September 2006 arXiv papers — page 22

Igal Sason, Idan Goldenberg

This paper is focused on the performance analysis of binary linear block codes (or ensembles) whose transmission takes place over independent and memoryless parallel channels. New upper bounds on the maximum-likelihood (ML) decoding error probability are derived. The framework of the second version of the Duman and Salehi (DS2) bounds is generalized to the c

Sang-Seon Byun, Chuck Yoo

In hierarchical reliable multicast environment, makespan is the time that is required to fully and successfully transmit a packet from the sender to all receivers. Low makespan is vital for achieving high throughput with a TCP-like window based sending scheme. In hierarchical reliable multicast methods, the number of repair servers and their locations influe

A. De Virgiliis, R. L. C. Vink, J. Horbach, K. Binder

Phase separation of colloid-polymer mixtures, described by the Asakura-Oosawa (AO) model, confined in a thin slit pore is studied by grand-canonical Monte Carlo simulation. While one wall is a hard wall for both particles, at the other wall there acts an additional repulsive potential on the colloids only. Varying the strength of this potential, a crossover

A. O. Dobry, D. C. Cabra, G. L. Rossini

We develop a theory of the spin-Peierls transition taking into account the three dimensional character of the phonon field. Our approach does not rely on the adiabatic or mean field treatment for the phonons. It is instead based in the exact integration of the phonon field, the exact long wavelength solution of the one chain spin problem, and then a mean fie

Marcin Raczkowski, Raymond Fresard, Andrzej M. Oles

Using the mean field theory in the slave-boson approach we analyzed the electron correlation effects in the stripe phases. One finds that a finite next-nearest neighbor hopping $t'$ plays an important role in the low doping regime, where it controls the crossover from the filled diagonal to half-filled vertical/horizontal stripes at doping $ x\simeq 1/16

M. D. Johannes, J. Richter, S. -L. Drechsler, H. Rosner

We present evidence that crystalline Sr_2Cu(PO_4)_2 is a nearly perfect one-dimensional (1D) spin-1/2 anti-ferromagnetic Heisenberg model (AHM) chain compound with nearest neighbor only exchange. We undertake a broad theoretical study of the magnetic properties of this compound using first principles (LDA, LDA+U calculations), exact diagonalization and Bethe

A. Hernandez-Minguez, F. Macia, J. M. Hernandez, J. Tejada

A comprehensive set of experiments on the effect of high-frequency surface acoustic waves, SAWs, in the spin relaxation in Mn12-acetate is presented. We have studied the quantum magnetic deflagration induced by SAWs under various experimental conditions extending the data shown in a very recent paper [A. Hernandez-Minguez et. al., Phys. Rev. Lett. 95, 217205

Fabio D. A. Aarao Reis, Janusz Stafiej

We study a model of corrosion and passivation of a metalic surface in contact with a solution using scaling arguments and simulation. The passive layer is porous so that the metal surface is in contact with the solution. The volume excess of the products may suppress the access of the solution to the metal surface, but it is then restored by a diffusion mech

Gianluca Ghigo, Francesco Laviano, Laura Gozzelino, Roberto Gerbaldo

The influence of dendritic magnetic-flux penetration on the microwave response of superconducting MgB2 films is investigated by a coplanar resonator technique. The peculiar feature consists of jumps in the resonance curve, induced by vortex avalanches freezing flux inside the resonator. Due to a shaking effect, microwave currents maintain the vortex system c

A. Moosavi, M. Rauscher, S. Dietrich

Nanodroplets residing near wedges or edges of solid substrates exhibit a disjoining pressure induced dynamics. Our nanoscale hydrodynamic calculations reveal that non-volatile droplets are attracted or repelled from edges or wedges depending on details of the corresponding laterally varying disjoining pressure generated, e.g., by a possible surface coating.

R. Guerrero, F. G. Aliev, R. Villar, J. Hauch

We report on tunnelling magnetoresistance (TMR), current-voltage (IV) characteristics and low frequency noise in epitaxially grown Fe(110)/MgO(111)/Fe(110) magnetic tunnel junctions (MTJs) with dimensions from 2x2 to 20x20 um2. The evaluated MgO energy barrier (0.50+/-0.08 eV), the barrier width (13.1+/-0.5 angstrom) as well as the resistance times area prod

Ankush Sengupta, Surajit Sengupta, Gautam I. Menon

We investigate the driven states of a two-dimensional crystal whose ground state can be tuned through a square-triangular transition. The depinning of such a system from a quenched random background potential occurs via a complex sequence of dynamical states, which include plastic flow states, hexatics, dynamically stabilized triangle and square phases and i

Jérémie Teisseire, F. Nallet, P. Fabre, Cyprien Gay

We perform traction experiments on viscous liquids highly confined between parallel plates, a geometry known as the probe-tack test in the adhesion community. Direct observation during the experiment coupled to force measurement shows the existence of several mechanisms for releasing the stress. Bubble nucleation and instantaneous growth had been observed in

Yatendra S. Jain

Energy of elementary excitations and the anomalous nature of small Q phonons in He-II are studied by using our macro-orbital microscopic theory of a system of interacting bosons (cond-mat/0606571). It is observed that : (i) the experimental E(Q) of He-II not only agrees with our theoretical relation $E(Q) = \hbar^2Q^2/4mS(Q)$ but also supports an important c

Laura Cano-Cortés, Andreas Dolfen, Jaime Merino, Jörg Behler

We employ density-functional theory to calculate realistic parameters for an extended Hubbard model of the molecular metal TTF-TCNQ. Considering both intra- and intermolecular screening in the crystal, we find significant longer-range Coulomb interactions along the molecular stacks, as well as inter-stack coupling. We show that the long-range Coulomb term of

S. Y. Liu, Norman J. M. Horing, X. L. Lei

We employ a helicity-basis kinetic equation approach to investigate the anomalous Hall effect in two-dimensional narrow-band semiconductors considering both Rashba and extrinsic spin-orbit (SO) couplings, as well as a SO coupling directly induced by an external driving electric field. Taking account of long-range electron-impurity scattering up to the second

Jean-Marc Costantini, Andrée Kahn-Harari, Francois Beuneu, François Couvreur

Sintered samples of monoclinic zirconia (alpha-ZrO2) have been irradiated at room temperature with 6.0-GeV Pb ions in the electronic slowing down regime. X-ray diffraction (XRD) and micro-Raman spectroscopy measurements showed unambiguously that a transition to the 'metastable' tetragonal phase (beta-ZrO2) occurred at a fluence of 6.5x10^12 cm-2 for

Björn Kubala, Jürgen König

We study thermal conductance and thermopower of a metallic single-electron transistor beyond the limit of weak tunnel coupling. Employing both a systematic second-order perturbation expansion and a non-perturbative approximation scheme, we find, in addition to sequential and cotunneling contributions, terms that are associated with the renormalization of sys

Michael Wilkinson, Bernhard Mehlig, Doron Cohen

We discuss the response of a quantum system to a time-dependent perturbation with spectrum Φ(ω). This is characterised by a rate constant D describing the diffusion of occupation probability between levels. We calculate the transition rates by first-order perturbation theory, so that multiplying Φ(ω) by a constant λchanges the diffusion constant to λD. Howev

Nassim Bozorgnia, Jonathan J. Fortney, Chris McCarthy, Debra A. Fischer

HD 149026b is a short-period, Saturn-mass planet that transits a metal-rich star. The planet's radius, determined by photometry, is remarkably small compared to other known transiting planets, with a heavy-element core that apparently comprises ~70% of the total planet mass. Time-series spectra were obtained at Keck before and during transit in order to

Nicolas Labrosse, Pierre Gouttebroze, Jean-Claude Vial

Even quiescent solar prominences may become active and sometimes erupt. These events are occasionally linked to coronal mass ejections. However we know very little about the plasma properties during the activation and eruption processes. We present new computations of the helium line profiles emitted by an eruptive prominence. The prominence is modelled as a

Lars Bergstrom, Torsten Bringmann, Martin Eriksson, Michael Gustafsson

The extra-dimensional origin of dark matter is a fascinating and nowadays often discussed possibility. Here, we present the gamma-ray signatures that are expected from the self-annihilation of Kaluza-Klein dark matter particles. For comparison, we contrast this with the case of supersymmetry, where the neutralino annihilation spectra take a very different fo

Craig E. DeForest, Charles C. Kankelborg

We have developed a new, quasi-Lagrangian approach for numerical modeling of magnetohydrodynamics in low to moderate $β$ plasmas such as the solar corona. We introduce the concept of a ``fluxon'', a discretized field line. Fluxon models represent the magnetic field as a skeleton of such discrete field lines, and interpolate field values from the geom

Sarbani Basu, H. M. Antia, Richard S. Bogart

We present results on the structure of the near-surface layers of the Sun obtained by inverting frequencies of high-degree solar modes from "ring diagrams". We have results for eight epochs between June 1996 and October 2003. The frequencies for each epoch were obtained from ring diagrams constructed from MDI Dopplergrams spanning complete Carrington

Naoki Seto

We discussed prospects for directly detecting circular polarization signal of gravitational wave background. We found it is generally difficult to probe the monopole mode of the signal due to broad directivity of gravitational wave detectors. But the dipole (l=1) and octupole (l=3) modes of the signal can be measured in a simple manner by combining outputs o

Scott W. McIntosh, Alisdair R. Davey, Donald M. Hassler, James D. Armstrong

Identifying the two physical mechanisms behind the production and sustenance of the quiescent solar corona and solar wind poses two of the outstanding problems in solar physics today. We present analysis of spectroscopic observations from the Solar and Heliospheric Observatory that are consistent with a single physical mechanism being responsible for a signi

Soheila Gharanfoli, Varsha P. Kulkarni, Mark R. Chun, Marianne Takamiya

We present Keck/LRIS spectra of a candidate damped Lyman-alpha (DLA) galaxy toward the QSO 3C196 (z_em = 0.871). The DLA absorption system has a redshift of z_DLA = 0.437, and a galaxy at 1.5" from the QSO has been identified in high resolution imaging with WFPC2/HST. We have detected emission lines of [O II] 3727A, Hbeta, [O III] 5007A, Halpha and [N II

D. R. Gies, W. G. Bagnuolo,, E. K. Baines, T. A. ten Brummelaar

We present the first K'-band, long-baseline interferometric observations of the northern Be stars gamma Cas, phi Per, zeta Tau, and kappa Dra. The measurements were made with multiple telescope pairs of the CHARA Array interferometer, and in every case the observations indicate that the circumstellar disks of the targets are resolved. We fit the interfer

Robert K. Soberman, Maurice Dubin

Fragile volatile aggregates with extremely low albedo, gravitationally drawn into the solar system are likely from the dark matter dominating the universal mass. Characteristics of this meteoric population permitted avoiding detection through a half-century's search. Measurements from space probes and in the upper atmosphere prove their existence and con

A. R. Lopez-Sanchez, C. Esteban, J. Garcia-Rojas, M. Peimbert

We present echelle spectrophotometry of the blue compact dwarf galaxy (BCDG) NGC 5253. The data have been taken with the Very Large Telescope UVES echelle spectrograph in the 3100 to 10400 angstroms range. We have measured the intensities of a large number of permitted and forbidden emission lines in four zones of the central part of the galaxy. In particula

Matthew Hayes, Goran Ostlin

Numerous surveys are underway or planned that aim to exploit the Lyman-alpha emission line as a probe of the distant universe. We investigate the reliability of such high-z Lya studies and the validity of the conclusions that are based upon them. We examine whether reliable Lya fluxes (F_Lya) and equivalent widths (W_Lya) can be estimated from narrowband ima

Zs. Hetesi, L. Végh

Anthropic principles were grown from the problem of fine tuning. Although anthropic principles have been discussed in cosmology for years there is no exact definition for fine tuning. Starting from the supposed similarity in the topologies of chaotic and fine tuned regions of the proper phase spaces, we introduce an alternative Lyapunov indicator for the mea

Zs. Hetesi, B. Balázs

During the last centuries of human history, many questions was repeated in connection with the great problems of the existence and origin of human beings, and also of the Universe. The old questions of common sense and philosophy have not been solved in spite of the indisputable results of modern natural sciences. Recently the so-called anthropic principles

T. B. Pyatunina, N. A. Kudryavtseva, D. C. Gabuzda, S. G. Jorstad

The combined data of the University of Michigan Radio Astronomy Observatory and Metsahovi Radio Observatory provide us with radio light curves for Active Galactic Nuclei monitored by both observatories from 4.8 to 37 GHz covering time intervals up to ~25 years. We consider here such composite light curves for four gamma-ray blazars that have been nearly cont

Andrew F. Nelson

(highly abridged) We define three requirements for accurate simulations that attempt to model circumstellar disks and the formation of collapsed objects (e.g. planets) within them. First, we define a resolution requirement based on the wavelength for neutral stability of self gravitating waves in the disk. For particle based or grid based simulations, this c

Jason H. Steffen

I present an initial investigation into a new planet detection technique that uses the transit timing of a known, transiting planet. The transits of a solitary planet orbiting a star occur at equally spaced intervals in time. If a second planet is present, dynamical interactions within the system will cause the time interval between transits to vary. These t

M. D. Caballero-García, E. Kuulkers, P. Kretschmar, A. Domingo

In this paper we present the results of the analysis of the INTEGRAL data for the black hole transient GRO J1655-40. The observations consist of four ToO (100 ks each) observations's AO-3 spread from February to April of 2005. We present here the preliminary spectral analysis of this source between 5 and 200 keV. Also, some comments of the light curves o

Joerg R. Hoerandel, Nikolai N. Kalmykov, Aleksei V. Timokhin

The propagation of high-energy cosmic rays in the Galaxy is investigated. Solutions of a diffusion model are combined with numerically calculated trajectories of particles. The resulting escape path length and interaction path length are presented and energy spectra obtained at Earth are discussed. It is shown that the energy spectra for heavy elements shoul

S. Savaglio

Long-duration gamma-ray bursts (GRBs) are associated with the death of metal-poor massive stars. Even though they are highly transient events very hard to localize, they are so bright that they can be detected in the most difficult environments. GRB observations are unveiling a surprising view of the chemical state of the distant universe (redshifts z > 2).

I. G. de la Rosa, R. R. de Carvalho, A. Vazdekis, B. Barbuy

We present the results of a study comparing the stellar populations in the elliptical galaxies of Hickson Compact Groups (HCGs) with those in low density environments. Three different population synthesis models and stellar population analyses are used to make the results more robust. The low-sigma galaxies in HCGs show an enhanced [Mg/Fe] ratio and a deplet

E. A. Den Hartog, J. E. Lawler, C. Sneden, J. J. Cowan

Radiative lifetimes, accurate to +/- 5%, have been measured for 49 even-parity and 14 odd-parity levels of Gd II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 611 lines of Gd II. This work is the largest-scale laboratory study to da

E. O. Vasiliev, Yu. A. Shchekinov

The presence of ultra-high-energy cosmic rays (UHECR) results in an increase in the degree of ionization in the post-recombination Universe, which stimulates the efficiency of the production of H$_2$ molecules and the formation of the first stellar objects. As a result, the onset of the formation of the first stars is shifted to higher redshifts, and the mas

Benjamin Winkel, Juergen Kerp, Stephan Stanko

In this paper we present an interference detection toolbox consisting of a high dynamic range Digital Fast-Fourier-Transform spectrometer (DFFT, based on FPGA-technology) and data analysis software for automated radio frequency interference (RFI) detection. The DFFT spectrometer allows high speed data storage of spectra on time scales of less than a second.

Georges Meynet, Andre Maeder, Raphael Hirschi, Sylvia Ekstroem

Some indirect observations, as the high fraction of Be stars at low metallicity, or the necessity for massive stars to be important sources of primary nitrogen, seem to indicate that very metal poor stars were fast rotators. As a consequence of this fast rotation, these stars, contrarily to current wisdom, might lose large amounts of mass during their lifeti

Christopher L. Fryer, Siming Liu, Gabriel Rockefeller, Aimee Hungerford

Recent observations of the Galactic center in high-energy gamma-rays (above 0.1TeV) have opened up new ways to study this region, from understanding the emission source of these high-energy photons to constraining the environment in which they are formed. We present a revised theoretical density model of the inner 5pc surrounding Sgr A* based on the fact tha

I. S. Glass

Period-luminosity sequences have been shown to exist among the Semi-Regular Variables (SRVs) of the Magellanic Clouds (Wood et al, 1999), the Bulge of the Milky Way galaxy (Glass & Schultheis, 2003) and elsewhere. It would clearly be useful to have absolute (trigonometric) calibrations of these relations. This paper investigates whether the sequences can be

G. W. Pratt, H. Boehringer, J. H. Croston, M. Arnaud

A study of the structural and scaling properties of the temperature distribution of the hot, X-ray emitting intra-cluster medium of galaxy clusters, and its dependence on dynamical state, can give insights into the physical processes governing the formation and evolution of structure. We analyse the X-ray temperature profiles from XMM-Newton observations of

I. N. Kirov, J. N. Stamenov

The method of isolines (contours) is proposed to be used for deter- mination of core location of extensive air shower on the array plane. As variable z=f(x,y) are used flux densities of particles, registrated from ground detectors. Obtained isolines are approximated with circles, which centers show impact point of shower axis. The method was demostrated on e

Simon P. Goodwin, Nate Bastian

We examine the luminosity and dynamical mass estimates for young massive stellar clusters. For many young (<50 Myr) clusters, the luminosity and dynamical mass estimates differ by a significant amount. We explain this as being due to many young clusters being out of virial equilibrium (which is assumed in dynamical mass estimates) because the clusters are un

Spyros Basilakos, Manolis Plionis

We re-examine the gravitational acceleration (dipole) induced on the Local Group of galaxies by the Infrared Astronomical Satellite (IRAS) galaxy distribution of the Point Source Catalogue redshift survey (PSCz). We treat the cirrus-affected low galactic latitudes by utilizing a spherical harmonic expansion of the galaxy surface density field up to the octap

F. Haberl, U. Geppert, B. Aschenbach, G. Hasinger

(abridged) We report on XMM-Newton observations of SN1987A in the Large Magellanic Cloud. The large collecting area telescopes together with the European Photon Imaging Cameras (EPIC) provide X-ray spectra with unprecedented statistical quality and make it possible to investigate the spectral evolution during the brightening observed since the discovery in X

Sylvain Chaty, Farid Rahoui

A new type of sources has been discovered by INTEGRAL. These sources are in the course of being unveiled by means of multi-wavelength optical, near- and mid-infrared observations. Among the high-energy binary sources, two distinct classes are appearing. The first class is constituted of intrinsically obscured high-energy sources, of which IGR J16318-4848 see

M. S. Rudner, L. S. Levitov

Spontaneous nuclear polarization is predicted in double quantum dots in the spin-blocked electron transport regime. The polarization results from an instability of the zero-polarization state when singlet and triplet electron energy levels are brought into resonance by the effective hyperfine field of the nuclei on the electrons. The nuclear spins, once pola

Y. S. Kim, Marilyn E. Noz

The present form of quantum mechanics is based on the Copenhagen school of interpretation. Einstein did not belong to the Copenhagen school, because he did not believe in probabilistic interpretation of fundamental physical laws. This is the reason why we are still debating whether there is a more deterministic theory. One cause of this separation between Ei

I. P. Hamilton, Ricardo A. Mosna, L. Delle Site

We employ a recently formulated dequantization procedure to obtain an exact expression for the kinetic energy which is applicable to all kinetic-energy functionals. We express the kinetic energy of an N-electron system as the sum of an N-electron classical kinetic energy and an N-electron purely quantum kinetic energy arising from the quantum fluctuations th

Bernhard Edegger, V. N. Muthukumar, Claudius Gros

We present a variational Monte Carlo (VMC) study of spontaneous Fermi surface symmetry breaking in the t-J model. We find that the variational energy of a Gutzwiller projected Fermi sea is lowered by allowing for a finite asymmetry between the x- and the y-directions. However, the best variational state remains a pure superconducting state with d-wave symmet

Aleks Kleyn

English Russian and Russian English dictionaries presented in this paper are dedicated to help translate a scientific text from one language to another. I also included the bilingual name index into this book.

S. Munier

High energy scattering was recently shown to be similar to a reaction-diffusion process. The latter defines a wide universality class that also contains e.g. some specific population evolution models. The common point of all these models is that their respective dynamics are described by noisy traveling wave equations. This observation has led to a new under

B. Muthukumar

We consider the probabilistic description of nonrelativistic, spinless one-particle classical mechanics, and immerse the particle in a deformed noncommutative phase space in which position coordinates do not commute among themselves and also with canonically conjugate momenta. With a postulated normalized distribution function in the quantum domain, the squa

Joachim Wehler

Bipolar synchronization systems (BP-systems) constitute a class of coloured Petri nets, well suited for modeling the control flow of discrete, dynamical systems. Every BP-system has an underlying ordinary Petri net, which is a T-system. Moreover, it has a second ordinary net attached, which is a free-choice system. We prove that a BP-system is live and safe

Youness Lamzouri

Let $n$ be a positive integer. In this paper we estimate the size of the set of linear forms $b_1\log a_1 + b_2\log a_2+...+b_n\log a_n$, where $|b_i|\leq B_i$ and $1\leq a_i\leq A_i$ are integers, as $A_i,B_i\to \infty$.

A. O. Schweiger, K. Barros, W. Klein

Nucleation is considered near the pseudospinodal in a one-dimensional $ϕ^4$ model with a non-conserved order parameter and long-range interactions. For a sufficiently large system or a system with slow relaxation to metastable equilibrium, there is a non-negligible probability of nucleation occurring before reaching metastable equilibrium. This process is re

J. Q. You, Xiang-bin Wang, Tetsufumi Tanamoto, Franco Nori

Highly entangled states called cluster states are a universal resource for measurement-based quantum computing (QC). Here we propose an efficient method for producing large cluster states using superconducting quantum circuits. We show that a large cluster state can be efficiently generated in just one step by turning on the inter-qubit coupling for a short

Masato Kuwata, Tetsuji Shioda

We pose the problem to determine explicit defining equations of various elliptic fibrations on a given $K3$ surface, and study the case of the Kummer surfaces of the product of two elliptic curves.

Hanzhong Zhang, Zhongbo Kang, Ben-Wei Zhang, Enke Wang

Using the opacity expansion technique we investigate the photon radiation and dilepton production induced by multiple rescattering as energetic parton jet passing through the strong interacting medium. The real photon radiation and dilepton invariant-mass spectrums of the bremsstrahlung contribution from an energetic quark jet are presented. The leading cont

A. Pankov

We present general results on exponential decay of finite energy solutions to stationary nonlinear Schrödinger equations.

Paul O&#39;Hara

In the normal presentation of the EPR problem a comparison is made between the (weak) Copenhagen interpretation of quantum mechanics which seems to suggest that at times action at a distance may take place, and the hidden parameter interpretation which must satisfy Bell&#39;s inequality, in contradiction to the predictions of quantum mechanics. In this paper

Y. -K. Liu, M. Christandl, F. Verstraete

We study the computational complexity of the N-representability problem in quantum chemistry. We show that this problem is QMA-complete, which is the quantum generalization of NP-complete. Our proof uses a simple mapping from spin systems to fermionic systems, as well as a convex optimization technique that reduces the problem of finding ground states to N-r

Andrei Khrennikov

We present a trivial probabilistic illustration for representation of quantum mechanics as an algorithm for approximative calculation of averages.

Rui Yang, Bing-Hong Wang, Jie Ren, Wen-Jie Bai

In this paper, we propose a modified susceptible-infected-recovered (SIR) model, in which each node is assigned with an identical capability of active contacts, $A$, at each time step. In contrast to the previous studies, we find that on scale-free networks, the density of the recovered individuals in the present model shows a threshold behavior. We obtain t

S. L. Arsenjev

Essentially new approach to analysis of internal forces, arising in cylindrical rod under action of an axial tension force, has allowed to detect the three-dimensional axisymmetric stress state. According to the new conceptual model the axial tension force causes the tangential - hoop and radial - stresses side by side with axial (normal) stress in the rod v

Enrico Rubiola, Rodolphe Boudot

We analyze the phase-noise measurement methods in which correlation and averaging is used to reject the background noise of the instrument. All the known methods make use of a mixer, used either as a saturated phase detector or as a linear synchronous detector. Unfortunately, AM noise is taken in through the power-to-dc-offset conversion mechanism that resul

V. Soma, P. Bozek

A self-consistent approach based on finite temperature Green&#39;s functions is used to investigate thermodynamic properties of nuclear matter. The internal energy is derived from the diagrams associated to the interaction energy. Pressure and entropy up to T=20 MeV are obtained from the generating functional form of the thermodynamic potential.

James Atkinson, Jarmo Hietarinta, Frank Nijhoff

Adler&#39;s lattice equation has acquired the status of a master equation among 2D discrete integrable systems. In this paper we derive what we believe are the first explicit solutions of this equation. In particular it turns out necessary to establish a non-trivial seed solution from which soliton solutions can subsequently be constructed using the Bäcklund

Andrea Posilicano

In the case of a single point interaction we improve, by different techniques, the existence theorem for the unitary evolution generated by a Schrödinger operator with moving point interactions obtained by Dell&#39;Antonio, Figari and Teta.

Taeyoung Lee, Melvin Leok, N. Harris McClamroch, Amit K. Sanyal

A deterministic attitude estimator for a rigid body under an attitude dependent potential is studied. This estimator requires only a single direction measurement to a known reference point at each measurement instant. The measurement cannot completely determine the attitude, but an attitude estimation scheme based on this measurement is developed; a feasible

Stefano Beltraminelli, Danilo Merlini

We consider the Riesz and Hardy-Littlewood wave i.e. a ``critical function&#39;&#39; whose behaviour is concerned with the possible truth of the Riemann Hypothesis (RH). The function is studied numerically for the case alpha = 15/2 and beta = 4 in some range of the critical strip, using Maple 10. In the experiments, N = 2000 is the maximum argument used in t

Henning Krause

These exercises complement my notes &#34;Derived categories, resolutions, and Brown representability&#34;.

S. Geninska, E. Leuzinger

The trace set of a Fuchsian group $Γ$ ist the set of length of closed geodesics in the surface $Γ\backslash \mathbb{H}$. Luo and Sarnak showed that the trace set of a cofinite arithmetic Fuchsian group satisfies the bounded clustering property. Sarnak then conjectured that the B-C property actually characterizes arithmetic Fuchsian groups. Schmutz stated the

Michael Farber, Mark Grant, Sergey Yuzvinsky

We study motion planning algorithms for collision free control of multiple objects in the presence of moving obstacles. We compute the topological complexity of algorithms solving this problem. We apply topological tools and use information about cohomology algebras of configuration spaces. The results of the paper may potentially be used in systems of autom

Weigen Yan, Yeong-Nan Yeh

Let $T$ be a weighted tree. The weight of a subtree $T_1$ of $T$ is defined as the product of weights of vertices and edges of $T_1$. We obtain a linear-time algorithm to count the sum of weights of subtrees of $T$. As applications, we characterize the tree with the diameter at least $d$, which has the maximum number of subtrees, and we characterize the tree

Jonathan Breuer

We introduce a family of trees that interpolate between the Bethe lattice and $\bbZ$. We prove complete localization for the Anderson model on any member of that family.

Henning Krause

These notes are based on a series of five lectures given during the summer school ``Interactions between Homotopy Theory and Algebra&#39;&#39; held at the University of Chicago in 2004.

I. V. Krasovsky

An asymptotic formula is found for a Toeplitz determinant with the symbol supported on an arc of the unit circle in the case when the symbol has Fisher-Hartwig singularities.

Misha Verbitsky

Paper is withdrawn due to errors (superseded by math.AG/0604303). Formula 6.5 is false. Section 6 is false, and the main statement is true only for bundles $B$ with $c_1(B)$ SU(2)-invariant.

Misha Verbitsky

Paper withdrawn due to errors (superseded by math.AG/0604303). Proposition 11.4 is false, Section 12 is false, and the main statement is true only for bundles $B$ with $c_1(B)$ SU(2)-invariant.

Gerald V. Dunne, Jin Hur, Choonkyu Lee

The computation of the one-loop effective action in a radially symmetric background can be reduced to a sum over partial-wave contributions, each of which is the logarithm of an appropriate one-dimensional radial determinant. While these individual radial determinants can be evaluated simply and efficiently using the Gel&#39;fand-Yaglom method, the sum over

Valery N. Marachevsky

The new exact formulas for the attractive Casimir force acting on each of the two perfectly conducting plates moving freely inside an infinite perfectly conducting cylinder with the same cross section are derived at zero and finite temperatures by making use of zeta function technique. The short and long distance behaviour of the plates&#39; free energy is i

Levent Solmaz

We present semi-analytical solutions of the supersymmetric non-universal masses models for low $\tanβ$ regime. In addition to this, scale and $\tanβ$ dependencies of the soft (mass)$^2$ terms are given in the form of numerical solutions. By using the constrained form of the semi-analtic results, particular attention is paid on the non-universality assumption

S. P. Baranov, V. L. Slad

The production of various heavy-quark-containing baryons in electron-positron annihilation is considered. On the basis of exact formulas that we obtained previously within full perturbation theory, new numerical calculations of the respective cross sections are performed, and simple approximate expressions are then constructed for the results of these calcul

Alexander Kusenko

Neutrino masses are likely to be a manifestation of the right-handed, or sterile neutrinos. The number of sterile neutrinos and the scales of their Majorana masses are unknown. We explore theoretical arguments in favor of the high and low scale seesaw mechanisms, review the existing experimental results, and discuss the astrophysical hints regarding sterile

Jorma Louko, Alejandro Satz

The instantaneous transition rate of an arbitrarily accelerated Unruh-DeWitt particle detector on four-dimensional Minkowski space is ill defined without regularisation. We show that Schlicht&#39;s regularisation as the zero-size limit of a Lorentz-function spatial profile yields a manifestly well-defined transition rate with physically reasonable asymptotic

Sean P. Robinson

We calculate, in d spacetime dimensions, the relationship between the coefficient 1/K^2 of the Einstein-Hilbert term in the action of general relativity and the coefficient G_N of the force law that results from the Newtonian limit of general relativity. The result is K^2=2[(d-2)/(d-3)]Vol(S^[d-2])G_N, where Vol(S^n) is the volume of the unit n-sphere. While

Ketan Savla, Francesco Bullo, Emilio Frazzoli

In this paper we propose some novel path planning strategies for a double integrator with bounded velocity and bounded control inputs. First, we study the following version of the Traveling Salesperson Problem (TSP): given a set of points in $\real^d$, find the fastest tour over the point set for a double integrator. We first give asymptotic bounds on the ti

Gil Wiechman, Igal Sason

This paper derives an improved sphere-packing (ISP) bound targeting codes of short to moderate block lengths. We first review the 1967 sphere-packing (SP67) bound for discrete memoryless channels, and a recent improvement by Valembois and Fossorier. These concepts are used for the derivation of a new lower bound on the decoding error probability (referred to

L. Vila, R. Giraud, L. Thevenard, A. Lemaitre

Mesoscopic transport measurements reveal a large effective phase coherence length in epitaxial GaMnAs ferromagnets, contrary to usual 3d-metal ferromagnets. Universal conductance fluctuations of single nanowires are compared for epilayers with a tailored anisotropy. At large magnetic fields, quantum interferences are due to structural disorder only, and an u

J. Wang, K. S. Chan

We extended McMillan&#39;s Green&#39;s function method to study the equilibrium spin current (ESC) in a ferromagnet/ferromagnet (FM/FM) tunnelling junction, in which the magnetic moments in both FM electrodes are not collinear. The single-electron Green&#39;s function of the junction system is directly constructed from the elements of the scattering matrix w

Liliana Formiggini, Elia M. Leibowitz

We analyze the historical light curve of the symbiotic star YY Her, from 1890 up to December 2005. A secular declining trend is detected, at a rate of ~.01 magn in 1000 d, suggesting that the system could belong to the sub-class of symbiotic novae. Several outburst events are superposed on this slow decline. Three independent periodicities are identified in

Joshua N. Winn, Matthew J. Holman, Cesar I. Fuentes

As part of our ongoing effort to measure exoplanet sizes and transit times with greater accuracy, we present I band observations of two transits of OGLE-TR-111b. The photometry has an accuracy of 0.15-0.20% and a cadence of 1-2 minutes. We derive a planetary radius of 1.067 +/- 0.054 Jupiter radii and a stellar radius of 0.831 +/- 0.031 solar radii. The unce

Kenji Bekki

We discuss how tidal interaction between the Large Magellanic Cloud (LMC), the Small Magellanic Cloud (SMC), and the Galaxy triggers galaxy-wide star formation in the Clouds for the last ~0.2 Gyr based on our chemodynamical simulations on the Clouds. Our simulations demonstrate that the tidal interaction induces the formation of asymmetric spiral arms with h