December 2007 arXiv papers — page 3

Antoine Delcroix

A new approach to the algebra G_τ of temperate nonlinear generalized functions is proposed, in which G_τ is based on the space O_{M} endowed with is natural topology in contrary to previous constructions. Thus, this construction fits perfectly in the general scheme of construction of Colombeau type algebras and reveals better properties of G_τ. This is illus

Néji Bettaibi, Rym H. bettaieb

In this paper, we consider a $q$-analogue of the Dunkl operator on $\mathbb{R}$, we define and study its associated Fourier transform which is a $q$-analogue of the Dunkl transform. In addition to several properties, we establish an inversion formula and prove a Plancherel theorem for this $q$-Dunkl transform. Next, we study the $q$-Dunkl intertwining operat

J. W. van de Leur, A. Yu. Orlov

We consider a version of random motion of hard core particles on the semi-lattice $ 1, 2, 3,...$, where in each time instant one of three possible events occurs, viz., (a) a randomly chosen particle hops to a free neighboring site, (b) a particle is created at the origin (namely, at site 1) provided that site 1 is free and (c) a particle is eliminated at the

Lidia Fernandez, Teresa E. Perez, Miguel A. Pinar, Yuan Xu

For a bilinear form obtained by adding a Dirac mass to a positive definite moment functional in several variables, explicit formulas of orthogonal polynomials are derived from the orthogonal polynomials associated with the moment functional. Explicit formula for the reproducing kernel is also derived and used to establish certain inequalities for classical o

Giovanna De Francesco, Alessandro Capetti, Alessandro Marconi

We present results from a kinematical study of the gas in the nucleus of a sample of three LINER galaxies, obtained from archival HST/STIS long-slit spectra. We found that, while for the elliptical galaxy NGC 5077, the observed velocity curves are consistent with gas in regular rotation around the galaxy's center, this is not the case for the two remaini

Jiri Rosicky, Walter Tholen

A simple definition of torsion theory is presented, as a factorization system with both classes satisfying the 3--for--2 property. Comparisons with the traditional notion are given, as well as connections with the notions of fibration and of weak factorization system, as used in abstract homotopy theory.

A. F. Barabanov, A. M. Belemuk, L. A. Maksimov

The problem of constructing the kinetic equation with the description of motion of a hole in systems with strong spin- hole interaction (such as high- temperature superconductors) in terms of the spin polaron has been considered in the framework of the regular antiferromagnetic $s-d$ model. It has been shown by the example of the electrical resistivity that

N. Kumar

The high speed of light in vacuo together with the weakness of Earth gravity rules out any experimental detection of gravitational deflection of light on the laboratory length scale. Recent advances in coherent optics that produce ultra slow light in highly dispersive media with the group velocities down to ~102 ms-1, or even less, however, open up this poss

Olli Punkkinen, Ali Naji, Rudolf Podgornik, Ilpo Vattulainen

Despite its importance, the understanding of ionic cloud distribution close to a charged macroion under physiological salt conditions has remained very limited especially for strongly coupled systems with, for instance, multivalent counterions. Here we present a formalism that predicts both counterion and coion distributions in the vicinity of a charged macr

V. M. Kontorovich, A. B. Flanchik

The model of pulsar radio emission is discussed in which a coherent radio emis-sion is excited in a vacuum gap above polar cap of neutron star. Pulsar X and gamma radiation are considered as the result of low-frequency radio emission inverse Comp-ton scattering on ultra relativistic electrons accelerated in the gap. The influence of the pulsar magnetic field

Richa Sethi, M. V. Sangaranarayanan

The cross-exchange electron transfer expression arising from Marcus theory is deduced using Onsager's non-equilibrium Thermodynamics formalism.

V. Burdyuzha, G. Vereshkov

Shortly the vacuum component of the Universe from the geometry point of view and from the point of view of the standard model of physics of elementary particles is discussed. Some arguments are given to the calculated value of the cosmological constant (Zeldovich approximation). A new component of space vacuum (the gravitational vacuum condensate) is involve

Takeru K. Suzuki

In this talk we introduce our recent results of global 1D MHD simulations for the acceleration of solar and stellar winds. We impose transverse photospheric motions corresponding to the granulations, which generate outgoing Alfven waves. The Alfven waves effectively dissipate by 3-wave coupling and direct mode conversion to compressive waves in density-strat

Hansjörg Geiges

A simple proof is given of the following result first observed by J. Adachi: embedded circles tangent to the standard Engel structure on Euclidean 4-space are classified, up to isotopy via such embeddings, by their rotation number.

V. Burdyuzha

A quark-gluon phase transition in the Universe is researched after which vacuum (dark) energy has hardened and become cosmological constant. Before this a vacuum component of the Universe was changing by jumps during phase transitions since vacuum condensates of quantum fields carried a negative contribution in its positive density energy. This quintessence

Hansjörg Geiges

The Whitney-Graustein theorem states that regular closed curves in the 2-plane are classified, up to regular homotopy, by their rotation number. Here we give a simple proof based on contact geometry.

V. Burdyuzha, G. Vereshkov, J. Pacheco

Production of gravitational vacuum defects and their contribution to the energy density of our Universe are discussed. These topological microstructures (defects) could be produced in the result of creation of the Universe from "nothing" when a gravitational vacuum condensate has appeared. They must be isotropically distributed over the isotropic exp

D. Makarov, I. Karachentsev

The Local Supercluster is an ideal laboratory to study distribution of luminous and dark matter in the nearby Universe. The 1100 small groups have been selected using algorithm based on assumption that a total energy of physical pair of galaxies must be negative. The properties of the groups have been considered.

B. V. Rajarama Bhat, Volkmar Liebscher, Michael Skeide

In the 2002 AMS summer conference on ``Advances in Quantum Dynamics'' in Mount Holyoke Robert Powers proposed a sum operation for spatial E0-semigroups. Still during the conference Skeide showed that the Arveson system of that sum is the product of spatial Arveson systems. This product may but need not coincide with the tensor product of Arveson syst

M. Morii, S. Kitamoto, N. Shibazaki, D. Takei

Anomalous X-ray pulsars (AXPs) are thought to be magnetars, which are neutron stars with ultra strong magnetic field of $10^{14}$-- $10^{15}$ G. Their energy spectra below $\sim$10 keV are modeled well by two components consisting of a blackbody (BB) ($\sim$0.4 keV) and rather steep power-law (POW) function (photon index $\sim$2-4). Kuiper et al.(2004) disco

John Menzies, Michael Feast, Patricia Whitelock, Enrico Olivier

JHKs near-infrared photometry of stars in the Phoenix dwarf galaxy is presented and discussed. Combining these data with the optical photometry of Massey et al. allows a rather clean separation of field stars from Phoenix members. The discovery of a Mira variable (P = 425 days), which is almost certainly a carbon star, leads to an estimate of the distance mo

V. P. Maslov

We provide a correction to the Stefan--Boltzmann law and discuss the problem of a phase transition from the superfluid state into the normal state.

Adrian Palcu

The charged and the neutral currents are obtained by using a formal algebraical approach (developed and applied by the author) within the exact solution of a 3-3-1 gauge model with right-handed neutrinos. The entire Standard Model phenomenology is recovered without imposing any supplemental condition, but only by choosing an adecquate set of parameters from

Yi-Fei Wang, Yang Zhao, Chang-De Gong

An intriguing magneto-transport property is demonstrated by tight-binding lattice electrons with Rashba spin-orbit coupling (SOC) in a magnetic field. With the flux strength $ϕ={2π/N}$ ($N$ is an integer) and the Zeeman splitting fixed, when increasing the Rashba SOC $λ$, the spin-Hall and charge-Hall conductances (SHC and CHC) undergo four-step evolutions:

Yuji Sakai, Kouji Kashiwa, Hiroaki Kouno, Masanobu Yahiro

The Polyakov loop extended Nambu--Jona-Lasinio (PNJL) model with imaginary chemical potential is studied. The model possesses the extended ${\mathbb Z}_{3}$ symmetry that QCD does. Quantities invariant under the extended ${\mathbb Z}_{3}$ symmetry, such as the partition function, the chiral condensate and the modified Polyakov loop, have the Roberge-Weiss (R

Gabriella Böhm, Dragos Stefan

In a recent paper arXiv:0705.3190, we gave a general construction of a para-cocyclic structure on a cosimplex, associated to a so called admissible septuple -- consisting of two categories, three functors and two natural transformations, subject to compatibility relations. The main examples of such admissible septuples were induced by algebra homomorphisms.

Chiang-Mei Chen

This is a report of our recent investigation on the extremal dilatonic black holes in four dimensional Gauss-Bonnet gravity. We found that a global solution can exist only when the dilaton coupling is less than a critical value which can be determined numerically. Moreover, the black hole horizon is stretched by the Gauss-Bonnet correction and the entropy is

T. Nakamori, H. kubo, T. Yoshida, T. Tanimori

We have observed the supernova remnant MSH 15-52 (G320.4-1.2), which contains the gamma-ray pulsar PSR B1509-58, using the CANGAROO-III imaging atmospheric Cherenkov telescope array from April to June in 2006. We detected gamma rays above 810 GeV at the 7 sigma level during a total effective exposure of 48.4 hours. We obtained a differential gamma-ray flux a

Luis Dieulefait, Jorge Jimenez Urroz

In a paper of P. Paillier and J. Villar a conjecture is made about the malleability of an RSA modulus. In this paper we present an explicit algorithm refuting the conjecture. Concretely we can factorize an RSA modulus n using very little information on the factorization of a concrete n' coprime to n. However, we believe the conjecture might be true, when

Shi-Jie Xiong, Ye Xiong

We investigate geometric phase of fermion states under relative vibrations of two sublattices in graphene by solving time-dependent Schödinger equation using Floquet scheme. In a period of vibration the fermions acquire different geometric phases depending on their momenta. There are two regions in the momentum space: the adiabatic region where the geometric

Peter J. Mohr, Barry N. Taylor, David B. Newell

This paper gives the 2006 self-consistent set of the basic constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA) for international use. Further, it describes in detail the adjustment of the values of the constants, including the selection of the final set of input data based on the

Shi-Jie Xiong, Ye Xiong

Anderson localization of electron states on graphene lattice with diagonal and off-diagonal (OD) disorder in the absence of magnetic field is investigated by using the standard finite-size scaling analysis. In the presence of diagonal disorder all states are localized as predicted by the scaling theory for two-dimensional systems. In the case of OD disorder,

J. Besprosvany

The consideration of dark energy's quanta, required also by thermodynamics, introduces its chemical potential into the cosmological equations. Isolating its main contribution, we obtain solutions with dark energy decaying to matter or radiation. When dominant, their energy densities tend asymptotically to a constant ratio, explaining today's dark ene

C. Q. Geng, S. H. Ho, J. N. Ng

We demonstrate that the cosmological birefringence can arise from CPT conserving effect, originated from the CPT-even dimension-six Chern-Simons-like term. We show that a sizable rotation polarization angle in the data of the cosmic microwave background radiation polarization can be induced.

C. Q. Geng, Y. K. Hsiao

We review the direct CP and T violation in the three-body baryonic B decays in the standard model. In particular, we emphasize that the direct CP violating asymmetry in $B^\pm\to p\bar p K^{*\pm}$ is around 22% and the direct $T$ violating asymmetry in $\bar B^0 \ra Λ\bar p π^+$ can be as large as 12%, which are accessible to the current B factories at KEK a

Ylva M. Pihlström, Vincent L. Fish, Loránt O. Sjouwerman, Laura K. Zschaechner

The collisionally pumped, ground-state 1720 MHz maser line of OH is widely recognized as a tracer for shocked regions and observed in star forming regions and supernova remnants. Whereas some lines of excited states of OH have been detected and studied in star forming regions, the subject of excited-state OH in supernova remnants -- where high collision rate

Andrew R. Hodge, Motohico Mulase

An effective family of spectral curves appearing in Hitchin fibrations is determined. Using this family the moduli spaces of stable Higgs bundles on an algebraic curve are embedded into the Sato Grassmannian. We show that the Hitchin integrable system, the natural algebraically completely integrable Hamiltonian system defined on the Higgs moduli space, coinc

Janos Polonyi

The contribution of different modes of the Coulomb field to decoherence and to the dynamical breakdown of the time reversal invariance is calculated in the one-loop approximation for non-relativistic electron gas. The dominant contribution was found to come from the usual collective modes in the plasma, namely the zero-sound and the plasmon oscillations. The

Nicolas Tabareau, Jean-Jacques Slotine, Quang-Cuong Pham

Synchronization phenomena are pervasive in biology. In neuronal networks, the mechanisms of synchronization have been extensively studied from both physiological and computational viewpoints. The functional role of synchronization has also attracted much interest and debate. In particular, synchronization may allow distant sites in the brain to communicate a

Jonathan Ariel Barmak, Elias Gabriel Minian

We investigate one-point reduction methods of finite topological spaces. These methods allow one to study homotopy theory of cell complexes by means of elementary moves of their finite models. We also introduce the notion of h-regular CW-complex, generalizing the concept of regular CW-complex, and prove that the h-regular CW-complexes, which are a sort of co

S. Doty, A. Giaquinto, J. Sullivan

We show that the defining relations needed to describe a generalized q-Schur algebra as a quotient of a quantized enveloping algebra are determined completely by the defining ideal of a certain finite affine variety, the points of which correspond bijectively to the set of weights. This explains, unifies, and extends previous results.

Gunter M. Schütz, Fernando Pigeard de Almeida Prado, Rosemary J. Harris, Vladimir Belitsky

We introduce a stochastic heterogeneous interacting-agent model for the short-time non-equilibrium evolution of excess demand and price in a stylized asset market. We consider a combination of social interaction within peer groups and individually heterogeneous fundamentalist trading decisions which take into account the market price and the perceived fundam

Ruadhan O'Flanagan

The concept of a judgment as a logical action which introduces new information into a deductive system is examined. This leads to a way of mathematically representing implication which is distinct from the familiar material implication, according to which "If A then B" is considered to be equivalent to "B or not-A". This leads, in turn, to a

Ian Vega, Steven Detweiler

We propose an approach for the calculation of self-forces, energy fluxes and waveforms arising from moving point charges in curved spacetimes. As opposed to mode-sum schemes that regularize the self-force derived from the singular retarded field, this approach regularizes the retarded field itself. The singular part of the retarded field is first analyticall

Patrick Berghaus

IceCube is a cubic kilometer-scale neutrino telescope under construction at the South Pole since the austral summer 2004/2005. At the moment it is taking data with 22 deployed strings. The full detector is expected to be completed in 2011 with up to 80 strings each holding 60 digital optical modules. The progenitor detector AMANDA has been operating at the s

Bert Schroer

Using the conformal equivalence of translational KMS states on chiral theories with dilational KMS states obtained from restricting the vacuum state to an interval (the chiral inversion of the Unruh-effect) it was shown in a previous publications that the diverging volume (length) factor of the thermodynamic limit corresponds to the logarithmic increase in t

Artan Borici

In a recent paper, Creutz has given a new action describing two species of Dirac fermions with exact chiral symmetry on the lattice. This action depends on a parameter which may be fixed at a certain value in order to get the right continuum limit. In this letter, we elaborate more on this idea and present an action which is free of any other parameter excep

Y. Dubi, Y. Meir, Y. Avishai

The existence of "superconducting islands" (i.e., locally confined regions with superconducting correlations) in amorphous superconducting thin films can account for numerous experimental findings. Such spatial fluctuations in the superconducting gap were indeed observed experimentally, and were shown to persist into the insulating side of the superc

Alan Kostelecky, Neil Russell, Jay Tasson

Exceptional sensitivity to spacetime torsion can be achieved by searching for its couplings to fermions. Recent experimental searches for Lorentz violation are exploited to extract new constraints involving 19 of the 24 independent torsion components down to levels of order 10^{-31} GeV.

Konstantin S. Kuzmin, Vladimir V. Lyubushkin, Vadim A. Naumov

We analyze available experimental data on the total and differential charged-current cross sections for quasielastic neutrino and antineutrino scattering off nucleons, measured with a variety of nuclear targets in the accelerator experiments at ANL, BNL, FNAL, CERN, and IHEP, dating from the end of sixties to the present day. The data are used to adjust the

K. F. Pál, T. Vértesi

We have determined numerically the maximum quantum violation of over 100 tight bipartite Bell inequalities with two-outcome measurements by each party on systems of up to four dimensional Hilbert spaces. We have found several cases, including the ones where each party has only four measurement choices, where two dimensional systems, i.e., qubits are not suff

V. K. Dobrev

Let G be a semi-simple non-compact Lie group with unitary lowest/highest weight representations. We consider explicitly the relation between three types of representations of G: positive energy (unitary lowest weight)representations, (holomorphic) discrete series representations and non-unitary finite-dimensional irreps. We consider mainly the conformal grou

Takayuki Tsuchida

We propose a new type of reduction for integrable systems of coupled matrix PDEs; this reduction equates one matrix variable with the transposition of another multiplied by an antisymmetric constant matrix. Via this reduction, we obtain a new integrable system of coupled derivative mKdV equations and a new integrable variant of the massive Thirring model, in

Niko Jokela, Matti Jarvinen, Esko Keski-Vakkuri

We study a two-dimensional Coulomb gas consisting of a mixture of particles carrying various positive multiple integer charges, confined on a unit circle. We consider the system in the canonical and grand canonical ensembles, and attempt to calculate the partition functions analytically, using Toeplitz and confluent Vandermonde determinants. Just like in the

M. Bonesini

The international Muon Ionization Cooling Experiment (MICE) will carry out a systematic investigation of ionization cooling of a muon beam. As the emittance measurement will be done on a particle-by-particle basis, a sophisticated beam instrumentation is needed to measure particle coordinates and timing vs RF. The MICE time-of-flight system will measure timi

M. Bonesini

The analysis of the deuteron production in p--Be interactions at 450 GeV/c taken by the NA56/SPY experiment at CERN SPS is presented. In the framework of the coalescence model, the coalescence factor $\kappa$ is determined as $(0.79 \pm 0.05 \pm 0.13) \times 10^{-2}$. Our results disfavour the hypothesis that coalescence be the dominant mechanism for deutero

Felipe Asenjo, Cristian A. Farías, Pablo S. Moya

Starting from a microcanonical statistical approach and special relativity, the relativistic transformations for temperature and pressure for an ideal gas of bradyons, luxons or tachyons is found. These transformations are in agreement with the three laws of thermodynamic and our temperature transformation is the same as Ott's. Besides, it is shown that

Sera Cremonini, Robert de Mello Koch, Antal Jevicki

We consider the question of reconstructing (cubic) SUGRA interactions in AdS/CFT. The method we introduce is based on the matrix model maps (MMP) which were previously successfully employed at the linearized level. The strategy is to start with the map for 1/2 BPS configurations which is exactly known (to all orders) in the hamiltonian framework. We then use

Dietrich Stauffer, Przemyslaw A. Grabowicz, Janusz A. Holyst

In Hopfield neural networks with up to 10^8 nodes we store two patterns through Hebb couplings. Then we start with a third random pattern which is supposed to evolve into one of the two stored patterns, simulating the cognitive process of associative memory leading to one of two possible opinions. With probability p each neuron independently, instead of foll

F. Castano Iglesias, Lars Kadison

For any k-coalgebra C it is shown that similar quasi-finite C-comodules have strongly equivalent coendomorphism coalgebras; (the converse is in general not true). As an application we give a general result about codepth two coalgebra homomorphisms. Also a notion of codepth two bicomodule is introduced. The last section applies similarity to an endomorphism r

V. I. Gerasimenko, V. O. Shtyk

The Cauchy problem for the von Neumann hierarchy of nonlinear equations is investigated. One describes the evolution of all possible states of quantum many-particle systems by the correlation operators. A solution of such nonlinear equations is constructed in the form of an expansion over particle clusters whose evolution is described by the corresponding or

D. H. Linares, F. Roma, A. J. Ramirez-Pastor

The isotropic-nematic (I-N) phase transition in a system of long straight rigid rods of length k on square lattices is studied by combining Monte Carlo simulations and theoretical analysis. The process is analyzed by comparing the configurational entropy of the system with the corresponding to a fully aligned system, whose calculation reduces to the 1D case.

Anıl Zenginoğlu

We discuss a gauge choice which allows us to avoid the introduction of artificial timelike outer boundaries in numerical studies of test fields based on a 3+1 decomposition of asymptotically flat background spacetimes. The main idea is to include null infinity in the computational domain by conformally compactifying the metric on hyperboloidal foliations and

Jungkai Alfred Chen, Meng Chen

Let $X$ be a terminal weak $\bQ$-Fano threefold. We prove that $P_{-6}(X)>0$ and $P_{-8}(X)>1$. We also prove that the anti-canonical volume has a universal lower bound $-K_X^3 \geq 1/330$. This lower bound is optimal.

Akihiro Ishibashi

A higher (even spacetime) dimensional generalization of the Bondi energy has recently been proposed by gr-qc/0304054 within the framework of conformal infinity and Hamiltonian formalizm. The gauge condition employed in gr-qc/0304054 to derive the Bondi energy expression is, however, peculiar in the sense that cross-sections of null infinity specified by that

M. Pudlak, R. Pincak

The electronic spectra for double-wall zigzag and armchair nanotubes are found. The influence of nanotube curvatures on the electronic spectra is also calculated. Our finding that the outer shell is hole doped by the inner shell is in the difference between Fermi levels of individual shells which originate from the different hybridization of pi-orbital. The

A. Chupin, R. Stepanov

We present a perturbation solution for a pressure-driven fluid flow in a rotating toroidal channel. The analysis shows the difference between the solutions of full and simplified equations studied earlier. The result is found to be reliable for {\it low} Reynolds number ($\R$) as was the case for a previously studied solution for high $\R$. The convergence c

A. Sherman, M. Schreiber

The charge susceptibility of the two-dimensional repulsive Hubbard model is investigated using the diagram technique developed for the case of strong correlations. In this technique, a power series in the hopping constant is used. It is shown that once the Fermi level crosses one of the Hubbard subbands a sharp peak appears in the momentum dependence of the

Kazuhide Ichikawa, Toyokazu Sekiguchi, Tomo Takahashi

We studied a constraint on the primordial helium abundance Y_p from current and future observations of CMB. Using the currently available data from WMAP, ACBAR, CBI and BOOMERANG, we obtained the constraint as Y_p = 0.25^{+0.10}_{-0.07} at 68% C.L. We also provide a forecast for the Planck experiment using the Markov chain Monte Carlo approach. In addition t

Da Xu

A random matrix model of black holes is given based on analysis of Gaussian complex ensembles, based on the generalization of chRMT of QCD. Spacetime freedoms are incorporated in terms of eigenvalues of the ensemble. Classical observables of black holes can be computed using this model and it satisfies asymptotic freedom and holographic principle.

Alexei Kovalev, Jason D. Lotay

Coassociative 4-folds are a particular class of 4-dimensional submanifolds which are defined in a 7-dimensional manifold M with a G_2 structure given by a `positive' differential 3-form, sometimes called G_2-form. Assuming that a G_2-form on M is closed, we study deformations of a compact coassociative submanifold N with boundary contained in fixed, codi

V. A. Margulis, A. V. Shorokhov

The absorption of electromagnetic radiation of an anisotropic quantum dot is theoretically investigated taking into account the processes associated with simultaneous scattering from ionized impurities. It is shown that the scattering of electrons by impurities leads to the resonance absorption even if we have only one impurity in the quantum dot. Explicit f

Salah A. Aly, Andreas Klappenecker

Subsystem codes are the most versatile class of quantum error-correcting codes known to date that combine the best features of all known passive and active error-control schemes. The subsystem code is a subspace of the quantum state space that is decomposed into a tensor product of two vector spaces: the subsystem and the co-subsystem. A generic method to de

Yong-Joo Doh, Aarnoud L. Roest, Erik P. A. M. Bakkers, Silvano De Franceschi

We report quantum interference effects in InAs semiconductor nanowires strongly coupled to superconducting electrodes. In the normal state, universal conductance fluctuations are investigated as a function of magnetic field, temperature, bias and gate voltage. The results are found to be in good agreement with theoretical predictions for weakly disordered on

I. Wayan Sudiarta, D. J. Wallace Geldart

A general method for numerical computation of the thermal density matrix of a single-particle quantum system is presented. The Schrodinger equation in imaginary time tau is solved numerically by the finite difference time domain (FDTD) method using a set of initial wave functions at tau=0 . By choosing this initial set appropriately, the set of wave function

Akihiro Tanaka, Keisuke Totsuka, Xiao Hu

The physics underlying the magnetization process of quantum antiferromagnets is revisited from the viewpoint of geometric phases. A continuum variant of the Lieb-Schultz-Mattis-type approach to the problem is put forth, where the commensurability condition of Oshikawa {\it et al} derives from a Berry connection formulation of the system's crystal momentu

Xiaoping Zheng, Nana Pan, Li Zhang

The recent discovery of burst oscillation at 1122Hz in the X-ray transient XTE J1739-285 supports the suggestion that it contains a submillisecond pulsar. In our estimations of the enormous dissipation effect in the transition boundary layer between quark matter core and hadron matter envelope, combing the viscosities of bulk mater in previous works, we show

Simon Griffiths

This paper has been withdrawn by the author.

Debashish Chowdhury, Ashok Garai, Jian-Sheng Wang

KIF1A kinesins are single-headed motor proteins which move on cylindrical nano-tubes called microtubules (MT). A normal MT consists of 13 protofilaments on which the equispaced motor binding sites form a periodic array. The collective movement of the kinesins on a MT is, therefore, analogous to vehicular traffic on multi-lane highways where each protofilamen

J. Ponce de Leon

There are many ways of embedding a 4D spacetime in a given higher-dimensional manifold while, satisfying the field equations. In this work we extend and generalize a recent paper by Mashhoon and Wesson ({\it Gen. Rel. Gravit.} {\bf 39}, 1403(2007)) by showing different ways of embedding a solution of the 4D Einstein equations, in vacuum with a cosmological c

Robert S. Maier

The usefulness of Riemann P-symbols in deriving identities involving the parametrized special function Hl is explored. Hl is the analytic local solution of the Heun equation, the canonical second-order differential equation on the Riemann sphere with four regular singular points. The identities discussed include ones coming from Moebius automorphisms and F-h

E. S. Abers, A. K. Bhatia, D. A. Dicus, W. W. Repko

Since Witten's seminal 1984 paper on the subject, searches for evidence of strange quark nuggets (SQNs) have proven unsuccessful. In the absence of experimental evidence ruling out SQNs, the validity of theories introducing mechanisms that increase their stability should continue to be tested. To stimulate electromagnetic SQN searches, particularly space

Jan E. Aman, Narit Pidokrajt

The Hessian of the entropy function can be thought of as a metric tensor on state space. In the context of thermodynamical fluctuation theory Ruppeiner has argued that the Riemannian geometry of this metric gives insight into the underlying statistical mechanical system; the claim is supported by numerous examples. We study these geometries for some families

C. J. Henney, C. U. Keller, J. W. Harvey, M. K. Georgoulis

The Vector Spectromagnetograph (VSM) instrument has been recording photospheric and chromospheric magnetograms daily since August 2003. Full-disk photospheric vector magnetograms are observed at least weekly and, since November 2006, area-scans of active regions daily. Quick-look vector magnetic images, plus X3D and FITS formated files, are now publicly avai

Eduardo J. Dubuc

A locally connected topos is a Galois topos if the Galois objects generate the topos. We show that the full subcategory of Galois objects in any connected locally connected topos is an inversely 2-filtered 2-category, and as an application of the construction of 2-filtered bi-limits of topoi, we show that every Galois topos has a point.

Jean-Paul Blaizot

These lectures are centered around a specific problem, the effect of weak repulsive interactions on the transition temperature $T_c$ of a Bose gas. This problem provides indeed a beautiful illustration of many of the techniques which have been discussed at this school on effective theories and renormalization group. Effective theories are used first in order

Luca Fabrizio Di Cerbo

In this brief note, we clarify that a Ricci nilsoliton cannot be of gradient type.

A. P. Huxor, N. R. Tanvir, A. M. N. Ferguson, M. J. Irwin

We report the discovery of 40 new globular clusters (GCs) that have been found in surveys of the halo of M31 based on INT/WFC and CHFT/Megacam imagery. A subset of these these new GCs are of an extended, diffuse nature, and include those already found in Huxor et al. (2005). The search strategy is described and basic positional and V and I photometric data a

Marcus K. Benna, Anatoly Dymarsky, Igor R. Klebanov, Alexander Solovyov

As shown in arXiv:hep-th/0405282, the warped deformed conifold has two bosonic massless modes, a pseudoscalar and a scalar, that are dual to the phase and the modulus of the baryonic condensates in the cascading gauge theory. We reconsider the scalar mode sector, mixing fluctuations of the NS-NS 2-form and the metric, and include non-zero 4-d momentum $k_μ$.

Anthony M. Bloch, Islam I. Hussein, Melvin Leok, Amit K. Sanyal

In this paper we study a discrete variational optimal control problem for the rigid body. The cost to be minimized is the external torque applied to move the rigid body from an initial condition to a pre-specified terminal condition. Instead of discretizing the equations of motion, we use the discrete equations obtained from the discrete Lagrange--d'Alem

Peter Hegarty

The inverse problem for representation functions takes as input a triple (X,f,L), where X is a countable semigroup, f : X --> N_0 \cup {\infty} a function, L : a_1 x_1 + ... + a_h x_h an X-linear form and asks for a subset A \subseteq X such that there are f(x) solutions (counted appropriately) to L(x_1,...,x_h) = x for every x \in X, or a proof that no such

William Bialek, Rama Ranganathan

Two recent streams of work suggest that pairwise interactions may be sufficient to capture the complexity of biological systems ranging from protein structure to networks of neurons. In one approach, possible amino acid sequences in a family of proteins are generated by Monte Carlo annealing of a "Hamiltonian" that forces pairwise correlations among

Mark S. Ashbaugh, Lotfi Hermi

We produce a new proof and extend results by Harrell and Stubbe for the discrete spectrum of a self-adjoint operator. An abstract approach--based on commutator algebra, the Rayleigh-Ritz principle, and an ``optimal'' usage of the Cauchy-Schwarz inequality--is used to produce ``parameter-free'', ``projection-free'' versions of their th

Zhiwei Yun

We use the fixed point arrangement technique developed by Goresky-MacPherson to calculate the part of the equivariant cohomology of the affine flag varieties generated by degree 2. This turns out to be a quadric cone. We also describe the spectrum of the full equivariant cohomology ring as an explicit geometric object. We use our results to show that the ver

A. Beraudo, J. -P. Blaizot, C. Ratti

We investigate the behavior of a pair of heavy fermions, denoted by $Q$ and $\bar{Q}$, in a hot/dense medium. Although we have in mind the situation where $Q$ and $\bar{Q}$ denote heavy quarks, our treatment will be limited to simplified models, which bear only some general similarities with QCD. We study in particular the limiting case where the mass of the

M. Asorey, J. M. Munoz-Castaneda

The vacuum structure is probed by boundary conditions. The behaviour of thermodynamical quantities like free energy, boundary entropy and entanglement entropy under the boundary renormalization group flow are analysed in 2D conformal field theories. The results show that whereas vacuum energy and boundary entropy turn out to be very sensitive to boundary con

M. Romero-Gomez, E. Athanassoula, J. J. Masdemont, C. Garcia-Gomez

We propose a new theory to explain the formation of spiral arms and of all types of outer rings in barred galaxies. We have extended and applied the technique used in celestial mechanics to compute transfer orbits. Thus, our theory is based on the chaotic orbital motion driven by the invariant manifolds associated to the periodic orbits around the hyperbolic

Paolo Molaro

Only astronomical observations can effectively probe in space-time the variabil ity of the physical dimensionless constants such as the fine structure constant and proton-to-electron mass ratio, μ, which are related to fund amental forces of nature. Several theories beyond the Standard Model (SM) allow fundamental constants to vary, but they cannot make quan

C. Milstene, A. Freitas, M. Schmitt, A. Sopczak

Precision measurement of the stop mass at the ILC is done in a method based on cross-sections measurements at two different center-of-mass energies. This allows to minimize both the statistical and systematic errors. In the framework of the MSSM, a light stop, compatible with electro-weak baryogenesis, is studied in its decay into a charm jet and neutralino,

Dan Edidin, Damiano Fulghesu

Let $g$ be an even positive integer. In this paper we compute the integral Chow ring of the stack of smooth hyperelliptic curves of genus $g$.