June 2009 arXiv papers — page 26
Showing 2,501–2,600 of 5,471 papers
The CLEO Collaboration, H. Mendez
Using data collected on the psi(3770) resonance and near the Ds*+ Ds- peak production energy by the CLEO-c detector, we study the decays of the possible D->PP modes and report measurements of or upper limits on all branching fractions for Cabibbo-favored, singly-Cabibbo-suppressed, and doubly-Cabibbo-suppressed D->PP decays except modes involving K0L (and ex
On the injectivity of the global function of a cellular automaton in the hyperbolic plane (extended abstract)
cs.CCMaurice Margenstern
In this paper, we look at the following question. We consider cellular automata in the hyperbolic plane, (see Margenstern, 2000, 2007 and Margenstern, Morita, 2001) and we consider the global function defined on all possible configurations. Is the injectivity of this function undecidable? The problem was answered positively in the case of the Euclidean plane
M. Fannes, J. Wouters
We study correlations in a bipartite, Fermionic, free state in terms of perturbations induced by one party on the other. In particular, we show that all so conditioned free states can be modelled by an auxiliary Fermionic system and a suitable completely positive map.
T. N. Ukwatta, K. S. Dhuga, W. C. Parke, T. Sakamoto
We present the results of our study of the variability time scales of a sample of 27 long Swift Gamma-Ray Bursts (GRBs) with known redshifts. The variability time scale can help our understanding of fundamental GRB parameters such as the initial bulk Lorentz factor and the characteristic size associated with the emission region. Fast Fourier Transform (FFT)
Secured Communication over Frequency-Selective Fading Channels: a practical Vandermonde precoding
cs.ITMari Kobayashi, Merouane Debbah, Shlomo Shamai
In this paper, we study the frequency-selective broadcast channel with confidential messages (BCC) in which the transmitter sends a confidential message to receiver 1 and a common message to receivers 1 and 2. In the case of a block transmission of N symbols followed by a guard interval of L symbols, the frequency-selective channel can be modeled as a N * (N
Non variability of intervening absorbers observed in the UVES spectra of the "naked-eye" GRB080319
astro-ph.COV. D'Elia, F. Fiore, P. Goldoni, V. D'Odorico
The aim of this paper is to investigate the properties of the intervening absorbers lying along the line of sight of Gamma-Ray Burst (GRB) 080319B through the analysis of its optical absorption features. To this purpose, we analyze a multi-epoch, high resolution spectroscopic observations (R=40000, corresponding to 7.5 km/s) of the optical afterglow of GRB08
Y. D. Peng, L. L. Jin, Y. P. Niu, S. Q. Gong
A scheme for getting a tunable ultranarrow linewidth of a cavity due to an embedded four-level atomic medium with double-dark resonances is proposed. It is shown that the steep dispersion induced by double-dark resonances in the transparency window leads to the ultranarrow transmission peak. Compared with the case of a single-dark-resonance system, the linew
L. De Groote, N. Van den Bergh, L. Wylleman
We present all Petrov type D pure radiation space-times, with or without cosmological constant, with a shear-free, non-diverging geodesic principal null congruence.
Exact non-circular symmetric N-skyrmions in helical magnets without inversion symmetry
cond-mat.otherAnjan Kundu
The unusual magnetic behaviour of helimagnet MnSi, noticed in recent years, prompted the suspicion that the magnetic states arising in such crystals are of topological nature. Recent experiments based on the topological Hall effect confirmed such topologically nontrivial states as the skyrmions, located on a plane perpendicular to the applied magnetic field.
UVES/VLT high resolution absorption spectroscopy of the GRB080330 afterglow: a study of the GRB host galaxy and intervening absorbers
astro-ph.COV. D'Elia, F. Fiore, R. Perna, Y. Krongold
We study the Gamma Ray Burst (GRB) environment and intervening absorbers by analyzing the optical absorption features produced by gas surrounding the GRB or along its line of sight. We analyzed high resolution spectroscopic observations (R=40000, S/N=3 - 6) of the optical afterglow of GRB080330, taken with UVES at the VLT ~ 1.5 hours after the GRB trigger. T
Philippe Moser
In this paper we introduce a general framework for defining the depth of a sequence with respect to a class of observers. We show that our general framework captures all depth notions introduced in complexity theory so far. We review most such notions, show how they are particular cases of our general depth framework, and review some classical results about
The structure of blue supergiant winds and the accretion in supergiant High Mass X-ray Binaries
astro-ph.HEL. Ducci, L. Sidoli, S. Mereghetti, A. Paizis
We have developed a stellar wind model for OB supergiants to investigate the effects of accretion from a clumpy wind on the luminosity and variability properties of High Mass X-ray Binaries. Assuming that the clumps are confined by ram pressure of the ambient gas and exploring different distributions for their mass and radii, we computed the expected X-ray l
Cyrille Marquet
I discuss the role played by large parton densities in the QCD description of high-pT observables in relativistic heavy-ion collisions. In pA collisions, high-pT particles probe large parton densities in the nucleus and provide tests of the Color Glass Condensate (CGC) picture of the small-x part of the nuclear wave function. In AA collisions, high-pT partic
Experimental search of bursts of gamma rays from primordial black holes using different evaporation models
astro-ph.COE. V. Bugaev, V. B. Petkov, A. N. Gaponenko, P. A. Klimai
Experimental data of arrays "Andyrchy" and "Carpet-2" of Baksan Neutrino Observatory (Institute for Nuclear Research), obtained in the regime of a detection of the single cosmic-ray component, are used for a search of the bursts of cosmic gamma rays from evaporating primordial black holes. Different theoretical models of the evaporation proce
Interplay of frustration and magnetic field in the two-dimensional quantum antiferromagnet Cu(tn)Cl$_2$
cond-mat.str-elA. Orendáčová, E. Čižmár, J. S. Xia, L. Yin
Specific heat and ac magnetic susceptibility measurements, spanning low temperatures ($T \geq 40$ mK) and high magnetic fields ($B \leq 14$ T), have been performed on a two-dimensional (2D) antiferromagnet Cu(tn)Cl$_{2}$ (tn = C$_{3}$H$_{10}$N$_{2}$). The compound represents an $S = 1/2$ spatially anisotropic triangular magnet realized by a square lattice wi
E. V. Bugaev, V. B. Petkov, A. N. Gaponenko, P. A. Klimai
The technical procedure of a search of bursts of very high energy gamma rays from evaporation of primordial black holes on air-shower array "Andyrchy" of Baksan Neutrino Observatory of Institute for Nuclear Research is described. The theoretical model used in the present work assumes that the chromosphere around the evaporating black hole does not fo
A. V. Shutov, R. Kreissig
The inelastic incompressibility is a typical feature of metal plasticity/viscoplasticity. Over the last decade, there has been a great amount of research related to construction of numerical integration algorithms which exactly preserve this geometric property. In this paper we examine, both numerically and mathematically, the excellent accuracy and converge
Sylvain Veilleux, Buell T. Jannuzi
Seven years ago, with the encouragement of the NSF and AURA, NOAO requested proposals from the community to partner with the national observatory to improve instrumentation and/or telescope capabilities at KPNO and CTIO. Of the proposals that were selected, one came from the University of Maryland with the goals of helping NOAO complete the development, cons
E. Iancu, A. H. Mueller
We propose a set of lattice measurements which could test whether the deconfined, quark-gluon plasma, phase of QCD shows strong coupling aspects at temperatures a few times the critical temperature for deconfinement, in the region where the conformal anomaly becomes unimportant. The measurements refer to twist-two operators which are not protected by symmetr
Thibault Damour
We briefly review the various contexts within which one might address the issue of ``why'' the dimensionless constants of Nature have the particular values that they are observed to have. Both the general historical trend, in physics, of replacing a-priori-given, absolute structures by dynamical entities, and anthropic considerations, suggest that co
A Remark on the global existence of a third order dispersive flow into locally Hermitian symmetric spaces
math.APEiji Onodera
We prove global existence of solutions to the initial value problem for a third order dispersive flow into compact locally Hermitian symmetric spaces. The equation we consider generalizes two-sphere-valued completely integrable systems modelling the motion of vortex filament. Unlike one-dimensional Schrödinger maps, our third order equation is not completely
Prediction of ternary vapor-liquid equilibria for 33 systems by molecular simulation,
physics.chem-phY. -L. Huang, J. Vrabec, H. Hasse
A set of molecular models for 78 pure substances from prior work is taken as a basis for systematically studying vapor-liquid equilibria (VLE) in ternary systems.All 33 ternary mixtures of these 78 components for which experimental VLE data is available are studied by molecular simulation. The mixture models are based on the modified Lorentz-Berthelot combin
Correlated electron physics in multilevel quantum dots: phase transitions, transport, and experiment
cond-mat.str-elDavid E. Logan, Christopher J. Wright, Martin R. Galpin
We study correlated two-level quantum dots, coupled in effective 1-channel fashion to metallic leads; with electron interactions including on-level and inter-level Coulomb repulsions, as well as the inter-orbital Hund's rule exchange favoring the spin-1 state in the relevant sector of the free dot. For arbitrary dot occupancy, the underlying phases, quan
N. Sipos, P. Ábrahám, J. Acosta-Pulido, A. Juhász
EX Lup is the prototype of EXors, a subclass of low-mass pre-main sequence stars whose episodic eruptions are attributed to temporarily increased accretion. In quiescence the optical and near-infrared properties of EX Lup cannot be distinguished from those of normal T Tau stars. Here we investigate whether it is the circumstellar disk structure which makes E
Francois Hamel, Lionel Roques
This paper is devoted to the analysis of the large-time behavior of solutions of one-dimensional Fisher-KPP reaction-diffusion equations. The initial conditions are assumed to be globally front-like and to decay at infinity towards the unstable steady state more slowly than any exponentially decaying function. We prove that all level sets of the solutions mo
Ye. O. Vekhov, A. P. Birchenko, N. P. Mikhin, E. Ya. Rudavskii
The study of phase structure of dilute $^3$He - $^4$He solid mixture of different quality is performed by spin echo NMR technique. The diffusion coefficient is determined for each coexistent phase. Two diffusion processes are observed in rapidly quenched (non-equilibrium) hcp samples: the first process has a diffusion coefficient corresponding to hcp phase,
Yonatan Bilu, Nathan Linial
We introduce the notion of a stable instance for a discrete optimization problem, and argue that in many practical situations only sufficiently stable instances are of interest. The question then arises whether stable instances of NP--hard problems are easier to solve. In particular, whether there exist algorithms that solve correctly and in polynomial time
P. Ábrahám, A. Juhász, C. P. Dullemond, Á. Kóspál
Our Solar System originated in interstellar gas and dust; the latter is in the form of amorphous silicate particles and carbonaceous dust. The composition of cometary material shows that a significant fraction of the amorphous silicates was transformed into crystalline form during the early evolution of the protosolar nebula. How and when this transformation
G. A. Fernandez, J. Vrabec, H. Hasse
Equilibrium molecular dynamics simulation and the Green-Kubo formalism were used to calculate self-diffusion coefficient, shear viscosity, and thermal conductivity for 38 different dipolar two-center Lennard-Jones fluids along the bubble line and in the homogeneous liquid. It was systematically investigated how anisotropy, i.e. elongation, and dipole momentu
G. A. Fernandez, J. Vrabec, H. Hasse
Equilibrium molecular dynamics simulation and the Green-Kubo formalism were used to calculate self-diffusion coefficient, shear viscosity,and thermal conductivity for 30 different quadrupolar two-center Lennard-Jones fluids along the bubble line and in the homogeneous liquid. It was systematically investigated how anisotropy, i.e. elongation, and quadrupole
S. Veilleux, D. -C. Kim, D. S. N. Rupke, C. Y. Peng
We report the results from a deep HST NICMOS H-band imaging survey of 28 z < 0.3 QSOs from the Palomar-Green (PG) sample. This program is part of QUEST (Quasar / ULIRG Evolution STudy) and complements a similar set of data on 26 highly-nucleated ULIRGs presented in Paper I. Our analysis indicates that the fraction of QSOs with elliptical hosts is higher amon
Propagation of extragalactic ultra-high energy cosmic-ray nuclei : implications for the observed spectrum and composition
astro-ph.HED. Allard
In this paper, we study the propagation of cosmic-ray nuclei and protons. We emphasize the influence of the source composition on the expected spectrum and composition on Earth as well as on the phenomenology of the transition from Galactic to extragalactic cosmic-rays and the interpretation of the ankle. We point out that the different source composition mo
M. Kromer, S. A. Sim
A Monte Carlo code (ARTIS) for modelling time-dependent three-dimensional spectral synthesis in chemically inhomogeneous models of Type Ia supernova ejecta is presented. Following the propagation of gamma-ray photons, emitted by the radioactive decay of the nucleosynthesis products, energy is deposited in the supernova ejecta and the radiative transfer probl
Microscopic mechanism of the non-crystalline anisotropic magnetoresistance in (Ga,Mn)As
cond-mat.mtrl-sciKarel Výborný, Jan Kucera, Jairo Sinova, A. W. Rushforth
Starting with a microscopic model based on the Kohn-Luttinger Hamiltonian and kinetic p-d exchange combined with Boltzmann formula for conductivity we identify the scattering from magnetic Mn combined with the strong spin-orbit interaction of the GaAs valence band as the dominant mechanism of the anisotropic magnetoresistance (AMR) in (Ga,Mn)As. This fact al
Phase transitions and crossovers in reaction-diffusion models with catalyst deactivation
cond-mat.stat-mechT. G. Mattos, Fabio D. A. Aarao Reis
The activity of catalytic materials is reduced during operation by several mechanisms, one of them being poisoning of catalytic sites by chemisorbed impurities or products. Here we study the effects of poisoning in two reaction-diffusion models in one-dimensional lattices with randomly distributed catalytic sites. Unimolecular and bimolecular single-species
David Tolpin, Solomon Eyal Shimony
We consider the following sequential decision problem. Given a set of items of unknown utility, we need to select one of as high a utility as possible (``the selection problem''). Measurements (possibly noisy) of item values prior to selection are allowed, at a known cost. The goal is to optimize the overall sequential decision process of measurement
Ricardo Lopez-Ruiz, Jaime Sanudo
The calculation of a statistical measure of complexity and the Fisher-Shannon information in nuclei is carried out in this work. We use the nuclear shell model in order to obtain the fractional occupation probabilities of nuclear orbitals. The increasing of both magnitudes, the statistical complexity and the Fisher-Shannon information, with the number of nuc
S. P. Baranov
Inclusive and exclusive production of scalar and pseudoscalar mesons via gluon-gluon fusion is considered. A new experimental test is proposed, which can probe the polarization state of the gluons in exclusive production processes and check the compatibility of the two-gluon exchange mechanism with the properties of conventional Pomeron
James Borger
The theory of Lambda-rings, in the sense of Grothendieck's Riemann-Roch theory, is an enrichment of the theory of commutative rings. In the same way, we can enrich usual algebraic geometry over the ring Z of integers to produce Lambda-algebraic geometry. We show that Lambda-algebraic geometry is in a precise sense an algebraic geometry over a deeper base
Jon F. Carlson, Daniel K. Nakano
It is well known that if G is a finite group then the group of endotrivial modules is finitely generated. In this paper we investigate endotrivial modules over arbitrary finite group schemes. Our results can be applied to computing the endotrivial group for several classes of infinitesimal group schemes which include the Frobenius kernels of parabolic subgro
Omar Benhar
Over the past two decades, electron scattering experiments have clearly exposed the limits of the independent particle model description of atomic nuclei. I will briefly outline the dynamics leading to the appearance of strong correlation effects, and their impact on the electroweak nuclear cross sections in the impulse approximation regime.
Hiroyuki Adachi, Makoto Tsubota
We performed the numerical simulation of quantum turbulence produced by thermal counterflow in superfluid $^{4}${\rm He} by using the vortex filament model. The pioneering work was made by Schwarz, which has two defects. One is neglecting non-local terms of the Biot-Savart integral (localized induction approximation, LIA), and the other is the unphysical mix
Yoshichika Miwa, Jun-ichi Yoshikawa, Peter van Loock, Akira Furusawa
We demonstrate a quadratic phase gate for one-way quantum computation in the continuous-variable regime. This canonical gate, together with phase-space displacements and Fourier rotations, completes the set of universal gates for realizing any single-mode Gaussian transformation such as arbitrary squeezing. As opposed to previous implementations of measureme
S. Pedicelli, G. Bono, B. Lemasle, P. Francois
Aims: The iron abundance gradient in the Galactic stellar disk provides fundamental constraints on the chemical evolution of this important Galaxy component. However the spread around the mean slope is, at fixed Galactocentric distance, larger than estimated uncertainties. Methods: To provide quantitative constraints on these trends we adopted iron abundance
Nienke Geerts, Erika Eiser
DNA plays a special role in polymer science not just because of the highly selective recognition of complementary single DNA strands but also because bacteria can express DNA chains that are very long yet perfectly monodisperse. The latter reason makes long DNA molecules widely used as model systems in polymer science. Here, we report the unusual self-assemb
Matti Herranen
In this thesis we develop a novel approximation scheme (eQPA), where the effects of nonlocal coherence are included in the kinetic approach to nonequilibrium quantum dynamics. The key element in our formalism is the finding of new singular shell solutions, located at $k_{0,z} = 0$ in the phase space of 2-point Wightman function, which describe the nonlocal q
M. R. Calvo, J. Fernández-Rossier, J. J. Palacios, D. Jacob
Iron, cobalt and nickel are archetypal ferromagnetic metals. In bulk, electronic conduction in these materials takes place mainly through the $s$ and $p$ electrons, whereas the magnetic moments are mostly in the narrow $d$-electron bands, where they tend to align. This general picture may change at the nanoscale because electrons at the surfaces of materials
J. R. Johansson, G. Johansson, C. M. Wilson, Franco Nori
We investigate the dynamical Casimir effect in a coplanar waveguide (CPW) terminated by a superconducting quantum interference device (SQUID). Changing the magnetic flux through the SQUID parametrically modulates the boundary condition of the CPW, and thereby, its effective length. Effective boundary velocities comparable to the speed of light in the CPW res
Mireille Bousquet-Mélou, James Propp, Julian West
In 1991, David Gale and Raphael Robinson, building on explorations carried out by Michael Somos in the 1980s, introduced a three-parameter family of rational recurrence relations, each of which (with suitable initial conditions) appeared to give rise to a sequence of integers, even though a priori the recurrence might produce non-integral rational numbers. T
Sylvain Arlot
In this paper, a new family of resampling-based penalization procedures for model selection is defined in a general framework. It generalizes several methods, including Efron's bootstrap penalization and the leave-one-out penalization recently proposed by Arlot (2008), to any exchangeable weighted bootstrap resampling scheme. In the heteroscedastic regre
Vladimir Vovk, Ilia Nouretdinov, Alex Gammerman
We consider the on-line predictive version of the standard problem of linear regression; the goal is to predict each consecutive response given the corresponding explanatory variables and all the previous observations. The standard treatment of prediction in linear regression analysis has two drawbacks: (1) the classical prediction intervals guarantee that t
Constraints on opacities from complex asteroseismology of B-type pulsators: the $β$ Cephei star $θ$ Ophiuchi
astro-ph.SRJ. Daszynska-Daszkiewicz, P. Walczak
We present results of a {\bf comprehensive} asteroseismic modelling of the $β$ Cephei variable $θ$ Ophiuchi. {\bf We call these studies {\it complex asteroseismology} because our goal is to reproduce both pulsational frequencies as well as corresponding values of a complex, nonadiabatic parameter, $f$, defined by the radiative flux perturbation.} To this end
Alexander Krassovitskiy, Yurii Rogozhin, Sergey Verlan
Recent investigations show insertion-deletion systems of small size that are not complete and cannot generate all recursively enumerable languages. However, if additional computational distribution mechanisms like P systems are added, then the computational completeness is achieved in some cases. In this article we take two insertion-deletion systems that ar
Hamiltonian stationary self-similar solutions for Lagrangian mean curvature flow in complex Euclidean plane
math.DGIldefonso Castro, Ana M. Lerma
We classify all Hamiltonian stationary Lagrangian surfaces in complex Euclidean plane which are self-similar solutions of the mean curvature flow.
Fabrication and characterization of iron pnictide wires and bulk materials through the powder-in-tube method
cond-mat.supr-conYanwei Ma, Zhaoshun Gao, Yanpeng Qi, Xianping Zhang
The recent discovery of superconductivity in the iron based superconductors with very high upper critical fields presents a new possibility for practical applications, but fabricating fine-wire is a challenge because of mechanically hard and brittle powders and the toxicity and volatility of arsenic. In this paper, we report the synthesis and the physical ch
Panagiotis Papadakos, Yannis Theoharis, Yannis Marketakis, Nikos Armenatzoglou
One of the distinctive features of Information Retrieval systems comparing to Database Management systems, is that they offer better compression for posting lists, resulting in better I/O performance and thus faster query evaluation. In this paper, we introduce database representations of the index that reduce the size (and thus the disk I/Os) of the posting
K. M. Hiremath
The influence of solar cycle and activity phenomena on the two climatic variabilities such as the rainfall and the surface temperature of the Indian subcontinent are critically examined. It is concluded from this study that the sun indeed strongly influences both of these climatic variabilities and the sun's influence simply cannot be ignored.
Stefano M. Iacus, Nakahiro Yoshida
We consider a multidimensional Itô process $Y=(Y_t)_{t\in[0,T]}$ with some unknown drift coefficient process $b_t$ and volatility coefficient $σ(X_t,θ)$ with covariate process $X=(X_t)_{t\in[0,T]}$, the function $σ(x,θ)$ being known up to $θ\inΘ$. For this model we consider a change point problem for the parameter $θ$ in the volatility component. The change
Analyzing the Accuracy of the Fitch Method for Reconstructing Ancestral States on Ultrametric Phylogenies
q-bio.PELouxin Zhang, Jian Shen, Jialiang Yang, Guoliang Li
Recurrence formulas are presented for studying the accuracy of the Fitch method for reconstructing the ancestral states in a given phylogenetic tree. As their applications, we analyze the convergence of the accuracy of reconstructing the root state in a complete binary tree of $2^n$ as $n$ goes to infinity and also give a lower bound on the accuracy of recon
Bin Yue, Benedetta Ciardi, Evan Scannapieco, Xuelei Chen
We study the statistical properties of the cosmological 21 cm signal from both the intergalactic medium (IGM) and minihalos, using a reionization simulation that includes a self--consistent treatment of minihalo photoevaporation. We consider two models for minihalo formation and three typical thermal states of the IGM -- heating purely by ionization, heating
Kota Yamaura
For a finite dimensional algebra $R$, we give an explicit description of quivers with relations of block extension of $R$. As an application, we describe quivers with relations of Harada algebras by using those of the corresponding quasi-Frobenius algebras.
Christine Michel, Marc-Eric Bobillier-Chaumon, Franck Tarpin-Bernard
Very old people accumulate the "handicaps": social, physical, psychological or cognitive. Various research thus developed to determine there waiting and needs and also to see the benefit possibly produced by technologies (called ?gerontechnology?) on their living conditions. The object of this article is to present the numerical service offer to very
Ben Green, Terence Tao
We establish a correspondence between inverse sumset theorems (which can be viewed as classifications of approximate (abelian) groups) and inverse theorems for the Gowers norms (which can be viewed as classifications of approximate polynomials). In particular, we show that the inverse sumset theorems of Freiman type are equivalent to the known inverse result
Daniel Kuempel, Karl-Heinz Kampert, Markus Risse
The composition of ultra-high energy (UHE) cosmic rays E>10^17 eV is still unknown. The observation of UHE photons would extend the observed electromagnetic spectrum to highest energy and open a new channel for multimessenger observations in the universe. Current limits on the photon flux already constrain ``exotic'' scenarios where a large number of
The Full Flag Hilbert Scheme of Nodal Curves and the Punctual Hilbert Scheme of Points of the Cusp Curve
math.AGHwayoung Lee
In this paper, we show the full flag Hilbert scheme of points of nodal curves has only complete intersection singularities. We study the Hilbert scheme of points of the cusp curve and show the punctual Hilbert scheme is isomorphic to \mathbb{P}^1. Furthermore Hilbert scheme has only one singularty along the punctual one.
Graham Everest, Jonny Griffiths
This article has been written for an educational magazine whose target audience consists of students and teachers of mathematics in universities, colleges and schools. It concerns a notion of duality between rectangles. A proof is given that only finitely many integral sided pairs of dual rectangles exist. Then a geometrical group law is shown to hold on the
S. Abd El-Samad, R. Bilger, K. -Th. Brinkmann, H. Clement
Data accumulated recently for the exclusive measurement of the $pp\to ppπ^+π^-$ reaction at a beam energy of 0.793 GeV using the COSY-TOF spectrometer have been analyzed with respect to possible events from the $pp \to nnπ^+π^+$ reaction channel. The latter is expected to be the only $ππ$ production channel, which contains no major contributions from resonan
Birgit Hein, Gregor Tanner
We investigate a set of discrete-time quantum search algorithms on the n-dimensional hypercube following a proposal by Shenvi, Kempe and Whaley. We show that there exists a whole class of quantum search algorithms in the symmetry reduced space which perform a search of a marked vertex in time of order $\sqrt{N}$ where $N = 2^n$, the number of vertices. In an
A. Patti, D. El Masri, R. van Roij, M. Dijkstra
Using simulations of hard rods in smectic-A states, we find non-gaussian diffusion and heterogeneous dynamics due to the equilibrium periodic smectic density profiles, which give rise to permanent barriers for layer-to-layer diffusion. This relaxation behavior is surprisingly similar to that of non-equilibrium supercooled liquids, although there the particle
Slim Ibrahim, Mohamed Majdoub, Nader Masmoudi
We investigate the initial value problem for some energy supercritical semilinear wave equations. We establish local existence in suitable spaces with continuous flow. We also obtain some ill-posedness/weak ill-posedness results. The proof uses the finite speed of propagation and a quantitative study of the associated ODE. It does not require any scaling inv
Sanat K. Sarkar, Wenge Guo
The concept of $k$-FWER has received much attention lately as an appropriate error rate for multiple testing when one seeks to control at least $k$ false rejections, for some fixed $k\ge 1$. A less conservative notion, the $k$-FDR, has been introduced very recently by Sarkar [Ann. Statist. 34 (2006) 394--415], generalizing the false discovery rate of Benjami
Jacques-Olivier Lachaud, François De Vieilleville
Discrete geometric estimators aim at estimating geometric characteristics of a shape with only its digitization as input data. Such an estimator is multigrid convergent when its estimates tend toward the geometric characteristics of the shape as the digitization step h tends toward 0. This paper studies the multigrid convergence of tangent estimators based o
Two-Pion Production in Proton-Proton Collisions -- Experimental Total Cross Sections and their Isospin Decomposition
nucl-exT. Skorodko, M. Bashkanov, D. Bogoslawsky, H. Calen
The two-pion production in pp-collisions has been investigated at CELSIUS in exclusive measurements from threshold up to $T_p$ = 1.36 GeV. Total and differential cross sections have been obtained for the channels $pnπ^+π^0$, $ppπ^+π^-$, $ppπ^0π^0$ and also $nnπ^+π^+$. For intermediate incident energies $T_p >$ 1 GeV, i.e. in the region which is beyond the Ro
Static Friction as a Function of Waiting Time Probed by Dynamics of Driven Vortices in La2-xSrxCuO4 Thin Films
cond-mat.supr-conD. Nakamura, T. Kubo, S. Kitamura, A. Maeda
We investigated the dynamics of driven vortices in high-$T_c$ superconductor as an ideal model system to study the physics of friction. The waiting-time dependence of the maximum static friction force, $F_s(t_w)$, was measured in La$_{2-x}$Sr$_x$CuO$_4$ thin films with different structures, sample sizes and pinning force. We found various kinds of $F_s(t_w)$
Christine Michel
In this paper we are using the poset representation to describe the complex answers given by IR systems after a clustering and ranking processes. The answers considered may be given by cartographical representations or by thematic sub-lists of documents. The poset representation, with the graph theory and the relational representation opens many perspectives
Christine Michel, Sebastien George, Elise Garrot
This article presents the results of a study which concerns Instrumented Collective Learning Situations (ICLS) used in higher education and according to different actors's point of view (instructional designer and tutor). Considered actors have been involved in ICLS conception or in their use with students. We determine several forms of ICLS (in terms of
Arthur Cohen, Harold B. Sackrowitz, Minya Xu
The most popular multiple testing procedures are stepwise procedures based on $P$-values for individual test statistics. Included among these are the false discovery rate (FDR) controlling procedures of Benjamini--Hochberg [J. Roy. Statist. Soc. Ser. B 57 (1995) 289--300] and their offsprings. Even for models that entail dependent data, $P$-values based on m
Li-Bin Fu, Jie Liu
We investigate the geometric phase or Berry phase of adiabatic quantum evolution in an atom-molecule conversion system, and find that the Berry phase in such system consists of two parts: the usual Berry connection term and a novel term from the nonlinearity brought forth by the atom-molecule conversion. The geometric phase can be viewed as the flux of the m
V. Yu. Babanly
A problem on propagation of waves in deformable shells with flowing liquid is very urgent in connection with wide use of liquid transportation systems in living organisms and technology. It is necessary to consider shell motion equations for influence of moving liquid in cavity on the dynamics of a shell by solving such kind problems. Nowadays a totality of
A. Isaev., W. Kaup
Let M be a connected generic real-analytic CR-submanifold of a finite-dimensional complex vector space E. Suppose that for every point a in M the Lie algebra hol(M,a) of germs of all infinitesimal real-analytic CR-automorphisms of M at a is finite-dimensional and its complexification contains all constant vector fields and the Euler vector field. Under these
4f-derived Fermi Surfaces of CeRu2(Si[1-x]Ge[x])2 near the Quantum Critical Point: Resonant Soft X-ray ARPES Study
cond-mat.str-elT. Okane, T. Ohkochi, Y. Takeda, S. -i. Fujimori
Angle-resolved photoelectron spectroscopy in the Ce 3d-4f excitation region was measured for the paramagnetic state of CeRu2Si2, CeRu2(Si0.82Ge0.18)2, and LaRu2Si2 to investigate the changes of the 4$f$ electron Fermi surfaces around the quantum critical point. While the difference of the Fermi surfaces between CeRu2Si2 and LaRu2Si2 was experimentally confir
Ralf Ulrich, Ralph Engel, Steffen Müller, Fabian Schüssler
Hadronic cross sections at ultra-high energy have a significant impact on the development of extensive air shower cascades. Therefore the interpretation of air shower data depends critically on hadronic interaction models that extrapolate the cross section from accelerator measurements to the highest cosmic ray energies. We discuss how extreme scenarios of c
Feynman Algorithm Implementation for Comparison with Euler in a Uniform Elastic Two-Layer 2D and 3D Object Dynamic Deformation Framework in OpenGL with GUI
cs.GRMiao Song
We implement for comparative purposes the Feynman algorithm within a C++-based framework for two-layer uniform facet elastic object for real-time softbody simulation based on physics modeling methods. To facilitate the comparison, we implement initial timing measurements on the same hardware against that of Euler integrator in the softbody framework by varyi
Hwankyung Sung, John R. Stauffer, Mike S. Bessell
We have performed mid-IR photometry of the young open cluster NGC 2264 using the images obtained with the Spitzer Space Telescope IRAC and MIPS instruments and present a normalized classification scheme of young stellar objects in various color-color diagrams to make full use of the information from multicolor photometry. These results are compared with the
A. Moncho Jordá, A. A. Louis, J. T. Padding
We use a mesoscopic simulation technique to study the effect of short-ranged inter-particle attraction on the steady-state sedimentation of colloidal suspensions. Attractions increase the average sedimentation velocity $v_s$ compared to the pure hard-sphere case, and for strong enough attractions, a non-monotonic dependence on the packing fraction $\phi$ wit
Jacques-Olivier Lachaud, Benjamin Taton
We present a parametric deformable model which recovers image components with a complexity independent from the resolution of input images. The proposed model also automatically changes its topology and remains fully compatible with the general framework of deformable models. More precisely, the image space is equipped with a metric that expands salient imag
Attila Popping, Romeel Dave, Robert Braun, Benjamin D. Oppenheimer
Observations of intergalactic neutral hydrogen can provide a wealth of information about structure and galaxy formation, potentially tracing accretion and feedback processes on Mpc scales. Below a column density of NHI ~ 10^19 cm-2, the "edge" or typical observational limit for HI emission from galaxies, simulations predict a cosmic web of extended e
Zhihai Zhang, Tian Fang, Bican Xia
Existing algorithms for isolating real solutions of zero-dimensional polynomial systems do not compute the multiplicities of the solutions. In this paper, we define in a natural way the multiplicity of solutions of zero-dimensional triangular polynomial systems and prove that our definition is equivalent to the classical definition of local (intersection) mu
M. Mohseni, A. T. Rezakhani, J. T. Barreiro, P. G. Kwiat
Performance of quantum process estimation is naturally limited to fundamental, random, and systematic imperfections in preparations and measurements. These imperfections may lead to considerable errors in the process reconstruction due to the fact that standard data analysis techniques presume ideal devices. Here, by utilizing generic auxiliary quantum or cl
T. G. Mattos, Fabio D. A. Aarao Reis
We study a model for unimolecular reaction on a supported catalyst including reactant diffusion and desorption, using analytical methods and scaling concepts. For rapid reactions, enhancing surface diffusion or increasing particle size favors the flux of reactants to the catalyst particles, which increases the turnover frequency (TOF). The reactant flux towa
Olivia Caramello
We show that the investigation of universal models in Topos Theory can shed light on problems of definability in Logic as well as on the investigation of De Morgan's law and the law of excluded middle on Grothendieck toposes.
Parameters of Cascade Gamma-Decay of Compound-Nuclei Nd-146, Gd-156, Yb-172, Ta-182, W-184, Os-191, Th-231,233, U-239, Pu-240 from Experimental Data of Reaction $(n,γ)$
nucl-exA. M. Sukhovoj, V. A. Khitrov
Re-analysis of experimental data on primary gamma-transitions averaged over some energy intervals of neutron resonances has been performed. Approximation of their cumulative sums together with extrapolation of the obtained distribution to zero value allowed us to determine mean intensities of of E1- and M1-transitions, their probable number and total dispers
Level Density and Radiative Strength Functions of the $^{237}$U Nucleus from the $(\overline{n},γ)$ Reaction
nucl-exA. M. Sukhovoj, V. A. Khitrov, V. M. Maslov
The independent analysis of the published data on the intensities of the primary gamma-quanta following resonance neutron capture in $^{236}U$ has been performed. Distribution of these intensities about the mean value was approximated in different energy intervals of the primary gamma-transitions and neutrons. Extrapolation of the obtained functions to the z
Lin Lin, Liang En Wei, Zhang Shuang Nan
GRB 090423 is the new high-z record holder of Gamma-ray bursts (GRBs) with z~ 8.2. We present a detailed analysis of both the spectral and temporal features of GRB 090423 observed with Swift/BAT and Fermi/GBM. We find that the T90 observed with BAT in the 15-150 keV band is 13.2 s, corresponding to ~ 1.4 s at z=8.2. It once again gives rise to an issue wheth
Chi Zhang, Gang Wang, Xiaoguang Liu, Jing Liu
In the Scheduling Machines with Capacity Constraints problem, we are given k identical machines, each of which can process at most m_i jobs. M jobs are also given, where job j has a non-negative processing time length t_j >= 0. The task is to find a schedule such that the makespan is minimized and the capacity constraints are met. In this paper, we present a
Esther Gruenhut, Saharon Shelah
In this paper the Erdos-Rado theorem is generalized to the class of well founded trees. We define an equivalence relation on the class rs(infty)^{< aleph_0} (finite sequences of decreasing sequences of ordinals) with aleph_0 equivalence classes, and for n< omega a notion of n-end-uniformity for a colouring of rs(infty)^{< aleph_0} with mu colours. We then sh
Shasha Li, Xueliang Li, Wenli Zhou
Let $G$ be a nontrivial connected graph of order $n$ and let $k$ be an integer with $2\leq k\leq n$. For a set $S$ of $k$ vertices of $G$, let $κ(S)$ denote the maximum number $\ell$ of edge-disjoint trees $T_1,T_2,...,T_\ell$ in $G$ such that $V(T_i)\cap V(T_j)=S$ for every pair $i,j$ of distinct integers with $1\leq i,j\leq \ell$. A collection $\{T_1,T_2,.
Markus Holzer, Martin Kutrib, Andreas Malcher
Multi-head finite automata were introduced in (Rabin, 1964) and (Rosenberg, 1966). Since that time, a vast literature on computational and descriptional complexity issues on multi-head finite automata documenting the importance of these devices has been developed. Although multi-head finite automata are a simple concept, their computational behavior can be a
Moran Cohen, Saharon Shelah
In this paper we explore the representation property over sets. This property generalizes constructibility, however is weak enough to enable us to prove that the class of theories $T$ whose models are representable is exactly the class of stable theories. Stronger results are given for omega-stable.
The Zeeman Effect in the Sobolev Approximation II: Split Monopole Fields and the "Heartbeat" Stokes V Profile
astro-ph.SRK. G. Gayley R. Ignace
We calculate the circularly polarized Stokes V profile for emission lines, formed in hot-star winds threaded with a weak radial magnetic field. For simplicity, the field is treated as a split monopole under the assumptions that it has been radially combed by the wind, and rotation is not playing a central role. Invoking the weak-field approximation, we find