging from the cusps of quiescent coronal streamers. In this paper, it is suggested that the formation of blobs is a consequence of an intrinsic instability of coronal streamers occurring at a very localized region around the cusp. The evolutionary process of the in

Gregory D. Fleishman, Gelu M. Nita, Dale E. Gary

We develop a practical forward fitting method based on the SIMPLEX algorithm with shaking, which allows the derivation of the magnetic field and other parameters along a solar flaring loop using microwave imaging spectroscopy of gyrosynchrotron emission. We illustrate the method using a model loop with spatially varying magnetic field, filled with uniform am

Lasse Leskelä

Order-preserving couplings are elegant tools for obtaining robust estimates of the time-dependent and stationary distributions of Markov processes that are too complex to be analyzed exactly. The starting point of this paper is to study stochastic relations, which may be viewed as natural generalizations of stochastic orders. This generalization is motivated

F. Lascaux, E. Masciadri, S. Hagelin, J. Stoesz

These last years ground-based astronomy has been looking towards Antarctica, especially its summits and the internal continental plateau where the optical turbulence (OT) appears to be confined in a shallow layer close to the surface. Preliminary measurements have so far indicated pretty good value for the seeing above 30-35 m: 0.36" (Agabi et al. 2006), 0.2

Vincenzo Vitelli, Bhuvnesh Jain, Randall D. Kamien

Shear fields due to weak gravitational lensing have characteristic coherent patterns. We describe the topological defects in shear fields in terms of the curvature of the surface described by the lensing potential. A simple interpretation of the characteristic defects is given in terms of the the umbilical points of the potential surface produced by ellipsoi

Olga Azenhas, Alessandro Conflitti, Ricardo Mamede

Benkart, Sottile, and Stroomer have completely characterized by Knuth and dual Knuth equivalence a bijective proof of the conjugation symmetry of the Littlewood-Richardson coefficients. Tableau-switching provides an algorithm to produce such a bijective proof. Fulton has shown that the White and the Hanlon-Sundaram maps are versions of that bijection. In thi

S. M. Troshin, N. E. Tyurin

We discuss effects of reflective scattering for heavy nuclei collisions and the deconfined matter formation at the LHC and asymptotical energies. Reflective scattering in hadron collisions leads to decreasing matter density with energy beyond the LHC energies. Limiting form of energy dependence of hadron density is obtained.

L M Robledo, R Rodriguez-Guzman, P Sarriguren

The evolution of the ground-state shape along the triaxial landscape of several isotopes of Yb, Hf, W, Os, and Pt is analyzed using the self-consistent Hartree-Fock-Bogoliubov approximation. Two well reputed interactions (Gogny D1S and Skyrme SLy4) have been used in the study in order to asses to which extent the results are independent of the details of the

Kang Kim, Shinji Saito

A multi-time probing of density fluctuations is introduced to investigate hidden time scales of heterogeneous dynamics in glass-forming liquids. Molecular dynamics simulations for simple glass-forming liquids are performed, and a three-time correlation function is numerically calculated for general time intervals. It is demonstrated that the three-time corre

Michael Boshernitzan, Jon Chaika

We exhibit the densest sequence on the unit circle R/Z, x_k= log(2k-1)/log(2) (mod 1).

A. Morozov, Sh. Shakirov

J. Harer and D. Zagier have found a strikingly simple generating function for exact (all-genera) 1-point correlators in the Gaussian Hermitian matrix model. In this paper we generalize their result to 2-point correlators, using Toda integrability of the model. Remarkably, this exact 2-point correlation function turns out to be an elementary function - arctan

R. G. Mani, W. B. Johnson, V. Umansky, V. Narayanamurti

We report the experimental results from a dark study and a photo-excited study of the high mobility GaAs/AlGaAs system at large filling factors, $ν$. At large-$ν$, the dark study indicates several distinct phase relations (&#34;Type-1&#34;, &#34;Type-2&#34;, and &#34;Type-3&#34;) between the oscillatory diagonal- and Hall- resistances, as the canonical Integ

Sven Bjarke Gudnason

We study non-Abelian Chern-Simon BPS-saturated vortices enjoying N=2 supersymmetry in d=2+1 dimensions, with generic gauge groups of the form U(1) x G&#39;, with G&#39; being a simple group, allowing for orientational modes in the solutions. We will keep the group as general as possible and utilizing the powerful moduli matrix formalism to provide the moduli

Jan de Boer, Sheer El-Showk, Ilies Messamah, Dieter Van den Bleeken

We determine, in two independent ways, the number of BPS quantum states arising from supergravity degrees of freedom in a system with fixed total D4D0 charge. First, we count states generated by quantizing the spacetime degrees of freedom of 'entropyless' multicentered solutions consisting of anti-D0-branes bound to a D6-anti-D6 pair. Second, we determine th