March 2008 arXiv papers — page 12

Hao Wei, Shuang Nan Zhang

The current accelerated expansion of our universe could be due to an unknown energy component (dark energy) or a modification to general relativity (modified gravity). In the literature, it has been proposed that combining the probes of the cosmic expansion history and growth history can distinguish between dark energy and modified gravity. In this work, wit

Rajeev Kapri, Somendra M. Bhattacharjee

We show the existence of a critical endpoint in the phase diagram of unzipping of an adsorbed double-stranded (ds) polymer like DNA. The competition of base pairing, adsorption and stretching by an external force leads to the critical end point. From exact results, the location of the critical end point is determined and its classical nature established.

Enrico Barausse, Thomas P. Sotiriou

Although the Kerr solution is common to many gravity theories, its perturbations are different in different theories. Hence, perturbed Kerr black holes can probe deviations from General Relativity.

Pier Luca Palla, Carlo Pierleoni, Giovanni Ciccotti

Non-equilibrium Molecular Dynamics (NEMD) calculations of the bulk viscosity of the triple point Lennard-Jones fluid are performed with the aim of investigating the origin of the observed disagreement between Green-Kubo estimates and previous NEMD data. We show that a careful application of the Doll's perturbation field, the dynamical NEMD method, the in

D. Asthagiri, Safir Merchant, Lawrence R. Pratt

On the basis of a gaussian quasi-chemical model of hydration, a model of non van der Waals character, we explore the role of attractive methane-water interactions in the hydration of methane and in the potential of mean force between two methane molecules in water. We find that the hydration of methane is dominated by packing and a mean-field energetic contr

B. I. Shklovskii

In a film with large dielectric constant $κ$ the electric field of an electron spreads inside the film before exiting the film at large distances of order of $κd$ ($d$ is the film width). This leads to the logarithmic Coulomb repulsion between electrons and modifies the shape of the Coulomb gap in the density of localized states in a doped film. As a result

Angel Ballesteros, Alberto Enciso, Francisco J. Herranz, Orlando Ragnisco

Perlick's classification of (3+1)-dimensional spherically symmetric and static spacetimes (\cal M,η=-1/V dt^2+g) for which the classical Bertrand theorem holds [Perlick V Class. Quantum Grav. 9 (1992) 1009] is revisited. For any Bertrand spacetime (\cal M,η) the term V(r) is proven to be either the intrinsic Kepler-Coulomb or the harmonic oscillator pote

Marek Czachor

Formal similarity between Minkowski tetrads and Bell bases allows to think of metric tensors in terms of quantum teleportation protocols. The role of null tetrads for quantum information processing is different. They define qubits resistant to a special kind of noise that occurs if coding and decoding of quantum information is performed in different referenc

Grigory Tkachov, Klaus Richter

Electron conductance in planar magnetic tunnel junctions with long-range barrier disorder is studied within Glauber-eikonal approximation enabling exact disorder ensemble averaging by means of the Holtsmark-Markov method. This allows us to address a hitherto unexplored regime of the tunneling magnetoresistance effect characterized by the crossover from momen

Andreas Alvermann, Holger Fehske, Stuart A. Trugman

We study Holstein polarons in three-dimensional anisotropic materials. Using a variational exact diagonalization technique we provide highly accurate results for the polaron mass and polaron radius. With these data we discuss the differences between polaron formation in dimension one and three, and at small and large phonon frequency. Varying the anisotropy

Chuck Hague

Let G be a semisimple complex algebraic group with Borel subgroup B and let P be a parabolic subgroup of G. Let T*(G/P) denote the cotangent bundle of G/P. Ranee Brylinski discovered a connection between cohomology of G-equivariant line bundles on T*(G/B) and the so-called Brylinski-Kostant filtration, which describes the action of principal sl_2 triples on

Alex Buchel

We study string theory duals of the expanding boost invariant conformal gauge theory plasmas at strong coupling. The dual supergravity background is constructed as an asymptotic late-time expansion, corresponding to equilibration of the gauge theory plasma. The absence of curvature singularities in the first few orders of the late-time expansion of the dual

Igor Kondrashuk, Anatoly Kotikov

We investigate triangle UD ladder integrals in the position space. The investigation is necessary to find an all-order in loop solution for an auxiliary Lcc correlator in Wess-Zumino-Landau gauge of the maximally supersymmetric Yang-Mills theory and to present correlators of dressed mean gluons in terms of it in all loops. We show that triangle UD ladder dia

John McKay, David Sevilla

We describe an algorithm to decompose rational functions from which we determine the poset of groups fixing these functions.

A. D. Giddings, O. N. Makarovsky, M. N. Khalid, S. Yasin

We report large anisotropic magnetoresistance (AMR) behaviours in single lateral (Ga,Mn)As nanoconstriction of up to 1300%, along with large multistable telegraphic switching. The nanoconstriction devices are fabricated using high-resolution electron beam lithography of a 5 nm thick (Ga,Mn)As epilayer. The unusual behaviour exhibited by these devices is disc

J. Cuevas, G. James, P. G. Kevrekidis, K. J. H. Law

In this paper, we consider the dynamical evolution of dark vortex states in the two-dimensional defocusing discrete nonlinear Schroedinger model, a model of interest both to atomic physics and to nonlinear optics. We find that in a way reminiscent of their 1d analogs, i.e., of discrete dark solitons, the discrete defocusing vortices become unstable past a cr

Jan Pachl

A topological group is said to be ambitable if each uniformly bounded uniformly equicontinuous set of functions on the group with its right uniformity is contained in an ambit. For n=0,1,2,..., every locally aleph_n bounded topological group is either precompact or ambitable. In the familiar semigroups constructed over ambitable groups, topological centres h

Juan C. Migliore, Fabrizio Zanello

We study a number of conditions on the Hilbert function of a level artinian algebra which imply the Weak Lefschetz Property (WLP). Possibly the most important open case is whether a codimension 3 SI-sequence forces the WLP for level algebras. In other words, does every codimension 3 Gorenstein algebra have the WLP? We give some new partial answers to this ol

Gang Li, Yuan-Jiang Zhang, Qiang Zhao

We study the reaction $e^+ e^-\to ωπ^0$ in the vicinity of $ϕ$ mass region. The isospin-violating $ϕ$ excitation is accounted for by two major mechanisms. One is electromagnetic (EM) transition and the other is strong isospin violations. For the latter, we consider contributions from the intermediate hadronic meson loops and $ϕ$-$ρ^0$ mixing as the major mec

Wesley Calvert, John E. Porter

This survey paper examines the effective model theory obtained with the BSS model of real number computation. It treats the following topics: computable ordinals, satisfaction of computable infinitary formulas, forcing as a construction technique, effective categoricity, effective topology, and relations with other models for the effective theory of uncounta

Tomi Koivisto

Nonlocal quantum corrections to gravity have been recently proposed as a possible solution to the cosmological fine tuning problems. We study the dynamics of a class of nonlocal actions defined by a function of the inverse d'Alembertian of the Ricci scalar. Power-law and expnential functions are considered in detail, but we also show a method to reconstr

Avraham Aizenbud, Dmitry Gourevitch, Eitan Sayag

In the first part of the paper we generalize a descent technique due to Harish-Chandra to the case of a reductive group acting on a smooth affine variety both defined over arbitrary local field F of characteristic zero. Our main tool is Luna slice theorem. In the second part of the paper we apply this technique to symmetric pairs. In particular we prove that

Avraham Aizenbud, Dmitry Gourevitch

In this paper we prove that the symmetric pair $(GL_{n+k}(F),GL_n(F) \times GL_k(F))$ is a Gelfand pair for any local field F of characteristic 0. For non-archimedean F it has been proven in [JR]. We use techniques developed in [AG2] to generalize their proof to general local fields.

Indranil Chakrabarty, B. S. Choudhury

In this work we describe a protocol by which one can secretly broadcast W-type state among three distant partners. This work is interesting in the sense that we introduce a new kind of local cloning operation to generate two W- type states between these partners from a W-type state initially shared by them.

Kausik Pal

We calculate pionic contribution to the relativistic Fermi Liquid parameters (RFLPs) using Chiral Effective Lagrangian. The RFLPs so determined are then used to calculate chemical potential, exchange and nuclear symmetry energies due to $π$$N$ interaction. We also evaluate two loop ring diagrams involving $σ$, $ω$ and $π$ meson exchanges and compare results

Johan Mattsson, Rikard Bergman, Per Jacobsson, Lars Börjesson

The supercooled state of bulk water is largely hidden by unavoidable crystallization, which creates an experimentally inaccessible temperature regime - a 'no man's land'. We address this and circumvent the crystallization problem by systematically studying the supercooled dynamics of hydrogen bonded oligomeric liquids (glycols), where water corre

M. R. Pennington, T. Mori, S. Uehara, Y. Watanabe

We perform an Amplitude Analysis of the world published data on $γγ\toπ^+π^-$ and $π^0π^0$. These are dominated in statistics by the recently published results from Belle on the charged pion channel. Nevertheless, having only limited angular information, a range of solutions remain possible. We present two solutions with $Γ(f_0(980)\toγγ) = 0.42$ and 0.10 ke

Kazuharu Bamba, Shin'ichi Nojiri, Sergei D. Odintsov

We study inflationary cosmology and the late-time accelerated expansion of the universe in non-minimal Yang-Mills (YM) theory, in which the YM field couples to a function of the scalar curvature. It is shown that power-law inflation can be realized due to the non-minimal YM field-gravitational coupling which maybe caused by quantum corrections. Moreover, it

A. T. Burkov, E. Bauer, E. Gratz, R. Resel

We present experimental results on thermoelectric power ({\em S}) and electrical resistivity ($ρ$) of pseudobinary alloys Ho(Al$_x$Co$_{1-x}$)$_2$ ($0 \leq x \leq 0.1 $), in the temperature range 4.2 K to 300 K. The work focuses on the effects of static (induced by alloying) and dynamic (induced by temperature) disorder on the magnetic state and electronic t

M. A. Silaev

We study a subgap quasiparticle spectrum in a mesoscopic disk of chiral superconductor. We find an exact expression for the spectrum of surface states localized at the disk edge. Considering an Abrikosov vortex placed at the center of a superconducting disk we investigate the spectrum transformation near the intersection points of surface and vortex anomalou

Takehiko Yasuda

For each variety in positive characteristic, there is a series of canonically defined blowups, called F-blowups. We are interested in the question of whether the $e+1$-th blowup dominates the $e$-th, locally or globally. It is shown that the answer is affirmative (globally for any $e$) when the given variety is F-pure. As a corollary, we obtain some result o

Santiago Encinas

This paper has been withdrawn by the author

Shuu'ichirou Yamamoto, Satoshi Sugahara

We propose and computationally analyze a nonvolatile static random access memory (NV-SRAM) cell using magnetic tunnel junctions (MTJs) with magnetic-field-free current-induced magnetization switching (CIMS) architecture. A pair of MTJs connected to the storage nodes of a standard SRAM cell with CIMS architecture enables fully electrical store and restore ope

G. E. Volovik

We discuss why the tunneling picture does not necessarily lead to Hawking radiation from the de Sitter horizon. The experience with the condensed matter analogs of event horizon suggests that the de Sitter vacuum is stable against the Hawking radiation. On the other hand the detector immersed into the de Sitter background will detect the radiation which look

Patrick Brosnan, Gregory Pearlstein

We show that the zero locus of a normal function on a smooth complex algebraic variety S is algebraic provided that the normal function extends to a admissible normal function on a smooth compactification of S with torsion singularity. This result generalizes our previous result for admissible normal functions on curves [arxiv:math/0604345 [math.AG]]. It has

Jiaqun Wei

We prove that the finitistic dimension conjecture, the Gorenstein Symmetry Conjecture, the Wakamatsu-tilting conjecture and the generalized Nakayama conjecture hold for artin algebras which can be realized as endomorphism algebras of modules over representation-finite algebras. Note it is a question whether or not all artin algebras have such realizations. I

Yoshiharu Maeno

In this paper, I present a method to solve a node discovery problem in a networked organization. Covert nodes refer to the nodes which are not observable directly. They affect social interactions, but do not appear in the surveillance logs which record the participants of the social interactions. Discovering the covert nodes is defined as identifying the sus

A. A. Isayev

Recent calculations with an effective isospin dependent contact interaction show the possibility of the crossover from superfluidity of neutron Cooper pairs in $^1S_0$ pairing channel to Bose-Einstein condensation (BEC) of di-neutron bound states in dilute nuclear matter. The density and spin correlation functions are calculated for a di-neutron condensate i

Guangyue Han, Brian Marcus

We study the classical problem of noisy constrained capacity in the case of the binary symmetric channel (BSC), namely, the capacity of a BSC whose inputs are sequences chosen from a constrained set. Motivated by a result of Ordentlich and Weissman [In Proceedings of IEEE Information Theory Workshop (2004) 117--122], we derive an asymptotic formula (when the

Jianda Wu, Meisheng Zhao, Jianlan Chen, Yongde Zhang

In this paper, we present a U(1)-invariant expansion theory of the adiabatic process. As its application, we propose and discuss new sufficient adiabatic approximation conditions. In the new conditions, we find a new invariant quantity referred as quantum geometric potential (QGP) contained in all time-dependent processes. Furthermore, we also give detailed

C. Douglas Haessig

Given a projective variety X defined over a finite field, the zeta function of divisors attempts to count all irreducible, codimension one subvarieties of X, each measured by their projective degree. When the dimension of X is greater than one, this is a purely p-adic function, convergent on the open unit disk. Four conjectures are expected to hold, the firs

Jesper Kleis, Elsebeth Schroder, Per Hyldgaard

The dispersive interaction between nanotubes is investigated through ab initio theory calculations and in an analytical approximation. A van der Waals density functional (vdW-DF) [Phys. Rev. Lett. 92, 246401 (2004)] is used to determine and compare the binding of a pair of nanotubes as well as in a nanotube crystal. To analyze the interaction and determine t

A. M. Hughes, D. J. Wilner, I. Kamp, M. R. Hogerheijde

The A star 49 Ceti, at a distance of 61 pc, is unusual in retaining a substantial quantity of molecular gas while exhibiting dust properties similar to those of a debris disk. We present resolved observations of the disk around 49 Ceti from the Submillimeter Array in the J=2-1 rotational transition of CO with a resolution of 1.0x1.2 arcsec. The observed emis

R. Esquivel-Sirvent

We present theoretical calculations of the Casimir force for Au thin films near the insulator-conductor transition that has been observed experimentally. The dielectric function of the Au thin films is described by the Drude-Smith model. The parameters needed to model the dielectric function such as the relaxation time, plasma frequency and the backscatterin

Ricardo L. C. Ogando, Marcio A. G. Maia, Paulo S. Pellegrini, Luiz N. da Costa

In this paper we present measurements of velocity dispersions and Lick indices for 509 galaxies in the local Universe, based on high signal-to-noise, long slit spectra obtained with the 1.52 m ESO telescope at La Silla. The conversion of our measurements into the Lick/IDS system was carried out following the general prescription of Worthey and Ottaviani 1997

Mariola O. Ramirez, Jeffrey Wisdom, Haifeng Li, Yan Lin Aung

Using confocal Raman and fluorescence spectroscopic imaging in 3-dimensions, we show direct evidence for Nd3+-Nd3+ interactions across grain boundaries (GBs) in Nd3+:YAG laser ceramics. It is clearly shown that Nd3+ segregation takes place at GBs leading to self-fluorescence quenching which affects a volume fraction as high as 20%. In addition, we show a cle

Jorge Pineiro

In the present work we establish the equality of the canonical metric of two commuting maps on an algebraic variety X. As a consequence the canonical height and measure associated to both maps are identical.

G. Guerrero, E. M. de Gouveia Dal Pino

The turbulent pumping effect corresponds to the transport of magnetic flux due to the presence of density and turbulence gradients in convectively unstable layers. In the induction equation it appears as an advective term and for this reason it is expected to be important in the solar and stellar dynamo processes. In this work, we have explored the effects o

Marco Hien

In previous work, we established a duality between the algebraic de Rham cohomology of a flat algebraic connection on a smooth quasi-projective surface over the complex numbers and the rapid decay homology of the dual connection relying on a conjecture by C. Sabbah, which has been proved recently by T. Mochizuki for algebraic connections in any dimension. In

F. A. Reboredo, P. R. C. Kent

We demonstrate the existence of different density-density functionals designed to retain selected properties of the many-body ground state in a non-interacting solution starting from the standard density functional theory ground state. We focus on diffusion quantum Monte Carlo applications that require trial wave functions with optimal Fermion nodes. The the

F. L. Marquezino, R. Portugal

Several research groups are giving special attention to quantum walks recently, because this research area have been used with success in the development of new efficient quantum algorithms. A general simulator of quantum walks is very important for the development of this area, since it allows the researchers to focus on the mathematical and physical aspect

Manuel A. Bautista

Spectroscopic studies of Planetary Nebulae (PNe) and H {\sc ii} regions have driven much development in atomic physics. In the last few years the combination of a generation of powerful observatories, the development of ever more sophisticated spectral modeling codes, and large efforts on mass production of high quality atomic data have led to important prog

S. Carlip

In view of the enormous difficulties we seem to face in quantizing general relativity, we should perhaps consider the possibility that gravity is a fundamentally classical interaction. Theoretical arguments against such mixed classical-quantum models are strong, but not conclusive, and the question is ultimately one for experiment. I review some work in prog

Steven Furlanetto, Zoltan Haiman, S. Peng Oh

One of the most dramatic signatures of the reionization era may be the enormous ionized bubbles around luminous quasars (with radii reaching ~40 comoving Mpc), which may survive as "fossil'' ionized regions long after their source shuts off. Here we study how the inhomogeneous intergalactic medium (IGM) evolves inside such fossils. The average re

Rainer Schulze-Pillot

We use results on the local theta correspondence to prove that for large degrees the Duke-Imamoglu-Ikeda lifting of an elliptic modular form is not a linear combination of theta series.

C. Anastopoulos, B. L. Hu

We investigate the meaning of gravity-induced decoherence in quantum theory, known as `intrinsic' or `fundamental' decoherence in the literature. We explore a range of issues relevant to this problem, including the meaning of modified uncertainty relations, the interpretations of the Planck scale, the distinction between quantum and stochastic fluctu

Martin Varbanov, Hari Krovi, Todd A. Brun

We define the hitting (or absorbing) time for the case of continuous quantum walks by measuring the walk at random times, according to a Poisson process with measurement rate $\lambda$. From this definition we derive an explicit formula for the hitting time, and explore its dependence on the measurement rate. As the measurement rate goes to either 0 or infin

Alexander B. Balakin, Heinz Dehnen, Alexei E. Zayats

Non-minimal interactions in the pp-wave Einstein - Yang - Mills - Higgs (EYMH) model are shown to give rise to color cross-effects analogous to the magneto-electricity in the Maxwell theory. In order to illustrate the significance of these color cross-effects, we reconstruct the effective (associated, color and color-acoustic) metrics for the pp-wave non-min

C. Paduani, N. S. Branco

The magnetic properties of the $Fe_{1-x}Ru_x$ alloy system for 0 $\leq$ x $\leq$ 0.10 are studied by using a mean-field approximation based on the Bogoliubov inequality. Ferromagnetic Fe-Fe spin correlations and antiferromagnetic Fe-Ru and Ru-Ru exchanges have been considered to describe the temperature dependence of the Curie temperature and low temperature

Nataliya V. Malyshkina

The influence of speed limits on roadway safety is an extremely important social issue and is subject to an extensive debate in the State of Indiana and nationwide. With around 800-900 fatalities and thousands of injuries annually in Indiana, traffic accidents place an incredible social and economic burden on the state. Still, speed limits posted on highways

Tomas Rokicki

How many moves does it take to solve Rubik's Cube? Positions are known that require 20 moves, and it has already been shown that there are no positions that require 27 or more moves; this is a surprisingly large gap. This paper describes a program that is able to find solutions of length 20 or less at a rate of more than 16 million positions a second. We

C. F. Doran, M. G. Faux, S. J. Gates,, T. Hubsch

We construct a model of an electrically charged magnetic dipole with arbitrary N-extended world-line supersymmetry, which exhibits a supersymmetric Zeeman effect. By including supersymmetric constraint terms, the ambient space of the dipole may be tailored into an algebraic variety, and the supersymmetry broken for almost all parameter values. The so exhibit

Victor Sergeev

The first (Russian) edition of the book was among the first monographs on econophysics. The book gives an explanation of several intriguing phenomena, providing new insights and answers to some deeply vexing questions. Why the economic "shock therapy" implemented in Eastern Europe was doomed to a failure whereas the approach adopted by China and Viet

Pierre Berger

We show that invariant submanifolds with boundary, and more generally with corners which are normally expanded by an endomorphism are persistent as $a$-regular stratifications. This result will be shown in class $C^s$, for $s\ge 1$. We present also a simple example of a submanifold with boundary which is normally expanded but non-persistent as a differentiab

Mingxia Gu, Sergij V. Shiyanovskii, Oleg D. Lavrentovich

The dielectric dispersion in the uniaxial nematic liquid crystals affects the switching dynamics of the director, as the dielectric torque is determined by not only the present values of the electric field and director but also by their past values. We demonstrate that this dielectric memory leads to an unusual contribution to the dielectric torque that is l

K. Bakke, J. R. Nascimento, C. Furtado

In this paper we study the quantum dynamics of a neutral particle in the presence of a topological defect. We investigate the appearance of a geometric phase in the relativistic quantum dynamics of neutral particle which possesses permanent magnetic and electric dipole moments in the presence of an electromagnetic fields in this curved background. The nonrel

J. Dong, H. J. Zhang, G. Xu, Z. Li

The interplay between different ordered phases, such as superconducting, charge or spin ordered phases, is of central interest in condensed matter physics. The very recent discovery of superconductivity with a remarkable T$_c$= 26 K in Fe-based oxypnictide La(O$_{1-x}$F$_x$)FeAs is a surprise to the scientific community\cite{Kamihara08}. The pure LaOFeAs its

The MiniBooNE Collaboration, A. A. Aguilar-Arevalo, C. E. Anderson, A. O. Bazarko

The MiniBooNE experiment at Fermilab has amassed the largest sample to date of $π^0$s produced in neutral current (NC) neutrino-nucleus interactions at low energy. This paper reports a measurement of the momentum distribution of $π^0$s produced in mineral oil (CH$_2$) and the first observation of coherent $π^0$ production below 2 GeV. In the forward directio

S. N. Dorogovtsev, J. F. F. Mendes, A. N. Samukhin, A. Y. Zyuzin

We examine the global organization of heterogeneous equilibrium networks consisting of a number of well distinguished interconnected parts--``communities'' or modules. We develop an analytical approach allowing us to obtain the statistics of connected components and an intervertex distance distribution in these modular networks, and to describe their

Yasunobu Uchiyama, Yoshitomo Maeda, Masatoshi Ebara, Ryuichi Fujimoto

We present an empirical correction of sky coordinates of X-ray photons obtained with the XIS aboard the Suzaku satellite to improve the source position accuracy and restore the point-spread function (PSF). The XIS images are known to have an uncertainty in position of up to 1 arcmin, and to show considerable degradations of the PSF. These problems are caused

Helmut G. Katzgraber, Alexander K. Hartmann, A. P. Young

The concept of replica symmetry breaking found in the solution of the mean-field Sherrington-Kirkpatrick spin-glass model has been applied to a variety of problems in science ranging from biological to computational and even financial analysis. Thus it is of paramount importance to understand which predictions of the mean-field solution apply to non-mean-fie

M. Swisdak, Y. H. Liu, J. F. Drake

The mass symmetry between the two species in electron-positron (pair) plasmas has interesting consequences for collisionless magnetic reconnection because the Hall term, which plays a crucial role in supporting fast reconnection in electron-proton plasmas, vanishes. We perform kinetic simulations of pair reconnection in systems of various sizes, show that it

Andrei Asinowski, Toufik Mansour

We characterize separable multidimensional permutations in terms of forbidden patterns and enumerate them by means of generating function, recursive formula and explicit formula. We find a connection between multidimensional permutations and guillotine partitions of a box. In particular, a bijection between $d$-dimensional permutations and guillotine partiti

Wei-Hao. Bian, Yan-Mei. Chen, Chen. Hu, Kai. Huang

We investigate the $\mbh- σ_*$ relation for radio-loud quasars with redshift $z<0.83$ in Data Release 3 of the Sloan Digital Sky Survey (SDSS). The sample consists of 3772 quasars with better model of H$β$ and \oiii lines and available radio luminosity, including 306 radio-loud quasars, 3466 radio-quiet quasars with measured radio luminosity or upper-limit o

Yasunobu Uchiyama, Felix Aharonian

Recent discovery of the year-scale variability in the synchrotron X-ray emission of the supernova remnant (SNR) RX J1713.7-3946 has initiated our study of multi-epoch X-ray images and spectra of the young SNR Cassiopeia A based on the Chandra archive data taken in 2000, 2002, and 2004. We have found year-scale time variations in the X-ray intensity for a num

T. F. Yi, G. Z. Xie

We study the correlations of the flux of the broad-line emission ($F_{BLR}$) with the X-ray emission flux, optical emission flux at 5500 Åand radio emission flux at 5 GHz, respectively, for a large sample of 50 Blazars (39 flat-spectrum radio quasars (FSRQs) and 11 BL Lac objects). Our main results are as follows. There are very strong correlations between $

Radha Balakrishnan, Rossen Dandoloff

We study the effect of conformations on charge transport in a thin elastic tube. Using the Kirchhoff model for a tube with any given Poisson ratio, cross-sectional shape and intrinsic twist, we obtain a class of exact solutions for its conformation. The tube&#39;s torsion is found in terms of its intrinsic twist and its Poisson ratio, while its curvature sat

A. Johansson, J. Kahn, V. Vu

Let $H$ be a fixed graph on $v$ vertices. For an $n$-vertex graph $G$ with $n$ divisible by $v$, an $H$-{\em factor} of $G$ is a collection of $n/v$ copies of $H$ whose vertex sets partition $V(G)$. In this paper we consider the threshold $th_{H} (n)$ of the property that an Erdős-Rényi random graph (on $n$ points) contains an $H$-factor. Our results determi

B. O&#39;Halloran, S. C. Madden, N. P. Abel

Archival Spitzer observations of 41 starburst galaxies that span a wide range in metallicity reveal for the first time a correlation between the [FeII]/[NeII] 26.0/12.8 micron ratio and the electron gas density as traced by the 18.7/33.4 micron [SIII] ratio, with the [FeII]/[NeII] ratio decreasing with increasing gas density. We also find a strong correlatio

George Costakis, Demetris Hadjiloucas, Antonios Manoussos

In this article we answer a question raised by N. Feldman in \cite{Feldman} concerning the dynamics of tuples of operators on $\mathbb{R}^n$. In particular, we prove that for every positive integer $n\geq 2$ there exist $n$ tuples $(A_1, A_2, ..., A_n)$ of $n\times n$ matrices over $\mathbb{R}$ such that $(A_1, A_2, ..., A_n)$ is hypercyclic. We also establi

Motohiko Kusakabe

I calculate the evolution of Be and B abundances produced by cosmic rays generated by massive stars in the pregalactic phase of the universe. The inputs for calculation, i.e. the star formation rate and the nuclear abundances of cosmic rays, which I assume to be the same as those of the ISM, are taken from the results of a detailed cosmic chemical evolution

Victor Atanasov, Vladimir Gerdjikov

The multi-component nonlinear Schrodinger equation related to C.I=Sp(2p)/U(p) and D.III=SO(2p)/U(p)-type symmetric spaces with non-vanishing boundary conditions is solvable with the inverse scattering method (ISM). As Lax operator L we use the generalized Zakharov-Shabat operator. We show that the ISM for L is a nonlinear analog of the Fourier-transform meth

Xinhua Peng, Jiangfeng Du, Dieter Suter

Experimental determination of an unknown quantum state usually requires several incompatible measurements. However, it is also possible to determine the full quantum state from a single, repeated measurement. For this purpose, the quantum system whose state is to be determined is first coupled to a second quantum system (the &#34;assistant&#34;) in such a wa

Xinhua Peng, Dieter Suter

Finding the factors of an integer can be achieved by various experimental techniques, based on an algorithm developed by Schleich et al., which uses specific properties of Gaußsums. Experimental limitations usually require truncation of these series, but if the truncation parameter is too small, it is no longer possible to distinguish between factors and so-

Patrick O&#39;Beirne

Human error research on overconfidence supports the benefits of early visibility of defects and disciplined development. If risk to the enterprise is to be reduced, individuals need to become aware of the reality of the quality of their work. Several cycles of inspection and defect removal are inevitable. Software Quality Management measurements of defect de

Victor Atanasov, Rossen Dandoloff

We investigate the effect of curvature on the behaviour of a quantum particle bound to move on a surface. For the Gaussian bump we derive and discuss the quantum potential which results in the appearance of a bound state for particles with vanishing angular momentum. The Gaussian bump provides a characteristic length for the problem. For completeness we prop

Victor Atanasov, Rossen Dandoloff

We investigate the effect of curvature on the behaviour of a quantum particle bound to move on a surface shaped as a helical tube. We derive and discuss the governing Schrödinger equation and the corresponding quantum effective potential which is periodic and points to the helical configuration as more energetically favorable as compared to the straight tube

I. Agudo

An increasing number of blazars have been reported to show jet wobbling (i.e., non-regular rotations of the structural position angle of their innermost jets in the plane of the sky with amplitudes between 20 deg. and 50 deg., and time scales between 2 yr. and 20 yr.). The physical origin for the observed jet wobbling is still poorly understood, but as this

D. V. Kolesnikov, V. A. Osipov

We study the electronic structure of graphene in the presence of either sevenfolds or eightfolds by using a gauge field-theory model. The graphene sheet with topological defects is considered as a negative cone surface with infinite Gaussian curvature at the center. The density of electronic states is calculated for a single seven- and eightfold as well as f

Zhongzhi Zhang, Shuigeng Zhou, Lichao Chen, Ming Yin

The Vicsek fractals are one of the most interesting classes of fractals and the study of their structural properties is important. In this paper, the exact formula for the mean geodesic distance of Vicsek fractals is found. The quantity is computed precisely through the recurrence relations derived from the self-similar structure of the fractals considered.

M. P. Garcia del Moral, J. M. Pena, A. Restuccia

In this note we summarize some of the properties found in [1], and its relation with [2]. We comment on the construction of the action of the 11D supermembrane with nontrivial central charges minimally immersed on a 7D toroidal manifold is obtained (MIM2).The transverse coordinates to the supermembrane are maps to a 4D Minkowski space-time. The action is inv

T. Gelander

These notes contain results concerning uniform exponential growth which were obtained in collaborations with E. Breuillard and A. Salehi-Golsefidy, mostly during 2005, improving Eskin-Mozes-Oh theorem \cite{EMO}, as well as a uniform uniform version of Tits alternative improving \cite{uti}.

Yaping Yang, Ran Zeng, Shutian Liu, Hong Chen

We investigate repulsive Casimir force between slabs containing left-handed materials with controllable electromagnetic properties. The sign of Casimir force is determined by the electric and magnetic properties of the materials, and it is shown that the formation of the repulsive force is related to the wave impedances of two slabs. The sign change of the C

Richard M. Jenkins, Andrew F. Blockley, J. Banerji, Alan R. Davies

Predictions and measurements of a multimode waveguide interferometer operating in a fibre coupled, ``dual-mode&#39;&#39; regime are reported. With a 1.32 micrometer source, a complete switching cycle of the output beam is produced by a 10.0 nanometer incremental change in the 8.0 micrometer width of the hollow planar mirror waveguide. This equates to a fring

E. Kirr, Ö. Mızrak

We consider a class of nonlinear Schroedinger equation in three space dimensions with an attractive potential. The nonlinearity is local but rather general encompassing for the first time both subcritical and supercritical (in $L^2$) nonlinearities. We study the asymptotic stability of the nonlinear bound states, i.e. periodic in time localized in space solu

L. Kampmeijer, J. K. Slingerland, B. J. Schroers, F. A. Bais

We analyze the set of magnetic charges carried by smooth BPS monopoles in Yang-Mills-Higgs theory with arbitrary gauge group G spontaneously broken to a subgroup H. The charges are restricted by a generalized Dirac quantization condition and by an inequality due to Murray. Geometrically, the set of allowed charges is a solid cone in the coroot lattice of G,

Belle Collaboration

We present an updated measurement of the unitarity triangle angle phi_3 using a Dalitz plot analysis of the K^0_S pi+ pi- decay of the neutral D meson produced in B+- ->D(*)K+- decays. The method exploits the interference between D^0 and Dbar^0 to extract the angle phi_3, strong phase delta and the ratio r of suppressed and allowed amplitudes. We apply this

C. Das, K. Bhattacharyya

The prevalent role of force in traditional quantum mechanics is outlined, with special reference to approximate calculations for stationary states. It will be explored how far this force concept can be made useful in the concerned area. The basic idea is to differentiate the Schroedinger stationary equation once. Thus, one can eliminate the unknown energy as

Naoto Kobayashi, Chikako Yasui, Alan T. Tokunaga, Masao Saito

We report the discovery of active star formation in Digel&#39;s Cloud 2, which is one of the most distant giant molecular clouds known in the extreme outer Galaxy (EOG). At the probable Galactic radius of ~20 kpc, Cloud 2 has a quite different environment from that in the solar neighborhood, including lower metallicity, much lower gas density, and small or n

Rakesh Voggu, Shrinwantu Paul, Swapan K. Pati, C. N. R. Rao

Single-walled carbon nanotubes (SWNTs) have been coated with gold and platinum nanoparticles either by microwave treatment or by the click reaction and the Raman spectra of these SWNT-metal nanoparticle composites have been investigated. Analysis of the G bands in the Raman spectra shows an increase in the proportion of metallic SWNTs on attachment with meta