April 2009 arXiv papers — page 20

T. Mei

Based on the MRDP theorem, we introduce the ideas of the proof equation of a formula and universal proof equation of Peano Arithmetic (PA); and then, combining universal proof equation and Gödel's Second Incompleteness Theorem, it is proved that, if PA is consistent, then for every axiom and every theorem of PA, we can construct a corresponding undecidab

S. Banisch, T. Araújo, J. Louçã

This paper examines the interplay of opinion exchange dynamics and communication network formation. An opinion formation procedure is introduced which is based on an abstract representation of opinions as $k$--dimensional bit--strings. Individuals interact if the difference in the opinion strings is below a defined similarity threshold $d_I$. Depending on $d

René David

I show that, if a term is $SN$ for $β$, it remains $SN$ when some permutation rules are added.

I. V. Lindell, A. H. Sihvola

A set of four scalar conditions involving normal components of the fields D and B and their normal derivatives at a planar surface is introduced, among which different pairs can be chosen to represent possible boundary conditions for the electromagnetic fields. Four such pairs turn out to yield meaningful boundary conditions and their responses for an incide

S. Casanova, F. A. Aharonian, Y. Fukui, S. Gabici

The advent of high sensitivity, high resolution gamma-ray detectors, together with a knowledge of the distribution of the atomic hydrogen and especially of the molecular hydrogen in the Galaxy on sub-degree scales creates a unique opportunity to explore the flux of cosmic rays in the Galaxy. We here present the new data on the distribution of the molecular h

Songbai Chen, Jiliang Jing

In this letter we consider a dark energy model in which the energy density is a function of the Hubble parameter $H$ and its derivative with respect to time $ρ_{de}=3α\ddot{H}H^{-1}+3β\dot{H}+3γH^2$. The behavior of the dark energy and the expansion history of the Universe depend heavily on the parameters of the model $α$, $β$ and $γ$. It is very interesting

Behzad Lari, Ali Saif M. Hassan, Pramod S. Joag

We develop a geometric approach to quantify the capability of creating entanglement for a general physical interaction acting on two qubits. We use the entanglement measure proposed by us for $N$-qubit pure states (PRA \textbf{77}, 062334 (2008)). Our procedure reproduces the earlier results (PRL \textbf{87}, 137901 (2001)). The geometric method has the dist

Hironari Okada, Hiroyuki Takahashi, Yoshikazu Mizuguchi, Yoshihiko Takano

We performed magnetization and electrical resistivity measurements under high pressures of up to 19 GPa for FeTe0.92. The compound shows an anomaly in magnetization and resistivity at atmospheric pressure due to a structural distortion accompanied by a magnetic transition. We also observed magnetic and resistive anomalies under high pressure, suggesting that

Bing Zhang, Asaf Pe'er

The composition of gamma-ray burst (GRB) ejecta is still a mystery. The standard model invokes an initially hot ``fireball'' composed of baryonic matter. Here we analyze the broad band spectra of GRB 080916C detected by the Fermi satellite. The featureless Band-spectrum of all five epochs as well as the detections of >~10 GeV photons in this burst pl

Baojiu Li, Hongsheng Zhao

We propose a new framework unifying cold dark matter (CDM) and Modified Newtonian Dynamics (MOND) to solve their respective problems on galactic scales and large scale structure formation. In our framework the dark matter clusters on large scales but not on galactic scales. This environment dependence of the dark matter behaviors is controlled by a vector fi

Jian-Hua Gao, Bo-Wen Xiao

In this paper, we investigate deep inelastic and elastic scattering on a polarized spin-1/2 hadron using gauge/string duality. This spin-1/2 hadron corresponds to a supergravity mode of the dilatino. The polarized deep inelastic structure functions are computed in supergravity approximation at large t' Hooft coupling $λ$ and finite $x$ with $λ^{-1/2}\ll

M. Debessai, J. J. Hamlin, J. S. Schilling, Y. Meng

The dependence of the superconducting transition temperature Tc of CaC6 has been determined as a function of hydrostatic pressure in both helium-loaded gas and diamond-anvil cells to 0.6 and 32 GPa, respectively. Following an initial increase at the rate +0.39(1) K/GPa, Tc drops abruptly from 15 K to 4 K at 10 GPa. Synchrotron x-ray measurements to 15 GPa po

Oleksandr Manzyuk

We prove that the 2-category of closed categories of Eilenberg and Kelly is equivalent to a suitable full 2-subcategory of the 2-category of closed multicategories.

Marcelo Samuel Berman

After a discussion on several limiting cases where General Relativity turns into less sophisticated theories, we find that in the correct thermodynamical and cosmological weak field limit of Einstein's field equations the entropy of the Universe is R^(3/2) -- dependent, where R stands for the radius of the causally related Universe. Thus, entropy grows i

P. C. Canfield, S. L. Bud'ko, N. Ni, J. Q. Yan

Study and comparison of over 30 examples of electron doped BaFe2As2 for transition metal (TM) = Co, Ni, Cu, and (Co/Cu mixtures) have lead to an understanding that the suppression of the structural/antiferromagnetic phase transition to low enough temperature in these compounds is a necessary condition for superconductivity, but not a sufficient one. Whereas

Jim Agler, John McCarthy, Greg Knese

We consider pairs of commuting isometries that are annihilated by a polynomial. We show that the polynomial must be inner toral, which is a geometric condition on its zero set. We show that cyclic pairs of commuting isometries are nearly unitarily equivalent if they are annihilated by the same minimal polynomial.

Ferihe Atalan

Let Ng be the connected closed nonorientable surface of genus g >= 5 and Mod(Ng) denote the mapping class group of Ng. We prove that the outer automorphism group of Mod(Ng) is either trivial or Z if g is odd, and injects into the mapping class group of sphere with four holes if g is even.

M. M. Nadareishvili, K. A. Kvavadze

The low temperature heat capacity investigations on pure(y=0) and Zn-doped La1.84Sr0.16Cu1-yZnyO4 samples have been performed in the interval of 1.8-60K by a new method of high-precision, pulsed differential calorimetry (PDC), which provides the measurements under the equilibrium conditions, in contrast to commonly used differential scanning calorimeters (DS

J. R. Thorstensen, R. Schwarz, A. D. Schwope, A. Staude

(Abridged). The cataclysmic binary V405 Peg, originally discovered as ROSAT Bright Source (RBS) 1955 (= 1RXS J230949.6+213523), shows a strong contribution from a late-type secondary star in its optical spectrum, which led Schwope et al. to suggest it to be among the nearest cataclysmic binaries. We present extensive optical observations of V405 Peg. Time-se

Dimitrios Giataganas

We find point-like and classical string solutions on the AdS_5 x X^5, where X^5 are the 5-dimensional Sasaki-Einstein manifolds Ypq and Lpqr. The number of acceptable solutions is limited drastically in order to satisfy the constraints on the parameters and coordinates of the manifolds. The energy of the solutions depends on the parameters of the Sasaki-Eins

M. Süzen

Given pseudo-random binary sequence of length $L$, assuming it consists of $k$ sub-sequences of length $N$. We estimate how $k$ scales with growing $N$ to obtain a {\it limiting} ergodic behaviour, to fulfill the basic definition of ergodicity (due to Boltzmann). The average of the consecutive sub-sequences plays the role of time (temporal) average. This ave

Fumi Egusa, Kotaro Kohno, Yoshiaki Sofue, Hiroyuki Nakanishi

We present a revised method for simultaneous determination of the pattern speed and star formation timescale of spiral galaxies, its application, and results for CO and Ha images of nearby spiral galaxies. Out of 13 galaxies, we were able to derive the 2 parameters for 5 galaxies. We categorize them as "C" galaxies, and find (1) The corotation radius is clos

Susanna Fishel, Monica Vazirani

It is well-known that Catalan numbers $C_n = \frac{1}{n+1} \binom{2n}{n}$ count the number of dominant regions in the Shi arrangement of type $A$, and that they also count partitions which are both $n$-cores as well as $(n+1)$-cores. These concepts have natural extensions, which we call here the $m$-Catalan numbers and $m$-Shi arrangement. In this paper, we

Chris P. Korthals Altes

The spatial 't Hooft loop measures the colour electric flux in SU(N)/Z(N) gauge theory. It is a closed loop of Dirac Z(N) flux and has strength k=1, 2,.., N-1. It is analyzed for generic k and small gauge coupling in the high temperature phase of {\cal N} =1, 2 and 4 SUSY theory up and including cubic order. In one loop order no qualitative difference wi

Ian U. Roederer, Karl-Ludwig Kratz, Anna Frebel, Norbert Christlieb

We examine the Pb and Th abundances in 27 metal-poor stars (-3.1 < [Fe/H] < -1.4) whose very heavy metal (Z > 56) enrichment was produced only by the rapid (r-) nucleosynthesis process. New abundances are derived from HST/STIS, Keck/HIRES, and VLT/UVES spectra and combined with other measurements from the literature to form a more complete picture of nucleos

Alexander Weiße

Microscopic models of classical degrees of freedom coupled to non-interacting fermions occur in many different contexts. Prominent examples from solid state physics are descriptions of colossal magnetoresistance manganites and diluted magnetic semiconductors, or auxiliary field methods for correlated electron systems. Monte Carlo simulations are vital for an

Christopher S. Reynolds, Andrew C. Fabian, Laura W. Brenneman, Giovanni Miniutti

Complexities in the X-ray spectrum of the nearby Seyfert 1.2 galaxy MCG-6-30-15 are commonly interpreted in terms of a broad iron line and the associated Compton reflection hump from the innermost relativistic regions of an accretion disk around a rapidly spinning black hole. However, an alternative model has recently been proposed in which these spectral fe

Gunnar Moller, Nigel R. Cooper

We study the groundstates of cold atomic gases on rotating optical lattices, as described by the Bose-Hubbard model in a uniform effective magnetic field. Mapping the bosons to composite fermions leads to the prediction of quantum Hall fluids that have no counterpart in the continuum. We construct trial wavefunctions for these phases, and perform numerical t

Ewan Cameron, Simon P. Driver, Alister W. Graham, Jochen Liske

We investigate the origin of the galaxy color-concentration bimodality at the bright-end of the luminosity function (M(B) - 5 log h < -18 mag) with regard to the bulge-disc nature of galaxies. Via (2D) surface brightness profile modeling with GIM2D, we subdivide the local galaxy population in the Millennium Galaxy Catalogue into one-component and two-compone

Tereasa G. Brainerd, Ingolfur Agustsson, Chad A. Madsen, Jeffrey A. Edmonds

We compute the two-point image correlation function for bright galaxies in the seventh data release of the Sloan Digital Sky Survey (SDSS) over angular scales 0.01&#39; <= θ<= 120&#39; and projected separations 0.01 Mpc <= r <= 10 Mpc. We restrict our analysis to SDSS galaxies with accurate spectroscopic redshifts, and we find strong evidence for intrinsic a

Andreas Björklund, Thore Husfeldt, Petteri Kaski, Mikko Koivisto

It is shown that one can count $k$-edge paths in an $n$-vertex graph and $m$-set $k$-packings on an $n$-element universe, respectively, in time ${n \choose k/2}$ and ${n \choose mk/2}$, up to a factor polynomial in $n$, $k$, and $m$; in polynomial space, the bounds hold if multiplied by $3^{k/2}$ or $5^{mk/2}$, respectively. These are implications of a more

Laura I. Cervino, Alvin. K. Y. Chao, Ajay Sandhu, Steve B. Jiang

Lung tumor motion due to respiration poses a challenge in the application of modern three-dimensional conformal radiotherapy. Direct tracking of the lung tumor during radiation therapy is very difficult without implanted fiducial markers. Indirect tracking relies on the correlation of the tumor&#39;s motion and the surrogate&#39;s motion. The present paper p

Wilson Simeoni

This paper examines the transition from isotropic to anisotropic beam profiles in a linear focusing channel. Considering a high-intensity ion beam in space-charge dominated regime and large mismatched {\it RMS} beam size initially, observe a fast anisotropy situation of the beam, characterized for a transition of the transversal section round to elliptical w

Giovanni Peccati, Jean-Renaud Pycke

It is proved that each Hoeffding space associated with a random permutation (or, equivalently, with extractions without replacement from a finite population) carries an irreducible representation of the symmetric group, equivalent to a two-block Specht module.

Oliver Matte, Edgardo Stockmeyer

We consider two different models of a hydrogenic atom in a quantized electromagnetic field that treat the electron relativistically. The first one is a no-pair model in the free picture, the second one is given by the semi-relativistic Pauli-Fierz Hamiltonian. We prove that the no-pair operator is semi-bounded below and that its spectral subspaces correspond

Michael Dreyer, Jonghee Lee, Hui Wang, Barry Barker

We designed and implemented our own versatile simulation software in order to understand the velocity changes and track patterns observed in slow moving vortex lattices. The data was obtained from time series of STM images on NbSe$_2$ in a magnetic field range of 250-750 mT. The main thrust is to explore possible driving mechanism and to test the effect of v

C. Henkel, K. M. Menten, M. T. Murphy, N. Jethava

Based on measurements with the Effelsberg 100-m telescope, a multi-line study of molecular species is presented toward the gravitational lens system PKS1830-211. Obtaining average radial velocities and performing Large Velocity Gradient radiative transfer calculations, the aims of this study are (1) to determine the density of the gas, (2) to constrain the t

The BABAR Collaboration, B. Aubert

We report an analysis of tau- decaying into omega.pi-.nu_tau with omega -> pi+pi-pi0 using a data sample containing nearly 320 million tau pairs collected with the BABAR detector at the PEP-II B-Factory. We find no evidence for second-class currents and we set an upper limit of 0.69% at 90% confidence level for the fraction of second-class currents in this d

Michael A. Popov

An attempt of a new kind of complexity anthropology is considered.

Lasse Rempe, Gwyneth M. Stallard

Let $f$ and $g$ be transcendental entire functions, each with a bounded set of singular values, and suppose that $f$ and $g$ are affinely equivalent (that is, $g \circ ϕ= ψ\circ f$, where $ϕ,ψ:\C\to\C$ are affine). We show that the escaping sets of $f$ and $g$ have the same Hausdorff dimension. Using a result of the second author, we deduce that there exists

Gary R. Goldstein, Simonetta Liuti

Exclusive pi0 electroproduction from nucleons at large photon virtuality can be described in terms of Generalized Parton Distributions, particularly the chiral odd subset. Chiral odd GPDs are related to transversity and can be accessed experimentally for various special choices of observables. This is accomplished by choosing C-parity odd and chiral odd comb

Randall D. Peters, Sheng-Chiang &#34;John&#34; Lee

An optical mouse that is in common use with personal computers is employed to measure the motion of a pendulum. The pendulum can be monitored (i) realtime only, or (ii) also with data storage for later detailed analysis using Excel. The software developed for this purpose is a LabView executable algorithm. It allows the user to select among several modes tha

Philippe Goy, Sylvain Caroopen, Michel Gross

Quasi-Optical Characterization of Dielectric and Ferrite Materials are made in the millimeter-submillimeter range by using a Quasi-Optical (QO) benches that can be relatively compact, typically of the order 10cm wide and 1m long.

M. Correnti, M. Bellazzini, F. R. Ferraro

We report on the detection of a population of Red Clump (RC) stars probably associated with the recently discovered stellar system Bootes III. The RC is identified as a 3 sigma peak in the Luminosity Function (LF) of colour-selected stars extracted from the SDSS database. The peak is consistently detected in the g,r,i and z LFs at the expected luminosity of

I. Marinova, S. Jogee, A. Heiderman, F. D. Barazza

We present a study of bar and host disk evolution in a dense cluster environment, based on a sample of ~800 bright (MV <= -18) galaxies in the Abell 901/2 supercluster at z~0.165. We use HST ACS F606W imaging from the STAGES survey, and data from Spitzer, XMM-Newton, and COMBO-17. We identify and characterize bars through ellipse-fitting, and other morpholog

Piotr Sułkowski

We show how to represent a class of expressions involving discrete sums over partitions as matrix models. We apply this technique to the partition functions of 2* theories, i.e. Seiberg-Witten theories with the massive hypermultiplet in the adjoint representation. We consider theories in four, five and six dimensions, and obtain new matrix models respectivel

C. M. Fernandes, J. J. Merelo, A. C. Rosa

Traditional Genetic Algorithms (GAs) mating schemes select individuals for crossover independently of their genotypic or phenotypic similarities. In Nature, this behaviour is known as random mating. However, non-random schemes - in which individuals mate according to their kinship or likeness - are more common in natural systems. Previous studies indicate th

Jeong San Kim

We show that bipartite entanglement distribution (or entanglement of assistance) in multipartite quantum systems is by nature polygamous. We first provide an analytic upper bound for the concurrence of assistance in bipartite quantum systems, and derive a polygamy inequality of multipartite entanglement in arbitrary dimensional quantum systems.

Heping Hu, Yingyu Zhang, Zhengding Lu

We consider the problem of finding one or more desired items out of an unsorted database. Patel has shown that if the database permits quantum queries, then mere digitization is sufficient for efficient search for one desired item. The algorithm, called factorized quantum search algorithm, presented by him can locate the desired item in an unsorted database

John Abbott

We gather together several bounds on the sizes of coefficients which can appear in factors of polynomials in Z[x]; we include a new bound which was latent in a paper by Mignotte, and a few minor improvements to some existing bounds. We compare these bounds and show that none is universally better than the others. In the second part of the paper we give sever

D. Aristizabal Sierra, Luis Alfredo Muñoz, Enrico Nardi

We consider variations of the standard leptogenesis picture arising from the presence of an additional scale related to the breaking of a $U(1)_X$ abelian flavor symmetry. We show that quite generically the presence of an additional energy scale might introduce new qualitative and quantitative changes on leptogenesis. Especially interesting is the possibilit

Anisur Rahaman

A model where a Dirac fermion is coupled to background dilaton field is considered to study s-wave scattering of fermion by a background dilaton black hole. It is found that the anomaly plays a dual role on information loss scenario. Some time it protects the fermion from the dangerous information loss problem and some times it itself through it up towards t

Xinmao Wang, Yaokun Wu

A configuration of a graph is an assignment of one of two states, on or off, to each vertex of it. A regular move at a vertex changes the states of the neighbors of that vertex. A valid move is a regular move at an on vertex. The following result is proved in this note: given any starting configuration $x$ of a tree, if there is a sequence of regular moves w

Y. -F. Xiao, T. Q. Nhan, M. W. B. Wilson, J. M. Fraser

Single air-suspended carbon nanotubes (length 2 - 5 microns) exhibit high optical quantum efficiency (7 - 20%) for resonant pumping at low intensities. Under ultrafast excitation, the photoluminescence dramatically saturates for very low injected exciton numbers (2 to 6 excitons per pulse per SWCNT). This PL clamping is attributed to highly efficient exciton

Ramin Golestanian

The stochastic dynamics of colloidal particles with surface activity--in the form of catalytic reaction or particle release--and self-phoretic effects is studied analytically. Three different time scales corresponding to inertial effects, solute redistribution, and rotational diffusion are identified and shown to lead to a plethora of different regimes invol

D. Aristizabal Sierra, Luis Alfredo Muñoz, Enrico Nardi

We study a model for leptogenesis in which the total CP asymmetries in the decays and scatterings involving the SU(2) singlet seesaw neutrinos $N_α$ vanish ($ε_{N_α}=0$). Leptogenesis is possible due to non-vanishing CP violating lepton flavor asymmetries, realizing a situation in which the baryon asymmetry is due exclusively to flavor effects. We study the

Ganquan Xie, Jianhua Li, Feng Xie, Lee Xie

The GL electromagnetic (EM) modeling is used to simulate the 3D EM full wave field propagation through cloaks. The 3D GL simulation of the EM wave field excited by a point source outside of the cloaks has been done. The simulation of the EM wave field from the point source excitation inside of the cloak device is presented in this paper. By using the GL mode

Jeffrey Burdges, Adrien Deloro

We examine Weyl groups of minimal connected simple groups of finite Morley rank of degenerate type. We show that they are cyclic, and lift isomorphically to subgroups of the ambient group.

A. Zocco, L. Chacon, Andrei N. Simakov

Inertial effects in nonlinear magnetic reconnection are studied within the context of 2D electron magnetohydrodynamics (EMHD) with resistive and viscous dissipation. Families of nonlinear solutions for relevant current sheet parameters are predicted and confirmed numerically in all regimes of interest. Electron inertia becomes important for current sheet thi

Tuna Altinel, Jeffrey Burdges

We prove that in a connected group of finite Morley rank the centralizers of decent tori are connected. We then apply this result to the analysis of minimal connected simple groups of finite Morley rank. Our applications include general covering properties by Borel subgroups, the description of Weyl groups and the analysis of toral automorphisms.

Abdullah Algin

We discuss possible connections between the thermostatistical properties of a gas of the two-parameter deformed bosonic particles called Fibonacci oscillators and the properties of the Tsallis thermostatistics. In this framework, we particularly focus on a comparison of the non-extensive entropy functions expressed by these two generalized theories. We also

Pierre Labeye

It has been recently demonstrated that integrated optics could enhance accuracy, stability, and ease of use of stellar interferometry techniques. The subject of this thesis is the study of an optical component based on singlemode waveguides for the coherent recombining of optical beams coming from four telescopes. Proposed architecture provides a simultaneou

Barrie Tonkinson

While adhering to the formalism of Special and General Relativity, this paper considers the interpretation of clock rates and the rating of clocks in detail. We also pay particular attention to the crucial requirement of reciprocity between inertial frames. Our overriding concern is to bring out a distinction between clocks which run slow (slowly) in the eve

Chuong V. Tran, Luke Blackbourn

We derive upper bounds for the number of degrees of freedom of two-dimensional Navier--Stokes turbulence freely decaying from a smooth initial vorticity field $ω(x,y,0)=ω_0$. This number, denoted by $N$, is defined as the minimum dimension such that for $n\ge N$, arbitrary $n$-dimensional balls in phase space centred on the solution trajectory $ω(x,y,t)$, fo

Jeffrey Burdges

We modify the Frecon-Jaligot construction of Carter subgroups to show that a degenerate type group has a Carter subgroup invariant under the Sylow 2-subgroup of a group of automorphisms; thus reducing the need to know that Carter subgroups are conjugate in degenerate type groups.

M. De Becker, M. Filho, T. Harries

In response to ESO&#39;s call for proposals for second generation instruments for the Very Large Telescope Interferometer (VLTI), a consortium is currently developing the VLTI-Spectro-Imager (VSI). In the context of the Phase A study, a science group has prepared a science case taking advantage of the expected performances of VSI. Among several science topic

M. De Becker

Massive binaries are crucial laboratories that allow us to investigate processes occurring in quite extreme conditions, such as particle acceleration, high-energy emission, or even dust formation. All these processes are intimately dependent on binarity. Our understanding of the underlying physics strongly requires preliminary multiplicity studies likely to

J. Ebrero, S. Mateos, G. C. Stewart, F. J. Carrera

In this paper we present the two-point angular correlation function of the X-ray source population of 1063 XMM-Newton observations at high Galactic latitudes, comprising up to ~30000 sources over a sky area of 125.5 sq. deg, in three energy bands: 0.5-2 (soft), 2-10 (hard), and 4.5-10 (ultrahard) keV. We have measured the angular clustering of our survey and

Myeongju Chae, Yonggeun Cho, Sanghyuk Lee

In this paper we establish mixed norm estimates of interactive Schrödinger waves and apply them to study smoothing properties and global well-posedness of the nonlinear Schrödinger equations with mass critical nonlinearity.

Myeongju Chae, Sunggeum Hong, Sanghyuk Lee

We consider the mass concentration phenomenon for the $L^2$-critical nonlinear Schrödinger equations of higher orders. We show that any solution $u$ to $iu_{t} + (-Δ)^{\fracα2} u =\pm |u|^\frac{2α}{d}u$, $u(0,\cdot)\in L^2$ for $α>2$, which blows up in a finite time, satisfies a mass concentration phenomenon near the blow-up time. We verify that as $α$ incre

Roelof Bruggeman, Fritz Grunewald, Roberto Miatello

Let $Γ$ be an irreducible lattice in $\PSL_2(\RR)^d$ ($d\in\NN$) and $z$ a point in the $d$-fold direct product of the upper half plane. We study the discrete set of componentwise distances ${\bf D}(\Gm,z)\subset \RR^d$ defined in (1). We prove asymptotic results on the number of $\gm\in\Gm$ such that $d(z,γz$ is contained in strips expanding in some directi

Fangzhou Liu, Subir Sachdev

Motivated by recent experiments on TmB4 (arXiv:0712.1537), we examine the phase diagram of the Shastry-Sutherland antiferromagnet in an applied magnetic field in the limit of strong Ising anisotropy. In classical Ising limit, we demonstrate that the only fractional magnetization plateau is at 1/3 of the saturated magnetization. We study the perturbative infl

M. Wimmer, M. Lobenhofer, J. Moser, A. Matos-Abiague

We report experiments on epitaxially grown Fe/GaAs/Au tunnel junctions demonstrating that the tunneling anisotropic magnetoresistance (TAMR) effect can be controlled by a magnetic field. Theoretical modelling shows that the interplay of the orbital effects of a magnetic field and the Dresselhaus spin-orbit coupling in the GaAs barrier leads to an independent

P. F. Harrison, D. R. J. Roythorne, W. G. Scott

The latest fits to the CKM matrix indicate that alpha=(90.7+4.5-2.9) degrees. The proximity of alpha to a right-angle raises the question: is it merely accidental or is it due to some physics beyond the Standard Model? In the framework of our recently-proposed flavour permutation symmetry, we consider the similarities between the quark and lepton mixing matr

Gábor Wiener, Makoto Araya

We present a planar hypohamiltonian graph on 42 vertices and show some consequences.

Igor Bjelakovic, Holger Boche, Janis Noetzel

We determine the optimal achievable rate at which entanglement can be reliably transmitted when the memoryless channel used during transmission is unknown both to sender and receiver. To be more precise, we assume that both of them only know that the channel belongs to a given set of channels. Thus, they have to use encoding and decoding schemes that work we

David A. Towers, Vicente R. Varea

A finite-dimensional Lie algebra $L$ over a field $F$ of characteristic zero is called elementary if each of its subalgebras has trivial Frattini ideal; it is an $A$-algebra if every nilpotent subalgebra is abelian. This paper is a continuation of the study of these algebras initiated by the authors in `Elementary Lie Algebras and Lie A-algebras&#39;, J. Alg

G. Brida, V. Caricato, M. Genovese, M. Gramegna

We verified operational approach based on direct measurement of entanglement degree for bipartite systems. In particular spectral distributions of single counts and coincidence for pure biphoton states generated by train of short pump pulses have been measured and entanglement quantifier calculated. The approach gives upper bound of entanglement stored in to

N. A. Kivel, M. V. Polyakov, A. A. Vladimirov

We develop the method of calculation of the leading chiral (infrared) logarithms to an arbitrary loop order for various form factors of Nambu-Goldstone bosons. The method is illustrated on example of scalar and vector form factors in massless 4D O(N+1)/O(N) sigma-model. The analytical properties of the form factors are derived. The leading chiral (infrared)

Emil Prodan, Roberto Car

We present an extended discussion of a recently proposed theoretical approach for off-resonance tunneling transport. The proofs and the arguments are explained at length and simple analogies and illustrations are used where possible. The result is an analytic formula for the asymptotic tunneling conductance which involves the overlap of three well defined ph

Guillermo F. Hagele, Angeles I. Diaz, Monica V. Cardaci, Elena Terlevich

(Abridged) Gas and star velocity dispersions have been derived for four circumnuclear star-forming regions (CNSFRs) and the nucleus of the spiral galaxy NGC2903 using high resolution spectroscopy in the blue and far red. Stellar velocity dispersions have been obtained from the CaII triplet (CaT) lines at 8494, 8542, 8662A, using cross-correlation techniques

Simone Marsili, Piero Procacci

We present non equilibrium molecular dynamics experiments of the unfolding and refolding of an alanine decapeptide in vacuo subject to a Nose-Hoover thermostat. Forward (unfolding) and reverse (refolding) work distribution are numerically calculated for various duration times of the non equilibrium experiments. Crooks theorem is accurately verified for all n

Wong Jian Cheng, Lian Heng, Cheong Siew Ann

In this paper, we perform statistical segmentation and clustering analysis of the Dow Jones Industrial Average time series between January 1997 and August 2008. Modeling the index movements and log-index movements as stationary Gaussian processes, we find a total of 116 and 119 statistically stationary segments respectively. These can then be grouped into be

Wojciech Broniowski, Enrique Ruiz Arriola

We show the results of low-energy chiral quark models for soft matrix elements involving pions and photons. Such soft elements, upon convolution with the hard matrix elements, are relevant in various high-energy processes. We focus on quantities related to the generalized parton distributions of the pion: the parton distribution functions, the parton distrib

Pierre Patie

The purpose of this note is to describe, in terms of a power series, the distribution function of the exponential functional, taken at some independent exponential time, of a spectrally negative Lévy process ξwith unbounded variation. We also derive a Geman-Yor type formula for Asian options prices in a financial market driven by e^ξ.

R. Decarli, M. T. Reynolds, M. Dotti

We present a photometric FUV to Ks-band study of the field around quasar SDSS J092712.65+294344.0. The SDSS spectrum of this object shows various emission lines with two distinct redshifts, at z=0.699 and z=0.712. Because of this peculiar spectroscopic feature this source has been proposed as a candidate recoiling or binary black hole. A third alternative mo

Andrew Melatos, Lila Warszawski

The scale-invariant glitch statistics observed in individual pulsars (exponential waiting-time and power-law size distributions) are consistent with a critical self-organization process, wherein superfluid vortices pin metastably in macroscopic domains and unpin collectively via nearest-neighbor avalanches. Macroscopic inhomogeneity emerges naturally if pinn

M. Juvela, K. Mattila, D. Lemke, U. Klaas

The cosmic infrared background (CIRB) consists mainly of the integrated light of distant galaxies. In the far-infrared the current estimates of its surface brightness are based on the measurements of the COBE satellite. Independent confirmation of these results is still needed from other instruments. In this paper we derive estimates of the far-infrared CIRB

Zhao-Qing Feng, Gen-Ming Jin

Within the framework of the improved isospin dependent quantum molecular dynamics (ImIQMD) model, the pion emission in heavy-ion collisions in the region 1 A GeV is investigated systematically, in which the pion is considered to be mainly produced by the decay of resonances $\triangle$(1232) and N*(1440). The in-medium dependence and Coulomb effects of the p

S. Pires, J. -L. Starck, A. Amara, A. Refregier

Weak gravitational lensing provides a unique method to map directly the dark matter in the Universe. The majority of lensing analyses uses the two-point statistics of the cosmic shear field to constrain the cosmological model yielding degeneracies, such as that between sigma_8 and Omega_M respectively the r.m.s. of the mass fluctuations at a scale of 8 Mpc/h

Zhao-Qing Feng, Jun-Qing Li, Gen-Ming Jin

Within the framework of the dinuclear system (DNS) model, the production cross sections of superheavy nuclei Hs (Z=108) and Z=112 combined with different reaction systems are analyzed systematically. It is found that the mass asymmetries and the reaction Q values of the combinations play a very important role on the formation cross sections of the evaporatio

B. Lorenz, B. N. J. Persson

Seals are extremely useful devices to prevent fluid leakage. We present experimental results for the leak-rate of rubber seals, and compare the results to a novel theory, which is based on percolation theory and a recently developed contact mechanics theory. We find good agreement between theory and experiment.

Arnaud Liefooghe, Laetitia Jourdan, El-Ghazali Talbi

This paper gives a concise overview of evolutionary algorithms for multiobjective optimization. A substantial number of evolutionary computation methods for multiobjective problem solving has been proposed so far, and an attempt of unifying existing approaches is here presented. Based on a fine-grained decomposition and following the main issues of fitness a

E. Lhotel, E. N. Khatsko, C. Paulsen

We have shown that resonant quantum tunnelling of the magnetisation (QTM), until now observed only in 0D cluster systems (SMMs), occurs in the molecular Ising spin chain, CoTAC ([(CH_3)_3NH]CoCl_3 - 2H_2O) which orders as a canted 3D-antiferromagnet at T_C=4.15 K. This effect was observed around a resonant like field value of 1025 Oe. We present here measure

Andrew G. Semenov, Dmitri S. Golubev, Andrei D. Zaikin

We theoretically analyze the effect of electron-electron interactions on Aharonov-Bohm (AB) current oscillations in ring-shaped systems with metallic quantum dots pierced by external magnetic field. We demonstrate that electron-electron interactions suppress the amplitude of AB oscillations $I_{AB}$ at all temperatures down to T=0 and formulate quantitative

E. Aristidi, E. Fossat, A. Agabi, D. Mekarnia

This paper analyses 3.5 years of site testing data obtained at Dome C, Antarctica, based on measurements obtained with three DIMMs located at three different elevations. Basic statistics of the seeing and the isoplanatic angle are given, as well as the characteristic time of temporal fluctuations of these two parameters, which we found to around 30 minutes a

Kirone Mallick

We use an effective Markovian description to study the long-time behaviour of a nonlinear second order Langevin equation with Gaussian noise. When dissipation is neglected, the energy of the system grows as with time a power-law with an anomalous scaling exponent that depends both on the confining potential and on the high frequency distribution of the noise

P. Figueira, F. Pont, C. Mordasini, Y. Alibert

The hot Neptune orbiting around GJ 436 is a unique example of an intermediate mass planet. Its close-in orbit suggests that the planet has undergone migration and its study is fundamental to understanding planet formation and evolution. As it transits its parent star, it is the only Neptune-mass extrasolar planet of known mass and radius, being slightly larg

George Casella, F. Javier Girón, M. Lina Martínez, Elías Moreno

It has long been known that for the comparison of pairwise nested models, a decision based on the Bayes factor produces a consistent model selector (in the frequentist sense). Here we go beyond the usual consistency for nested pairwise models, and show that for a wide class of prior distributions, including intrinsic priors, the corresponding Bayesian proced

Jussi Klemelä, Enno Mammen

We study estimation of a multivariate function $f:{\bf R}^d \to {\bf R}$ when the observations are available from function $Af$, where $A$ is a known linear operator. Both the Gaussian white noise model and density estimation are studied. We define an $L_2$ empirical risk functional, which is used to define an $δ$-net minimizer and a dense empirical risk min