May 2009 arXiv papers — page 42

Mikael de la Salle

In this short note we give a short proof of a recent result by Potapov and Sukochev (arXiv:0904.4095v1), stating that a Lipschitz function on the real line remains Lipschitz on the (self-adjoint part of) non-commutative $L_p$ spaces with $1<p<\infty$.

Johan Carlsson, John R. Cary

A new Jacobian approximation is developed for use in quasi-Newton methods for solving systems of nonlinear equations. The new hypersecant Jacobian approximation is intended for the special case where the evaluation of the functions whose roots are sought dominates the computation time, and additionally the Jacobian is sparse. One example of such a case is th

Carl Kingsford, Guillaume Marçais

A multigraph is exactly k-edge-connected if there are exactly k edge-disjoint paths between any pair of vertices. We characterize the class of exactly 3-edge-connected graphs, giving a synthesis involving two operations by which every exactly 3-edge-connected multigraph can be generated. Slightly modified syntheses give the planar exactly 3-edge-connected gr

Pierre Gaspard, Thomas Gilbert

We study heat transport in a class of stochastic energy exchange systems that characterize the interactions of networks of locally trapped hard spheres under the assumption that neighbouring particles undergo rare binary collisions. Our results provide an extension to three-dimensional dynamics of previous ones applying to the dynamics of confined two-dimens

C. Bekh-Ochir, S. A. Rankin

We describe the T-space of central polynomials for both the unitary and the nonunitary infinite dimensional Grassmann algebra over a field of characteristic p not equal to 2 (infinite field in the case of the unitary algebra).

S. Hony, A. M. Heras, F. J. Molster, K. Smolders

We investigate the composition of the solid-state materials in the winds around S-type AGB stars. The S stars produce dust in their wind that bears a resemblance to the dust produced in some O-rich AGB stars. However, the reported resemblance is mostly based on IRAS/LRS spectra with limited spectral resolution, sensitivity, and wavelength coverage. We invest

Borexino Collaboration, D. Franco

Borexino is an experiment designed to detect in real-time low energy solar neutrinos. It is installed at the Gran Sasso Underground Laboratory and has started taking data in May 2007. We report the direct measurement of the 7Be solar neutrino signal rate after 1 year of data taking. Implications and perspectives are discussed.

V. Braito, J. N. Reeves, R. Della Ceca, A. Ptak

We discuss here a long Suzaku observation of IRAS 19254-7245 (also known as the Superantennae), one of the brightest and well studied Ultra Luminous Infrared Galaxies in the local Universe. This long observation provided the first detection of IRAS 19254-7245 above 10 keV, and measured a 15-30 keV flux of ~5x10^(-12) erg cm^-2 s^-1. The detection above 10 ke

Thomas D. Cohen, Garrett Goon

We test the applicability of the Bohigas conjecture to systems whose Hamiltonian is not written as a closed form analytic expression. A class of such Hamiltonians is created and appear to violate the conjecture. Numerical methods are employed to find the spectra of a two-dimensional, classically chaotic &#34;billiard&#34; system whose Hamiltonian is in this

Paolo Amore, Francisco M. Fernandez

We have applied a collocation approach to obtain the numerical solution to the stationary Schrödinger equation for systems of coupled oscillators. The dependence of the discretized Hamiltonian on scale and angle parameters is exploited to obtain optimal convergence to the exact results. A careful comparison with results taken from the literature is performed

Jin Zhou, Wenwu Yu, Xiaoqun Wu, Michael Small

Flocking behavior of multiple agents can be widely observed in nature such as schooling fish and flocking birds. Recent literature has proposed the possibility that flocking is possible even only a small fraction of agents are informed of the desired position and velocity. However, it is still a challenging problem to determine which agents should be informe

Naoum Karchev

The present paper is a sequel to the paper by Karchev (2008 J.Phys.:Condens.Matter {\bf 20} 325219). A two-sublattice ferrimagnet, with spin-$s_1$ operators $\bf{S_{1i}}$ at the sublattice $A$ site and spin-$s_2$ operators $\bf{S_{2i}}$ at the sublattice $B$ site, is considered. Renormalized spin-wave theory, which accounts for the magnon-magnon interaction,

Roland Gillen, Marcel Mohr, Janina Maultzsch, Christian Thomsen

We investigated the vibrational properties of graphene nanoribbons by means of first-principles calculations on the basis of density functional theory. We confirm that the phonon modes of graphene nanoribbons with armchair and zigzag type edges can be interpreted as fundamental oscillations and their overtones. These show a characteristic dependence on the n

René David, Karim Nour

The symmetric $λμ$-calculus is the $λμ$-calculus introduced by Parigot in which the reduction rule $\m&#39;$, which is the symmetric of $μ$, is added. We give arithmetical proofs of some strong normalization results for this calculus. We show (this is a new result) that the $μμ&#39;$-reduction is strongly normalizing for the un-typed calculus. We also show t

René David, Karim Nour

We give an arithmetical proof of the strong normalization of the $λ$-calculus (and also of the $λμ$-calculus) where the type system is the one of simple types with recursive equations on types. The proof using candidates of reducibility is an easy extension of the one without equations but this proof cannot be formalized in Peano arithmetic. The strength of

Roberta Poloni, Enric Canadell, Jean Paul Pouget

We comment a recent work titled &#34;Direct evidence for hidden one-dimensional Fermi surface of hexagonal K0.25WO3&#34;. In this paper the authors report photoemission and theoretical results on the K0.25WO3 system which led them to propose that a Charge Density Wave (CDW), associated with hidden one-dimensional bands, was responsible for the well known res

Wolfgang Kundt

This article -- written in honour of Juergen Ehlers -- consists of two different, though interlocking parts: Section 1 describes my 54 years of perpetual experiences and exchanges with him, both science and episodes, whilst section 2 describes the history of astrophysical black holes, which evolved during the same epoque though largely independently, with it

M. Iskin, J. K. Freericks

We develop two methods to calculate the momentum distribution of the insulating (Mott and charge-density-wave) phases of the extended Bose-Hubbard model with on-site and nearest-neighbor boson-boson repulsions on $d$-dimensional hypercubic lattices. First we construct the random phase approximation result, which corresponds to the exact solution for the infi

David Taj, Rita Claudia Iotti, Fausto Rossi

We shall revisit the conventional adiabatic or Markov approximation, which --contrary to the semiclassical case-- does not preserve the positive-definite character of the corresponding density matrix, thus leading to highly non-physical results. To overcome this serious limitation, originally pointed out and partially solved by Davies and co-workers almost t

Vadim E. Levit, Eugen Mandrescu

A maximum stable set in a graph G is a stable set of maximum cardinality. S is a local maximum stable set of G, if S is a maximum stable set of the subgraph induced by its closed neighborhood. It is known that the family of all local maximum stable sets of a forest forms a greedoid on its vertex set. Bipartite, triangle-free, and well-covered graphs whose fa

Zeng-Qiang Yu, Kun Huang, Lan Yin

We study the effect of the induced interaction on the superfluid transition temperature of a Fermi gas with a BEC-BCS crossover. The Gorkov-Melik-Barkhudarov theory about the induced interaction is extended from the BCS side to the entire crossover, and the pairing fluctuation is treated in the approach by Nozières and Schmitt-Rink. At unitarity, the induced

B. Golob

An overview of selected experimental results in the field of $D^0$-$\bar{D}^0$ oscillations is presented. The average results for the mixing parameters, $x=(0.89\pm{0.26\atop 0.27})%$ and $y=(0.75\pm{0.17\atop 0.18})%$, exclude the no-mixing hypothesis at the level of 6.7 standard deviations. No sign of CP violation in the $D^0$ system is observed. The measu

David Taj, Fausto Rossi

We obtain new types of exponential decay laws for solutions of density-matrix master equations in the weak-coupling limit: after comparing with results already present in the literature and developing the necessary techniques, we study the crucial aspect of complete positivity under fairly general conditions. We propose a new type of time average that guaran

David Taj

In a recent work we have found a contraction semigroup able to correctly approximate a projected and perturbed one-parameter group of isometries in a generic Banach space, in the limit of weak-coupling. Here we study its generator by specializing to $W^*$-algebras: after defining a Physical Subsystem in terms of a completely positive projecting conditional e

CLEO Collaboration, Jonas Rademacker

Dalitz analyses in charm give access to both magnitudes and phases of the charm decay amplitudes. They play a significant role in charm-mixing measurements, in the measurement of the CP-violating phase gamma in B decays to charm, and in the analysis of light meson resonances. We review recent results in all three categories.

Robin de Jong

S.-W. Zhang recently introduced a new adelic invariant for curves of genus at least 2 over number fields and function fields. We calculate this invariant when the genus is equal to 2.

Antonio Ronaldo G. Garcia, Moises D. dos Santos, Adriao D. D. Neto

In this work we use variational methods to show the existence of weak solutions for a nonlinear problem of the type elliptic. This problem was initially study by the authors Ahmad, Lazer and Paul (see \cite{ALP}) considering the space $Ω\subset\Rset^n$ a bounded domains. In this work we extend your result now considering the domain $\Rset^n$. Indeed, the mai

V. V. Lehtola, R. P. Linna, K. Kaski

We present results from our simulations of biopolymer translocation in a solvent which explain the main experimental findings. The forced translocation can be described by simple force balance arguments for the relevant range of pore potentials in experiments and biological systems. Scaling of translocation time with polymer length varies with pore force and

D. Banerjee, L. Teriaca, G. R. Gupta, S. Imada

To study the dynamics of coronal holes and the role of waves in the acceleration of the solar wind, spectral observations were performed over polar coronal hole regions with the SUMER spectrometer on SoHO and the EIS spectrometer on Hinode. Using these observations, we aim to detect the presence of propagating waves in the corona and to study their propertie

David Taj

We consider the class of quantum mechanical master equations defined on a generic Banach space, arising by projecting weakly perturbed one-parameter groups of isometries. We show that the possible semigroup approximations are far from unique. However, uniqueness can be reestablished through the introduction of a dynamical time averaging map. The generator of

C. Beck, E. Khomenko, R. Rezaei, M. Collados

Acoustic waves are one of the primary suspects besides magnetic fields for the chromospheric heating process to temperatures above radiative equilibrium (RE). We derived the mechanical wave energy as seen in line-core velocities to obtain a measure of mechanical energy flux with height for a comparison with the energy requirements in a semi-empirical atmosph

Soenke Hansen, Joachim Hilgert, Sameh Keliny

In the late nineties T. Kobayashi wrote a series of papers in which he established a criterion for the discrete decomposablity of restrictions of unitary representations of reductive Lie groups to reductive subgroups. A key tool in the proof of sufficiency of his criterion was the use of the theory of hyperfunctions to study the microlocal behavior of charac

Z. Usubov

We explore the opportunity to look for quark compositeness in the early stages of the LHC running by analyzing high-$E_T$ dijet production. The quark substructure that will manifest itself by affecting various kinematic distributions at the center-of-mass energy $E_{CM}$=10 TeV and in the integrated luminosity range from 0.5 to 10 fb$^{-1}$ is investigated.

K. A. Stoyanov, R. K. Zamanov

Our aim is to investigate tidal interaction in High-Mass X-ray Binary stars in order to determine in which objects the rotation of the mass donors is synchronized or pseudosynchronized with the orbital motion of the compact companion. We calculate the pseudosynchronization period (P_ps) and compare it with the rotational period of the mass donors (P_rot). We

Edgardo Stockmeyer

We consider a (semi-)relativistic spin-1/2 particle interacting with quantized radiation. The Hamiltonian has the form $\hat{H}_c^V:=\{c^2[(\mathbf{p}+{\bf A})^2+{\bf σ}\cdot{\bf B}]+(mc^2)^2\}^{1/2}-mc^2+V+H_f$. Assuming that the potential $|V|$ is bounded with respect to the momentum $|\mathbf{p}|$, we show that $\hat{H}_c^V$ converges in norm-resolvent se

Y. Khodorkovsky, G. Kurizki, A. Vardi

We study the effect of decoherence on dynamical phase diffusion in the two-site Bose-Hubbard model. Starting with an odd parity excited coherent state, the initial loss of single particle coherence varies from small bound oscillations in the Rabi regime, through hyperbolic depletion in the Josephson regime, to a Gaussian decay in the Fock regime. The inclusi

Frank Aurzada, Leif Doering

For the symbiotic branching model introduced by Etheridge/Fleischmann (2004), it is shown that aging and intermittency exhibit different behaviour for negative, zero, and positive correlations. Our approach also provides an alternative, elementary proof and refinements of classical results concerning second moments of the parabolic Anderson model with Browni

H. Meyer, T. Kreer, M. Aichele, A. Cavallo

Self-avoiding polymers in two-dimensional ($d=2$) melts are known to adopt compact configurations of typical size $R(N) \sim N^{1/d}$ with $N$ being the chain length. Using molecular dynamics simulations we show that the irregular shapes of these chains are characterized by a perimeter length $L(N) \sim R(N)^{\dpm}$ of fractal dimension $\dpm = d-Θ_2 =5/4$ w

Barbara Ercolano, Cathie J. Clarke, Jeremy J. Drake

We present new models for the X-ray photoevaporation of circumstellar discs which suggest that the resulting mass loss (occurring mainly over the radial range 10-40 AU) may be the dominant dispersal mechanism for gas around low mass pre-main sequence stars, contrary to the conclusions of previous workers. Our models combine use of the MOCASSIN Monte Carlo ra

P. Bydzovsky

Isobar models for the electromagnetic production of K+ and K0 are discussed with emphasis on the K0 photoproduction off neutron. Predictions of the models for the K0 photoproduction on deuteron are compared with the recent data and some properties of the elementary amplitudes are shown.

Christoph A. Stephan

During the last two decades Alain Connes developed Noncommutative Geometry (NCG), which allows to unify two of the basic theories of modern physics: General Relativity (GR) and the Standard Model (SM) of Particle Physics as classical field theories. In the noncommutative framework the Higgs boson, which had previously to be put in by hand, and many of the ad

A. Bret, F. J. Marín Fernández, J. M. Anfray

Quantum and collisional effects on the unstable spectrum of a relativistic electron beam-plasma system are investigated through a two-fluids model. Application is made to the near target center interaction of the relativistic electron beam in the Fast Ignition Scenario. Partial degeneracy effects are found negligible while the most influential factors are th

Fatkhulla Kh. Abdullaev, Ravil M. Galimzyanov, Marijana Brtka, Lauro Tomio

We study trapping and propagation of a matter-wave soliton through the interface between uniform medium and a nonlinear optical lattice (NOL). Different regimes for transmission of a broad and a narrow soliton are investigated. Reflections and transmissions of solitons are predicted as function of the lattice phase. The existence of a threshold in the amplit

Roberto Amato, Michele Pinelli, Daniel D&#39;Andrea, Gennaro Miele

Complex diseases are multifactorial traits caused by both genetic and environmental factors. They represent the most part of human diseases and include those with largest prevalence and mortality (cancer, heart disease, obesity, etc.). Despite of a large amount of information that have been collected about both genetic and environmental risk factors, there a

Peter Hegarty, Desmond MacHale

We show that 3^7 is the smallest order of a non-trivial odd order group which occurs as the full automorphism group of a finite group.

Lijun Bo, Kehua Shi, Yongjin Wang

This paper investigates a damped stochastic wave equation driven by a non-Gaussian Levy noise. The weak solution is proved to exist and be unique. Moreover we show the existence of a unique invariant measure associated with the transition semigroup under mild conditions.

Tom Michoel, Riet De Smet, Anagha Joshi, Yves Van de Peer

We have compared a recently developed module-based algorithm LeMoNe for reverse-engineering transcriptional regulatory networks to a mutual information based direct algorithm CLR, using benchmark expression data and databases of known transcriptional regulatory interactions for Escherichia coli and Saccharomyces cerevisiae. A global comparison using recall v

M. Fromont, B. Laurent, P. Reynaud-Bouret

We propose to test the homogeneity of a Poisson process observed on a finite interval. In this framework, we first provide lower bounds for the uniform separation rates in $\mathbb{L}^2$ norm over classical Besov bodies and weak Besov bodies. Surprisingly, the obtained lower bounds over weak Besov bodies coincide with the minimax estimation rates over such c

Alessio Zaccone

We propose a simple route to evaluate the static structure, in terms of average coordination, of completely disordered solids with spherical constituents, from ca. 55% volume fraction up to random close packing, in the absence of structural heterogeneities. Based on the current understanding, according to which the structure-determining interaction in amorph

S. M. Vlaming, V. A. Malyshev, J. Knoester

We compare localization properties of one-dimensional Frenkel excitons with Gaussian and Lorentzian uncorrelated diagonal disorder. We focus on the states of the Lifshits tail, which dominate the optical response and low-temperature energy transport in molecular J-aggregates. The absence of exchange narrowing in chains with Lorentzian disorder is shown to ma

Vladimir Chernov, Stefan Nemirovski

It is shown that if the universal cover of a manifold $M$ is an open manifold, then two different fibres of the spherical cotangent bundle $ST^*M$ cannot be connected by a non-negative Legendrian isotopy. This result is applied to the study of causality in globally hyperbolic spacetimes. It is also used to strengthen a result of Eliashberg, Kim, and Polterov

Eamonn Long, David Stuart

We consider the nonlinear Klein Gordon Maxwell system on four dimensional Minkowski space-time. For appropriate nonlinearities the system admits soliton solutions which are gauge invariant generalizations of the non-topological solitons introduced and studied by T.D. Lee and collaborators for pure complex scalar fields. We develop a rigorous dynamical pertur

Isaac Roseboom, Seb Oliver, Duncan Farrah, Mark Frost

The advent of the Spitzer Space Telescope has revolutionized our understanding of the history of star formation and galaxy mass assembly in the Universe. The tremendous leap in sensitivity from previous mid-to-far IR missions has allowed Spitzer to perform deeper, and wider, surveys than previously possible at these wavelengths. In this brief review I highli

X. Yuan, M. Buescher, D. Chiladze, S. Dymov

The total cross section for the dd -> 4He K+ K- reaction has been measured at a beam momentum of 3.7 GeV/c, corresponding to an excess energy of 39 MeV, which is the maximum possible at the Cooler Synchrotron COSY-Jülich. A deuterium cluster-jet target and the ANKE forward magnetic spectrometer, placed inside the storage ring, have been employed in this inve

Jung-Wan Ryu, Soo-Young Lee, Sang Wook Kim

We investigate two coupled microdisks with non-identical radii focusing on the parametric evolution of energy levels and the unidirectional far-field emission. We show that the evolution of energy levels is characterized by the avoided crossing intrinsically associated with the exceptional point or the non-Hermitian degeneracy. These spectral properties expl

B. -W. Schulze

We give a brief survey on some new developments on elliptic operators on manifolds with polyhedral singularities. The material essentially corresponds to a talk given by the author during the Conference &#34;Elliptic and Hyperbolic Equations on Singular Spaces&#34;, October 27 - 31, 2008, at the MSRI, University of Berkeley.

Vinko Zlatić, Gourab Ghoshal, Guido Caldarelli

Recent years have witnessed the emergence of a new class of social networks, that require us to move beyond previously employed representations of complex graph structures. A notable example is that of the folksonomy, an online process where users collaboratively employ tags to resources to impart structure to an otherwise undifferentiated database. In a rec

G. Cohen-Tannoudji

Taking into account four universal constants, namely the Planck&#39;s constant $h$, the velocity of light $c$, the constant of gravitation $G$ and the Boltzmann&#39;s constant $k$ leads to structuring theoretical physics in terms of three theories each taking into account a pair of constants: the quantum theory of fields ($h$ and $c$), the general theory of

E. Oset, A. Ramos

We study the interaction of vector mesons with the octet of stable baryons in the framework of the local hidden gauge formalism using a coupled channels unitary approach. We examine the scattering amplitudes and their poles, which can be associated to known J^P=1/2^-,3/2^- baryon resonances, in some cases, or give predictions in other ones. The formalism emp

Svante Janson, Andrzej Rucinski

General upper tail estimates are given for counting edges in a random induced subhypergraph of a fixed hypergraph H, with an easy proof by estimating the moments. As an application we consider the numbers of arithmetic progressions and Schur triples in random subsets of integers. In the second part of the paper we return to the subgraph counts in random grap

Yue Chang, T. Shi, Yu-xi Liu, C. P. Sun

We study how an oscillating mirror affects the electromagnetically induced transparency (EIT) of an atomic ensemble, which is confined in a gas cell placed inside a micro-cavity with an oscillating mirror in one end. The oscillating mirror is modeled as a quantum mechanical harmonic oscillator. The cavity field acts as a probe light of the EIT system and als

J. A. Furst, J. Hashemi, T. Markussen, M. Brandbyge

Fullerene functionalized carbon nanotubes -- NanoBuds -- form a novel class of hybrid carbon materials, which possesses many advantageous properties as compared to the pristine components. Here, we report a theoretical study of the electronic transport properties of these compounds. We use both ab initio techniques and tight-binding calculations to illustrat

Ruta Kale, K. S. Dwarakanath

We present a low frequency study of the diffuse radio emission in the galaxy cluster A754. We present new 150 MHz image of the galaxy cluster A754 made with the Giant Metrewave Radio Telescope (GMRT) and discuss the detection of 4 diffuse features. We compare the 150 MHz image with the images at 74, 330 and 1363 MHz; one new diffuse feature is detected. The

Yan Chai, Reinhard Lipowsky, Stefan Klumpp

The transport by molecular motors along cytoskeletal filaments is studied theoretically in the presence of static defects. The movements of single motors are described as biased random walks along the filament as well as binding to and unbinding from the filament. Three basic types of defects are distinguished, which differ from normal filament sites only in

Nicolas Doiron-Leyraud, P. Auban-Senzier, S. Rene de Cotret, A. Sedeki

A linear temperature dependence of the electrical resistivity as T -> 0 is the hallmark of quantum criticality in heavy-fermion metals and the archetypal normal-state property of high-Tc superconductors, yet in both cases it remains unexplained. We report a linear resistivity on the border of spin-density-wave order in the organic superconductor (TMTSF)2X (X

K. -I. Ishikawa, N. Ishizuka, T. Izubuchi, D. Kadoh

We investigate the quark mass dependence of baryon masses in 2+1 flavor lattice QCD using SU(3) heavy baryon chiral perturbation theory up to one-loop order. The baryon mass data used for the analyses are obtained for the degenerate up-down quark mass of 3 MeV to 24 MeV and two choices of the strange quark mass around the physical value. We find that the SU(

Azeem Haider, Sardar Mohib Ali Khan

Let S=K[x_1,x_2,...,x_n] be a polynomial ring in n variables over a field K. Stanley&#39;s conjecture holds for the modules I and S/I, when I is a critical monomial ideal. We calculate the Stanley depth of S/I when I is a canonical critical monomial ideal. For non critical monomial ideals we show the existence of a Stanley ideal with the same depth and Hilbe

M. Borkowski, R. Ciurylo, P. S. Julienne, S. Tojo

The properties of bosonic Ytterbium photoassociation spectra near the intercombination transition $^{1}S_{0}$--$^{3}P_{1}$ are studied theoretically at ultra low temperatures. We demonstrate how the shapes and intensities of rotational components of optical Feshbach resonances are affected by mass tuning of the scattering properties of the two colliding grou

Xavier Calmet, Swarup Kumar Majee

An effective theory for dark matter has recently been proposed. The key assumption is that the dark matter particle which is a Dirac fermion is protected from decaying by a global U(1) symmetry. We point out that quantum gravity effects will violate this symmetry and that the dark matter candidate thus decays very fast. In order to solve that problem, we pro

A. A. Grib

It is shown that nonlinear terms in equations of gravitons on the background of curved space-time of the expanding Universe can solve the problem of the negative square of the effective mass formally arising in linear approximation for gravitons. Similar to well known spontaneous breaking of symmetry in Goldstone model one must take another vacuum so that no

Chia-Min Lin, Kingman Cheung

Following \cite{Lin:2009yt}, we explore the parameter space of the case when the supersymmetry (SUSY) breaking scale is lower, for example, in gauge mediated SUSY breaking model. During inflation, the form of the potential is $V_0$ plus MSSM (MSSM stands for Minimal Supersymmetric Standard Model) (or A term (It is called A-term inflation when the inflaton fi

Gauhar Abbas, B. Ananthanarayan

We obtain stringent bounds in the < r^2 >_S^{K pi}-c plane where these are the scalar radius and the curvature parameters of the scalar pi K form factor respectively using analyticity and dispersion relation constraints, the knowledge of the form factor from the well-known Callan-Treiman point m_K^2-m_pi^2, as well as at m_pi^2-m_K^2 which we call the second

Hiroko Ito, Wako Aoki, Satoshi Honda, Timothy C. Beers

We present a 1D LTE chemical abundance analysis of the very bright (V=9.1) Carbon-Enhanced Metal-Poor (CEMP) star BD +44 493, based on high-resolution, high signal-to-noise spectra obtained with Subaru/HDS. The star is shown to be a subgiant with an extremely low iron abundance ([Fe/H]=-3.7), while it is rich in C ([C/Fe]=+1.3) and O ([O/Fe]=+1.6). Although

Zhifeng Xie

In planar ${\cal N}=4$ supersymmetric Yang-Mills theory we have studied supersymmetric Wilson loops composed of a large number of light-like segments, i.e., null zig-zags. These contours oscillate around smooth underlying spacelike paths. At one-loop in perturbation theory we have compared the finite part of the expectation value of null zig-zags to the fini

John V. Corbett

The mathematical structure of the sheaf of Dedekind real numbers $\RsubD(X)$ for a quantum system is discussed. The algebra of physical qualities is represented by an $O^{*}$ algebra $\mathcal M$ that acts on a Hilbert space that carries an irreducible representation of the symmetry group of the system. $X =\EsubS(\mathcal M)$, the state space for $\mathcal

Peng-Bo Li, Ying Gu, Qi-Huang Gong, Guang-Can Guo

We propose an efficient scheme for the implementation of quantum information transfer in a onedimensional coupled resonator waveguide. We show that, based on the effective long-range dipole-dipole interactions between the atoms mediated by the cavity modes, Raman transitions between the atoms trapped in different nodes can take place. Quantum information cou

Tomoyuki Sasaki, Tohru Oikawa, Toshio Suzuki, Masashi Shiraishi

We observed spin injection into silicon through Fe/MgO tunnel barrier by using non-local magnetoresistance measurement technique. Fe/MgO tunnel barrier contacts with a lateral spin valve structure were fabricated on phosphorous doped silicon-on-insulator substrate. Spin injection signals in the non-local scheme were observed up to 120K, which is the highest

Jian Song

We investigate the limiting behavior of the unnormalized Kahler-Ricci flow on a Kahler manifold with a polarized initial Kahler metric. We prove that the Kahler-Ricci flow becomes extinct in finite time if and only if the manifold has positive first Chern class and the initial Kahler class is proportional to the first Chern class of the manifold. This proves

Marek Kuś, Ingemar Bengtsson

We show that several classes of mixed quantum states in finite-dimensional Hilbert spaces which can be characterized as being, in some respect, &#39;most classical&#39; can be described and analyzed in a unified way. Among the states we consider are separable states of distinguishable particles, uncorrelated states of indistinguishable fermions and bosons, a

Bradley A. Chase, JM Geremia

We consider the effective dynamics obtained by double-passing a far-detuned laser probe through a large atomic spin system. The net result of the atom-field interaction is a type of coherent positive feedback that amplifies the values of selected spin observables. An effective equation of motion for the atomic system is presented, and an approximate 2-parame

Ricardo E. Gamboa Saravi

We discuss the exact solution of Einstein's equation corresponding to a static and plane symmetric distribution of matter with constant positive density located below $z=0$ matched to vacuum solutions.

Yi-Zhong Fan

Since the launch of the Fermi Gamma-ray Space Telescope on 11 June 2008, significant detections of high energy emission have been reported only in six Gamma-ray Bursts (GRBs) until now. In this work we show that the lack of detection of a GeV spectrum excess in almost all GRBs, though somewhat surprisingly, can be well understood within the standard internal

Jun Chul Park

It is a well established result that, in classical dynamical systems with sufficient time-scale separation, the fast chaotic degrees of freedom are well modeled by (Gaussian) white noise. In this paper, we present the stochastic dynamical description for intermediate time-scale motions with insufficient time-scale separation from the slow dynamical system. F

Kin Fai Mak, Chun Hung Lui, Jie Shan, Tony F. Heinz

It has been predicted that application of a strong electric field perpendicular to the plane of bilayer graphene can induce a significant band gap. We have measured the optical conductivity of bilayer graphene with an efficient electrolyte top gate for a photon energy range of 0.2 - 0.7 eV. We see the emergence of new transitions as a band gap opens. A band

Victor Guillemin, Zuoqin Wang

In this article we study the semiclassical spectral measures associated with Schrödinger operators on $R^n$. In particular we compute the first few coefficients of the asymptotic expansions of these measures and, as an application, give an alternative proof of Colin de Verdiere&#39;s result on recovering one dimensional potential wells from semiclassical spe

Andrew Robertson, Victor Galitski

Non-equilibrium stimulation of superfluidity in trapped Fermi gases is discussed by analogy to the work of Eliashberg [G. M. Eliashberg, in &#34;Nonequilibrium Superconductivity,&#34; edited by D. N. Langenberg and A. I. Larkin (North-Holland, New York, 1986)] on the microwave enhancement of superconductivity. Optical excitation of the fermions balanced by h

Anders Eriksson, Martin Nilsson Jacobi, Johan Nystrom, Kolbjorn Tunstrom

In this paper we introduce a method for determining local interaction rules in animal swarms. The method is based on the assumption that the behavior of individuals in a swarm can be treated as a set of mechanistic rules. The principal idea behind the technique is to vary parameters that define a set of hypothetical interactions to minimize the deviation bet

Matthias R. Gaberdiel, Ingo Runkel, Simon Wood

The logarithmic triplet model W_2,3 at c=0 is studied. In particular, we determine the fusion rules of the irreducible representations from first principles, and show that there exists a finite set of representations, including all irreducible representations, that closes under fusion. With the help of these results we then investigate the possible boundary

S. Floerchinger, C. Wetterich

We propose an exact flow equation for composite operators and their correlation functions. This can be used for a scale-dependent partial bosonization or &#34;flowing bosonization&#34; of fermionic interactions, or for an effective change of degrees of freedom in dependence on the momentum scale. The flow keeps track of the scale dependent relation between e

Jakub Gismatullin

A group is boundedly simple if, for some constant N, every nontrivial conjugacy class generates the whole group in N steps. For a large class of trees, Tits proved simplicity of a canonical subgroup of the automorphism group, which is generated by pointwise stabilizers of edges. We prove that only for uniform subdivisions of biregular trees are such groups b

Stefan Antusch, Mar Bastero-Gil, Koushik Dutta, Steve F. King

We propose the introduction of a Heisenberg symmetry of the Kahler potential to solve the problems with chaotic inflation in supergravity, as a viable alternative to the use of shift symmetry. The slope of the inflaton potential emerges from a small Heisenberg symmetry breaking term in the superpotential. The modulus field of the Heisenberg symmetry is stabi

Dave Bacon, Steven T. Flammia

The difficulty in producing precisely timed and controlled quantum gates is a significant source of error in many physical implementations of quantum computers. Here we introduce a simple universal primitive, adiabatic gate teleportation, which is robust to timing errors and many control errors and maintains a constant energy gap throughout the computation a

F. Tavecchio, G. Ghisellini, G. Ghirlanda, L. Costamante

The BL Lac object 1ES 0229+200 (z=0.14) has been detected by HESS during observations taking place in 2005-2006. The TeV spectrum, when corrected for the absorption of gamma-ray photons through the interaction with the extragalactic background light, is extremely hard, even if the most conservative level for the background is considered. The case of 1ES 0229

S. R. Saha, N. P. Butch, K. Kirshenbaum, Johnpierre Paglione

Single crystals of the Ni-doped FeAs-based superconductor SrFe2-xNixAs2 were grown using a self-flux solution method and characterized via x-ray measurements and low temperature transport, magnetization, and specific heat studies. A doping phase diagram has been established where the antiferromagnetic order associated with the magnetostructural transition of

Milen Yakimov

De Concini, Kac and Procesi defined a family of subalgebras U^w_+ of a quantized universal enveloping algebra U_q(g), associated to the elements of the corresponding Weyl group W. They are deformations of the universal enveloping algebras U(n_+ \cap Ad_w(n_-)) where n_\pm are the nilradicals of a pair of dual Borel subalgebras. Based on results of Gorelik an

Mansour Kalantar

We will prove that a function u(x,y) defined on a domain of RpxRq that is subharmonic in one variable and harmonic in the other is (jointly) subharmonic. This solves a long-standing open problem.

M. Gorelik, V. Kac

In this paper we study the complete reducibility of representations of infinite-dimensional Lie algebras from the perspective of the representation theory of vertex algebras.

T. Antal, P. L. Krapivsky, S. Redner

We construct a tractable model to describe the rate at which a knotted polymer is ejected from a spherical capsid via a small pore. Knots are too large to fit through the pore and must reptate to the end of the polymer for ejection to occur. The reptation of knots is described by symmetric exclusion on the line, with the internal capsid pressure represented

David Kubiznak, Hari K. Kunduri, Yukinori Yasui

We propose a generalization of the (conformal) Killing-Yano equations relevant to D=5 minimal gauged supergravity. The generalization stems from the fact that the dual of the Maxwell flux, the 3-form *F, couples naturally to particles in the background as a `torsion&#39;. Killing-Yano tensors in the presence of torsion preserve most of the properties of the

D. Wittman

We use simulations to demonstrate that photometric redshift &#34;errors&#34; can be greatly reduced by using the photometric redshift probability distribution p(z) rather than a one-point estimate such as the most likely redshift. In principle this involves tracking a large array of numbers rather than a single number for each galaxy. We introduce a very sim