April 2006 arXiv papers — page 23

P. F. Borges, H. Boschi-Filho, A. N. Vaidya

We calculate the Green's functions for the particle-vortex system, for two anyons on a plane with and without a harmonic regulator and in a uniform magnetic field. These Green's functions which describe scattering or bound states (depending on the specific potential in each case) are obtained exactly using an algebraic method related to the SO(2,1) L

Radhakrishnan Nagarajan, Meenakshi Upreti

Affymetrix Genechip microarrays are used widely to determine the simultaneous expression of genes in a given biological paradigm. Probes on the Genechip array are atomic entities which by definition are randomly distributed across the array and in turn govern the gene expression. In the present study, we make several interesting observations. We show that th

Eric V. Linder

In the quest for precision cosmology, one must ensure that the cosmology is accurate as well. We discuss figures of merit for determining from observations whether the dark energy is a cosmological constant or dynamical, with special attention to the best determined equation of state value, at the ``pivot'' or decorrelation redshift. We show this is

Alessandro Armando, Maria Paola Bonacina, Silvio Ranise, Stephan Schulz

Program analysis and verification require decision procedures to reason on theories of data structures. Many problems can be reduced to the satisfiability of sets of ground literals in theory T. If a sound and complete inference system for first-order logic is guaranteed to terminate on T-satisfiability problems, any theorem-proving strategy with that system

Zoltan Ligeti, Michele Papucci, Gilad Perez

We analyze the significant new model independent constraints on extensions of the standard model (SM) that follow from the recent measurements of the B^0_s-\bar B^0_s mass difference. The time-dependent CP asymmetry in B_s -> ψϕ, S_{ψϕ}, will be measured with good precision in the first year of LHC data taking, which will further constrain the parameter spac

D. P. Stark, A. J. Bunker, R. S. Ellis, L. P. Eyles

We present a new measurement of the integrated stellar mass per comoving volume at redshift 5 determined via spectral energy fitting drawn from a sample of 214 photometrically-selected galaxies with z&#39;<26.5 in the southern GOODS field. Following procedures introduced by Eyles et al. (2005), we estimate stellar masses for various sub-samples for which rel

Eun-Ah Kim, Michael J. Lawler, Smitha Vishveshwara, Eduardo Fradkin

A central long standing prediction of the theory of fractional quantum Hall (FQH) states that it is a topological fluid whose elementary excitations are vortices with fractional charge and fractional statistics. Yet, the unambiguous experimental detection of this fundamental property, that the vortices have fractional statistics, has remained an open challen

Krysta M. Svore, David P. DiVincenzo, Barbara M. Terhal

We consider a model of quantum computation in which the set of operations is limited to nearest-neighbor interactions on a 2D lattice. We model movement of qubits with noisy SWAP operations. For this architecture we design a fault-tolerant coding scheme using the concatenated [[7,1,3]] Steane code. Our scheme is potentially applicable to ion-trap and solid-s

J. Pivarski

The di-electron width of an Upsilon meson is the decay rate of the Upsilon into an electron-positron pair, expressed in units of energy. We measure the di-electron width of the Upsilon(1S) meson to be 1.354 +- 0.004 +- 0.020 keV (the first uncertainty is statistical and the second is systematic), the di-electron width of the Upsilon(2S) to be 0.619 +- 0.004

Pavel Chigansky, Ramon van Handel

We investigate the robustness of nonlinear filtering for continuous time finite state Markov chains, observed in white noise, with respect to misspecification of the model parameters. It is shown that the distance between the optimal filter and that with incorrect model parameters converges to zero uniformly over the infinite time interval as the misspecifie

Christos Charmousis, Ruth Gregory, Nemanja Kaloper, Antonio Padilla

We systematically explore the spectrum of gravitational perturbations in codimension-1 DGP braneworlds, and find a 4D ghost on the self-accelerating branch of solutions. The ghost appears for any value of the brane tension, although depending on the sign of the tension it is either the helicity-0 component of the lightest localized massive tensor of mass $0<

Klaus Fleischmann, Peter Morters, Vitali Wachtel

We investigate random walks in independent, identically distributed random sceneries under the assumption that the scenery variables satisfy Cramer&#39;s condition. We prove moderate deviation principles in dimensions two and larger, covering all those regimes where rate and speed do not depend on the actual distribution of the scenery. In the case of dimens

G. Barbatis

We obtain a series improvement to higher-order $L^p$-Rellich inequalities on a Riemannian manifold $M$. The improvement is shown to be sharp as each new term of the series is added.

Andre Henriques

We investigate a variant of the octahedron recurrence which lives in a 3-dimensional lattice contained in [0,n] x [0,m] x R. Generalizing results of David Speyer math.CO/0402452, we give an explicit non-recursive formula for the values of this recurrence in terms of perfect matchings. We then use it to prove that the octahedron recurrence is periodic of peri

Eric Katz

In this paper, we consider weighted counts of tropical plane curves of particular combinatorial type through a certain number of generic points. We give a criterion, derived from tropical intersection theory on the secondary fan, for a weighted count to give a number invariant of the position of the points. By computing a certain intersection multiplicity, w

R. O. Kuzian, A. M. Daré, P. Sati, R. Hayn

We present a crystal field theory of transition metal impurities in semiconductors in a trigonally distorted tetrahedral coordination. We develop a perturbative scheme to treat covalency effects within the weak ligand field case (Coulomb interaction dominates over one-particle splitting) and apply it to ZnO:Co$^{2+}$ (3d$^7$). Using the large value of the ch

M. I. Katsnelson, K. S. Novoselov, A. K. Geim

The so-called Klein paradox - unimpeded penetration of relativistic particles through high and wide potential barriers - is one of the most exotic and counterintuitive consequences of quantum electrodynamics (QED). The phenomenon is discussed in many contexts in particle, nuclear and astro- physics but direct tests of the Klein paradox using elementary parti

Eugenio Lippiello, Federico Corberi, Marco Zannetti

In order to check on a recent suggestion that local scale invariance [M.Henkel et al. Phys.Rev.Lett. {\bf 87}, 265701 (2001)] might hold when the dynamics is of Gaussian nature, we have carried out the measurement of the response function in the kinetic Ising model with Glauber dynamics quenched to $T_C$ in $d=4$, where Gaussian behavior is expected to apply

G. C. Branco, D. Emmanuel-Costa, J. C. Romao

It is pointed out that the recent measurement of the angle $γ$ of the unitarity triangle, providing irrefutable evidence for a complex Cabibbo-Kobayashi-Maskawa (CKM) matrix, presents a great challenge for supersymmetric models with spontaneous CP violation. We construct a new minimal extension of the minimal supersymmetric standard model (MSSM), with sponta

Jawad A. Abuhlail

Prime objects were defined as generalization of simple objects in the categories of rings (modules). In this paper we introduce and investigate what turns out to be a suitable generalization of simple corings (simple comodules), namely fully coprime corings (fully coprime comodules). Moreover, we consider several primeness notions in the category of comodule

M. Tentyukov, J. A. M. Vermaseren

We describe the implementation of facilities for the communication with external resources in the Symbolic Manipulation System FORM. This is done according to the POSIX standards defined for the UNIX operating system. We present a number of examples that illustrate the increased power due to these new capabilities.

Heng-Yu Chen, David Tong

Two dimensional N=(4,4) gauge theories flow to interacting superconformal field theories on their Higgs branch. We examine worldsheet instantons in these theories through the eyes of a D-brane construction. The effective instanton partition function is shown to reveal an emergent background AdS_3 x S^3 geometry.

Hua-Tong Yang, Chengshi Liu

By generalizing the usual current density to a matrix with respect to spin variables, a general equation of continuity satisfied by the density matrix and current density matrix has been derived. This equation holds in arbitrary spin-orbit coupling systems as long as its Hamiltonian can be expressed in terms of a power series in momentum. Thereby, the expres

N. Armesto

The phenomenon of shadowing of nuclear structure functions at small values of Bjorken-$x$ is analyzed. First, multiple scattering is discussed as the underlying physical mechanism. In this context three different but related approaches are presented: Glauber-like rescatterings, Gribov inelastic shadowing and ideas based on high-density Quantum Chromodynamics

Michel Dubois-Violette

In this paper we investigate the class of the connected graded algebras which are finitely generated in degree 1, which are finitely presented with relations of degrees greater or equal to 2 and which are of finite global dimension D and Gorenstein. For D greater or equal to 4 we add the condition that these algebras are homogeneous and Koszul. It is shown t

Stefano Morisi

Recently in arXiv:hep-ph/0510321 has been proposed a GUT model for fermion masses and mixings with spontaneously broken S3 discrete flavor symmetry, where S_3 is the permutation group of three objects. The S3 breaking pattern in the quark sector is not studied and need further investigation. Since in such a model the number of free parameters is greater than

C. McNeile, C. Michael

Lattice QCD with $N_f=2$ flavours of sea quark is used to explore the spectrum and decay of scalar mesons. We are able to determine the $b_1$ - $a_0$ mass difference and this leads to the conclusion that the lightest non-singlet scalar meson ($a_0$) has a mass of 1.01(4) GeV. We determine from the lattice the coupling strength to KK and $πη$. We compute the

Eduardo H. M. Brietzke

We consider an identity relating Fibonacci numbers to Pascal&#39;s triangle discovered by G. E. Andrews. Several authors provided proofs of this identity, all of them rather involved or else relying on sophisticated number theoretical arguments. We not only give a simple and elementary proof, but also show the identity generalizes to arrays other than Pascal

Hiroo Azuma

In this paper, we consider a method for implementing a quantum logic gate with photons whose wave function propagates in a one-dimensional Kerr-nonlinear photonic crystal. The photonic crystal causes the incident photons to undergo Bragg reflection by its periodic structure of dielectric materials and forms the photonic band structure, namely, the light disp

Mu-Chun Chen, Sally Dawson, Tadas Krupovnickas

In this letter, we present our results on a global fit to precision electroweak data in a Higgs triplet model. In models with a triplet Higgs boson, a consistent renormalization scheme differs from that of the Standard Model and the global fit shows that a light Higgs boson with mass of 100-200 GeV is preferred. Triplet Higgs bosons arise in many extensions

Sergio Albeverio, Saidakhmat N. Lakaev, Zahriddin I. Muminov

A family of Friedrichs models under rank one perturbations $h_μ(p),$ $p \in (-π,π]^3$, $μ>0,$ associated to a system of two particles on the three dimensional lattice $\Z^3$ is considered. We prove the existence of a unique eigenvalue below the bottom of the essential spectrum of $h_μ(p)$ for all nontrivial values of $p$ under the assumption that $h_μ(0)$ ha

A. L. Roytburd, J. Slutsker

The equilibrium domain structure and its evolution under an electric field in ferroelectric bilayers and graded multilayers are considered. The equilibrium bilayer is self-poled and contains a single-domain and a polydomain (with 180 domains) layers. The polarization of a graded multilayer proceeds by movement of wedge-like domains as a result of progressive

Victor F. Sokolov, Gennady N. Chuev

To calculate the solvation of hydrophobic solutes we have developed the method based on the fundamental measure treatment of the density functional theory. This method allows us to carry out calculations of density profiles and the solvation energy for various hydrophobic molecules with a high accuracy. We have applied the method to the hydration of various

G. N. Chuev, V. F. Sokolov

We have developed a method to calculate the hydration of hydrophobic solutes by the fundamental measure theory. This method allows us to carry out calculations of the density profile and the hydration energy for hydrophobic molecules. An additional benefit of the method is the possibility to calculate interaction forces between solvated nanoparticles. On the

Morten S. Risager

We exhibit the analogy between prime geodesics on hyperbolic Riemann surfaces and ordinary primes. We present new asymptotic counting results concerning pairs of prime geodesics whose homology difference is fixed.

M. Cadoni, R. De Leo, G. Gaeta

DNA torsion dynamics is essential in the transcription process; a simple model for it, in reasonable agreement with experimental observations, has been proposed by Yakushevich (Y) and developed by several authors; in this, the DNA subunits made of a nucleoside and the attached nitrogen bases are described by a single degree of freedom. In this paper we propo

J. R. Ellis, N. E. Mavromatos, V. A. Mitsou, D. V. Nanopoulos

We discuss fits of cosmological dark energy models to the available data on high-redshift supernovae. We consider a conventional model with Cold Dark Matter and a cosmological constant (LambdaCDM), a model invoking super-horizon perturbations (SHCDM) and models based on Liouville strings in which dark energy is provided by a rolling dilaton field (Q-cosmolog

Maximilien Portier, Steven Moal, Jaewan Kim, Michèle Leduc

We present an exhaustive analysis of the light-induced frequency shifts of the photoassociation lines of ultracold metastable 4He* atoms in a magnetic trap. The measurements of the shifts of several vibrational levels bound in the purely long-range J=1,0u+ potential linked to the 23S1-23P0 asymptote were reported in a previous paper and are analyzed here. Th

T. Ferguson

Recent results from the CLEO experiment on decays and partial widths of various bottomonium and charmonium resonances are presented. New measurements of the di-electron partial widths for the 3 bound-state Upsilons and the J/psi are discussed. A determination of the total hadronic cross section for the psi(3770) is made, which solves a 20-year-old puzzle. Th

Marco Boggi

Let ${\cal M}_{g,n}$, for $2g-2+n>0$, be the moduli stack of $n$-pointed, genus $g$, smooth curves. For a family $C\to S$ of such curves over a connected base and a geometric point $ξ$ on $S$, the associated monodromy representation is the induced homomorphism $π_1(S,ξ)\toπ_1({\cal M}_{g,n},[C_ξ])$ on algebraic fundamental groups. It is well known that, if $

Anna Beliakova

The results become part of an upcoming paper.

Marco Boggi

Let $\widetilde{\cal M}_{g,n}$, for $2g-2+n>0$, be the moduli stack of $n$-pointed, genus $g$, stable complex curves of compact type. Various characterizations and properties are obtained of both the algebraic and topological fundamental groups of the stack $\widetilde{\cal M}_{g,n}$. Let $Γ_{g,n}$, for $2g-2+n>0$, be the Teichmüller group associated with a

A. H. Hoang, C. J. Reisser

We determine the real parts of electroweak matching conditions relevant for top quark pair production close to threshold in e+e- annihilation at next-to-next-to-leading logarithmic (NNLL) order. Numerically the corrections are comparable to the NNLL QCD corrections.

Mikael Fjallborg

We prove existence of static solutions to the cylindrically symmetric Einstein-Vlasov system, and we show that the matter cylinder has finite extension. The same results are also proved for a quite general class of equations of state for perfect fluids coupled to the Einstein equations, extending the class of equations of state considered in \cite{BL}. We al

Somesh Kr. Bhattacharya, Anjali Kshirsagar

We present results of a study of small stoichiometric $Cd_{n}Te_{n}$ ($1{\leq}n{\leq}6$) clusters and few medium sized non-stoichiometric $Cd_{m}Te_{n}$ [($m,n= 13, 16, 19$); ($m{\neq}n$)] clusters using the Density Functional formalism and projector augmented wave method within the generalized gradient approximation. Structural properties {\it viz.} geometr

J. Eroms, L. C. van Schaarenburg, E. F. C. Driessen, J. H. Plantenberg

We have studied low-frequency resistance fluctuations in shadow-evaporated Al/AlOx/Al tunnel junctions. Between 300 K and 5 K the spectral density follows a 1/f-law. Below 5 K, individual defects distort the 1/f-shape of the spectrum. The spectral density decreases linearly with temperature between 150 K and 1 K and saturates below 0.8 K. At 4.2 K, the spect

Rong-Gen Cai, Nobuyoshi Ohta

The Lovelock gravity is a fascinating extension of general relativity, whose action consists of the dimensionally extended Euler densities. Compared to other higher order derivative gravity theories, the Lovelock gravity is attractive since it has a lot of remarkable features such as that there are no more than second order derivatives with respect to metric

Shimul Akhanjee, Joseph Rudnick

We report the existence of a localization-delocalization transition in the classical plasma modes of a one dimensional Wigner Crystal with a white noise potential environment at T=0. Finite size scaling analysis reveals a divergence of the localization length at a critical eigenfrequency. Further scaling analysis indicates power law behavior of the critical

Lvzhou Li, Daowen Qiu

Quantum sequential machines (QSMs) are a quantum version of stochastic sequential machines (SSMs). Recently, we showed that two QSMs M_1 and M_2 with n_1 and n_2 states, respectively, are equivalent iff they are (n_1+n_2)^2--equivalent (Theoretical Computer Science 358 (2006) 65-74). However, using this result to check the equivalence likely needs exponentia

Patrick Valageas

We study the relaxation towards thermodynamical equilibrium of a 1-D gravitational system. This OSC model shows a series of critical energies $E_{cn}$ where new equilibria appear and we focus on the homogeneous ($n=0$), one-peak ($n=\pm 1$) and two-peak ($n=2$) states. Using numerical simulations we investigate the relaxation to the stable equilibrium $n=\pm

Wen-Xu Wang, Jie Ren, Guanrong Chen, Bing-Hong Wang

We present a memory-based snowdrift game (MBSG) taking place on networks. We found that, when a lattice is taken to be the underlying structure, the transition of spatial patterns at some critical values of the payoff parameter is observable for both 4 and 8-neighbor lattices. The transition points as well as the styles of spatial patterns can be explained b

Paolo Lisca, Andras I. Stipsicz

In this paper we prove a vanishing theorem for the contact Ozsvath--Szabo invariants of certain contact 3--manifolds having positive Giroux torsion. We use this result to establish similar vanishing results for contact structures with underlying 3--manifolds admitting either a torus fibration over the circle or a Seifert fibration over an orientable base. We

C. Navarrete-Benlloch, A. Perez, Eugenio Roldan

We generalize the concept of optical Galton board (OGB), first proposed by Bouwmeester et al. {[}Phys. Rev. A \textbf{61}, 013410 (2000)], by introducing the possibility of nonlinear self--phase modulation on the wavefunction during the walker evolution. If the original Galton board illustrates classical diffusion, the OGB, which can be understood as a grid

Zeqian Chen

An differential equation for wave functions is proposed, which is equivalent to Schrödinger&#39;s wave equation and can be used to determine energy-level gaps of quantum systems. Contrary to Schrödinger&#39;s wave equation, this equation is on `bipartite&#39; wave functions. It is shown that those `bipartite&#39; wave functions satisfy all the basic properti

A. Vuorinen, Laurence G. Yaffe

A three-dimensional effective theory for high temperature SU(3) gauge theory, which maintains the Z(3) center symmetry of the full theory, is constructed. Such a Z(3) invariant effective theory should be applicable to a wider temperature range than the usual effective theory, known as EQCD, which fails to respect the center symmetry. This center-symmetric ef

L. Canet, M. A. Moore

We re-examine mode-coupling theory for the Kardar-Parisi-Zhang (KPZ) equation in the strong coupling limit and show that there exists two branches of solutions. One branch (or universality class) only exists for dimensionalities $d<d_c=2$ and is similar to that found by a variety of analytic approaches, including replica symmetry breaking and Flory-Imry-Ma a

Chin-Yet Lin, M. Schick

Self-Consistent Field Theory is applied to a film of cylindrical-forming block copolymer subject to a surface field which tends to align the cylinders parallel to electrical plates, and to an external electric field tending to align them perpendicular to the plates. The Maxwell equations and self-consistent field equations are solved exactly, numerically, in

T. Hokuue

We report measurements of the charmless semileptonic decays $B^0 \to \pi^- / \rho^- \ell^{+} \nu$ and $B^+ \to \pi^0 / \rho^0 \ell^{+} \nu$, based on a sample of $2.75 \times 10^8$ $B \bar{B}$ events collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB $e^+e^-$ asymmetric collider. In this analysis, the accompanying $B$ meson is reco

Olaf Müller, Miguel Sánchez

The intention of this article is to give a flavour of some global problems in General Relativity. We cover a variety of topics, some of them related to the fundamental concept of &#39;Cauchy hypersurfaces&#39;: (1) structure of globally hyperbolic spacetimes, (2) the relativistic initial value problem, (3) constant mean curvature surfaces, (4) singularity th

Xiongfeng Ma, Chi-Hang Fred Fung, Frédéric Dupuis, Kai Chen

Decoy states have recently been proposed as a useful method for substantially improving the performance of quantum key distribution protocols when a coherent state source is used. Previously, data post-processing schemes based on one-way classical communications were considered for use with decoy states. In this paper, we develop two data post-processing sch

T. Golubeva, Yu. Golubev

The statistical properties of three-level lasing are investigated theoretically. It is assumed that the three-level medium is coherently excited by another laser with an arbitrary photon statistics. It is proved that, under the specific conditions, the photon statistics of the three-level laser duplicate the photon statistics of the exciting laser. We call t

Anna Jencova, Denes Petz

This paper attempts to give an overview about sufficiency in the setting of quantum statistics. The basic concepts are treated paralelly to the the measure theoretic case. It turns out that several classical examples and results have a non-commutative analogue. Some of the results are presented without proof (but with exact references) and the presentation i

J. Maurice Rojas

We reveal a natural algebraic problem whose complexity appears to interpolate between the well-known complexity classes BQP and NP: (*) Decide whether a univariate polynomial with exactly m monomial terms has a p-adic rational root. In particular, we show that while (*) is doable in quantum randomized polynomial time when m=2 (and no classical randomized pol

T. Vértesi

It has been recently shown (Bartlett et al. 2003) that information encoded into relative degrees of freedom enables communication without a common reference frame using entangled bipartite states. In this case the relative information stored in the two-qubit system is shared between the polarization degrees of freedom and the degree of entanglement. In the p

Daniela Dragoman

We show that the quantum wavefunction, interpreted as the probability density of finding a single non-localized quantum particle, which evolves according to classical laws of motion, is an intermediate description of a material quantum particle between the quantum and classical realms. Accordingly, classical and quantum mechanics should not be treated separa

A. S. Sanz, H. Han, P. Brumer

Aspects of coherence and decoherence are analyzed within the optical Bloch equations. By rewriting the analytic solution in an alternate form, we are able to emphasize a number of unusual features: (a) despite the Markovian nature of the bath, coherence at long times can be retained; (b) the long-time asymptotic degree of coherence in the system is intertwin

Otfried Gühne, Geza Toth

We investigate the relation between the entanglement properties of a quantum state and its energy for macroscopic spin models. To this aim, we develop a general method to compute energy bounds for states without certain forms of multipartite entanglement. Violation of these bounds implies the presence of these types of multipartite entanglement. As examples,

Geza Toth, Otfried Guehne, Hans J. Briegel

We present Bell inequalities for graph states with high violation of local realism. In particular, we show that there is a two-setting Bell inequality for every nontrivial graph state which is violated by the state at least by a factor of two. These inequalities are facets of the convex polytope containing the many-body correlations consistent with local hid

Akira R. Kinjo, Ken Nishikawa

Background: One-dimensional protein structures such as secondary structures or contact numbers are useful for three-dimensional structure prediction and helpful for intuitive understanding of the sequence-structure relationship. Accurate prediction methods will serve as a basis for these and other purposes. Results: We implemented a program CRNPRED which pre

P. Lecomte, D. Luckey, F. Nessi-Tedaldi, F. Pauss

Eight PbWO4 crystals produced for the electromagnetic calorimeter of the CMS experiment at LHC have been irradiated in a 20 GeV/c proton beam up to fluences of 5.4 E13 p/cm2. The damage recovery in these crystals, stored in the dark at room temperature, has been followed for over a year. Comparative irradiations with 60Co photons have been performed on seven

R. Zimmermann

In this article the physics motivation and the detector design of the OPERA experiment will be reviewed. The construction status of the detector, which will be situated in the CNGS beam from CERN to the Gran Sasso laboratory, will be reported. A survey on the physics performance will be given and the physics plan in 2006 will be presented.

Akhilesh Tanwar, Debesh Ranjan Roy, Sourav Pal, Pratim Kumar Chattaraj

A new electronic structure principle, viz. the minimum magnetizability principle (MMP) has been proposed and also has been verified through ab initio calculations, to extend the domain of applicability of the conceptual density functional theory (DFT) in explaining the magnetic interactions and magnetochemistry. This principle may be stated as, &#34;A stable

M. S. Safronova, W. R. Johnson. U. I. Safronova, T. E. Cowan

Stark-induced amplitudes for the 6P1/2 - 7P1/2 transition in Tl I are calculated using the relativistic SD approximation in which single and double excitations of Dirac-Hartree-Fock levels are summed to all orders in perturbation theory. Our SD values alpha S = 368 a0 3 and beta S= 298 a 0 3 are in good agreement with the measurements alpha S=377(8) a 0 3$ a

Paolo M. Ruti, Valerio Lucarini, Alessandro Dell&#39;Aquila, Sandro Calmanti

Understanding the atmospheric low-frequency variability is of crucial importance in fields such as climate studies, climate change detection, and extended-range weather forecast. The Northern Hemisphere climate features the planetary waves as a relevant ingredient of the atmospheric variability. Several observations and theoretical arguments seem to support

S. B. Leble, B. Reichel

We generalize the projection to orthogonal function basis (including polarization modes) method for nonlinear (Kerr medium) fiber and use this method in a case of two-mode waveguide. We consider orthogonal Bessel functions basis that fit the choice of cylindrical geometry of a fiber. The coupled nonlinear Schrödinger equations (CNLS) are derived. Analytic ex

Arne Hoell, Craig D. Roberts, Stewart V. Wright

The phenomena of confinement and dynamical chiral symmetry breaking are basic to understanding hadron observables. They can be explored using Dyson-Schwinger equations. The existence of a systematic, nonperturbative and symmetry preserving truncation of these equations enables the proof of exact results in QCD, and their illustration using simple but accurat

A. A. Isayev

The density, spin and isospin correlation functions in nuclear matter with a neutron-proton ($np$) condensate are calculated to study the possible signatures of the BEC-BCS crossover in the low-density region. It is shown that the criterion of the crossover (Phys. Rev. Lett. {\bf 95}, 090402 (2005)), consisting in the change of the sign of the density correl

L. Satpathy, S. K. Patra, R. K. Choudhury

Superheavy isotopes are highly neutron rich nuclei in the vicinity of neutron drip-line, stabilized by shell effect against the instability due to repulsive component of nuclear force, analogous to superheavy elements similarly stabilized against Coulomb instability. Here we discuss the stability and fission decay properties of such nuclei in the $^{254}$Th

Hiroshi Uechi

Properties of nuclear and neutron matter are discussed in a nonlinear $σ$-$ω$-$ρ$ mean-field approximation with self-interactions and mixing-interactions of mesons and baryons. The nonlinear interactions are renormalized by employing the theory of conserving approximations, which results in a thermodynamically consistent approximation that maintains Hugenhol

Rieuwert J. Blok, Corneliu Hoffman

We obtain the symplectic group as an amalgam of low rank subgroups akin to Levi components. We do this by having the group act flag-transitively on a new type of geometry and applying Tits&#39; lemma. This provides a new way of recognizing the symplectic groups from a small collection of small subgroups. The geometry consists of all subspaces of maximal rank

Apostolos Giannopoulos, Alain Pajor, Grigoris Paouris

We give an alternative proof of a recent result of Klartag on the existence of almost subgaussian linear functionals on convex bodies. If $K$ is a convex body in ${\mathbb R}^n$ with volume one and center of mass at the origin, there exists $x\neq 0$ such that $$|\{y\in K: |< y,x> |\gr t\|<\cdot, x>\|_1\}|\ls\exp (-ct^2/\log^2(t+1))$$ for all $t\gr 1$, where

Phillip E. Parker

This is a survey article with a limited list of references (as required by the publisher) which appears in the Encyclopedia of Mathematical Physics, eds. J.-P. Francoise, G.L. Naber and Tsou S.T. Oxford: Elsevier, 2006. vol.4, pp.94--104.

Ian P. Goulden, David M. Jackson, Ravi Vakil

We give a short and direct proof of the $λ_g$-Conjecture. The approach is through the Ekedahl-Lando-Shapiro-Vainshtein theorem, which establishes the ``polynomiality&#39;&#39; of Hurwitz numbers, from which we pick off the lowest degree terms. The proof is independent of Gromov-Witten theory. We briefly describe the philosophy behind our general approach to

Jonathan Block

This is the second in a series of papers intended to set up a framework to study categories of modules in the context of non-commutative geometries. In \cite{mem} we introduced the basic DG category $\Pc_{\A^\bullet}$, the perfect category of $\A^\bullet$, which corresponded to the category of coherent sheaves on a complex manifold. In this paper we enlarge

Karlheinz Grochenig, Thomas Strohmer

We investigate pseudodifferential operators on arbitrary locally compact abelian groups. As symbol classes for the Kohn-Nirenberg calculus we introduce a version of Sjoestrand&#39;s class. Pseudodifferential operators with such symbols form a Banach algebra that is closed under inversion. Since &#34;hard analysis&#34; techniques are not available on locally

Bruce E. Sagan

The study of patterns in permutations in a very active area of current research. Klazar defined and studied an analogous notion of pattern for set partitions. We continue this work, finding exact formulas for the number of set partitions which avoid certain specific patterns. In particular, we enumerate and characterize those partitions avoiding any partitio

W. Radzki, S. Rybicki

We study connected branches of non-constant {$2π$-pe}riodic solutions of the Hamilton equation \begin{displaymath} \dot{x}(t)=λJ\nabla H(x(t)), \end{displaymath} where $λ\in\halfline,$ $H\in C^2(\R^n\times\R^n,\R)$ and $ \displaystyle \nabla^2H(x_0)= [ \begin{array}{cc} A&0 0&B \end{array} ] $ for $x_0\in\nabla H^{-1}(0).$ The Hessian $\nabla^2H(x_0)$ can be

F. J. Calderon-Moreno, L. Narvaez-Macarro

Let $X$ be a complex analytic manifold, $D\subset X$ a locally quasi-homogeneous free divisor, $E$ an integrable logarithmic connection with respect to $D$ and $L$ the local system of the horizontal sections of $E$ on $X-D$. In this paper we give an algebraic description in terms of $E$ of the regular holonomic D-module whose de Rham complex is the intersect

J. Fura, A. Ratajczak, S. Rybicki

In this article we study the existence and the continuation of periodic solutions of autonomous Newtonian systems. To prove the results we apply the infinite-dimensional version of the degree for SO(2)-equivariant gradient operators. Using the results due to Rabier we show that the Leray-Schauder degree is not applicable in the proofs of our theorems, becaus

J. Fura, S. Rybicki

The goal of this article is to study closed connected sets of periodic solutions, of autonomous second order Hamiltonian systems, emanating from infinity. The main idea is to apply the degree for SO(2)-equivariant gradient operators defined by the second author. Using the results due to Rabier we show that we cannot apply the Leray-Schauder degree to prove t

J. Antezana, E. Pujals, D. Stojanoff

Given an $r\times r$ complex matrix $T$, if $T=U|T|$ is the polar decomposition of $T$, then, the Aluthge transform is defined by $$ Δ(T)= |T|^{1/2} U |T |^{1/2}. $$ Let $Δ^{n}(T)$ denote the n-times iterated Aluthge transform of $T$, i.e. $Δ^{0}(T)=T$ and $Δ^{n}(T)=Δ(Δ^{n-1}(T))$, $n\in\mathbb{N}$. We prove that the sequence $\{Δ^{n}(T)\}_{n\in\mathbb{N}}$

Sergio Albeverio, Saidakhmat N. Lakaev, Ramiza Kh. Djumanova

A family of Friedrichs models with rank one perturbations $h_μ(p),$ $p \in (-π,π]^3,μ>0$ associated to a system of two particles on the lattice $\Z^3$ is considered. The existence of a unique strictly positive eigenvalue below the bottom of the essential spectrum of $h_μ(p)$ for all nontrivial values $p \in (-π,π]^3$ under the assumption that $h_μ(0)$ has ei

Vyjayanthi Chari, Adriano Moura

We define and study the Kirillov--Reshetikhin modules for algebras of type $G_2$. We compute the graded character of these modules and verify that they are in accordance with the conjectures in math.QA/981202 and math.QA/0102113. These results give the first complete description of families of Kirillov--Reshetikhin modules whose isotypical components have mu

Vladimir P. Burskii, Alexei S. Zhedanov

We consider conditions for uniqueness of the solution of the Dirichlet or the Neumann problem for 2-dimensional wave equation inside of bi-quadratic algebraic curve. We show that the solution is non-trivial if and only if corresponding Poncelet problem for two conics associated with the curve has periodic trajectory and if and only if corresponding Pell-Abel

Luis A. Florit, Wolfgang Ziller

We study the topology of the 13 dimensional positively curved Bazaikin spaces. We show that there is only one such manifold which is homotopy equivalent to a homogeneous space, the so called Berger space. This is in contrast to the case of the 7 dimensional positively curved Eschenburg spaces. In addition, we compute the Pontryagin classes and the linking fo

Lluis Quer-Sardanyons, Samy Tindel

In this paper, we develop a Young integration theory in dimension 2 which will allow us to solve a non-linear one dimensional wave equation driven by an arbitrary signal whose rectangular increments satisfy some Hölder regularity conditions, for some Hölder exponent greater than 1/2. This result will be applied to the infinite dimensional fractional Brownian

William Crawley-Boevey

We describe recent work on preprojective algebras and moduli spaces of their representations. We give an analogue of Kac&#39;s Theorem, characterizing the dimension types of indecomposable coherent sheaves over weighted projective lines in terms of loop algebras of Kac-Moody Lie algebras, and explain how it is proved using Hall algebras. We discuss applicati

Ronald Fulp

Consider a physical system for which a mathematically rigorous geometric quantization procedure exists. Now subject the system to a finite set of irreducible first class (bosonic) constraints. It is shown that there is a mathematically rigorous BRST quantization of the constrained system whose cohomology at ghost number zero recovers the constrained quantum

K. Cho, A. Nakayashiki

The space of abelian functions of a principally polarized abelian variety J is studied as a module over the ring D of global holomorphic differential operators on J. We construct a D-free resolution in case the theta divisor is non-singular. As an application, in the case of dimension 2 and 3, we construct a new linear basis of the space of abelian functions

Lancelot F. James

This paper describes briefly how one may utilize a class of species sampling mixture models derived from Doksum&#39;s (1974) neutral to the right processes. For practical implementation we describe an ordered/ranked variant of the generalized weighted Chinese restaurant process.