March 2008 arXiv papers — page 6

S. Tornow, R. Bulla, F. B. Anders, A. Nitzan

We investigate non-equilibrium two-electron transfer in a model redox system represented by a two-site extended Hubbard model and embedded in a dissipative environment. The influence of the electron-electron interactions and the coupling to a dissipative bosonic bath on the electron transfer is studied in different temperature regimes. At high temperatures M

Yulan Liang, Arpad Kelemen

Recent advances of information technology in biomedical sciences and other applied areas have created numerous large diverse data sets with a high dimensional feature space, which provide us a tremendous amount of information and new opportunities for improving the quality of human life. Meanwhile, great challenges are also created driven by the continuous a

L. Golinskii, F. Peherstorfer, P. Yuditskiy

In 2002 C. Berg, Y. Chen, and M. Ismail found a nice relation between the determinancy of the Hamburger moment problem and asymptotic behavior of the smallest eigenvalues of the corresponding Hankel matrices. We investigate whether an analog of this statement holds for the Nevanlinna--Pick interpolation problem.

Arne Kesting, Martin Treiber

The car-following behavior of individual drivers in real city traffic is studied on the basis of (publicly available) trajectory datasets recorded by a vehicle equipped with an radar sensor. By means of a nonlinear optimization procedure based on a genetic algorithm, we calibrate the Intelligent Driver Model and the Velocity Difference Model by minimizing th

Luca Cortese

We present preliminary results of a multi-wavelength study focused on the evolution of spiral galaxies in the UV-optical colour-magnitude (CM) diagram. By combining HI, UV and optical observations of the Coma-Abell1367 supercluster we are able to identify galaxies at different stages of their evolution: from healthy star-forming galaxies, to blue HI-poor spi

Giovanni Bussi, Davide Donadio, Michele Parrinello

We present a new molecular dynamics algorithm for sampling the canonical distribution. In this approach the velocities of all the particles are rescaled by a properly chosen random factor. The algorithm is formally justified and it is shown that, in spite of its stochastic nature, a quantity can still be defined that remains constant during the evolution. In

M. Ikeda, T. Yoshida, A. Fujimori, M. Kubota

We have performed angle-resolved photoemission spectroscopy (ARPES) measurements and first-principles electronic structure calculations on the electron-doped high-Tc superconductors Ln1.85Ce0.15CuO4 (Ln = Nd, Sm, and Eu). The observed Fermi surface and band dispersion show such changes that with decreasing ionic size of Ln3+, the curvature of the Fermi surfa

Clifford Spiegelman, S. J. Sheather, W. A. Tobin, W. D. James

This paper has attracted interest around the world from the media (both TV and newspapers). In addition, we have received letters, emails and telephone calls. One of our favorites was a voicemail message asking us to return a call to Australia at which point we would learn who really killed JFK. We welcome the opportunity to respond to the letter to the edit

Michele Ceriotti, Fabio Pietrucci, Marco Bernasconi

Based on density functional perturbation theory, we have studied the vibrational properties of three crystalline phases of tellurium dioxide: paratellurite alpha-TeO2, tellurite beta-TeO2, and the new phase gamma-TeO2, recently identified experimentally. Calculated Raman and IR spectra are in good agreement with available experimental data. The vibrational s

John E. Fiorentino

Occasionally during the course of the human learning experience we are faced with an anomaly. An aberration of sorts, which try as we might, defies appropriate classification. The recent paper by Spiegelman et al.--Chemical and forensic analysis of JFK assassination bullet lots: Is a second shooter possible?--is one such aberration. It is riddled with both m

Ferran Cedo, Eric Jespers, Angel del Rio

In 1992 Drinfeld posed the question of finding the set theoretic solutions of the Yang-Baxter equation. Recently, Gateva-Ivanova and Van den Bergh and Etingof, Schedler and Soloviev have shown a group theoretical interpretation of involutive non-degenerate solutions. Namely, there is a one-to-one correspondence between involutive non-degenerate solutions on

G. Seibold, F. Becca, J. Lorenzana

We present a method to compute pairing fluctuations on top of the Gutzwiller approximation (GA). Our investigations are based on a charge-rotational invariant GA energy functional which is expanded up to second order in the pair fluctuations. Equations of motion for the fluctuations lead to a renormalized ladder type approximation. Both spectral functions an

Dapeng CAI, Takashi Gyoshin NITTA

We aim to generalize the results of Cai and Nitta (2007) by allowing both the utility and production function to depend on time. We also consider an additional intertemporal optimality criterion. We clarify the conditions under which the limit of the solutions for the finite horizon problems is optimal among all attainable paths for the infinite horizon prob

S. F. Caballero Benitez, E. A. Ostrovskaya, M. Gulacsi, Yu. S. Kivshar

We study the macroscopic quantum self-trapping effect in a mixture of Bose-Einstein condensate and a large number of quantum degenerate fermions, trapped in a double-well potential with a variable separation between the wells. The large number of fermions localized in each well form quasi-static impurities that affect the dynamics of the bosonic cloud. Our s

Dapeng CAI, Takashi Gyoshin NITTA

We aim to construct the optimal solutions to the undiscounted continuous-time infinite horizon optimization problems, the objective functionals of which may be unbounded. We identify the condition under which the limit of the solutions to the finite horizon problems is optimal for the infinite horizon problems under the overtaking criterion.

Ph. N. Usmanov, A. A. Okhunov, U. S. Salikhbaev, R. Rajabbaev

To describe the ground (gr) and excited states of even-even deformed nuclei with the phenomenological model, which takes into account the mixing ground $(gr)$, $0^{+}_{2}(β_1)$--, $0^{+}_{3}(β_2)$--, $2^{+}_{1}(γ_1)$--, $2^{+}_{2}(γ_2)$-- and $K^π=1^{+}_ν$ rotational bands the calculation has been done for the isotope $^{172}Yb$. The energy specterum is desc

Chris Dodd, Phakawa Jeasakul, Anne Jirapattanakul, Daniel M. Kane

We define a class of discrete abelian group extensions of rank-one transformations and establish necessary and sufficient conditions for these extensions to be power weakly mixing. We show that all members of this class are multiply recurrent. We then study conditions sufficient for showing that cartesian products of transformations are conservative for a cl

Indranil Biswas, Ugo Bruzzo

Let G be a simple linear algebraic group defined over the complex numbers. Fix a proper parabolic subgroup P of G and a nontrivial antidominant character χof P. We prove that a holomorphic principal G-bundle E over a connected complex projective manifold M is semistable and the second Chern class of its adjoint bundle vanishes in rational cohomology if and o

V. M. Matic

x dependences of Tc in YBa2Cu3O6+x and Y1-b(Ca)bBa2Cu3O6+x (b=0.1 and b=0.2) have been calculated assuming that the net doping of CuO2 layers is a sum of contributions from CuO chains and from substitution of Y3+ by Ca2+. We applied the concept of minimal (critical) chain length lcr needed to trigger charge transfer from chains to planes. The model proposed

Thomas Callaghan, Joseph B. Keller

The probability density of the resistance of a two dimensional rectangular network between two conducting plates is calculated. The nodes form an $M$ by $N$ lattice, and each edge has a random resistance. The Monte Carlo method is used.

Wei-Zhong Liu, Dao-Jun Liu

The cosmological dynamics of minimally coupled scalar field that couples to the background matter with thermal interactions is investigated by using statefinder diagnostics. The time evolution of the statefinder pairs $\{r,s\}$ and $\{r,q\}$ are obtained under the circumstance that different values of model parameters are chosen. We show that the thermal cou

Tuo-Hung Hou, Hassan Raza, Kamran Afshari, Daniel J. Ruebusch

We report a novel field-sensitive tunneling barrier by embedding C60 in SiO2 for nonvolatile memory applications. C60 is a better choice than ultra-small nanocrystals due to its monodispersion. Moreover, C60 provides accessible energy levels to prompt resonant tunneling through SiO2 at high fields. However, this process is quenched at low fields due to HOMO-

Sang-Sung Lee, Andrei P. Lobanov, Thomas P. Krichbaum, Arno Witzel

We present results from a large 86GHz global VLBI survey of compact radio sources. The main goal of the survey is to increase by factors of 3--5 the total number of objects accessible for future 3-mm VLBI imaging. The survey observations reach the baseline sensitivity of 0.1Jy and image sensitivity of better than 10 mJy/beam. The total of 127 compact radio s

Plamen Stefanov, Gunther Uhlmann

We study the direct and an inverse source problem for the radiative transfer equation arising in optical molecular imaging. We show that for generic absorption and scattering coefficients, the direct problem is well-posed and the inverse one is uniquely solvable, with a stability estimate.

Cheol-Hwan Park, Feliciano Giustino, Jessica L. McChesney, Aaron Bostwick

We show that the electron-phonon coupling strength obtained from the slopes of the electronic energy vs. wavevector dispersion relations, as often done in analyzing angle-resolved photoemission data, can differ substantially from the actual electron-phonon coupling strength due to the curvature of the bare electronic bands. This effect becomes particularly i

David Eppstein

We describe the algorithms used by the ALEKS computer learning system for manipulating combinatorial descriptions of human learners' states of knowledge, generating all states that are possible according to a description of a learning space in terms of a partial order, and using Bayesian statistics to determine the most likely state of a student. As we d

H. E. Montgomery, G. Campoy, N. Aquino

We study the size effect on the energy levels of the D-dimensional isotropic harmonic oscillator confined within a box of radius $r_c$ with impenetrable walls. Two different approaches are used to obtain the energy eigenvalues and eigenfunctions for D=1,2,...,5. In the first we solve the Schroedinger equation exactly. In the second we use a series expansion

A. O. Jaunsen, E. Rol, D. J. Watson, D. Malesani

We report on the highly extinguished afterglow of GRB 070306 and the properties of the host galaxy. An optical afterglow was not detected at the location of the burst, but in near-infrared a doubling in brightness during the first night and later power-law decay in the K band provided a clear detection of the afterglow. The host galaxy is relatively bright,

Sandro Silva e Costa

The purpose of the present study is to show that in a particular cosmological model, with an affine equation of state, one can obtain, besides the background given by the scale factor, Hubble and deceleration parameters, a representation in terms of scalar fields and, more important, explicit mathematical expressions for the density contrast and the power sp

Adam A. Miller, Jonathan Irwin, Suzanne Aigrain, Simon Hodgkin

We present the results of a systematic search for transiting planets in a ~5 Myr open cluster, NGC 2362. We observed ~1200 candidate cluster members, of which ~475 are believed to be genuine cluster members, for a total of ~100 hours. We identify 15 light curves with reductions in flux that pass all our detection criteria, and 6 of the candidates have occult

Bojan Ramadanovic, Gordon W. Semenoff

The quantization of the giant magnon away from the infinite size limit is discussed. We argue that this quantization inevitably leads to string theory on a Z_M-orbifold of S^5. This is shown explicitly and examined in detail in the near plane-wave limit.

D. A. Shapiro, D. DePonte, R. B. Doak, P. Fromme

We demonstrate that powder diffraction data can be collected from sub-micron crystals of a mbrane protein with nearly two orders of magnitude more atoms than the molecules commonly used for powder diffraction. The crystals of photosystem-1 protein were size-selected using a 500 nm pore- size filter and delivered to a soft x-ray beam with a photon energy of 1

Arash A. Amini, Martin J. Wainwright

Principal component analysis (PCA) is a classical method for dimensionality reduction based on extracting the dominant eigenvectors of the sample covariance matrix. However, PCA is well known to behave poorly in the ``large $p$, small $n$'' setting, in which the problem dimension $p$ is comparable to or larger than the sample size $n$. This paper stu

Thomas A. Trainor

I present the first isolation of azimuth quadrupole components from published $v_2(p_t)$ data (called elliptic flow) as spectra on transverse rapidity $y_t$ for identified pions, kaons and lambdas/protons from minimum-bias Au-Au collisions at 200 GeV. The form of the spectra on $y_t$ indicates that the three hadron species are emitted from a common boosted s

Eric Katz, Hannah Markwig, Thomas Markwig

If (Q,A) is a marked polygon with one interior point, then a general polynomial f in K[x,y] with support A defines an elliptic curve C on the toric surface X_A. If K has a non-archimedean valuation into the real numbers we can tropicalize C to get a tropical curve Trop(C). If the Newton subdivision induced by f is a triangulation, then Trop(C) will be a grap

Y. Martel, F. Merle, T. Mizumachi

We prove that the collision of two solitary waves of the BBM equation is inelastic but almost elastic in the case where one solitary wave is small in the energy space. We show precise estimates of the nonzero residue due to the collision. Moreover, we give a precise description of the collision phenomenon (change of size of the solitary waves).

Bruno Goncalves, Jose J. Ramasco

When the World Wide Web was first conceived as a way to facilitate the sharing of scientific information at the CERN (European Center for Nuclear Research) few could have imagined the role it would come to play in the following decades. Since then, the increasing ubiquity of Internet access and the frequency with which people interact with it raise the possi

C. Vuissoz, F. Courbin, D. Sluse, G. Meylan

Gravitationally lensed quasars can be used to map the mass distribution in lensing galaxies and to estimate the Hubble constant H0 by measuring the time delays between the quasar images. Here we report the measurement of two independent time delays in the quadruply imaged quasar WFI J2033-4723 (z = 1.66). Our data consist of R-band images obtained with the S

L. Frankfurt, G. A Miller, M. Strikman

We study the electroproduction of rho mesons in nuclei at intermediate energies, deriving a treatment of the energy lost by the rho in each step of multiple-scattering. This enables a close match between calculations and the experimental kinematic conditions. A standard Glauber calculation is presented, and then the effects of color-transparency are included

J. Vink

I determine the expansion of the supernova remnant of SN1604 (Kepler's supernova) based on archival Chandra ACIS-S observations made in 2000 and 2006. The measurements were done in several distinct energy bands, and were made for the remnant as a whole, and for six individual sectors. The average expansion parameter indicates that the remnant expands as

J. D. Teufel, C. A. Regal, K. W. Lehnert

Recent theoretical work has shown that radiation pressure effects can in principle cool a mechanical degree of freedom to its ground state. In this paper, we apply this theory to our realization of an opto-mechanical system in which the motion of mechanical oscillator modulates the resonance frequency of a superconducting microwave circuit. We present experi

Frank J. Petriello, Seth Quackenbush, Kathryn M. Zurek

We study the feasibility of observing an invisibly decaying Z' at the LHC through the process pp -> ZZ' -> l+l-XX*, where X is any neutral, (quasi-) stable particle, whether a Standard Model (SM) neutrino or a new state. The measurement of the invisible width through this process facilitates both a model independent measurement of Gamma_{Z' -> \b

Jurjen F. Koksma, Tomislav Prokopec

It has been argued that the quantum (conformal) trace anomaly could potentially provide us with a dynamical explanation of the cosmological constant problem. In this paper, however, we show by means of a semiclassical analysis that the trace anomaly does not affect the cosmological constant. We construct the effective action of the conformal anomaly for flat

Andrew E. Blechman, Siew-Phang Ng

The leading-log QCD corrections to K-Kbar mixing in R-symmetric supersymmetric models are computed using effective field theory techniques. The spectrum topology where the gluino is significantly heavier than the squarks is motivated and focused on. It is found that, like in the MSSM, QCD corrections can tighten the kaon mass difference bound by roughly a fa

S. Carlip, S. Deser, A. Waldron, D. K. Wise

We study topologically massive (2+1)-dimensional gravity with a negative cosmological constant. The masses of the linearized curvature excitations about AdS_3 backgrounds are not only shifted from their flat background values but, more surprisingly, split according to chirality. For all finite values of the topological mass, we find a single bulk degree of f

T. Domanski, J. Ranninger

In a recent preprint [0803.3052] A. Kanigel et al report evidence for Bogoliubov-type excitations in the pseudogap phase in the anti-nodal region, where a robust pseudogap remains well above Tc. This important experimental result has been theoretically predicted by us almost 6 years ago on a basis of the phenomenological boson fermion model. An earlier theor

Shih-Yuin Lin, Chung-Hsien Chou, B. L. Hu

We study the dynamics of quantum entanglement between two Unruh-DeWitt detectors, one stationary (Alice), and another uniformly accelerating (Rob), with no direct interaction but coupled to a common quantum field in (3+1)D Minkowski space. We find that for all cases studied the initial entanglement between the detectors disappears in a finite time ("sudd

Nemanja Kaloper, Lorenzo Sorbo, Jun'ichi Yokoyama

We revisit inflation in induced gravity. Our focus is on models where the low scale Planck mass is completely determined by the breaking of the scaling symmetry in the field theory sector. The Higgs-like field which breaks the symmetry with a GUT-scale vacuum expectation value has non-minimal couplings to the curvature, induced by the gravitational couplings

Shuguang Song, Jon A. Wellner

This paper has been withdrawn by the authors due to a crucial error in a bound on page 19 and some other errors earlier in the paper.

A. C. Carciofi, J. E. Bjorkman

We discuss the basic hydrodynamics that determines the density structure of the disks around hot stars. Observational evidence supports the idea that these disks are Keplerian (rotationally supported) gaseous disks. A popular scenario in the literature, which naturally leads to the formation of Keplerian disks, is the viscous decretion model. According to th

Keisuke Okamura

In this dissertation, we discuss how our understanding of the large-N spectrum of AdS/CFT has been deepened by integrability-based approaches. We begin with a comprehensive review of the integrability of the gauge theory spin-chain and that of the string sigma model. In the light of the AdS/CFT duality, they should be just two ways of describing the same und

D. R. G. Schleicher, D. Galli, F. Palla, M. Camenzind

Previous works have demonstrated that the generation of secondary CMB anisotropies due to the molecular optical depth is likely too small to be observed. In this paper, we examine additional ways in which primordial chemistry and the dark ages might influence the CMB. We present a detailed and updated chemical network and give an overview of the interactions

Nicolas Bouche

One way to characterize and understand HI-selected galaxies is to study their metallicity properties. In particular, we show that the metallicity of absorbers is a bivariate function of the HI column density (NHI) and the MgII equivalent width (Wr(2796)). Thus, a selection upon Wr(2796) is not equivalent to a HI selection for intervening absorbers. A direct

L. Steinke, P. Cantwell, D. Zakharov, E. Stach

A corner-overgrown GaAs/AlGaAs heterostructure is investigated with transmission and scanning transmission electron microscopy, demonstrating self-limiting growth of an extremely sharp corner profile of 3.5 nm width. In the AlGaAs layers we observe self-ordered diagonal stripes, precipitating exactly at the corner, which are regions of increased Al content m

S. D. Bennett, A. A. Clerk

We study theoretically the full distribution of transferred charge in a tunnel junction (or quantum point contact) coupled to a nanomechanical oscillator, as well as the conditional evolution of the oscillator. Even if the oscillator is very weakly coupled to the tunnel junction, it can strongly affect the tunneling statistics and lead to a highly non-Gaussi

Hironobu Kihara

Itoyama-Tokura type USp matrix model is discussed. Non-Abelian Berry's phases in a T-dualized model of IT model were reconsidered. These phases describe the higher dimensional monopoles; Yang monopole and nine-dimensional monopole. They are described by the connections of the BPST instanton on S^4 and the Tchrakian-GKS instanton on S^8, respectively. As

Cédric Weber, Andreas Laeuchli, Frédéric Mila, Thierry Giamarchi

Motivated by the recent report of broken time-reversal symmetry and zero momentum magnetic scattering in underdoped cuprates, we investigate under which circumstances orbital currents circulating inside a unit cell might be stabilized in extended Hubbard models that explicitly include oxygen orbitals. Using Gutzwiller projected variational wave functions tha

Xi Dai, Zhong Fang, Yi Zhou, Fu-chun Zhang

In the present paper, we propose the parity even,orbital singlet and spin triplet pairing state as the ground state of the newly discovered super-conductor $LaO_{1-x}F_xFeAs$.The pairing mechanism involves both the special shape of the electron fermi surface and the strong ferromagnetic fluctuation induced by Hund's rule coupling.The special behavior of

Lei Fang, Huan Yang, Peng Cheng, Xiyu Zhu

We report the synthesizing and characterization of the hole doped Ni-based superconductor ($La_{1-x}Sr_{x})ONiAs$. By substituting La with Sr, the superconducting transition temperature $T_c$ is increased from 2.75 K of the parent phase $LaONiAs$ to 3.7 K at the doping levels x= 0.1 - 0.2. The curve $T_c$ versus hole concentration shows a symmetric behavior

Jaime Gutierrez, David Sevilla

A classical theorem by Ritt states that all the complete decomposition chains of a univariate polynomial satisfying a certain tameness condition have the same length. In this paper we present our conclusions about the generalization of these theorem in the case of finite coefficient fields when the tameness condition is dropped.

Agapitos Hatzinikitas, Jiannis K. Pachos

Fox's H-function provide a unified and elegant framework to tackle several physical phenomena. We solve the space fractional diffusion equation on the real line equipped with a delta distribution initial condition and identify the corresponding H-function by studying the small $x$ expansion of the solution. The asymptotic expansions near zero and infinit

J. Piest

The derivation of the Navier-Stokes equation starting from the Liouville equation using projector techniques yields a friction term which is nonlinear in the velocity. As has been explained in the 1. version of this paper, when the second-order part of the term is non-zero, this leads to an incorrect formula for the equation. In this 2. version, it is shown

A. P. Young, S. Knysh, V. N. Smelyanskiy

We study the typical (median) value of the minimum gap in the quantum version of the Exact Cover problem using Quantum Monte Carlo simulations, in order to understand the complexity of the quantum adiabatic algorithm (QAA) for much larger sizes than before. For a range of sizes, N <= 128, where the classical Davis-Putnam algorithm shows exponential median co

Jan A. Bergstra, Inge Bethke, Alban Ponse

Let Q_0 denote the rational numbers expanded to a &#34;meadow&#34;, that is, after taking its zero-totalized form (0^{-1}=0) as the preferred interpretation. In this paper we consider &#34;cancellation meadows&#34;, i.e., meadows without proper zero divisors, such as $Q_0$ and prove a generic completeness result. We apply this result to cancellation meadows

Markus Aichhorn, Martin Hohenadler, Charles Tahan, Peter B. Littlewood

The superfluid to Mott insulator transition in cavity polariton arrays is analyzed using the variational cluster approach, taking into account quantum fluctuations exactly on finite length scales. Phase diagrams in one and two dimensions exhibit important non-mean-field features. Single-particle excitation spectra in the Mott phase are dominated by particle

Yves Elskens

The one-dimensional motion of $N$ particles in the field of many incoherent waves is revisited numerically. When the wave complex amplitudes are independent, with a gaussian distribution, the quasilinear approximation is found to always overestimate transport and to become accurate in the limit of infinite resonance overlap.

F. Bournaud, E. Daddi, B. G. Elmegreen, D. M. Elmegreen

We investigate the properties of a clump-cluster galaxy at redshift 1.57. The morphology of this galaxy is dominated by eight star-forming clumps in optical observations, and has photometric properties typical of most clump-cluster and chain galaxies. Its complex asymmetrical morphology has led to the suggestion that this system is a group merger of several

Jaykov Foukzon, S. A. Podosenov

Simple derivation of the classical generalized Moller-Wu-Lee transformations from general master equation is presented.We will argue that in fact we can implement Born&#39;s notion of rigid motion in both flat spacetime and arbitrary curved non-holonomic spacetimes containing classical and Colombeau&#39;s distributional sources.

Anirban Saha

A thorough analysis of Galilean symmetries for the gravitational well problem on a noncommutative plane is presented. A complete closure of the one-parameter centrally extended Galilean algebra is realised for the model. This implies that the field theoretic model constructed to describe noncommutative gravitational quantum well in \cite{ani} is indeed indep

Shiva Prasad Kasiviswanathan, Adam Smith

Differential privacy is a definition of "privacy'" for algorithms that analyze and publish information about statistical databases. It is often claimed that differential privacy provides guarantees against adversaries with arbitrary side information. In this paper, we provide a precise formulation of these guarantees in terms of the inferences drawn by a Bay

M. J. Coe, M. Schurch, R. H. D. Corbet, J. Galache

Optical and X-ray observations are presented here of a newly reported X-ray transient system in the Small Magellanic Cloud. The data reveal many previously unknown X-ray detections of this system and clear evidence for a 49.995d binary period. In addition, the optical photometry show recurring outburst features at the binary period which may well be indicati

Sudipta Das, Narayan Banerjee

In this paper it is shown that in Brans - Dicke theory, if one considers a non-minimal coupling between the matter and the scalar field, it can give rise to a late time accelerated expansion for the universe preceded by a decelerated expansion for very high values of the Brans - Dicke parameter $ω$.

Giorgio Faina, Cristiano Parrettini, Fabio Pasticci

In PG(2,32) the following two results are proven by a computer aided search. (i) Uniqueness of hyperfocused 12-arcs, up to projectivities; (ii) Non-existence of hyperfocused 14-arcs. The existence problem for hyperfocused 16-arcs remains open.

J. M. Ramírez, S. Komossa, V. Burwitz, S. Mathur

We present an analysis of our Chandra Low Energy Transmission Grating Spectrometer (LETGS) observation of the quasar MR2251-178. The warm absorber of MR2251-178 is well described by a hydrogen column density, N_H~2x10^21 cm^-2, and an ionization parameter log(xi)~0.6. We find in the spectrum weak evidence for narrow absorption lines from Carbon and Nitrogen

I. Hambleton, L. R. Taylor, E. B. Williams

We define and study the Burnside quotient Green ring of a Mackey functor. Some refinements of Dress induction theory are presented, together with applications to computation results for $K$-theory and $L$-theory of finite and infinite groups.

Reinhold Oppermann, Manuel J. Schmidt

A scaling theory of replica symmetry breaking (RSB) in the SK-model is presented in the framework of critical phenomena for the scaling regime of small inverse RSB-orders, small temperatures, small magnetic fields, and near opposite pseudo-dynamic limits. We employ the pseudo-dynamical picture (PRL98, 127201 (2007)) with two critical points, where separated

Guanghao Jin, Jin-Hee Yoon, Dongwoo Cha

We applied our recently proposed empirical formula, a formula quite successful in describing essential trends of the lowest excitation energies of the natural parity even multipole states, to the lowest excitation energies of the natural parity odd multipole states in even-even nuclei throughout the entire periodic table. Even though the systematic behavior

Debasish Banerjee, R. V. Gavai, Sayantan Sharma

The thermodynamics of massless ideal gas of overlap quarks has been investigated both analytically and numerically for both zero and nonzero baryon chemical potential. Any μ^2-divergence is shown analytically to be absent for a class of actions with nonzero chemical potential. All such actions are shown to violate chiral invariance. While the parameter M can

Tomoya Ono

The electron-transport properties of single-row monoatomic nanowires made of 5$d$ elements are examined by first-principles calculations based on the density functional theory. We found that oscillation patterns with a period longer than two-atom length are dominant in the conductance of Ir and Pt monoatomic nanowires, although the transmission of the $s$-$d

Yann Palu

We compute the Grothendieck group of certain 2-Calabi--Yau triangulated categories appearing naturally in the study of the link between quiver representations and Fomin--Zelevinsky&#39;s cluster algebras. In this setup, we also prove a generalization of Fomin--Zelevinsky&#39;s mutation rule.

Ye Jun, Yue Li, Yu Liu, Sha Hua

There is much interest in the multiparty quantum communications where quantum teleportation using high dimensional entangled quantum channel is one of the promising tools. In this paper, we propose a more general scheme for M-party controlled teleportation of an arbitrary N-particle quantum state using N-1 identical Einstein-Podolsky-Rosen pairs and one (M+2

Urna Basu, P. K. Mohanty

We introduce an auto-regressive model which captures the growing nature of realistic markets. In our model agents do not trade with other agents, they interact indirectly only through a market. Change of their wealth depends, linearly on how much they invest, and stochastically on how much they gain from the noisy market. The average wealth of the market cou

J. C. Eilbeck, S. Matsutani, Y. Onishi

We discuss a family of multi-term addition formulae for Weierstrass functions on specialized curves of genus one and two with many automorphisms. In the genus one case we find new addition formulae for the equianharmonic and lemniscate cases, and in genus two we find some new addition formulae for a number of curves, including the Burnside curve.

Gaetan Bisson, Takakazu Satoh

The Brezing-Weng method is a general framework to generate families of pairing-friendly elliptic curves. Here, we introduce an improvement which can be used to generate more curves with larger discriminants. Apart from the number of curves this yields, it provides an easy way to avoid endomorphism rings with small class number.

A. Pinter, M. Lücke, Ch. Hoffmann

Previous numerical investigations of the stability and bifurcation properties of different nonlinear combination structures of spiral vortices in a counterrotating Taylor-Couette system that were done for fixed axial wavelengths are supplemented by exploring the dependence of the vortex phenomena waves on their wavelength. This yields information about the e

Nuno Franco, Luis Silva

We describe the Lorenz links generated by renormalizable Lorenz maps with reducible kneading invariant $(K_f^-,K_f^+)=(X,Y)*(S,W)$, in terms of the links corresponding to each factor. This gives one new kind of operation that permits us to generate new knots and links from old. Using this result we obtain explicit formulas for the genus and the braid index o

Paweł Sieczka, Janusz A. Hołyst

In this paper we analyzed dependencies in commodity markets investigating correlations of future contracts for commodities over the period 1998.09.01 - 2007.12.14. We constructed a minimal spanning tree based on the correlation matrix. The tree provides evidence for sector clusterization of investigated contracts. We also studied dynamical properties of comm

Nicolae Mihalache

We show that Fatou components of a semi-hyperbolic rational map are John domains and that the converse does not hold. This generalizes a famous result of Carleson, Jones and Yoccoz. We show that a connected Julia set is locally connected for a large class of non-uniformly hyperbolic rational maps. This class is more general than semi-hyperbolicity and includ

J. A. Aguilar-Saavedra

We investigate single top production in the presence of anomalous Wtb couplings. We explicitly show that, if these couplings arise from gauge invariant effective operators, the only relevant couplings for single top production and decay are the usual gamma^mu and sigma^mu nu q_nu terms, where q is the W boson momentum. This happens even in the single top pro

G. K. Chaudhary, R. Ramakumar

In this paper, we present results of our calculations on the effects of next to nearest neighbor boson hopping ($t^{\prime}$) energy on Bose-Einstein condensation in cubic lattices. We consider both non-interacting and repulsively interacting bosons moving in the lowest Bloch band. The interacting bosons are studied making use of the Bogoliubov method. We fi

A. D. Dolgov

This is a brief review for particle physicists on cosmological impact of neutrinos and on restrictions on neutrino properties from cosmology. The paper includes discussion of upper bounds on neutrino mass and possible ways to relax them, methods to observe the cosmic neutrino background, bounds on the cosmological lepton asymmetry which are strongly improved

Floriana Gargiulo, Alberto Mazzoni

Many models have been proposed to explain opinion formation in groups of individuals; most of these models study opinion propagation as the interaction between nodes/agents in a social network. Opinion formation is a complex process and a realistic model should also take into account the important feedbacks that the opinions of the agents have on the structu

ZEUS Collaboration

The charged multiplicity distributions and the mean charged multiplicity have been investigated in inclusive neutral current deep inelastic $ep$ scattering with the ZEUS detector at HERA, using an integrated luminosity of 38.6 pb$^{-1}$. The measurements were performed in the current region of the Breit frame, as well as in the current fragmentation region o

H. C. Potter

For over a century physicists have sought a mathematical theory that unites the dual, wave and corpuscle, behaviors that light exhibits. In the early twentieth century H. Bateman was studying a solution that uses wave functions with singularities to mark light quanta location in space and time as potential singularities do for material particles. He publishe

Danila O. Revin, Evgenii P. Vdovin

In the paper we obtain an existence criterion for Hall subgroups of finite groups in terms of a composition series.

Alvaro Arias, Frederic Latremoliere

We describe the structure of the irreducible representations of crossed products of unital C*-algebras by actions of finite groups in terms of irreducible representations of the C*-algebras on which the groups act. We then apply this description to derive a characterization of irreducible representations of crossed-products by finite cyclic groups in terms o

S. B. Igamov, R. Yarmukhamedov

A new analysis of the precise experimental astrophysical S-factors for the direct capture $^7Be(p,γ)$ $^8B$ reaction [A.J.Junghans et al.Phys.Rev. C 68 (2003) 065803 and L.T. Baby et al. Phys.Rev. C 67 (2003) 065805] is carried out based on the modified two - body potential approach in which the direct astrophysical S-factor, $ {\rm S_{17}(E)}$, is expressed

Ashoke Sen

We derive the wall crossing formula for the decay of a quarter BPS dyon into a pair of half-BPS dyons by analyzing the quantum dynamics of multi-centered black holes in N=4 supersymmetric string theories. Our analysis encompasses the cases where the final decay products are non-primitive dyons. The results are in agreement with the microscopic formula for th

Alex S. Leong, Subhrakanti Dey, Jamie S. Evans

This paper considers state estimation of linear systems using analog amplify and forwarding with multiple sensors, for both multiple access and orthogonal access schemes. Optimal state estimation can be achieved at the fusion center using a time varying Kalman filter. We show that in many situations, the estimation error covariance decays at a rate of $1/M$

Alexander Tchekhovskoy, Jonathan C. McKinney, Ramesh Narayan

Long-duration gamma-ray bursts (GRBs) require an engine capable of driving a jet of plasma to ultrarelativistic bulk Lorentz factors of up to several hundred and into narrow opening angles of a few degrees. We use global axisymmetric stationary solutions of magnetically-dominated (force-free) ultrarelativistic jets to test whether the popular magnetic-drivin