October 2006 arXiv papers — page 53

F. -P. Schilling

This report presents recent results on track reconstruction and alignment with the silicon tracker of the CMS experiment at the LHC, obtained with a full detector simulation. After an overview of the layout of the tracker and its material budget, the baseline algorithm for track reconstruction is discussed. The performance of the track reconstruction and its

Li-Gang Wang, Cheng-Liang Zhao, Li-Qin Wang, Xuan-Hui Lu

The radiation forces on a Rayleigh dielectric sphere induced by a partially coherent light beam are greatly affected by the coherence of the light beam. The magnitude of the radiation forces on a dielectric sphere near the focus point greatly decreases as the coherence decreases. For the light beam with good coherence, the radiation force may be used to trap

Sergei Ovchinnikov

Media theory is a new branch of discrete applied mathematics originally developed in mid-nineties to deal with stochastic evolution of preference relations in political science and mathematical psychology. The theory focuses on a particular semigroup of `messages' acting as transformations of a set of `states', called a `medium', whose axioms are

Nabil L. Youssef, S. H. Abed, A. Soleiman

The aim of the present paper is to establish a global theory of conformal changes in Finsler geometry. Under this change, we obtain the relationships between the most important geometric objects associated to $(M,L)$ and the corresponding objects associated to $(M,\tilde{L})$, $\widetilde{L}=e^{σ(x)} L$ being the Finsler conformal transformation. We have fou

Emmanuel Candes, Laurent Demanet, Lexing Ying

We introduce a general purpose algorithm for rapidly computing certain types of oscillatory integrals which frequently arise in problems connected to wave propagation and general hyperbolic equations. The problem is to evaluate numerically a so-called Fourier integral operator (FIO) of the form $\int e^{2πi Φ(x,ξ)} a(x,ξ) \hat{f}(ξ) \mathrm{d}ξ$ at points gi

Jack Morava

The second relative homotopy group π_2(V(\C),V(\R)) (of the complex relative to the real points of an algebraic variety) encodes interesting information about the `bubbling' phenomena of quantum cohomology. We consider these groups in particular for genus zero Deligne-Mumford moduli spaces, as well as for certain generalizations introduced more recently

Dang Duc Trong, Truong Trung Tuyen

In this paper we shall consider the assymptotic growth of $|P_n(z)|^{1/k_n}$ where $P_n(z)$ is a sequence of entire functions of genus zero. Our results extend a result of J. Muller and A. Yavrian. We shall prove that if the sequence of entire functions has a geometric growth at each point in a set $E$ being non-thin at $\infty$ then it has a geometric growt

Bozhidar Z. Iliev

The main subject of the book is an up-to-date and in-depth survey of the theory of normal frames and coordinates in differential geometry. The book can be used as a reference manual, review of the existing results and introduction to some new ideas and developments. In the book can be found practically all existing essential results and methods concerning no

Xiaomin Chen, Vašek Chvátal

De Bruijn and Erdős proved that every noncollinear set of n points in the plane determines at least n distinct lines. We suggest a possible generalization of this theorem in the framework of metric spaces and provide partial results on related extremal combinatorial problems.

Benjamin Steinberg, Mariya Vorobets, Yaroslav Vorobets

We construct automata over a binary alphabet with $2n$ states, $n\geq 2$, whose states freely generate a free group of rank $2n$. Combined with previous work, this shows that a free group of every finite rank can be generated by finite automata over a binary alphabet. We also construct free products of cyclic groups of order two via such automata.

Yiqiang Li, Zongzhu Lin

We describe the affine canonical basis elements in the case when the affine quiver has arbitrary orientation. This generalizes Lusztig's description.

Silvia Heubach, Sergey Kitaev, Toufik Mansour

A partially ordered (generalized) pattern (POP) is a generalized pattern some of whose letters are incomparable, an extension of generalized permutation patterns introduced by Babson and Steingrimsson. POPs were introduced in the symmetric group by Kitaev [Partially ordered generalized patterns, Discrete Math. 298 (2005), 212-229; Introduction to partially o

Syoiti Ninomiya, Nicolas Victoir

The authors present a new simple algorithm to approximate weakly stochastic differential equations in the spirit of [1] and [2]. They apply it to the problem of pricing Asian options under the Heston stochastic volatility model, and compare it with other known methods. It is shown that the combination of the suggested algorithm and quasi-Monte Carlo methods

E. -M. Ilgenfritz, S. A. Paston, H. -J. Pirner, E. V. Prokhvatilov

We review the fundamental ideas of quantizing a theory on a Light Front including the Hamiltonian approach to the problem of bound states on the Light Front and the limiting transition from formulating a theory in Lorentzian coordinates (where the quantization occurs on spacelike hyperplanes) to the theory on the Light Front, which demonstrates the equivalen

Abhishek Agarwal

We present a method for computing the non-perturbative mass-gap in the theory of Bosonic membranes in flat background spacetimes with or without background fluxes. The computation of mass-gaps is carried out using a matrix regularization of the membrane Hamiltonians. The mass gap is shown to be naturally organized as an expansion in a 'hidden' parame

Gia Dvali

We consider theories that modify gravity at cosmological distances, and show that any such theory must exhibit a strong coupling phenomenon, or else it is either inconsistent or is already ruled out by the solar system observations. We show that all the ghost-free theories that modify dynamics of spin-2 graviton on asymptotically flat backgrounds, automatica

Keshav Dasgupta, Josh Guffin, Rhiannon Gwyn, Sheldon Katz

We study a particular N = 1 confining gauge theory with fundamental flavors realised as seven branes in the background of wrapped five branes on a rigid two-cycle of a non-trivial global geometry. In parts of the moduli space, the five branes form bound states with the seven branes. We show that in this regime the local supergravity solution is surprisingly

TeV4LHC QCD Working Group, M. Albrow, M. Begel, D. Bourilkov

The experiments at Run 2 of the Tevatron have each accumulated over 1 inverse femtobarn of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD

Loretta M. Johnson, R. Seton Williams, Laura F. Spencer, Burton J. DeWilde

MiniBooNE is expected to soon report analysis of their closed data set, and we here consider what effect direct non-standard neutrino interactions would have on their observations. Current direct limits on non-standard interactions make interpretation of a $ν_e$ signal at MiniBooNE as three-flavor oscillations plus direct interactions untenable. However, $ν_

Sarben Sarkar

We shall review methods used in the description of decoherence on particle probes in experiments due to surrounding media. This will include conventional media as well as a model for space-time foam arising from non-critical string theory.

B. A. Magradze

Recently, the QCD renormalization group (RG) equation at higher orders in MS-like renormalization schemes has been solved for the running coupling as a series expansion in powers of the exact 2-loop order coupling. In this work, we prove that the power series converges to all orders in perturbation theory. Solving the RG equation at higher orders, we determi

Masatoshi Hamada, Hiroaki Kouno, Atsushi Nakamura, Takuya Saito

We study properties of the finite temperature quark propagator by using the SU(3) quenched lattice simulation in the Landau gauge and report numerical results of the standard Wilson quark case as well as the improved clover one. The mass function in the deconfinement phase is different from that of the confinement phase, especially at low momentum regions.

Heechang Na, Steven Gottlieb

We study the heavy baryon mass spectrum on gauge configurations that include 2+1 flavors of dynamical improved staggered quarks. A valence clover heavy quark is combined with two improved staggered light quark propagators to form baryons with different flavors. We are using MILC coarse gauge configurations with a lattice spacing of about 0.12 fm. In this pre

Gregory M. Harry, Matthew R. Abernathy, Andres E. Becerra-Toledo, Helena Armandula

Reducing thermal noise from optical coatings is crucial to reaching the required sensitivity in next generation interferometric gravitational-waves detectors. Here we show that adding TiO$_2$ to Ta$_2$O$_5$ in Ta$_2$O$_5$/SiO$_2$ coatings reduces the internal friction and in addition present data confirming it reduces thermal noise. We also show that TiO$_2$

S. N. Pandey, B. K. Sinha, Raj Kumar

Previous work on exact solutions has been shown that sources need to be appended to the field equation of Einstein's unified field theory in order to achieve physically meaningful results,such sources can be included in a variational formulation by Borchsenius and moffat.The resulting field equations and conservation identities related to the theory that

Gérard Bécher, Patrice Enjalbert, Estelle Fievé, Laurent Gosselin

This repport concerns automatic understanding of (french) iterative sentences, i.e. sentences where one single verb has to be interpreted by a more or less regular plurality of events. A linguistic analysis is proposed along an extension of Reichenbach's theory, several formal representations are considered and a corpus of 18000 newspaper extracts is des

Peter Slavov

In this paper the validity of the diffusion approximation for multiple scattering of classical waves in random medium in different regimes is investigated, with emphasize to weak localization effects. Many principle topics are discussed once again. We obtain new expressions for the incoherent and coherent multiple scattering intensities for the more general

Sudipto Muhuri, Madan Rao, Sriram Ramaswamy

We study the effects of externally applied shear flow on a model of suspensions of motors and filaments, via the equations of active hydrodynamics [PRL {\bf 89} (2002) 058101; {\bf 92} (2004) 118101]. In the absence of shear, the orientationally ordered phase of {\it both} polar and apolar active particles is always unstable at zero-wavenumber. An imposed st

Sougato Bose

We show how the remotest sites of a finite lattice can be entangled, with the amount of entanglement exceeding that of a singlet, solely through the dynamics of an ideal Bose gas in a special initial state in the lattice. When additional occupation number measurements are made on the intermediate lattice sites, then the amount of entanglement and the length

Simone Bianco

We study the properties of memory of a financial time series adopting two different methods of analysis, the detrended fluctuation analysis (DFA) and the analysis of the power spectrum (PSA). The methods are applied on three time series: one of high-frequency returns, one of shuffled returns and one of absolute values of returns. We prove that both DFA and P

Mesfin Asfaw, Bartosz Rozycki, Reinhard Lipowsky, Thomas R. Weikl

The adhesion of biological membranes is controlled by various types of receptor and ligand molecules. In this letter, we present a statistical-mechanical model for membranes that interact via receptor/ligand bonds of two different lengths. We show that the equilibrium phase behavior of the membranes is governed by an effective double-well potential. The dept

C. Bulutay

The $k \cdot p$ is a versatile technique that describes the semiconductor band structure in the vicinity of the bandgap. The technique can be extended to full Brillouin zone by including more coupled bands into consideration. For completeness, a detailed formulation is provided where the associated $k \cdot p$ parameters are extracted from the local empirica

Jiunn-Wei Chen, Eiji Nakano

The epsilon expansion (expansion around four spacial dimensions) developed by Nishida and Son for a cold fermi gas with infinite scattering length is extended to finite scattering length to study the BEC-BCS crossover. A resummation of higher order logarithms and a suitable extension of fermion coupling in d-dimensions are developed in order to apply the the

M. Ziegler, T. Rauch, K. Werner, J. W. Kruk

The far-ultraviolet spectrum of the DAO White Dwarf LS V+4621, the exciting star of the possible planetary nebula Sh 2-216,is strongly contaminated by absorption features from the interstellar medium (ISM). For an ongoing spectral analysis, we aim to extract the pure photospheric spectrum in order to identify and model metal lines of species which are not de

T. Rauch, M. Ziegler, K. Werner, J. W. Kruk

The DAO-type white dwarf LS V+4621 is the hydrogen-rich central star of the possible planetary nebula Sh 2-216. We have taken high-resolution, high-S/N ultraviolet spectra with STIS aboard the HST and FUSE in order to constrain its photospheric parameters. A detailed spectral analysis by means of state-of-the-art NLTE model-atmosphere techniques is presented

Timothy C. Beers, Chris Flynn, Silvia Rossi, Jesper Sommer-Larsen

We report broadband UBV and/or BVRI CCD photometry for a total of 1857 stars in the thick-disk and halo populations of the Galaxy. The majority of our targets were selected as candidate field horizontal-branch or other A-type stars (FHB/A, N = 576), or candidate low-metallicity stars (N = 1221), from the HK and Hamburg/ESO objective-prism surveys. Similar da