June 2008 arXiv papers — page 6
Showing 501–600 of 4,915 papers
I. Bierenbaum, J. Blümlein, S. Klein
In the asymptotic limit $Q^2 \gg m^2$, the heavy flavor Wilson coefficients for deep--inelastic scattering factorize into the massless Wilson coefficients and the universal heavy flavor operator matrix elements resulting from light--cone expansion. In this way, one can calculate all but the power corrections in $(m^2/Q^2)^k, k > 0$. The heavy flavor operator
M. D. Vannette, R. Prozorov
Whereas dc measurements of magnetic susceptibility, $χ$, fail to distinguish between local and weak itinerant ferromagnets, radio-frequency (rf) measurements of $χ$ in the ferromagnetic state show dramatic differences between the two. We present sensitive tunnel-diode resonator measurements of $χ$ in the weak itinerant ferromagnet ZrZn$_2$ at a frequency of
S. Ramirez, B. Ali, R. Baker, G. B. Berriman
The NASA Star and Exoplanet Database (NStED) is a general purpose stellar archive with the aim of providing support for NASA's planet finding and characterization goals, stellar astrophysics, and the planning of NASA and other space missions. There are two principal components of NStED: a database of (currently) 140,000 nearby stars and exoplanet-hosting
J. L. Donley, G. H. Rieke, P. G. Perez-Gonzalez, G. Barro
(abridged) Infrared selection is a potentially powerful way to identify heavily obscured AGN missed in even the deepest X-ray surveys. Using a 24 micron-selected sample in GOODS-S, we test the reliability and completeness of three infrared AGN selection methods: (1) IRAC color-color selection, (2) IRAC power-law selection, and (3) IR-excess selection; we als
Current-driven transformations of the intermediate state patterns in type-I superconductors
cond-mat.supr-conJ. R. Hoberg, R. Prozorov
Dynamic structure of the intermediate state was studied in pinning-free thick Pb strips using real-time magneto-optical visualization. It is found that topological hysteresis can be lifted by applying sufficiently large current. Namely, laminar structure that appears on flux exit in a static case is turned into tubular when the sufficiently large transport c
Nicolas B. Cowan, Eric Agol
One of the most exciting results of the Spitzer era has been the ability to construct longitudinal brightness maps from the infrared phase variations of hot Jupiters. We presented the first such map in Knutson et al. (2007), described the mapping theory and some important consequences in Cowan & Agol (2008) and presented the first multi waveband map in Knuts
Formation epochs, star formation histories and sizes of massive early-type galaxies in cluster and field environments at z=1.2: insights from the rest-frame UV
astro-phA. Rettura, P. Rosati, M. Nonino, R. A. E. Fosbury
We derive stellar masses, ages and star formation histories of massive early-type galaxies in the z=1.237 RDCS1252.9-2927 cluster and compare them with those measured in a similarly mass-selected sample of field contemporaries drawn from the GOODS South Field. Robust estimates of these parameters are obtained by comparing a large grid of composite stellar po
Effects of different geometries on the conductance, shot noise and tunnel magnetoresistance of double quantum dots
cond-mat.mes-hallI. Weymann
The spin-polarized transport through a coherent strongly coupled double quantum dot (DQD) system is analyzed theoretically in the sequential and cotunneling regimes. Using the real-time diagrammatic technique, we analyze the current, differential conductance, shot noise and tunnel magnetoresistance (TMR) as a function of both the bias and gate voltages for d
G. Dissertori, A. Gehrmann-De Ridder, T. Gehrmann, E. W. N. Glover
We report on the calculation of NNLO corrections to the 3-jet cross section and related event shape distributions in electron-positron annihilation. The corrections are sizable for all variables, however the magnitude of the corrections is substantially different for different observables. We observe that inclusion of the NNLO corrections yields a considerab
Christian Gérard, Annalisa Panati
We introduce an abstract class of bosonic QFT Hamiltonians and study their spectral and scattering theories. These Hamiltonians are of the form $H=\d\G(ω)+ V$ acting on the bosonic Fock space $\G(\ch)$, where $ω$ is a massive one-particle Hamiltonian acting on $\ch$ and $V$ is a Wick polynomial $\Wick(w)$ for a kernel $w$ satisfying some decay properties at
Rigidity-based approach to the boson peak in amorphous solids: from sphere packing to amorphous silica
cond-mat.mtrl-sciMatthieu Wyart
Glasses have a large excess of low-frequency vibrational modes in comparison with continuous elastic body, the so-called Boson Peak, which appears to correlate with several crucial properties of glasses, such as transport or fragility. I review recent results showing that the Boson Peak is a necessary consequence of the weak connectivity of the solid. I expl
H. F. Coronel-Brizio, A. R. Hernandez-Montoya, Fabio Rapallo, Enrico Scalas
One of the most popular lottery games worldwide is the so-called ``lotto k/N''. It considers N numbers 1,2,...,N from which k are drawn randomly, without replacement. A player selects k or more numbers and the first prize is shared amongst those players whose selected numbers match all of the k randomly drawn. Exact rules may vary in different countr
Masaki Satoh, Jiro Soda
We study higher curvature corrections to the scalar spectral index, the tensor spectral index, the tensor-to-scalar ratio, and the polarization of gravitational waves. We find that the higher curvature corrections can not be negligible in the dynamics of the scalar field, although they are energetically negligible. Indeed, it turns out that the tensor-to-sca
Infrared Photometry and Evolution of Mass-Losing AGB Stars. II. Luminosity and Colors of MS and S Stars
astro-phR. Guandalini, M. Busso
AGB phases mark the end of the evolution for Low- and Intermediate-Mass Stars. Our understanding of the mechanisms through which they eject the envelope and our assessment of their contribution to the chemical evolution of Galaxies are hampered by poor knowledge of their Luminosities and mass loss rates,both for C-rich and for O-rich sources.We plan to estab
The HARPS search for southern extra-solar planets. XIII. A planetary system with 3 Super-Earths (4.2, 6.9, & 9.2 Earth masses)
astro-phM. Mayor, S. Udry, C. Lovis, F. Pepe
This paper reports on the detection of a planetary system with three Super-Earths orbiting HD40307. HD40307 is a K2V metal-deficient star at a distance of only 13 parsec, part of the HARPS GTO high-precision planet-search programme. The three planets on circular orbits have very low minimum masses of respectively 4.2, 6.9 and 9.2 Earth masses and periods of
J. Borissova, V. D. Ivanov, M. M. Hanson, L. Georgiev
Recent near- and mid-infrared surveys have brought evidence that the Milky Way continues to form massive clusters. We carry out a program to determine the basic physical properties of the new massive cluster candidate [DBS2003]179. Medium-resolution K-band spectra and deep near-infrared images of [DBS2003]179 were used to derive the spectral types of eight m
Lucio Isa, Rut Besseling, Alexander N. Morozov, Wilson C. K. Poon
We study the pressure-driven flow of concentrated colloids confined in glass micro-channels at the single particle level using fast confocal microscopy. For channel to particle size ratios $a/\bar{D} \lesssim 30$, the flow rate of the suspended particles shows fluctuations. These turn into regular oscillations for higher confinements ($a/\bar{D} \simeq 20$).
M. Abud, F. Buccella, D. Falcone, G. Ricciardi
We present the spectrum of the lightest pentaquark states of both parities and compare it with the present experimental evidence for these states. We have assumed that the main role for their mass splittings is played by the chromo-magnetic interaction. We have also kept into account the $SU(3)_F$ breaking for their contribution and for the spin orbit term.
Vsevolod F. Lev
Sharpening (a particular case of) a result of Szemeredi and Vu and extending earlier results of Sarkozy and ourselves, we find, subject to some technical restrictions, a sharp threshold for the number of integer sets needed for their sumset to contain a block of consecutive integers of length, comparable with the lengths of the set summands. A corollary of o
"Kohn-Shamification" of the classical density-functional theory of inhomogeneous polar molecular liquids with application to liquid hydrogen chloride
cond-mat.softJohannes Lischner, T. A. Arias
The Gordian knot of density-functional theories for classical molecular liquids remains finding an accurate free-energy functional in terms of the densities of the atomic sites of the molecules. Following Kohn and Sham, we show how to solve this problem by considering noninteracting molecules in a set of effective potentials. This shift in perspective leads
Torus bifurcations, isolas and chaotic attractors in a simple dengue model with ADE and temporary cross immunity
q-bio.PEMaira Aguiar, Nico Stollenwerk, Bob W. Kooi
We analyse an epidemiological model of competing strains of pathogens and hence differences in transmission for first versus secondary infection due to interaction of the strains with previously aquired immunities, as has been described for dengue fever (in dengue known as antibody dependent enhancement, ADE). Such models show a rich variety of dynamics thro
C. B. Das, S. Das Gupta
Isotopic spin dependent lattice gas model is used to examine if it produces the isoscaling behaviour seen in intermediate energy heavy ion collisions. Qualitative features are reproduced but quantitative agreement with experiments is lacking.
Modeling the Impulsive Noise Component and its Effect on the Operation of a Simple Coherent Network Algorithm for Unmodeled Gravitational Wave Bursts Detection
gr-qcMaria Principe, Innocenzo M Pinto
An analytic model a la Middleton of the impulsive noise component in the data of interferometric gravitational wave detectors is proposed, based on an atomic representation of glitches. A fully analytic characterization of the coherent network data analysis algorithm proposed by Rakhmanov and Klimenko is obtained, for the simplest relevant case of triggered
V. V. V'yugin
The Lempel-Ziv universal coding scheme is asymptotically optimal for the class of all stationary ergodic sources. A problem of robustness of this property under small violations of ergodicity is studied. A notion of deficiency of algorithmic randomness is used as a measure of disagreement between data sequence and probability measure. We prove that universal
M. Wyart, H. Liang, A. Kabla, L. Mahadevan
We study the role of connectivity on the linear and nonlinear elastic behavior of amorphous systems using a two-dimensional random network of harmonic springs as a model system. A natural characterization of these systems arises in terms of the network coordination relative to that of an isostatic network $δz$; a floppy network has $δz<0$, while a stiff netw
Nico Stollenwerk, Maira Aguiar
We generalize the well known formulation of the susceptibles, infected, susceptibles (SIS) spatial epidemics with creation and annihilation operators to the reinfection model including recovered which can be reinfected, the SIRI model, using ladder operators constructed from the Gell-Mann matrices known in quantum chromodynamics.
Yann Michel, Boris Pioline, Clement Rousset
Stationary, spherically symmetric solutions of N=2 supergravity in 3+1 dimensions have been shown to correspond to holomorphic curves on the twistor space of the quaternionic-Kähler space which arises in the dimensional reduction along the time direction. In this note, we generalize this result to the case of 1/4-BPS black holes in N=4 supergravity, and show
Oluseyi Latunde-Dada
We study the effects of gluon radiation in top pair production and their decays for e+e- annihilation at the ILC. To achieve this we apply the POWHEG method and interface our results to the Monte Carlo event generator Herwig++. We consider a center-of-mass energy of \sqrt{s}=500 GeV and compare decay correlations and bottom quark and anti-quark distributions
Aparna Baskaran, M. Cristina Marchetti
Starting from a minimal physical model of self propelled hard rods on a substrate in two dimensions, we derive a modified Smoluchowski equation for the system. Self -propulsion enhances longitudinal diffusion and modifies the mean field excluded volume interaction. From the Smoluchowski equation we obtain hydrodynamic equations for rod concentration, polariz
Rouzbeh Allahverdi, Bhaskar Dutta, Anupam Mazumdar
Many models of high energy physics possess metastable vacua. It is conceivable that the universe can get trapped in such a false vacuum, irrespective of its origin and prior history, at an earlier stage during its evolution. The ensuing false vacuum inflation results in a cold and empty universe and has a generic graceful exit problem. We show that an inflec
Completeness of the Lattice-Boltzmann IKT approach for classical incompressible fluids
physics.flu-dynE. Fonda, M. Tessarotto, P. Nicolini, M. Ellero
Despite the abundant literature on the subject appeared in the last few years, the lattice Boltzmann method (LBM) is probably the one for which a complete understanding is not yet available. As an example, an unsolved theoretical issue is related to the construction of a discrete kinetic theory which yields \textit{exactly} the fluid equations, i.e., is non-
Francesca Bucci, Igor Chueshov
We prove the existence of a compact, finite dimensional, global attractor for a coupled PDE system comprising a nonlinearly damped semilinear wave equation and a nonlinear system of thermoelastic plate equations, without any mechanical (viscous or structural) dissipation in the plate component. The plate dynamics is modelled following Berger's approach;
Toshio Ohshima
It is shown that efficient and robust universal quantum computation is possible using the stimulated Raman adiabatic passage with a qubit chain as a pointer register.
Alexandru E. Stanculescu
We examine the proof of a classical localization theorem of Bousfield and Friedlander and we remove the assumption that the underlying model category be right proper. The key to the argument is a lemma about factoring in morphisms in the arrow category of a model category.
C. Cremaschini, and M. Tessarotto
An interesting issue in fluid dynamics is represented by the possible existence of inverse kinetic theories (IKT) which are able to deliver, in a suitable sense, the complete set of fluid equations which are associated to a prescribed fluid. From the mathematical viewpoint this involves the formal description of a fluid by means of a classical dynamical syst
P. Salomé, F. Combes
We report CO observations towards MS0735.6+7421 a distant cooling core galaxy, and towards M87, the nearest cooling core in the center of the Virgo cluster. Both galaxies contain radio cavities that are thought to be responsible for the heating that can regulate or stop the cooling of the surrounding gas. In this feedback process, there could still be some g
Roman V. Baluev
Applications of the theory of optimal design of experiments to radial velocity planet search surveys are considered. Different optimality criteria are discussed, basing on the Fisher, Shannon, and Kullback-Leibler informations. Algorithms of optimal scheduling of RV observations for two important practical problems are considered. The first problem is findin
Casey A. Meakin
The hydrodynamic processes operating within stellar interiors are far richer than represented by the best stellar evolution model available. Although it is now widely understood, through astrophysical simulation and relevant terrestrial experiment, that many of the basic assumptions which underlie our treatments of stellar evolution are flawed, we lack a sui
A. J. van Marle, S. P. Owocki, N. J. Shaviv
We present the results of numerical simulations of continuum-driven winds of stars that exceed the Eddington limit and compare these against predictions from earlier analytical solutions. Our models are based on the assumption that the stellar atmosphere consists of clumped matter, where the individual clumps have a much larger optical thickness than the mat
S. Serra-Capizzano, C. Tablino Possio
In recent contributions, algebraic multigrid methods have been designed and studied from the viewpoint of the spectral complementarity. In this note we focus our efforts on specific applications and, more precisely, on large linear systems arising from the approximation of weighted Laplacian with various boundary conditions. We adapt the multigrid idea to th
Timothy B. P. Clark
We introduce the class of lattice-linear monomial ideals and use the LCM-lattice to give an explicit construction for their minimal free resolution. The class of lattice-linear ideals includes (among others) the class of monomial ideals with linear free resolution and the class of Scarf monomial ideals. Our main tool is a new construction by Tchernev that pr
M. Tessarotto, M. Ellero, P. Nicolini
A fundamental aspect of turbulence theory is related to the identification of realizable phase-space statistical descriptions able to reproduce in some suitable sense the stochastic fluid equations of a turbulent fluid. In particular, a major open issue is whether a purely Markovian statistical description of hydrodynamic turbulence actually can be achieved.
M. A. Laakso, T. T. Heikkilä
We study the the transport properties of multiterminal ballistic graphene samples, concentrating on the conductance matrix, fluctuations and cross-correlations. Far away from Dirac point, the current is carried mostly by propagating modes and the results can be explained with the conventional semiclassical picture familiar from ray optics, where electrons pr
P. Abolmasov, A. V. Moiseev
We report the results of our observations of the nebular complex MH9/10/11, associated with the ULX HoIX X-1, with scanning Fabry-Perot Interferometer. Two regions differing by their kinematics and line ratios may be distinguished, roughly corresponding to the bubble nebula MH9/10 and fainter HII-region MH11. For MH9/10 we find the expansion rate of 20-70km/
Pierre Germain
We consider the iterative resolution scheme for the Navier-Stokes equation, and focus on the second iterate, more precisely on the map from the initial data to the second iterate at a given time t. We investigate boundedness properties of this bilinear operator. This new approach yields very interesting results: a new perspective on Koch-Tataru solutions; a
C. Cremaschini, A. Beklemishev, J. Miller, M. Tessarotto
The consistent theoretical description of gravitational Hall-MHD (G-Hall-MHD) equilibria is of fundamental importance for understanding the phenomenology of accretion disks (AD) around compact objects (black holes, neutron stars, etc.). The very existence of these equilibria is actually suggested by observations, which show evidence of quiescent, and essenti
The motility of normal and cancer cells in response to the combined influence of substrate rigidity and anisotropic microstructure
q-bio.CBTzvetelina Tzvetkova-Chevolleau, Angélique Stéphanou, David Fuard, Jacques Ohayon
Cell adhesion and migration are strongly influenced by extracellular matrix (ECM) architecture and rigidity, but little is known about the concomitant influence of such environmental signals to cell responses, especially when considering cells of similar origin and morphology, but exhibiting a normal or cancerous phenotype. Using micropatterned polydimethyls
T. V. Shubina, V. A. Kosobukin, T. A. Komissarova, V. N. Jmerik
InN/In nanocomposites with periodical In inclusions amounting up to 30% of the total volume exhibit bright emission near 0.7 eV explicitly associated with In clusters. Its energy and intensity depend on the In amount. The principal absorption edge in the semiconductor host, as given by a photovoltaic response, is markedly higher than the onset of thermally d
Sigfrido Boffi
The rise of quantum mechanics is reviewed with special attention to the development between June 1925 and October 1927 when the Copenhagen interpretation was proposed.
Mikael Persson
We study the Schroedinger operator with a constant magnetic field in the exterior of a compact domain in $\mathbb{R}^{2d}$, $d\geq 1$. The spectrum of this operator consists of clusters of eigenvalues around the Landau levels. We give asymptotic formulas for the rate of accumulation of eigenvalues in these clusters. When the compact is a Reinhart domain we a
Olav Geil, Ryutaroh Matsumoto, Casper Thomsen
Using tools from algebraic geometry and Groebner basis theory we solve two problems in network coding. First we present a method to determine the smallest field size for which linear network coding is feasible. Second we derive improved estimates on the success probability of random linear network coding. These estimates take into account which monomials occ
Pierre Bäcklund
We prove existence and uniqueness of a sequence of differential intertwining operators for spherical principal series representations, which are realized on boundaries of anti de Sitter spaces. Algebraically, these operators correspond to homomorphisms of generalized Verma modules. We relate these families to the asymptotics of eigenfunctions on anti de Sitt
Molecular dynamics simulations of ultrathin water film confined between flat diamond plates
cond-mat.stat-mechA. V. Khomenko, N. V. Prodanov
Molecular dynamics simulations of ultrathin water film confined between atomically flat rigid diamond plates are described. Films with thickness of one and two molecular diameters are concerned and TIP4P model is used for water molecules. Dynamical and equilibrium characteristics of the system for different values of the external load and shear force are inv
P. J. Mulders
We investigate the emergence of single spin asymmetries (SSA) in hard processes using transverse momentum dependent (TMD) distribution and fragmentation functions. Specifically, the description of SSA involves time reversal-odd functions. Process-dependence (non-universality) in measurements of SSA can be attributed to the non-trivial gauge link structure in
S. Bauch, M. Bonitz
We present angular distributions of photoelectrons of atomic model systems excited by intense linearly polarized laser pulses in the VUV- and XUV-regime. We solve the multi-dimensional time-dependent Schrödinger equation for one particle on large spatial grids and investigate the direction dependence of the ionized electrons for isotropic s-states as well as
Joan E. Hart, Kenneth Kunen
We consider a class of compacta X such that the maps from X onto metric compacta define an Aronszajn tree of closed subsets of X.
Serhiy M. Zhuk
In this report we address the linear state estimation problem: to estimate a linear transformation $\ell(φ)$ of the state $φ$ through an algorithm $\widehat{\ell(φ)}$ operating on measurements $y$, where $Lφ=f,y=Hφ+η$. We study the estimation problem in terms of the minimax estimation framework: to find a linear algorithm $\widehat{\widehat{\ell(φ)}}$ that m
Ayadi Slim
We study the normalized eigenvalue counting measure dσof matrices of long-range percolation model. These are (2n+1)\times (2n+1) random real symmetric matrices H=\{H(i,j)\}_{i,j} whose elements are independent random variables taking zero value with probability 1-ψ[(i-j)/b], b\in \mathbb{R}^{+}, where ψis an even positive function ψ(t)\le{1} vanishing at inf
Jean-Marie Bois
This paper is a continuation of earlier work on generators of simple Lie algebras in arbitrary characteristic (see arXiv:0708.1711). We show that, in contrast to classical Lie algebras, simple graded Lie algebras of Cartan type S,H or K never enjoy the 'one-and-a-half generation' property. The methods rely on a study of centralisers in Cartan type Li
Yao Yao, Hui Zhao, Joel E. Moore, Chang-Qin Wu
We investigate the spin/charge transport in a one-dimensional strongly correlated system by using the adaptive time-dependent density-matrix renormalization group method. The model we consider is a non-half-filled Hubbard chain with a bond of controllable spin-dependent electron hoppings, which is found to cause a blockade of spin current with little influen
Hao Liu, Ti-Pei Li
Sky temperature map of the cosmic microwave background (CMB) is one of the premier probes of cosmology. To minimize instrumentally induced systematic errors, CMB anisotropy experiments measure temperature differences across the sky using paires of horn antennas with a fixed separation angle, temperature maps are recovered from temperature differences obtaine
The Poincare series of divisorial valuations in the plane defines the topology of the set of divisors
math.AGA. Campillo, F. Delgado, S. M. Gusein-Zade
To a plane curve singularity one associates a multi-index filtration on the ring of germs of functions of two variables defined by the orders of a function on irreducible components of the curve. The Poincare series of this filtration turnes out to coincide with the Alexander polynomial of the curve germ. For a finite set of divisorial valuations on the ring
A. Sinha, P. Roy
New non Hermitian Hamiltonians are generated, as isospectral partners of the generalized Swanson model, viz., $ H_- = {\cal{A}}^{\dagger} {\cal{A}} + α{\cal{A}} ^2 + β{\cal{A}}^{\dagger 2} $, where $ αβ$ are real constants, with $ α\neq β$, and ${\cal{A}}^{\dagger}$ and ${\cal{A}}$ are generalized creation and annihilation operators. It is shown that the ini
J. Hakala, S. Rahaman, V. -V. Elomaa, T. Eronen
Atomic masses of the neutron-rich isotopes $^{76-80}$Zn, $^{78-83}$Ga, $^{80-85}Ge, $^{81-87}$As and $^{84-89}$Se have been measured with high precision using the Penning trap mass spectrometer JYFLTRAP at the IGISOL facility. The masses of $^{82,83}$Ga, $^{83-85}$Ge, $^{84-87}$As and $^{89}$Se were measured for the first time. These new data represent a maj
Thomas Bauer, Christoph Schulz
The purpose of this paper is to study Seshadri constants on the self-product $E\times E$ of an elliptic curve $E$. We provide explicit formulas for computing the Seshadri constants of all ample line bundles on the surfaces considered. As an application, we obtain a good picture of the behaviour of the Seshadri function on the nef cone.
Spin-flip scattering in time-dependent transport through a quantum dot: Enhanced spin-current and inverse tunneling magnetoresistance
cond-mat.mes-hallEnrico Perfetto, Gianluca Stefanucci, Michele Cini
We study the effects of spin-flip scatterings on the time-dependent transport properties through a magnetic quantum dot attached to normal and ferromagnetic leads. The transient spin-dynamics as well as the steady-state tunneling magnetoresistance (TMR) of the system are investigated. The absence of a definite spin quantization axis requires the time-propaga
Santosh Ansumali
I propose an extension to Boltzmann BGK equation for Hard Spheres. The present model has an $H$-theorem and it allows choice of Prandtl number as an independent parameter. I show that similar to Enskog equation this equation can reproduce dynamics of hard spheres in dense systems.
A. Bianchi, A. Bovier, D. Ioffe
In this paper we study the metastable behavior of one of the simplest disordered spin system, the random field Curie-Weiss model. We will show how the potential theoretic approach can be used to prove sharp estimates on capacities and metastable exit times also in the case when the distribution of the random field is continuous. Previous work was restricted
Diego Rainis, Fabio Taddei, Fabrizio Dolcini, Marco Polini
We study Andreev reflection in graphene nanoribbon/superconductor hybrid junctions. By using a tight-binding approach and the scattering formalism we show that finite-size effects lead to notable differences with respect to the bulk graphene case. At subgap voltages, conservation of pseudoparity, a quantum number characterizing the ribbon states, yields eith
C. Sanchez Contreras, R. Sahai, A. Gil de Paz, R. Goodrich
We present echelle long-slit optical spectra of a sample of objects evolving off the AGB, most of them in the pre-planetary nebula (pPN) phase, obtained with the ESI and MIKE spectrographs at Keck-II and Magellan-I, respectively. The total wavelength range covered with ESI (MIKE) is ~3900 to 10900 A (~3600 to 7200A). In this paper, we focus our analysis main
Konrad J. Swanepoel
We adapt a construction of Klee (1981) to find a packing of unit balls in $\ell_p$ ($1\leq p<\infty$) which is efficient in the sense that enlarging the radius of each ball to any $R>2^{1-1/p}$ covers the whole space. We show that the value $2^{1-1/p}$ is optimal.
Dimitris Sardelis
The aim of the present article is to explore the possibilities of representing positive integers as sums of other positive integers and highlight certain fundamental connections between their multiplicative and additive properties. In particular, we shall be concerned with the representation of positive integers as arithmetic series of the simplest kind, i.e
J. C. Ndogmo
A general expression for a relative invariant of a linear ordinary differential equations is given in terms of the fundamental semi-invariant and an absolute invariant. This result is used to established a number of properties of relative invariants, and it is explicitly shown how to generate fundamental sets of relative and absolute invariants of all orders
Immanuel Halupczok
To a definable subset of Z_p^n (or to a scheme of finite type over Z_p) one can associate a tree in a natural way. It is known that the corresponding Poincare series P(X) = \sum_i N_i X^i is rational, where N_i is the number of nodes of the tree at depth i. This suggests that the trees themselves are far from arbitrary. We state a conjectural, purely combina
Magdalena Pelc
In this paper the modified Klein - Gordon equation for market processes is proposed and solved. It is argued that the oscillations in market propagate with the light velocity. The initial pulse in the market is damped and for very large time diffused according to the Fourier law.
Ricardo Carrera, Carme Gallart, Antonio Aparicio, Edgardo Costa
We present stellar metallicities derived from Ca II triplet spectroscopy in over 350 red giant branch stars in 13 fields distributed in different positions in the SMC, ranging from $\sim$1\arcdeg\@ to $\sim$4\arcdeg\@ from its center. In the innermost fields the average metallicity is [Fe/H] $\sim -1$. This value decreases when we move away towards outermost
Magnetic incommensurability and fluctuating charge density waves in the repulsive Hubbard model
cond-mat.str-elA Sherman, M Schreiber
Magnetic and charge susceptibilities of the two-dimensional repulsive Hubbard model are investigated applying a strong coupling diagram technique in which the expansion in powers of the hopping constants is used. For small lattices and high temperatures results are in agreement with Monte Carlo simulations. With the departure from half-filling $x$ the low-fr
Comparing the performance of stellar variability filters for the detection of planetary transits
astro-phA. S. Bonomo, A. F. Lanza
We have developed a new method to improve the transit detection of Earth-sized planets in front of solar-like stars by fitting stellar microvariability by means of a spot model. A large Monte Carlo numerical experiment has been designed to test the performance of our approach in comparison with other variability filters and fitting techniques for stars of di
M. Combescot, O. Betbeder-Matibet, M. A. Dupertuis
To test the validity of replacing a composite fermion by an elementary fermion, we here calculate the transition rate from a state made of one free electron and one trion to a similar electron-trion pair, through the time evolution of such a pair induced by Coulomb interaction between elementary fermions. To do it in a convenient way, we describe the trion a
Renaud Trouilloud, Tony S. Yu, A. E. Hosoi, Eric Lauga
Reciprocal movement cannot be used for locomotion at low-Reynolds number in an infinite fluid or near a rigid surface. Here we show that this limitation is relaxed for a body performing reciprocal motions near a deformable interface. Using physical arguments and scaling relationships, we show that the nonlinearities arising from reciprocal flow-induced inter
J. M. Borrero, S. K. Solanki
The vertical stratification of the magnetic field strength in sunspot penumbrae is investigated by means of spectropolarimetric observations at high spatial resolution from the Hinode spacecraft. Assuming that the magnetic field changes linearly with optical depth we find that, in those regions where the magnetic field is more inclined and the Evershed flow
Ennio Poretti, Gisella Clementini, Enrico V. Held, Claudia Greco
We have carried out an intensive survey of the northern region of the Fornax dwarf spheroidal galaxy with the aim of detecting the galaxy's short--period pulsating stars (P<0.25 days). Observations collected over three consecutive nights with the Wide Field Imager of the 2.2m MPI telescope at ESO allowed us to detect 85 high-amplitude (0.20-1.00 mag in B-lig
M. van Zalk, J. Huijben, A. J. M. Giesbers, M. Huijben
We present low-temperature and high-field magnetotransport data on SrTiO3-LaAlO3 interfaces. The resistance shows hysteresis in magnetic field and a logarithmic relaxation as a function of time. Oscillations in the magnetoresistance are observed, showing a square root periodicity in the applied magnetic field, both in large-area unstructured samples as well
Impact of road mitigation measures on amphibian populations: A stage-class population mathematical model
q-bio.PERenaud Jolivet, Michel Antoniazza, Catherine Strehler-Perrin, Antoine Gander
It is now well established that amphibians are suffering widespread decline and extinctions. Among other causes, urbanization is responsible for habitat reduction, habitat fragmentation and massive road kills. In this context, it is urgent to develop and assess appropriate conservation measures. Using yearly censuses of migrating adults of two anuran species
Emmanuel Gobet, Jean-Philippe Lemor
This article deals with the numerical resolution of backward stochastic differential equations. Firstly, we consider a rather general case where the filtration is generated by a Brownian motion and a Poisson random measure. We provide a simulation algorithm based on iterative regressions on function bases, which coefficients are evaluated using Monte Carlo s
Bertrand Clarke, Subhashis Ghosal
Jayanta Kumar Ghosh is one of the most extraordinary professors in the field of Statistics. His research in numerous areas, especially asymptotics, has been groundbreaking, influential throughout the world, and widely recognized through awards and other honors. His leadership in Statistics as Director of the Indian Statistical Institute and President of the
Mean encounter times for cell adhesion in hydrodynamic flow: analytical progress by dimensional reduction
q-bio.CBC. B. Korn, U. S. Schwarz
For a cell moving in hydrodynamic flow above a wall, translational and rotational degrees of freedom are coupled by the Stokes equation. In addition, there is a close coupling of convection and diffusion due to the position-dependent mobility. These couplings render calculation of the mean encounter time between cell surface receptors and ligands on the subs
Gy Gyürky, J. Farkas, C. Yalcin, G. G. Kiss
The branching ratio between the beta- and beta+/electron capture decay of 74As has been measured in different host materials such as Ta, Al, Ge and mylar. No significant dependence of the branching ratio on the host material has been observed. The half-life of 74As has also been measured in metallic Ta and in semiconductor Ge, no difference has been found an
Deborah Nolan, Terry Speed
This volume is our tribute to David A. Freedman, whom we regard as one of the great statisticians of our time. He received his B.Sc. degree from McGill University and his Ph.D. from Princeton, and joined the Department of Statistics of the University of California, Berkeley, in 1962, where, apart from sabbaticals, he has been ever since. In a career of over
Gunter M. Schütz, Marian Brandau, Steffen Trimper
The susceptible-infectious-recovered (SIR) model describes the evolution of three species of individuals which are subject to an infection and recovery mechanism. A susceptible $S$ can become infectious with an infection rate $β$ by an infectious $I$- type provided that both are in contact. The $I$- type may recover with a rate $γ$ and from then on stay immu
Masashi Torikai
A spherocylinder-like molecule with a Lennard-Jones type interaction is proposed as a model of smectic-A (Sm-A) liquid crystals, which can form a free-standing film. By means of Gibbs ensemble simulations, the isotropic, nematic, and Sm-A phases of the model fluid are found to coexist with a vapor phase; and the coexistence conditions of the liquid crystal p
Alexander E. Hramov, Alexey A. Koronovskii, Pavel V. Popov
A new type of noise-induced synchronous behavior is described. This phenomenon, called incomplete noise-induced synchronization, arises for one-dimensional Ginzburg-Landau equations driven by common noise. The mechanisms resulting in the incomplete noise-induced synchronization in the spatially extended systems are revealed analytically. The different model
Peter Schenzel
Let $(R,\mathfrak m)$ denote an $n$-dimensional complete local Gorenstein ring. For an ideal $I$ of $R$ let $H^i_I(R), i \in \mathbb Z,$ denote the local cohomology modules of $R$ with respect to $I.$ If $H^i_I(R) = 0$ for all $i \not= c = \height I,$ then the endomorphism ring of $H^c_I(R)$ is isomorphic to $R$ (cf. \cite{HSt} and \cite{HS}). Here we prove
Observation of Spin Fluctuations in a High-Tc Parent Compound Using Resonant Inelastic X-ray Scattering
cond-mat.supr-conB. Freelon, P. G. Medaglia, A. Tebano, G. Balestrino
We report the first observation of soft-x-ray scattering from spin fluctuations in a high-Tc parent compound. An antiferromagnetic charge transfer insulator, CaCuO2, was irradiated by Cu M-edge soft x-rays. Ultra-high resolution measurements of scattered intensity revealed magnon-magnon excitations, due to spin exchange scattering, as low-energy loss feature
Dephasing in two decoupled one-dimensional Bose-Einstein condensates and the subexponential decay of the interwell coherence
cond-mat.stat-mechI. E. Mazets, J. Schmiedmayer
We provide a simple physical picture of the loss of coherence between two coherently split one-dimensional Bose-Einstein condensates. The source of the dephasing is identified with nonlinear corrections to the elementary excitation energies in either of the two independent condensates. We retrieve the result by Burkov, Lukin and Demler [Phys. Rev. Lett. 98,
I. Maruyama, Y. Hatsugai
We have numerically studied a non-adiabatic charge transport in the quantum Hall system pumped by a magnetic flux, as one of the simplest theoretical realizations of non-adiabatic Thouless pumping. In the adiabatic limit, a pumped charge is quantized, known as Laughlin's argument in a cylindrical lattice. In a uniform electric field, we obtained a formul
Miguel Socolovsky
We show that the collapse of the wave function of an entangled state of two spin 1/2 particles or two photons in the singlet state can be geometrically understood as a change of fibre bundles.
M. N. Serbyn, M. A. Skvortsov, A. A. Varlamov, Victor Galitski
A theory of the fluctuation-induced Nernst effect is developed for arbitrary magnetic fields and temperatures beyond the upper critical field line in a two-dimensional superconductor. First, we derive a simple phenomenological formula for the Nernst coefficient, which naturally explains the giant Nernst signal due to fluctuating Cooper pairs. The latter is s
Yashwant Singh
In the present paper a generalization of Gurland distribution [3] is obtained as a beta mixture of the generalized Poisson distribution (GPD) of Consul and Jain [2]. The first two moments of the distribution and a recurrence relation among probabilities are obtained. The present distribution is supposed to be more general in nature and wider in scope.
Ping Li
Applications in machine learning and data mining require computing pairwise Lp distances in a data matrix A. For massive high-dimensional data, computing all pairwise distances of A can be infeasible. In fact, even storing A or all pairwise distances of A in the memory may be also infeasible. This paper proposes a simple method for p = 2, 4, 6, ... We first