September 2006 arXiv papers — page 44

Simon Portegies Zwart, Stephanie Rusli

We study the evolution of bound pairs of star clusters by means of direct N-body simulations. Our simulations include mass loss by stellar evolution. The initial conditions are selected to mimic the observed binary star cluster NGC 2136 and NGC 2137 in the Large Magellanic Cloud. Based on the rather old ages ($\sim 100$ Myr), masses, sizes of the two cluster

R. C. Shellard

We review in these notes the status of the construction of the Pierre Auger Observatory and present the first Physics results, based on the data collected during the first year and a half of operation. These results are preliminary, once the work to understand the systematics of the detectors are still underway. We discuss the cosmic ray spectrum above 3 EeV

Po Hu, Igor Kriz

In this note, we calculate all untwisted and twisted (Z/2)^n-equivariant K-groups with compact supports of real finite-dimensional linear representations of (Z/2)^n. The question was motivated by the question of D-brane charges for orbifold type II string vacua.

Igor Kriz

We investigate the moduli space of conformal field theories by setting up a canonical mathematical process for exponentiating perturbations corresponding to critical fields. We apply this process to the free field theory and the Gepner models of the Fermat quintic and quartic. We find algebraic obstructions to exponentiating purely perturbative deformations

B. Mazur, K. Rubin, A. Silverberg

If $V$ is a commutative algebraic group over a field $k$, $O$ is a commutative ring that acts on $V$, and $I$ is a finitely generated free $O$-module with a right action of the absolute Galois group of $k$, then there is a commutative algebraic group $I \otimes_O V$ over $k$, which is a twist of a power of $V$. These group varieties have applications to cryp

Jack L. Uretsky

A gauge theory of pions interacting with rho-mesons at elevated temperatures is used to calculate the pressure in a hot pion gas. No reference is made to the pion's status as a QCD Goldstone boson. The role of the pion is merely that of a carrier of an SU(2) symmetry, gauged to create a vector-meson interaction, the rho playing the role of the interacting ve

H. Dery, L. J. Sham

Extraction of electrons from a semiconductor to a ferromagnet as well as the case of injection in the reverse direction may be formulated as a scattering theory. However, the presence of bound states at the interface arising out of doping on the semiconductor side must be taken into account in the scattering theory. Inclusion of the interface states yields a

The Belle Collaboration, K. Abe

We present the results of a time-dependent Dalitz plot analysis of B0 -> pi+ pi- pi0 decays based on a 414fb^-1 data sample that contains 449MBB pairs collected on the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e- collider. The direct CP violating parameters of B0 -> rho+-pi-+ decay mode are measured to be A_rhopi^+- = +0.2

Yunfeng Shan, Xiu-Qing Li

Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single g

Mustansir Barma, Marcelo D. Grynberg, Robin B. Stinchcombe

We discuss dynamical aspects of an asymmetric version of assisted diffusion of hard core particles on a ring studied by G. I. Menon {\it et al.} in J. Stat Phys. {\bf 86}, 1237 (1997). The asymmetry brings in phenomena like kinematic waves and effects of the Kardar-Parisi-Zhang nonlinearity, which combine with the feature of strongly broken ergodicity, a cha

Eric Zhi Chen

As a generalization of cyclic codes, quasi-cyclic (QC) codes contain many good linear codes. But quasi-cyclic codes studied so far are mainly limited to one generator (1-generator) QC codes. In this correspondence, 2-generator and 3-generator QC codes are studied, and many good, new QC codes are constructed from simplex codes. Some new binary QC codes or rel

M. G. Castellano, F. Chiarello, R. Leoni, F. Mattioli

We report on a direct quantitative comparison between Thom's general catastrophe theory for systems presenting discontinuous behavior and experimental reality. It is demonstrated that the model provides a striking quantitative description of the measured experimental features of the complex nonlinear system generating the most appealing class of sensors

Moustapha Diaby

In this paper, we present a polynomial-sized linear programming formulation of the Traveling Salesman Problem (TSP). The proposed linear program is a network flow-based model. Numerical implementation issues and results are discussed. (The exposition and proofs are much more detailed in an edition which I wrote in collaboration with Dr. M.H. Karwan in 2012-2

Igor A. Luk'yanchuk, Yakov Kopelevich

Spectral analysis of Shubnikov de Haas (SdH) oscillations of magnetoresistance and of Quantum Hall Effect (QHE) measured in quasi-2D highly oriented pyrolytic graphite (HOPG) [Phys. Rev. Lett. 90, 156402 (2003)] reveals two types of carriers: normal (massive) electrons with Berry phase 0 and Dirac-like (massless) holes with Berry phase pi. We demonstrate tha

Moustapha Diaby

In this paper, we present a polynomial-sized linear programming formulation of the Quadratic Assignment Problem (QAP). The proposed linear program is a network flow-based model. Hence, it provides for the solution of the QAP in polynomial time. Computational testing and results are discussed.

Alexey V. Bolsinov, Bozidar Jovanovic

We consider magnetic geodesic flows of the normal metrics on a class of homogeneous spaces, in particular (co)adjoint orbits of compact Lie groups. We give the proof of the non-commutative integrability of flows and show, in addition, for the case of (co)adjoint orbits, the usual Liouville integrability by means of analytic integrals. We also consider the po

Laurent Sanchez-Palencia

We theoretically investigate the physics of interacting Bose-Einstein condensates at equilibrium in a weak (possibly random) potential. We develop a perturbation approach to derive the condensate wavefunction for an amplitude of the potential smaller than the chemical potential of the condensate and for an arbitrary spatial variation scale of the potential.

E. Harikumar, Amilcar R. Queiroz, P. Teotonio-Sobrinho

We calculate the index of the Dirac operator defined on the q-deformed fuzzy sphere. The index of the Dirac operator is related to its net chiral zero modes and thus to the trace of the chirality operator. We show that for the q-deformed fuzzy sphere, a $\uq$ invariant trace of the chirality operator gives the q-dimension of the eigenspace of the zero modes

Tetsuo Hyodo, Daisuke Jido, Atsushi Hosaka

We study s-wave scattering of a hadron and a Nambu-Goldstone boson induced by the model-independent low energy interaction in the flavor SU(3) symmetric limit. Establishing the general structure of the low energy interaction based on group theoretical arguments, we find that the interaction in the exotic channels are in most cases repulsive, and that for pos

M. V. Catalisano, A. V. Geramita, A. Gimigliano

If $\X \subset ¶^n$ is a reduced and irreducible projective variety, it is interesting to find the equations describing the (higher) secant varieties of $\X$. In this paper we find those equations in the following cases: $\X = ¶^{n_1}\times...\times¶^{n_t}\times¶^n$ is the Segre embedding of the product and $n$ is "large" with respect to the $n_i$ (T

Avi Pe'er, Evgeny A. Shapiro, Matthew C. Stowe, Moshe Shapiro

We present a general and highly efficient scheme for performing narrow-band Raman transitions between molecular vibrational levels using a coherent train of weak pump-dump pairs of shaped ultrashort pulses. The use of weak pulses permits an analytic description within the framework of coherent control in the perturbative regime, while coherent accumulation o

Arti Chamoli, C. M. Bhandari

Entanglement plays a crucial role in quantum processes particularly those pertaining to quantum information and computation. An analytical expression for entanglement measure defined in terms of success rate of Grover's search algorithm has been obtained for a two-qutrit system and the calculated results agree well with the conventional entropy based mea

Wei Li, Ari K. Tuchman, Hui-Chun Chien, Mark A. Kasevich

Coherence properties of Bose-Einstein condensates offer the potential for improved interferometric phase contrast. However, decoherence effects due to the mean-field interaction shorten the coherence time, thus limiting potential sensitivity. In this work, we demonstrate increased coherence times with number squeezed states in an optical lattice using the de

Stuart R. Borrett, Brian D. Fath, Bernard C. Patten

Large-scale structural patterns commonly occur in network models of complex systems including a skewed node degree distribution and small-world topology. These patterns suggest common organizational constraints and similar functional consequences. Here, we investigate a structural pattern termed pathway proliferation. Previous research enumerating pathways t

C. Milstene, G. Fisk, A. Para

This paper describes a new way to reconstruct and identify muons with high efficiency and high pion rejection. Since muons at the ILC are often produced with or in jets, for many of the physics channels of interest[1], an efficient algorithm to deal with the identification and separation of particles within jets is important. The algorithm at the core of the

C. Milstene, A. Sopczak

A vertex detector concept of the Linear Collider Flavour Identification (LCFI) collaboration, which studies pixel detectors for heavy quark flavour identification, has been implemented in simulations for c-quark tagging in scalar top studies. The production and decay of scalar top quarks (stops) is particularly interesting for the development of the vertex d

Kwang-Hua W. Chu

We obtain possibly valuable information about the phase diagram of rather dense composite particles at high fermion as well as boson number density but low temperature, which is not accessible to relativistic heavy ion collision experiments. Our calculations could qualitatively measure the number of thermodynamic degrees of freedom at the time at which the m

Gershon Wolansky

The continuous limit of large systems of particles of finite size on the line is described. The particles are assumed to move freely and stick under collision, to form compound particles whose mass and size is the sum of the masses and sizes of the particles before collision, and whose velocity is determined by conservation of linear momentum.

Avner Ash, David Pollack, Glenn Stevens

We extend the work of Ash and Stevens [Ash-Stevens 97] on p-adic analytic families of p-ordinary arithmetic cohomology classes for GL(N,Q) by introducing and investigating the concept of p-adic rigidity of arithmetic Hecke eigenclasses. An arithmetic eigenclass is said to be "rigid" if (modulo twisting) it does not admit a nontrivial p-adic deformati

Jonas Reitz

A new axiom is proposed, the Ground Axiom, asserting that the universe is not a nontrivial set-forcing extension of any inner model. The Ground Axiom is first-order expressible, and any model of ZFC has a class-forcing extension which satisfies it. The Ground Axiom is independent of many well-known set-theoretic assertions including the Generalized Continuum

Yong Wang

In this paper we give a proof of the Lefschetz fixed point formula of Freed$^{\rm [1]}$ for an orientation-reversing involution on an odd dimensional spin manifold by using the direct geometric method introduced in [2] and then we generalize this formula under the noncommutative geometry framework.

Yong Wang

In [3], Connes found a conformal invariant using Wodzicki's 1-density and computed it in the case of 4-dimensional manifold without boundary. In [14], Ugalde generalized the Connes' result to $n$-dimensional manifold without boundary. In this paper, we generalize the results of [3] and [14] to the case of manifolds with boundary.

Yong Wang

In [Wu], the noncommutative Atiyah-Patodi-Singer index theorem was proved. In this paper, we extend this theorem to the equivariant case.

Yong Wang

In this paper, for an even dimensional compact manifold with boundary which has the non-product metric near the boundary, we use the noncommutative residue to define a conformal invariant pair. For a 4-dimensional manifold, we compute this conformal invariant pair under some conditions and point out the way of computations in the general.

Kefeng Liu, Yong Wang

In this paper, we compute the adiabatic limit of the scalar curvature and prove several vanishing theorems, we also derive a Kastler-Kalau-Walze type theorem for the noncommutative residue in the case of foliations.

Yong Wang

We prove a Kastler-Kalau-Walze type theorem for the Dirac operator and the signature operator for $3,4$-dimensional manifolds with boundary. As a corollary, we give two kinds of operator theoretic explanations of the gravitational action in the case of 4-dimensional manifolds with flat boundary.

Man-Wai Ho

A Bayesian nonparametric method for unimodal densities on the real line is provided by considering a class of species sampling mixture models containing random densities that are unimodal and not necessarily symmetric. This class of densities generalize the model considered by Brunner (1992, Statist. Probab. Lett.), in which the Dirichlet process is replaced

Barry Mazur, Karl Rubin

We obtain lower bounds for Selmer ranks of elliptic curves over dihedral extensions of number fields. Suppose $K/k$ is a quadratic extension of number fields, $E$ is an elliptic curve defined over $k$, and $p$ is an odd prime. Let $F$ denote the maximal abelian $p$-extension of $K$ that is unramified at all primes where $E$ has bad reduction and that is Galo

A. Sopczak, A. Finch, A. Freitas, C. Milstene

Light scalar top quarks with a small mass difference with respect to the neutralino mass are of particular cosmological interest. This study uses an Iterative Discriminant Analysis method to optimize the expected selection efficiency at a International Linear Collider (ILC).

Emanuel Diamant

In the last years we witness a dramatic growth of research focused on semantic image understanding. Indeed, without understanding image content successful accomplishment of any image-processing task is simply incredible. Up to the recent times, the ultimate need for such understanding has been met by the knowledge that a domain expert or a vision system supe

Lyderic Bocquet, Patrick Tabeling, Sebastien Manneville

In a recent Letter (Phys. Rev. Lett. vol 96, 066001 (2006), ref [1]), Choi and Kim reported slip lengths of a few tens of microns for water on nanoengineered superhydrophobic surfaces, on the basis of rheometry (cone-and-plate) measurements. We show that the experimental uncertainty in the experiment of Ref. [1], expressed in term of slip lengths, lies in th

P. Joseph, C. Cottin-Bizonne, J. -M. Benoit, C. Ybert

We present in this letter an experimental characterization of liquid flow slippage over superhydrophobic surfaces made of carbon nanotube forests, incorporated in microchannels. We make use of a micro-PIV (Particule Image Velocimetry) technique to achieve the submicrometric resolution on the flow profile necessary for accurate measurement of the surface hydr

Benjamin Balke, Kristian Kroth, Gerhard H. Fecher, Claudia Felser

Half-Heusler compounds with 18 valence electrons are semi-conducting. It will be shown that doping with electrons results in half-metallic ferromagnets, similar to the case of diluted semi-conductors. CoTiSb is known to be a semi-conducting Half-Heusler compound. Doping by Fe is expected to result in ferromagnetic order. It was found that Ti can be replaced

Philip W. Anderson

Many investigators have joined the search for a bosonic glue which is hypothecated to be the mechanism which binds the electron pairs in the cuprate high Tc superconductors, often referring to the Eliashberg formalism which was developed to reveal the role of phonons in the conventional polyelectronic metal superconductors. In this paper we point out that th

Yi-Ying Chin, Jui-Yu Chiu, Ming-Che Chang, Chung-Yu Mou

The non-equilibrium transportation of two-dimensional electrons through a narrow channel is investigated under the influence of the Rashba interaction. By introducing suitable lifetime in the Green's function, the average spin values can be calculated from the ballistic regime to the diffusive regime. It is shown that the spin accumulation is a combined

T. Kondo, R. Khasanov, J. Karpinski, S. M. Kazakov

We use microprobe Angle-Resolved Photoemission Spectroscopy (muARPES) to separately investigate the electronic properties of CuO2 planes and CuO chains in the high temperature superconductor, YBa2Cu4O8. In the CuO2 planes, a two dimensional (2D) electronic structure with nearly momentum independent bilayer splitting is observed. The splitting energy is 150 m

Bong-Jun Kim, Yong Wook Lee, Byung-Gyu Chae, Sun Jin Yun

The temperature dependence of the Mott metal-insulator transition (MIT) is studied with a VO_2-based two-terminal device. When a constant voltage is applied to the device, an abrupt current jump is observed with temperature. With increasing applied voltages, the transition temperature of the MIT current jump decreases. We find a monoclinic and electronically

Huaiming Guo, Shiping Feng

Within the framework of the kinetic energy driven superconductivity, we study the electronic structure of cuprate superconductors. It is shown that the spectral weight of the electron spectrum in the antinodal point of the Brillouin zone decreases as the temperature is increased. With increasing the doping concentration, this spectral weigh increases, while

Somak Raychaudhury, Trevor A. Miles

We present a study of the optical (BRI) and near-infrared (JHK) luminosity fuctions (LFs) of the GEMS sample of 60 nearby groups of galaxies between 0<z<0.04, with our optical CCD photometry and near-IR photometry from the 2MASS survey. The LFs in all filters show a depletion of galaxies of intermediate luminosity, two magnitudes fainter than L*, within 0.3

T. L. Wilson, C. Henkel, S. Huettemeister

The first astronomical detection of the metastable ($J,K$) = (18,18) line of NH3 is reported. With 3130 K above the ground state, this is the NH3 line with by far the highest energy detected in interstellar space. It is observed in absorption toward the galactic center star forming region Sgr B2. There is a clear detection toward Sgr B2(M) and a likely one t

Mathieu De Naurois, the H. E. S. S. Collaboration Collaboration

Recent observations of the binary system LS5039 with the High Energy Stereoscopic System (H.E.S.S.) revealed that its Very High Energy (VHE) gamma-ray emission is modulated at the 3.9 days orbital period of the system. The bulk of the emission is largely confined to half of the orbit, peaking around the inferior conjunction epoch of the compact object. The f

Ryuichi Kurosawa, Tim J. Harries, S. P. Littlefair

We present the results of a radial velocity (RV) survey of 14 brown dwarfs (BDs) and very low-mass (VLM) stars in the Upper Scorpius OB association (UScoOB) and 3 BD candidates in the rho Ophiuchi dark cloud core. We obtained high-resolution echelle spectra at the Very Large Telescope using Ultraviolet and Visual Echelle Spectrograph (UVES) at two different

R. Feldmann, C. M. Carollo, C. Porciani, S. J. Lilly

We present ZEBRA, the Zurich Extragalactic Bayesian Redshift Analyzer. The current version of ZEBRA combines and extends several of the classical approaches to produce accurate photometric redshifts down to faint magnitudes. In particular, ZEBRA uses the template-fitting approach to produce Maximum Likelihood and Bayesian redshift estimates based on: (1.) An

M. Zoccali, A. Lecureur, B. Barbuy, V. Hill

AIMS: We spectroscopically characterize the Galactic Bulge to infer its star formation timescale, compared to the other Galactic components, through the chemical signature on its individual stars. METHODS: We derived iron and oxygen abundances for 50 K giants in four fields towards the Galactic bulge. High resolution (R=45,000) spectra for the target stars w

Pavle V. M. Blagojevic, Aleksandra S. Dimitrijevic Blagojevic

A significant group of problems coming from the realm of Combinatorial Geometry can only be approached through the use of Algebraic Topology. From the first such application to Kneser&#39;s problem in 1978 by Lov% ász \cite{Lovasz} through the solution of the Lovász conjecture \cite% {Babson-Kozlov}, \cite{Carsten}, many methods from Algebraic Topology have

Jeremy Kahn, Mikhail Lyubich

A decoration of the Mandelbrot set $M$ is a part of $M$ cut off by two external rays landing at some tip of a satellite copy of $M$ attached to the main cardioid. In this paper we consider infinitely renormalizable quadratic polynomials satisfying the decoration condition, which means that the combinatorics of the renormalization operators involved is select

Ivan Hubeny, Adam Burrows

We derive new equations using the mixed-frame approach for one- and two-dimensional (axisymmetric) time-dependent radiation transport and the associated couplings with matter. Our formulation is multi-group and multi-angle and includes anisotropic scattering, frequency(energy)-dependent scattering and absorption, complete velocity dependence to order v/c, ro

Miron J. Cristea

Based on semiconductor materials fundamental equations, the calculation of the depletion region width and barrier capacitance of practical diffused -Gaussian profile- semiconductor junctions was achieved for the first time in this work. The obtained formulas are valid for p-n junctions, Schottky junctions, hetero-junctions and other types of semiconductor ju

Jeremy Kahn

We prove the a priori bounds for infinitely renormalizable quadratic polynomials for which we can find an infinite sequence of primitive renormalizations such that the ratios of the periods of successive renormalizations is bounded. This implies the local connectivity of the Mandelbrot set at the corresponding points.

A. Cingoz, A. Lapierre, A. -T. Nguyen, N. Leefer

Over a period of eight months, we have monitored transition frequencies between nearly degenerate, opposite-parity levels in two isotopes of atomic dysprosium (Dy). These transition frequencies are highly sensitive to temporal variation of the fine-structure constant ($α$) due to relativistic corrections of large and opposite sign for the opposite-parity lev

M. T. Sargent, C. M. Carollo, S. J. Lilly, C. Scarlata

We study a sample of approximately 16,500 galaxies with I_AB <= 22.5 in the COSMOS field. Structural information on the galaxies is derived by fitting single Sersic models to their two-dimensional surface brightness distributions. We investigate the evolution of the number density of disk galaxies larger than 5 kpc between redshift z~1 and the present epoch.

Yael Karshon, Liat Kessler, Martin Pinsonnault

Let (M,ω) be a four dimensional compact connected symplectic manifold. We prove that (M,ω) admits only finitely many inequivalent Hamiltonian effective 2-torus actions. Consequently, if M is simply connected, the number of conjugacy classes of 2-tori in the symplectomorphism group Sympl(M,ω) is finite. Our proof is &#34;soft&#34;. The proof uses the fact tha

Dmitri A. Uzdensky, Andrew I. MacFadyen

We consider a newly-born millisecond magnetar, focusing on its interaction with the dense stellar plasma in which it is initially embedded. We argue that the confining pressure and inertia of the surrounding plasma acts to collimate the magnetar&#39;s Poynting-flux-dominated outflow into tightly beamed jets and increases its magnetic luminosity. We propose t

Ryan M. O&#39;Leary, Abraham Loeb

Stars within 0.1 pc of the supermassive black hole Sgr A* at the Galactic centre are expected to encounter a cluster of stellar-mass black holes (BHs) that have segregated to that region. Some of these stars will scatter off an orbiting BH and be kicked out of the Galactic centre with velocities up to ~2000 km/s. We calculate the resulting ejection rate of h

Helge Glockner

The General Curve Lemma is a tool of Infinite-Dimensional Analysis, which enables refined studies of differentiability properties of mappings between real locally convex spaces. In this article, we generalize the General Curve Lemma in two ways: First, we remove the condition of local convexity in the real case. Second, we adapt the lemma to the case of curv

Nathan Berkovits, Nikita Nekrasov

Using the non-minimal version of the pure spinor formalism, manifestly super-Poincare covariant superstring scattering amplitudes can be computed as in topological string theory without the need of picture-changing operators. The only subtlety comes from regularizing the functional integral over the pure spinor ghosts. In this paper, it is shown how to regul

George Androulakis, Pandelis Dodos, Gleb Sirotkin, Vladimir G. Troitsky

V. D. Milman proved in \cite{Milman:70} that the product of two strictly singular operators on $L_p[0,1]$ ($1\le p<\infty$) or on $C[0,1]$ is compact. In this note we utilize Schreier families $§_ξ$ in order to define the class of $§_ξ$-strictly singular operators, and then we refine the technique of Milman to show that certain products of operators from thi

Paul Seidel

These are (heavily revised) notes from lectures given at the AMS Algebraic Geometry meeting in Seattle, 2005. The main topic is symplectic homology seen from the point of view of Lefschetz fibrations. Most of the content is speculative, but some supporting evidence is included.

David G. Taylor, Weiqiang Wang

Bloch and Okounkov introduced an n-point correlation function on the infinite wedge space and found an elegant closed formula in terms of theta functions. This function has connections to Gromov-Witten theory, Hilbert schemes, symmetric groups, etc, and it can also be interpreted as correlation functions on integrable gl_\infty-modules of level one. Such gl_

M. A. Hoefer, T. J. Silva

A nonlinear model of spin-wave excitation involving a point contact in a thin ferromagnetic film that includes the Oersted magnetic field contribution is presented. We consider the case of an external dc field applied perpendicular to the film plane. The two-dimensional vectorial model reduces to an exact one-dimensional equation of motion. Large-amplitude v

Hiranya Peiris, Richard Easther

We study the constraints on the inflationary parameter space derived from the 3 year WMAP dataset using ``slow roll reconstruction&#39;&#39;, using the SDSS galaxy power spectrum to gain further leverage where appropriate. This approach inserts the inflationary slow roll parameters directly into a Monte Carlo Markov chain estimate of the cosmological paramet

Stephen Klinksiek

Fermilab Experiment 866 took single muon data from 800 GeV/c (sqrt{s}=38.8 GeV) p-Cu and p-Be interactions in an attempt to extract the inclusive nuclear open charm/anti-charm differential cross sections as a function of transverse momentum. The muons were decay products from semi-leptonic decays of open charm mesons as well as decays from lighter non-charme

Paul B. Slater

Due to recent important work of Zyczkowski and Sommers (quant-ph/0302197 and quant-ph/0304041), exact formulas are available (both in terms of the Hilbert-Schmidt and Bures metrics) for the (n^2-1)-dimensional and (n(n-1)/2-1)-dimensional volumes of the complex and real n x n density matrices. However, no comparable formulas are available for the volumes (an

A. Surzhykov, M. Lubasch, J. Zinn-Justin, U. D. Jentschura

This article is concerned with a special class of the ``double-well-like&#39;&#39; potentials that occur naturally in the analysis of finite quantum systems. Special attention is paid, in particular, to the so-called Fokker-Planck potential, which has a particular property: the perturbation series for the ground-state energy vanishes to all orders in the cou

Alexander Komech, Andrew Komech

The long-time asymptotics is analyzed for all finite energy solutions to a model U(1)-invariant nonlinear Klein-Gordon equation in one dimension, with the nonlinearity concentrated at a single point: each finite energy solution converges as time goes to plus or minus infinity to the set of all ``nonlinear eigenfunctions&#39;&#39; of the form $ψ(x)e\sp{-iωt}$

Christopher J. Fewster, Ken D. Olum, Michael J. Pfenning

The Averaged Null Energy Condition (ANEC) requires that the average along a complete null geodesic of the projection of the stress-energy tensor onto the geodesic tangent vector can never be negative. It is sufficient to rule out many exotic phenomena in general relativity. Subject to certain conditions, we show that the ANEC can never be violated by a quant

Ricardo A. Mosna, Marcos Jardim

We consider a general ansatz for solving the 2-dimensional Hitchin&#39;s equations, which arise as dimensional reduction of the 4-dimensional self-dual Yang-Mills equations, with remarkable integrability properties. We focus on the case when the gauge group G is given by a real form of SL(2,C). For G=SO(2,1), the resulting field equations are shown to reduce

Nathan Geer, Bertrand Patureau-Mirand

This paper generalize [7](math.GT/0601291): We construct new links invariants from g, a type I basic classical Lie superalgebra. The construction uses the existence of an unexpected replacement of the vanishing quantum dimension of typical module. Using this, we get a multivariable link invariant associated to any one parameter family of irreducible g-module

Kwanghyun Jo, Youngman Kim, Hyun Kyu Lee, Sang-Jin Sin

Withdrawn: replaced by e-Print: arXiv:0810.0063 [hep-ph]

Laura Mersini-Houghton

Motivated by the mounting evidence for dark energy, here we explore the consequences of a fundamental cosmological constant $Λ$ for our universe. We show that when the gravitational entropy of a pure DeSitter state ultimately wins over matter, then the thermodynamic arrow of time in our universe must reverse in scales of order a Hubble time. We find that due

Peter P. Rohde, Wolfgang Mauerer, Christine Silberhorn

We discuss the spectral structure and decomposition of multi-photon states. Ordinarily `multi-photon states&#39; and `Fock states&#39; are regarded as synonymous. However, when the spectral degrees of freedom are included this is not the case, and the class of `multi-photon&#39; states is much broader than the class of `Fock&#39; states. We discuss the crite

Hendrik Hubrechts

In recent algorithms that use deformation in order to compute the number of points on varieties over a finite field, certain differential equations of matrices over p-adic fields emerge. We present a novel strategy to solve this kind of equations in a memory efficient way. The main application is an algorithm requiring quasi-cubic time and only quadratic mem

Giovanni Ossola, Costas G. Papadopoulos, Roberto Pittau

We show how to extract the coefficients of the 4-, 3-, 2- and 1-point one-loop scalar integrals from the full one-loop amplitude of arbitrary scattering processes. In a similar fashion, also the rational terms can be derived. Basically no information on the analytical structure of the amplitude is required, making our method appealing for an efficient numeri

M. I. Katsnelson

It is shown that a ``vacuum polarization&#39;&#39; induced by Coulomb potential in graphene leads to a strong suppression of electric charges even for undoped case (no charge carriers). A standard linear response theory is therefore not applicable to describe the screening of charge impurities in graphene. In particular, it overestimates essentially the cont

E. R. Siegel, J. N. Fry

Although observations point to the neutrality and lack of currents on large scales in the universe, many mechanisms are known that can generate charges or currents during the early universe. We examine the question of survivability of relic charges and currents in a realistic model of the universe. We show that the dynamics of cosmological perturbations driv

Akitsugu Miwa, Tamiaki Yoneya

We study the expectation values of Wilson-loop operators with the insertionsof local operators Z^J and Zbar^J with large R-charge J from the bulk viewpoint of AdS/CFT correspondence. Classical solutions of strings attached to such deformed Wilson loops at the conformal boundary are constructed and are applied to the computation of Wilson-loop expectation val

Jean-Baptiste Gramain

In a paper of 2003, B. Külshammer, J. B. Olsson and G. R. Robinson defined $\ell$-blocks for the symmetric groups, where $\ell >1$ is an arbitrary integer, and proved that they satisfy an analogue of the Nakayama Conjecture. Inspired by this work and the definitions of generalized blocks and sections given by the authors, we give in this paper a definition o

Yuxiang Li, Cheikh Birahim Ndiaye

Given a compact closed four dimensional smooth Riemannian manifold, we prove existence of extremal functions for Moser-Trudinger type inequality. The method used is Blow-up analysis combined with capacity techniques.

J. H. Wei, Yijing Yan, S. J. Xie, L. M. Mei

We investigate the bias-induced insulator-metal transition in organic electronics devices, on the basis of the Su-Schrieffer-Heeger model combined with the non-equilibrium Green&#39;s function formalism. The insulator-metal transition is explained with the energy levels crossover that eliminates the Peierls phase and delocalizes the electron states near the

Anna Grigorieva, Pawel Artymowicz, Philippe Thébault

We quantitatively investigate how collisional avalanches may developin debris discs as the result of the initial break-up of a planetesimal or comet-like object, triggering a collisional chain reaction due to outward escaping small dust grains. We use a specifically developed numerical code that follows both the spatial distribution of the dust grains and th

Frédéric Blanqui, Claude Kirchner, Colin Riba

The confluence of untyped lambda-calculus with unconditional rewriting has already been studied in various directions. In this paper, we investigate the confluence of lambda-calculus with conditional rewriting and provide general results in two directions. First, when conditional rules are algebraic. This extends results of Muller and Dougherty for unconditi

P. Koval, F. Wilken, D. Bauer, C. H. Keitel

A second plateau in the harmonic spectra of laser-driven two-electron atoms is observed both in the numerical solution of a low-dimensional model helium atom and using an extended strong field approximation. It is shown that the harmonics well beyond the usual cut-off are due to the simultaneous recombination of the two electrons, which were emitted during d

Anjan Kundu

An operator deformed quantum algebra is discovered exploiting the quantum Yang-Baxter equation with trigonometric R-matrix. This novel Hopf algebra along with its $q \to 1$ limit appear to be the most general Yang-Baxter algebra underlying quantum integrable systems. Three different directions of application of this algebra in integrable systems depending on

A. Siddiki F. Marquardt

In this work we implement the self-consistent Thomas-Fermi-Poisson approach to a homogeneous two dimensional electron system (2DES). We compute the electrostatic potential produced inside a semiconductor structure by a quantum-point-contact (QPC) placed at the surface of the semiconductor and biased with appropriate voltages. The model is based on a semi-ana

Torsten Asselmeyer-Maluga, Helge Rosé

This paper has been withdrawn by the authors due to the too limited range of the current version of the model (the dark energy fraction is constant, but it has to be a function of the scale factor). We will resubmit the paper after extension.

Andrew Comech

We obtain optimal continuity in Sobolev spaces for the Fourier integral operators associated to singular canonical relations, when one of the two projections is a Whitney fold. The regularity depends on the type, $k$, of the other projection from the canonical relation ($k=1$ for a Whitney fold). We prove that one loses $(4+\frac{2}{k})^{-1}$ of a derivative

Diego Garlaschelli, Maria I. Loffredo

The choice of free parameters in network models is subjective, since it depends on what topological properties are being monitored. However, we show that the Maximum Likelihood (ML) principle indicates a unique, statistically rigorous parameter choice, associated to a well defined topological feature. We then find that, if the ML condition is incompatible wi

Libo Guo, Qian-gui Xu, Zhen-jun Xiao

We calculate the branching ratios and CP-violating asymmetries for $B^0 \to K^{0} \ov K^{*0}$, $\ov K^{0} K^{*0}$, $K^+ K^{*-}$, $K^- K^{*+}$, and $B^+\to K^+ \ov K^{*0}$ and $ \ov K^0 K^{*+} $ decays by employing the low energy effective Hamiltonian and the perturbative QCD (pQCD) factorization approach. The theoretical predictions for the branching ratios

Alberto Marcone

We study the reverse mathematics of interval orders. We establish the logical strength of the implications between various definitions of the notion of interval order. We also consider the strength of different versions of the characterization theorem for interval orders: a partial order is an interval order if and only if it does not contain $2 \oplus 2$. W

Dirk Kreimer

We consider the structure of renormalizable quantum field theories from the viewpoint of their underlying Hopf algebra structure. We review how to use this Hopf algebra and the ensuing Hochschild cohomology to derive non-perturbative results for the short-distance singular sector of a renormalizable quantum field theory. We focus on the short-distance behavi