October 2008 arXiv papers — page 30

S. Lizzit, Y. Zhang, K. L. Kostov, L. Petaccia

In previous work on adsorbate-induced surface core level shifts (SCLSs), the effects caused by O atom adsorption on Rh(111) and Ru(0001) were found to be additive: the measured shifts for first layer Ru atoms depended linearly on the number of directly coordinated O atoms. Density-functional theory calculations quantitatively reproduced this effect, allowed

C. Yang, B. N. J. Persson, J. Israelachvili, K. Rosenberg

The logarithmic relation between interfacial separation and squeezing pressure between randomly rough surfaces, has been predicted by both theory and experiment. However, the experimental slope between interfacial separation and logarithmic squeezing pressure, is slightly bigger than that predicted by theory. Here we present a detailed explanation on the slo

Ralf Gehrke, Philipp Gruene, Andre Fielicke, Gerard Meijer

Far-infrared vibrational spectroscopy by multiple photon dissociation has proven to be a very useful technique for the structural fingerprinting of small metal clusters. Contrary to previous studies on cationic V, Nb and Ta clusters, measured vibrational spectra of small cationic cobalt clusters show a strong dependence on the number of adsorbed Ar probe ato

Alex G. Muslimov, Alice K. Harding

We propose a simple analytic model for the innermost (within the light cylinder of canonical radius) structure of open-magnetic-field lines of a rotating neutron star (NS) with relativistic outflow of charged particles (electrons/positrons) and arbitrary angle between the NS spin and magnetic axes. We present the self-consistent solution of Maxwell's equ

P. J. Boyle

TRACER ('Transition Radiation Array for Cosmic Energetic Radiation') is a balloon borne instrument that has been developed to directly measure the composition and energy spectra of individual heavy elements up to 10^15 eV per particle. TRACER achieves a large geometric factor (5 m^2 sr) through the use of a Transition Radiation Detector utilizing arr

Artur Avila

We prove that the spectrum of the almost Mathieu operator is absolutely continuous if and only if the coupling is subcritical. This settles Problem 6 of Barry Simon's list of Schrödinger operator problems for the twenty-first century.

E. W. Nigel Glover, Ciaran Williams

We show that one-loop amplitudes in massless gauge theories can be determined from single cuts. By cutting a single propagator and putting it on-shell, the integrand of an n-point one-loop integral is transformed into an (n+2)-particle tree level amplitude. The single-cut approach described here is complementary to the double or multiple unitarity cut approa

A. H. Córsico, L. G. Althaus, M. M. Miller Bertolami, E. García-Berro

We reexamine the theoretical instability domain of pulsating DB white dwarfs (DBV or V777 Her variables). We performed an extensive $g$-mode nonadiabatic pulsation analysis of DB evolutionary models considering a wide range of stellar masses, for which the complete evolutionary stages of their progenitors from the ZAMS, through the thermally pulsing AGB and

A. Gaëtan, Y. Miroshnychenko, T. Wilk, A. Chotia

The dipole blockade between Rydberg atoms has been proposed as a basic tool in quantum information processing with neutral atoms. Here we demonstrate experimentally the Rydberg blockade of two individual atoms separated by 4 $μ$m. Moreover, we show that, in this regime, the single atom excitation is enhanced by a collective two-atom behavior associated with

Hilmar Forkel, Eberhard Klempt

We introduce an improved mass formula for the nucleon and delta resonances and show how it emerges from AdS/QCD in a straightforward extension of the 'metric soft wall' gravity dual. The resulting spectrum depends on just one adjustable parameter, characterizing confinement-induced IR deformations of the anti-de Sitter (AdS) metric, and on the fracti

Krzysztof Byczuk, Walter Hofstetter, Dieter Vollhardt

The magnetic ground state phase diagram of the disordered Hubbard model at half-filling is computed in dynamical mean-field theory supplemented with the spin resolved, typical local density of states. The competition between many-body correlations and disorder is found to stabilize paramagnetic and antiferromagnetic metallic phases at weak interactions. Stro

Thomas Hearty, Inseok Song, Sam Kim, Giovanna Tinetti

We have investigated mid-infrared spectra of Earth obtained by the Atmospheric Infrared Sounder (AIRS) instrument on-board the AQUA spacecraft to explore the characteristics that may someday be observed in extrasolar terrestrial planets. We have used the AIRS infrared (R ~ 1200; 3.75-15.4 microns) spectra to construct directly-observed high-resolution spectr

M. L. Gallin-Martel, L. Gallin-Martel, Y. Grondin, O. Rossetto

A detector using liquid Xenon (LXe) in the scintillation mode is studied for Positron Emission Tomography (PET) of small animals. Its specific design aims at taking full advantage of the Liquid Xenon scintillation properties. This paper reports on energy, time and spatial resolution capabilities of the first LXe prototype module equipped with a Position Sens

Onur Ozan Koyluoglu, Hesham El Gamal

This paper considers the generalized cognitive radio channel where the secondary user is allowed to reuse the frequency during both the idle and active periods of the primary user, as long as the primary rate remains the same. In this setting, the optimal power allocation policy with single-input single-output (SISO) primary and secondary channels is explore

Leonid Malyshkin, Stanislav Boldyrev

We investigate the growth and structure of magnetic fields amplified by kinematic dynamo action in turbulence with non-zero kinetic helicity. We assume a simple Gaussian velocity correlation tensor, which allows us to consider very large magnetic Reynolds numbers, up to one trillion. We use the kinematic Kazantsev-Kraichnan model of dynamo and find a complet

Charles E. Lane

The Double Chooz experiment returns to the site of the Chooz experiment with a pair of detectors for a differential neutrino flux measurement, providing sensitivity to sin^2(2theta13) > 0.03. Reaching this goal requires significant improvements in systematic uncertainties, based on the experience with previous reactor neutrino experiments.

Alexander Glushko, Lyudmila Karachevtseva

In this paper we analyze theoretically how the introduction of the third component into the two-dimensional photonic crystal influences the photonic band structure and the density-of-states of the system. We consider the periodic array of cylindrical air rods in a dielectric, and the third medium is introduced as a ring-shaped intermediate layer between the

Aleksandra M. Walczak, Peter G. Wolynes

We show how to construct a reduced description of interacting genes in noisy, small regulatory networks using coupled binary "spin" variables. Treating both the protein number and gene expression state variables stochastically and on equal footing we propose a mapping which connects the molecular level description of networks to the binary representa

Alberto Petri, Andrea Baldassarri, Fergal Dalton, Giorgio Pontuale

We experimentally investigate the response of a sheared granular medium in a Couette geometry. The apparatus exhibits the expected stick-slip motion and we probe it in the very intermittent regime resulting from low driving. Statistical analysis of the dynamic fluctuations reveals notable regularities. We observe a possible stability property for the torque

A. S. Kutuzov, A. M. Skvortsova, S. I. Belov, J. Sichelschmidt

We consider the local properties of the Yb3+ ion in the crystal electric field in the Kondo lattice compounds YbRh2Si2 and YbIr2Si2. On this basis we have calculated the magnetic susceptibility taking into account the Kondo interaction in the simplest molecular field approximation. The resulting Curie-Weiss law and Van Vleck susceptibilities could be excelle

Daniel A Stariolo, Orlando V. Billoni

We show results of Monte Carlo simulations of an array of monodispersed magnetic monodomain particles, in a square lattice with dipolar interactions and perpendicular uniaxial anisotropy. We first show the equilibrium phase diagram of the system, which shows three phases, superparamagnetic (SP), out-of-plane antiferromagnetic and in-plane antiferromagnetic w

Grzegorz Wilk, Zbigniew Wlodarczyk

We review from the point of view of nonextensive statistics the ubiquitous presence in elementary and heavy-ion collisions of power-law distributions. Special emphasis is placed on the conjecture that this is just a reflection of some intrinsic fluctuations existing in the hadronic systems considered. These systems summarily described by a single parameter q

D. F. Urban, Hermann Grabert

The Josephson junction noise detector measures the skewness of non-Gaussian noise via the asymmetry of the rate of escape from the zero-voltage state upon reversal of the bias current. The feedback of this detector on the noise generating device is investigated in detail. Concise predictions are made for a second Josephson junction as noise generating device

A. Ramsak, J. Mravlje, T. Rejec

Spin-entanglement of two electrons occupying two spatial regions -- domains -- is expressed in a compact form in terms of spin-spin correlation functions. The power of the formalism is demonstrated on several examples ranging from generation of entanglement by scattering of two electrons to the entanglement of a pair of qubits represented by a double quantum

Andre H. Hoang, Christoph J. Reisser, Pedro Ruiz-Femenia

The effects of the finite top quark width in the top pair production cross section close to the threshold are discussed in this talk. We introduce a $t\bar{t}$ cross section with a cut on the invariant masses of the top and antitop that can be calculated theoretically with effective field theory (EFT) methods. The matching procedure to implement the physical

Jose Gallardo, Isabelle Baraffe, Gilles Chabrier

In the poster presented in Cool Star 15, we analyzed the effect of disk accretion on the evolution of very low mass pre-main sequence stars and young brown dwarfs and the resulting uncertainties on the determination of masses and ages. We use the Lyon evolutionary 1-D code assuming a magnetospheric accretion process, i.e., the material falls covering a small

M. Salanne, C. Simon, P. Turq, P. A. Madden

The presence of first sharp diffraction peaks in the partial structure factors is investigated in computer simulations of molten mixtures of alkali halides. An intermediate range ordering appears for the Li+ ions only, which is associated with clustering of this species and is not reflected in the arrangement of other ions. This ordering is surprising in vie

Eivind Eriksen, Trond Stølen Gustavsen

Let $k$ be an algebraically closed field of characteristic 0, let $R$ be a commutative $k$-algebra, and let $M$ be a torsion free $R$-module of rank one with a connection $\nabla$. We consider the Lie-Rinehart cohomology with values in $End_{R}(M)$ with its induced connection, and give an interpretation of this cohomology in terms of the integrable connectio

Abla Kammoun, Malika Kharouf, Walid Hachem, Jamal Najim

This paper is devoted to the study of the performance of the Linear Minimum Mean-Square Error receiver for (receive) correlated Multiple-Input Multiple-Output systems. By the random matrix theory, it is well-known that the Signal-to-Noise Ratio (SNR) at the output of this receiver behaves asymptotically like a Gaussian random variable as the number of receiv

D. Lopez Nacir, F. D. Mazzitelli

We consider a free quantum scalar field satisfying modified dispersion relations in curved spacetimes, within the framework of Einstein-Aether theory. Using a power counting analysis, we study the divergences in the adiabatic expansion of <ϕ^2> and <T_{μν}>, working in the weak field approximation. We show that for dispersion relations containing up to $2s$

Ben D. Pecjak

The calculation of partial decay rates in B --> X_u l nu decays at next-to-next-to-leading order (NNLO) in alpha_s and to leading order in 1/m_b is described. New results for the hard function are combined with known results for the jet function and shape-function moments in a numerical analysis which explores the impact of the NNLO corrections on partial de

Gerardo Cristofano, Vincenzo Marotta, Adele Naddeo, Giuliano Niccoli

Recently a one-dimensional closed ladder of Josephson junctions has been studied (G. Cristofano et al., Phys. Lett. A 372 (2008) 2464) within a twisted conformal field theory (CFT) approach (G. Cristofano et al., Mod. Phys. Lett. A 15 (2000) 1679; Nucl. Phys. B 641 (2002) 547) and shown to develop the phenomenon of flux fractionalization (G. Cristofano et al

Dmitri I. Panyushev

We study weight posets of weight multiplicity free (=wmf) representations $R$ of reductive Lie algebras. Specifically, we are interested in relations between $\dim R$ and the number of edges in the Hasse diagram of the corresponding weight poset, $# E(R)$. We compute the number of edges and upper covering polynomials for the weight posets of all wmf-represen

Xu Xu, Xiaoji Zhou, Xuzong Chen

We theoretically study the superradiant gain and the direction of this coherent radiant for an array of Bose-Einstein condensates in an optical lattice. We find that the density grating is formed to amplify the scattering light within the phase match condition. The scattering spectroscopy in the momentum space can provide a method for measuring the overlap o

Kenichi Hatakeyama

Recent measurements on the vector boson plus heavy-flavor jets production by the CDF and D0 experiments are presented in comparisons with recent theoretical predictions. Good understanding of such processes is important to improve our understanding of QCD and also to enhance the potential to search for yet-to-be-discovered new physics phenomena which lead to

X. L. Huang, X. X. Yi, Chunfeng Wu, X. L. Feng

By using the effective Hamiltonian approach, we present a self-consistent framework for the analysis of geometric phases and dynamically stable decoherence-free subspaces in open systems. Comparisons to the earlier works are made. This effective Hamiltonian approach is then extended to a non-Markovian case with the generalized Lindblad master equation. Based

Sangchul Oh, Zhen Huang, Uri Peskin, Sabre Kais

The relation between level crossings, entanglement, and Berry phases is investigated for the Breit-Rabi Hamiltonian of hydrogen and sodium atoms, describing a hyperfine interaction of electron and nuclear spins in a magnetic field. It is shown that the entanglement between nuclear and electron spins is maximum at avoided crossings. An entangled state encircl

Jerzy Szczesny, Marek Biesiada, Marek Szydlowski

Using the idea of the degree of a smooth mapping between two manifolds of the same dimension we present here the topological (homotopical) classification of the mappings between spheres of the same dimension, vector fields, monopole and instanton solutions. Starting with a review of the elements of Riemannian geometry we also present an original elementary p

B. K. Lubsandorzhiev

We review photodetectors used in present running neutrino telescopes. After a brief historical discourse, the photodetector requirements for the next generation deep underwater neutrino telescopes are discussed. It is shown that large area vacuum hybrid phototubes are the closest to the ideal photodetector for such kind of applications when compared with oth

Jakub Cieslak, Benilde F. O. Costa, Stanislaw M. Dubiel, Michael Reissner

Magnetic properties of four sigma-phase Fe_(100-x)V_x samples with 34.4<x<55.1 were investigated by Mossbauer spectroscopy and magnetic measurements in the temperature interval 5-300 K. Four magnetic quantities viz. hyperfine field, Curie temperature, magnetic moment and susceptibility were determined. The sample containing 34.4 at% V was revealed to exhibit

Kaifu Luo, Tapio Ala-Nissila, See-Chen Ying, Aniket Bhattacharya

We investigate the dynamics of DNA translocation through a nanopore driven by an external force using Langevin dynamics simulations in two dimensions (2D) to study how the translocation dynamics depend on the details of the DNA sequences. We consider a coarse-grained model of DNA built from two bases $A$ and $C$, having different base-pore interactions, {\te

F. Buisseret, C. Semay, Fl. Stancu, N. Matagne

We establish a connection between the quark model and the 1/N_c expansion mass formulas used in the description of baryon resonances. We show that a remarkable compatibility exists between the two methods in the light and heavy baryon sectors. In particular, the band number used to classify baryons in the 1/N_c expansion is explained by the quark model and t

F. Jarai-Szabo, L. Nagy

In this work our previous fully differential ionization cross section calculations using the semiclassical, impact parameter method are improved by a new method suitable to calculate impact parameter values corresponding to different momentum transfers. This goal is achieved by two successive steps. First, using the transverse momentum balance different proj

M. Rengel, P. Hartogh, C. Jarchow

We present submillimeter observations of 12CO J=3-2 and J=2-1, and 13CO J = 2-1 lines of the Venusian mesosphere and lower thermosphere with the Heinrich Hertz Submillimeter Telescope (HHSMT) taken around the second MESSENGER flyby of Venus on 5 June 2007. The observations cover a range of Venus solar elongations with different fractional disk illuminations.

A. Pályi, J. Cserti

We present a theoretical study of elastic spin-dependent electron scattering caused by a charged impurity in the vicinity of a two-dimensional electron gas. We find that the symmetry properties of the spin-dependent differential scattering cross section are different for an impurity located in the plane of the electron gas and for one at a finite distance fr

Anders Tranberg

I set out the 2PI formalism for quantum fields in a Friedmann-Robertson-Walker Universe. I show how one can solve self-consistently for the quantum field evolution and the evolution of the cosmological scale factor, using a renormalised semi-classical Friedmann equation. In a 2PI coupling expansion truncated at O(lambda^2), I perform sample calculations demo

Li Ma, Lin Zhao, Jing Wang

In this short note, we show a uniqueness result of the energy solutions for the Cauchy problem of Schrodinger flow in the whole space $R^n$ provided there is a smooth solution in the energy class.

Elisabetta Grazzini, Elisa Pergola, Maddalena Poneti

A permutomino of size n is a polyomino determined by a pair of permutations of size n+1, such that they differ in each position. In this paper, after recalling some enumerative results about permutominoes, we give a first algorithm for the exhaustive generation of a particular class of permutominoes, the convex permutominoes, proving that its cost is proport

T. Kojima, J. Shiraishi

We give one parameter deformation of level $k$ free field realization of the screening current of the elliptic algebra $U_{q,p}(sl_2^)$. By means of these free field realizations, we construct infinitly many commutative operators, which we call the nonlocal integrals of motion associated with level $k$ realization of the elliptic algebra $U_{q,p}(sl_2^)$. Th

G. Burt, P. Ambattu, R. Carter, A. Dexter

Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9

D. Nagae, H. Ueno, D. Kameda, M. Takemura

Ground-state electric quadrupole moment of 31Al (I =5/2+, T_1/2 = 644(25) ms) has been measured by means of the beta-NMR spectroscopy using a spin-polarized 31Al beam produced in the projectile fragmentation reaction. The obtained Q moment, |Q_exp(31Al)| = 112(32)emb, are in agreement with conventional shell model calculations within the sd valence space. Pr

P. K. Ambattu, G. Burt, R. G. Carter, A. C. Dexter

The compact linear collider (CLIC) requires a crab cavity to align bunches prior to collision. The bunch structure demands tight amplitude and phase tolerances of the RF fields inside the cavity, for the minimal luminosity loss. Beam loading effects require special attention as it is one potential sources of field errors in the cavity. In order to assist the

Viorica Sofronie-Stokkermans

In this paper we show that states, transitions and behavior of concurrent systems can often be modeled as sheaves over a suitable topological space. In this context, geometric logic can be used to describe which local properties (i.e. properties of individual systems) are preserved, at a global level, when interconnecting the systems. The main area of applic

J. Segovia, D. R. Entem, F. Fernández

We study the nature of the new charm and charmonium like states observed in the last few years, using a constituent quark model with an screened confinement potential. In the open charm sector we discuss different options for the $D_{sJ}(2860)$ including tetraquark configurations. In the hidden charm sector the new Y(4360) and Y(4660) are interpreted as $1^{

Michael Wick, Wolfgang Altmannshofer

We present a MSSM study of the b -> s gamma decay in a Minimal Flavor Violating (MFV) framework, where the form of the soft SUSY breaking terms is determined by the Standard Model Yukawa couplings. In particular, we address the role of gluino contributions, which are set to zero in most studies of the MFV MSSM. Gluino contributions can play an important role

Jan Eichhorn, Fabian Sinz, Matthias Bethge

Orientation selectivity is the most striking feature of simple cell coding in V1 which has been shown to emerge from the reduction of higher-order correlations in natural images in a large variety of statistical image models. The most parsimonious one among these models is linear Independent Component Analysis (ICA), whereas second-order decorrelation transf

D. A. Slavnov

A scheme for constructing quantum mechanics is given that does not have Hilbert space and linear operators as its basic elements. Instead, a version of algebraic approach is considered. Elements of a noncommutative algebra (observables) and functionals on this algebra (elementary states) associated with results of single measurements are used as primary comp

Fabrice Silva, Jean Kergomard, Christophe Vergez, Joël Gilbert

Sound emergence in clarinetlike instruments is investigated in terms of instability of the static regime. Various models of reed-bore coupling are considered, from the pioneering work of Wilson and Beavers [&#34;Operating modes of the clarinet&#34;, J. Acoust. Soc. Am. 56, 653--658 (1974)] to more recent modeling including viscothermal bore losses and vena c

Krzysztof R. Apt, Vincent Conitzer, Mingyu Guo, Evangelos Markakis

A common objective in mechanism design is to choose the outcome (for example, allocation of resources) that maximizes the sum of the agents&#39; valuations, without introducing incentives for agents to misreport their preferences. The class of Groves mechanisms achieves this; however, these mechanisms require the agents to make payments, thereby reducing the

J. Kunes, Dm. M. Korotin, M. A. Korotin, V. I. Anisimov

The Local Density Approximation combined with Dynamical Mean-Field Theory (LDA+DMFT method) is applied to the study of the paramagnetic and magnetically ordered phases of hematite Fe$_2$O$_3$ as a function of volume. As the volume is decreased, a simultaneous 1st order insulator-metal and high-spin to low-spin transition occurs close to the experimental valu

A. P. Kuznetsov, Ju. P. Roman

The particular properties of synchronization are discussed for coupled auto-oscillating systems, which are characterized by non-quadratic law of potential dependence on the coordinate. In particular, structure of the parameter plane (frequency mismatch - coupling value) is considered for coupled van der Pol - Duffing oscillators. The arrangement of synchroni

Gui-Qiang Chen, Benoit Perthame

We are interested in the large-time behavior of periodic entropy solutions in $L^\infty$ to anisotropic degenerate parabolic-hyperbolic equations of second-order. Unlike the pure hyperbolic case, the nonlinear equation is no longer self-similar invariant and the diffusion term in the equation significantly affects the large-time behavior of solutions; thus t

Krzysztof R. Apt, Francesca Rossi, K. Brent Venable

The notion of optimality naturally arises in many areas of applied mathematics and computer science concerned with decision making. Here we consider this notion in the context of two formalisms used for different purposes and in different research areas: graphical games and soft constraints. We relate the notion of optimality used in the area of soft constra

Fei Gao, Qiao-Yan Wen, Su-Juan Qin, Fu-Chen Zhu

Based on quantum encryption, we present a new idea for quantum public-key cryptography (QPKC) and construct a whole theoretical framework of a QPKC system. We show that the quantum-mechanical nature renders it feasible and reasonable to use symmetric keys in such a scheme, which is quite different from that in conventional public-key cryptography. The securi

Francois David, Michel Bauer

We give a physicist&#39;s derivation of the geometrical (in the spirit of Duplantier-Sheffield) KPZ relations, via heat kernel methods. It gives a covariant way to define neighborhoods of fractals in 2d quantum gravity, and shows that these relations are in the realm of conformal field theory.

Giovanni Vignale, Massimiliano Di Ventra

We show that the Landauer multi-terminal formula for the conductance of a nanoscale system is incomplete because it does not take into account many-body effects which cannot be treated as contributions to the single-particle transmission probabilities. We show that the physical origin of these effects is related to the viscous nature of the electron liquid,

S. Pfalzner

Context: The brightness of FUors increases by several magnitudes within one to several years. The currently favoured explanation for this brightness boost is that of dramatically rising accretion from the disc material around a young star. The mechanism leading to this accretion increase is a point of debate. Aims: Choosing the Orion Nebula Cluster as repres

Toshiyuki Tashima, Sahin Kaya Ozdemir, Takashi Yamamoto, Masato Koashi

We propose a simple probabilistic optical gate to expand polarization entangled W states. The gate uses one polarization-dependent beamsplitter and a horizontally polarized single photon as an ancilla. The gate post-selectively expands $N$-photon W states to $(N+1)$-photon W states. A feasibility analysis considering the realistic experimental conditions sho

Donald W. Barnes

Engel subalgebras of finite-dimensional Leibniz algebras are shown to have similar properties to those of Lie algebras. Using these, it is shown that a left Leibniz algebra, all of whose maximal subalgebras are right ideals, is nilpotent. A primitive Leibniz algebra is shown to split over its minimal ideal and that all the complements to its minimal ideal ar

Takuya Shoji, Yoshifumi R. Shimizu

The wobbling excitations of the triaxial superdeformed (TSD) bands in the Lu and Hf region are studied by the microscopic framework of the cranked mean-field and the random-phase approximation (RPA). In contrast to the previous works, where the Nilsson potential was used, the more realistic Woods-Saxon potential is employed as a nuclear mean-field. The wobbl

Yoichi Motohashi

The main aim of this article is to develop, in a fully detailed fashion, a {\bf unified} theory of the spectral theory of mean values of individual automorphic L-functions which is a natural extension of the fourth moment of the Riemann zeta-function but does not admit any analogous argument and requires a genuinely new method. Thus we first develop a relati

Lei Chang, Yu-xin Liu, Wei-min Sun, Hong-shi Zong

We re-investigate the vector and axial-vector vacuum susceptibilities by taking advantage of the vector and axial-vector Ward-Takahashi identities. We show analytically that, in the chiral limit, the vector vacuum susceptibility is zero and the axial-vector vacuum susceptibility equals three fourths of the square of the pion decay constant. Besides, our anal

Jan Forbrich, Helmut Wiesemeyer, Clemens Thum, Arnaud Belloche

The Goldreich-Kylafis (GK) effect causes certain molecular line emission to be weakly linearly polarized, e.g., in the presence of a magnetic field. Compared to polarized dust emission, the GK effect has the potential to yield additional information along the line of sight through its dependence on velocity in the line profile. Our goal was to detect polariz

Hong-shi Zong, Wei-min Sun

In this paper, we give a direct method for calculating the partition function, and hence the equation of state (EOS) of Quantum Chromodynamics (QCD) at finite chemical potential and zero temperature. In the EOS derived in this paper the pressure density is the sum of two terms: the first term ${\cal P}(μ)|_{μ=0}$ (the pressure density at $μ=0$) is a $μ$-inde

Iwan Duursma, Bjorn Poonen, Michael Zieve

We consider a tower of function fields F_0 < F_1 < ... over a finite field such that every place of every F_i ramified in the tower and the sequence genus(F_i)/[F_i:F_0] has a finite limit. We also construct a tower in which every place ramifies and the sequence N_i/[F_i:F_0] has a positive limit, where N_i is the number of degree-one places of F_i. These to

Hui Liu, Defu Hou, Jiarong Li

In this paper, we compare the dispersion relations of hard thermal loop and complete one loop. It is shown that in the dynamical screening regime, the completely one-loop calculation presents a prominent threshold frequency, below which no pure imaginary mode survives. This phenomenon is responsible for the oscillatory static in-medium potential and ultimate

Wenchuan Hu

In this paper, the homotopy groups of Chow variety $C_{p,d}(P^n)$ of effective $p$-cycles of degree $d$ is proved to be stable in the sense that $p$ or $n$ increases. We also obtain a negative answer to a question by Lawson and Michelsohn on homotopy groups for the space of degree two cycles.

Simeon Ball, Michael E. Zieve

Every symplectic spread of PG(3,q), or equivalently every ovoid of Q(4,q), is shown to give rise to a certain family of permutation polynomials of GF(q) and conversely. This leads to an algebraic proof of the existence of the Tits-Luneburg spread of W(2^{2h+1}) and the Ree-Tits spread of W(3^{2h+1}), as well as to a new family of low-degree permutation polyn

Se-Wan Ji, Jinhyoung Lee, James Lim, Koji Nagata

We propose a generalized Bell inequality for two three-dimensional systems with three settings in each local measurement. It is shown that this inequality is maximally violated if local measurements are configured to be mutually unbiased and a composite state is maximally entangled. This feature is similar to Clauser-Horne-Shimony-Holt inequality for two qub

Martin Levesque, Halima Elbiaze, Wael Hosny Fouad Aly

Burst contention is a well known challenging problem in Optical Burst Switching (OBS) networks. Deflection routing is used to resolve contention. Burst retransmission is used to reduce the Burst Loss Ratio (BLR) by retransmitting dropped bursts. Previous works show that combining deflection and retransmission outperforms both pure deflection and pure retrans

Zhen hua Ni, Ying ying Wang, Ting Yu, Ze xiang Shen

Graphene has many unique properties that make it an ideal material for fundamental studies as well as for potential applications. Here we review the recent results on the Raman spectroscopy and imaging of graphene. Raman spectroscopy and imaging can be used as a quick and unambiguous method to determine the number of graphene layers. Following, the strong Ra

K. Hamaya, K. Ueda, Y. Kishi, Y. Ando

To develop silicon-based spintronic devices, we have explored high-quality ferromagnetic Fe$_{3}$Si/silicon (Si) structures. Using low-temperature molecular beam epitaxy at 130 $^circ$C, we realize epitaxial growth of ferromagnetic Fe$_{3}$Si layers on Si (111) with keeping an abrupt interface, and the grown Fe$_{3}$Si layer has the ordered $DO_{3}$ phase. M

Andrei Alexandru, Frank X. Lee

The background field method has been used successfully to determine hadron electromagnetic polarizabilities. Recently questions have been raised regarding the proper way to deal with the electric field on the lattice. In this paper, we show how the presence of a background electric field affects the quark hopping matrix. We use this formulation to carry out

Goulven Quéméner, Naduvalath Balakrishnan, Brian K. Kendrick

We report quantum dynamics calculations of the O + OH -> H + O2 reaction on two different representations of the electronic ground state potential energy surface (PES) using a time-independent quantum formalism based on hyperspherical coordinates. Calculations show that several excited vibrational levels of the product O2 molecule are populated in the reacti

Steven Weinberg

The results of a recent paper [0808.2909] are generalized. A more detailed proof is presented that under essentially all conditions, the non-linear classical equations governing matter and gravitation in cosmology have ``adiabatic&#39;&#39; solutions in which, far outside the horizon, in a suitable gauge, the reduced spatial metric $g_{ij}({\bf x},t)/a^2(t)$

Michael E. Zieve

I present a construction of permutation polynomials based on cyclotomy, an additive analogue of this construction, and a generalization of this additive analogue which appears to have no multiplicative analogue. These constructions generalize recent results of J. Marcos from arXiv:0810.2738v1.

Lanlan Tian, Henk Hoekstra, Hongsheng Zhao

We study the amplitude of the weak gravitational lensing signal as a function of stellar mass around a sample of relatively isolated galaxies. This selection of lenses simplifies the interpretation of the observations, which consist of data from the Red- sequence Cluster Survey and the Sloan Digital Sky Survey. We find that the amplitude of the lensing signa

J. W. Rich, W. J. G. de Blok, T. J. Cornwell, E. Brinks

A practical evaluation of the Multi-Scale CLEAN algorithm is presented. The data used in the comparisons are taken from The HI Nearby Galaxy Survey (THINGS). The implementation of Multi-Scale CLEAN in the CASA software package is used, although comparisons are made against the very similar Multi-Resolution CLEAN algorithm implemented in AIPS. Both are compar

M. E. Manley, A. J. Sievers, J. W. Lynn, S. A. Kiselev

Inelastic neutron measurements of the high-temperature lattice excitations in NaI show that in thermal equilibrium at 555 K an intrinsic mode, localized in three dimensions, occurs at a single frequency near the center of the spectral phonon gap, polarized along [111]. At higher temperatures the intrinsic localized mode gains intensity. Higher energy inelast

Gang Wang, Huan Zhong Huang

We present empirical features of parton energy loss in nucleus-nucleus collisions at RHIC through studies of the spectra and nuclear modification factors ($R_{AA}$) for charged hadrons, neutral pions ($π^0$) and non-photonic electrons. The flat distribution of $R_{AA}$ at high transverse momentum ($p_{T}$) for a given collision centrality is consistent with

Fabio Gagliardi Cozman

This paper presents concentration inequalities and laws of large numbers under weak assumptions of irrelevance, expressed through lower and upper expectations. The results are variants and extensions of De Cooman and Miranda&#39;s recent inequalities and laws of large numbers. The proofs indicate connections between concepts of irrelevance for lower/upper ex

Chris W. Purcell, Stelios Kazantzidis, James S. Bullock

Most Galaxy-sized systems (M_host ~ 10^12 M_sun) in the LCDM cosmology are expected to have accreted at least one satellite with a total mass M_sat ~ 10^11 M_sun = 3M_disk in the past 8 Gyr. Analytic and numerical investigations suggest that this is the most precarious type of merger for the survival of thin galactic disks because more massive accretion even

Daniel Remenik

There is a widespread recent interest in using ideas from statistical physics to model certain types of problems in economics and finance. The main idea is to derive the macroscopic behavior of the market from the random local interactions between agents. Our purpose is to present a general framework that encompasses a broad range of models, by proving a law

Sean Sather-Wagstaff, Sandra Spiroff

Let f: A\to B be a ring homomorphism between Noetherian normal integral domains. We establish a general criterion for f to induce a homomorphism Cl(f): Cl(A)\to Cl(B) on divisor class groups. For instance, this criterion applies whenever f has finite flat dimension; this special case generalizes the more classical situations where f is flat or is surjective

Matthew Headrick

A number of spacetime fields in string theory (notably the metric, dilaton, bosonic and type 0 bulk closed-string tachyon, and bosonic open-string tachyon) have the following property: whenever the spacetime field configuration factorizes in an appropriate sense, the matter sector of the world-sheet theory factorizes into a tensor product of two decoupled th

Anton Rebhan

Plasma instabilities are parametrically the dominant nonequilibrium dynamics of a weakly coupled quark-gluon plasma. In recent years the time evolution of the corresponding collective colour fields has been studied in stationary anisotropic situations. Here I report on recent numerical results on the time evolution of the most unstable modes in a longitudina

Karin M. Sandstrom, Alberto D. Bolatto, Snezana Stanimirovic, Jacco van Loon

We present mid-infrared spectral mapping observations of the core-collapse supernova remnant 1E 0102.2-7219 in the Small Magellanic Cloud using the InfraRed Spectrograph (IRS) on the Spitzer Space Telescope. The remnant shows emission from fine structure transitions of neon and oxygen as well as continuum emission from dust. Comparison of the mid-IR dust emi

Raghani Pushpa, Javier Rodriguez-Laguna, Silvia N. Santalla

The reconstruction of an Ag monolayer on Ag/Pt(111) is analyzed theoretically, employing a vertically extended Frenkel-Kontorova model whose parameters are derived from density functional theory. Energy minimization is carried out using simulated quantum annealing techniques. Our results are compatible with the STM experiments, where a striped pattern is ini

Georgi Mihaylov

Coadjoint orbits for the group SO(6) parametrize Riemannian G-reductions in six dimensions, and we use this correspondence to interpret symplectic fibrations between these orbits, and to analyse moment polytopes associated to the standard Hamiltonian torus action on the coadjoint orbits. The theory is then applied to describe so-called intrinsic torsion vari

Karl M. Menten, Robert W. Wilson, Silvia Leurini, Peter Schilke

We present molecular line mapping of the Giant Molecular Cloud G1.6-0.025, which is located at the high longitude end of the Central Molecular Zone of our Galaxy. We assess the degree of star formation activity in that region using several tracers and find very little. We made a large scale, medium (2&#39;) resolution map in the J = 2-1 transition of SiO for