August 2008 arXiv papers — page 3
Showing 201–300 of 4,272 papers
On the structure of the Sun and alpha Centauri A and B in the light of seismic and non-seismic constraints
astro-phM. Yildiz
The small separation (delta nu 01, delta nu 02 and delta nu 13) between the oscillations with low degree l is dependent primarily on the sound speed profile within the stellar core, where nuclear evolution occurs. The detection of such oscillations for a star offers a very good opportunity to determine the stage of its nuclear evolution, and hence its age. I
Situational diagnosis for preservice elementary teachers on some basic astronomical phenomena
physics.ed-phAlejandro Gangui, Maria Iglesias, Cynthia Quinteros
The present situation of the teaching-learning relationship in astronomy is rarely investigated in our country. This is so, even when it is widely recognized that astronomy is an integral discipline, at the crossroads of advances in physics, geology, chemistry, etc. In this project we aim at contributing with the situational diagnosis in topics of astronomy
Roman Shcherbakov
The transfer of polarized radiation in magnetized and non-magnetized relativistic plasmas is an area of research with numerous flaws and gaps. The present paper is aimed at filling some gaps and eliminating the flaws. Starting from a Trubnikov's linear response tensor for a vacuum wave with ${\bf k}=ω/c$ in thermal plasma, the analytic expression for the
Tanya Khovanova
In this paper I discuss the kinds of information that can be extracted by our enemy if our jamming is too precise. I show geometric solutions for reconstructing linear routes given certain information about them, such as the shortest distance to a point or the times of entering and exiting a circle.
Periodic Radio and H-alpha Emission from the L Dwarf Binary 2MASSW J0746425+200032: Exploring the Magnetic Field Topology and Radius of an L Dwarf
astro-phE. Berger, R. E. Rutledge, N. Phan-Bao, G. Basri
[Abridged] We present an 8.5-hour simultaneous radio, X-ray, UV, and optical observation of the L dwarf binary 2MASSW J0746+20. We detect strong radio emission, dominated by short-duration periodic pulses at 4.86 GHz with P=124.32+/-0.11 min. The stability of the pulse profiles and arrival times demonstrates that they are due to the rotational modulation of
Using Relative Entropy to Find Optimal Approximations: an Application to Simple Fluids
cond-mat.stat-mechChih-Yuan Tseng, Ariel Caticha
We develop a maximum relative entropy formalism to generate optimal approximations to probability distributions. The central results consist in (a) justifying the use of relative entropy as the uniquely natural criterion to select a preferred approximation from within a family of trial parameterized distributions, and (b) to obtain the optimal approximation
M. Meléndez, S. B. Kraemer, H. R. Schmitt, D. M. Crenshaw
We have studied the relationship between the high- and low-ionization [O IV] lambda 25.89 micron, [Ne III] lambda 15.56 micron and [Ne II] lambda 12.81 micron emission lines with the aim of constraining the active galactic nuclei (AGN) and star formation contributions for a sample of 103 Seyfert galaxies. We used the [O IV] and [Ne II] emission as tracers fo
Aigen Li
Polycyclic aromatic hydrocarbon (PAH) molecules, ubiquitously seen in the interstellar medium (ISM) of our own and external galaxies, might have been incorporated into comets if they are formed from relatively unprocessed interstellar matter. The detection of PAHs in comets would be an important link between the ISM and comets. This review compiles our curre
J. Santos, J. S. Alcaniz, F. C. Carvalho, N. Pires
A class of modified gravity, known as $f(R)$-gravity, has presently been applied to Cosmology as a realistic alternative to dark energy. In this paper we use the most recent Type-Ia Supernova (SNe Ia) data, the so-called \emph{Union} sample of 307 SNe Ia, to place bounds on a theory of the form $f(R)=R - β/R^n$ within the Palatini approach. Given the complem
J. T. Haraldsen, M. B. Stone, M. D. Lumsden, E. Mamontov
We report inelastic and elastic neutron scattering, magnetic susceptibility, and heat capacity measurements of polycrystalline sodium ruthenate (Na$_3$RuO$_4$). Previous work suggests this material consists of isolated tetramers of $S=3/2$ Ru$^{5+}$ ions in a so-called "lozenge" configuration. Using a Heisenberg antiferromagnet Hamiltonian, we analyt
E. Canessa
Since laws of physics exist in nature, their possible relationship to terrestial growth is introduced. By considering the human body as a dynamic system of variable mass (and volume), growing under a gravity field, it is shown how natural laws may influence the vertical growth of humans. This approach makes sense because the non-linear percentile curves of d
Martin Brumberg, Juergen Leiterer
Let X be a complex manifold of dimension 2, which admits a strictly plurisubharmonic function r which is proper as a function with values in the intervall ]inf r, sup r[. We prove that the concave end of X can be compactified, if and only if, the first cohomology of X is Hausdorff.
Resistance Fluctuations in Composite Fermion State near Landau Level Filling Factor $ν= 1/2$ in A Square Quantum Well
cond-mat.mes-hallJian Zhang, R. R. Du, J. A. Simmons, J. L. Reno
We have studied the magnetotransport near Landau level filling factor $ν= 1/2$ in a GaAs-Al0.3Ga0.7As square quantum well (width 35 nm) in magnetic field up to 42 T and in a temperature range between 50 mK and 1.5 K. In low temperatures T < 200 mK, the Rxx exhibits a deep, strongly temperature-dependent minimum centered at $ν= 1/2$. The concomitant Rxy is no
Werner Hoffmann
We rewrite Arthur's asymptotic formula for weighted orbital integrals on real groups with the aid of a residue calculus and extend the resulting formula to the Schwartz space. Then we extract the available information about the coefficients in the decomposition of the Fourier transforms of Arthur's invariant distributions I_M(γ) in terms of standard
General Relativistic Hydrodynamic Simulations and Linear Analysis of the Standing Accretion Shock Instability around a Black Hole
astro-phHiroki Nagakura, Shoichi Yamada
We study the stability of standing shock waves in advection-dominated accretion flows into a Schwarzschild black hole by 2D general relativistic hydrodynamic simulations as well as linear analysis in the equatorial plane. We demonstrate that the accretion shock is stable against axisymmetric perturbations but becomes unstable to non-axisymmetric perturbation
Rui Pacheco
We characterize Bianchi-Bäcklund transformations of surfaces of positive constant Gauss curvature in terms of dressing actions of the simplest type on the space of harmonic maps.
Tableau-based decision procedure for the multi-agent epistemic logic with operators of common and distributed knowledge
cs.LOValentin Goranko, Dmitry Shkatov
We develop an incremental-tableau-based decision procedure for the multi-agent epistemic logic MAEL(CD) (aka S5_n (CD)), whose language contains operators of individual knowledge for a finite set Ag of agents, as well as operators of distributed and common knowledge among all agents in Ag. Our tableau procedure works in (deterministic) exponential time, thus
Z. A. Pyatakova
The paper shows that silicon-based 2D photonic crystal can be a promising material for acoustooptical devices. Isotropic and anisotropic Bragg diffraction of light in photonic crystal is considered. The computational method for calculation of frequency dependences of Bragg angle is developed. A simple method of optimization of photonic crystal parameters to
H. G. Roe, R. E. Pike, M. E. Brown
We report a multi-week sequence of B-band photometric measurements of the dwarf planet Eris using the {\it Swift} satellite. The use of an observatory in low-Earth orbit provides better temporal sampling than is available with a ground-based telescope. We find no compelling evidence for an unusually slow rotation period of multiple days, as has been suggeste
M. P. Li, G. Zhao, Aigen Li
An accurate knowledge of the mineralogy (chemical composition and crystal structure) of the silicate dust in the interstellar medium (ISM) is crucial for understanding its origin in evolved stars, the physical and chemical processing in the ISM, and its subsequent incorporation into protostellar nebulae, protoplanetary disks and cometary nuclei where it is s
Predictions for Supersymmetric Particle Masses in the CMSSM using Indirect Experimental and Cosmological Constraints
hep-phO. Buchmueller, R. Cavanaugh, A. De Roeck, J. R. Ellis
In view of the imminent start of the LHC experimental programme, we use the available indirect experimental and cosmological information to estimate the likely range of parameters of the constrained minimal supersymmetric extension of the Standard Model (CMSSM), using a Markov-chain Monte Carlo (MCMC) technique to sample the parameter space. The 95% confiden
Aigen Li, J. H. Chen, M. P. Li, Q. J. Shi
The carrier of the 2175 Angstrom interstellar extinction feature remains unidentified since its first detection over 40 years ago. In recent years carbon buckyonions have been proposed as a carrier of this feature, based on the close similarity between the electronic transition spectra of buckyonions and the 2175 Angstrom interstellar feature. We examine thi
Paulo Antunes
We define the Poisson quasi-Nijenhuis structures with background on Lie algebroids and we prove that to any generalized complex structure on a Courant algebroid which is the double of a Lie algebroid is associated such a structure. We prove that any Lie algebroid with a Poisson quasi-Nijenhuis structure with background constitutes, with its dual, a quasi-Lie
Recent PHENIX Results on pi+, pi-, and eta Production in polarized pp Collisions at RHIC at sqrt(s) = 200 GeV
hep-exFrank Ellinghaus
Measurements of double helicity asymmetries for inclusive hadron production in polarized proton-proton collisions are sensitive to spin-dependent parton distribution functions, in particular to the gluon distribution function. This study focuses on double helicity asymmetries in eta and charged pion production at mid-rapidity, as well as on the eta cross sec
Aigen Li
Except in a few cases cosmic dust can be studied in situ or in terrestrial laboratories, essentially all of our information concerning the nature of cosmic dust depends upon its interaction with electromagnetic radiation. This chapter presents the theoretical basis for describing the optical properties of dust -- how it absorbs and scatters starlight and rer
On the Anomalous Silicate Emission Features of AGNs: A Possible Interpretation Based on Porous Dust
astro-phM. P. Li, Q. J. Shi, Aigen Li
The recent Spitzer detections of the 9.7 micron Si--O silicate emission in type 1 AGNs provide support for the AGN unification scheme. The properties of the silicate dust are of key importance to understanding the physical, chemical and evolutionary properties of the obscuring dusty torus around AGNs. Compared to that of the Galactic interstellar medium (ISM
Aigen Li
Dust plays an essential role in the unification theory of active galactic nuclei (AGNs). This review summarizes our current understanding of the extinction and infrared emission properties of the circumnuclear dust in AGNs as well as the inferred dust composition and size distribution.
V. I. Dokuchaev, S. V. Chernov
The method of an effective potential is used to investigate the possible types of evolution of vacuum shells in the Friedman-Schwarzschild world. Such shells are assumed to emerge during phase transitions in the early Universe. The possible global geometries are constructed for the Friedman- Schwarzschild worlds. Approximate solutions to the equation of moti
Aigen Li, S. L. Liang, D. A. Kann, D. M. Wei
Although it is well recognized that gamma-ray burst (GRB) afterglows are obscured and reddened by dust in their host galaxies, the wavelength-dependence and quantity of dust extinction are still poorly known. Current studies on this mostly rely on fitting the afterglow spectral energy distributions (SEDs) with template extinction models. The inferred extinct
Sooraj Kuttykrishnan
We study the structure of length four polynomial automorphisms of $R[X,Y]$ when $R$ is a UFD. The results from this study are used to prove that if $\text{SL}_m(R[X_1,X_2,..., X_n]) = \text{E}_m(R[X_1,X_2,..., X_n])$ for all $n, m \ge 0$ then all length four polynomial automorphisms of $R[X,Y]$ that are conjugates are stably tame.
M. Koehler, I. Mann, Aigen Li
The red spectral shape of the visible to near infrared reflectance spectrum of the sharply-edged ring-like disk around the young main sequence star HR 4796A was recently interpreted as the presence of tholin-like complex organic materials which are seen in the atmosphere and surface of Titan and the surfaces of icy bodies in the solar system. However, we sho
Z. Bern, J. J. M. Carrasco, L. J. Dixon, H. Johansson
Using the method of maximal cuts, we obtain a form of the three-loop four-point scattering amplitude of N=8 supergravity in which all ultraviolet cancellations are made manifest. The Feynman loop integrals that appear have a graphical representation with only cubic vertices, and numerator factors that are quadratic in the loop momenta, rather than quartic as
S. Gnutzmann, J. P. Keating, F. Piotet
We investigate the equidistribution of the eigenfunctions on quantum graphs in the high-energy limit. Our main result is an estimate of the deviations from equidistribution for large well-connected graphs. We use an exact field-theoretic expression in terms of a variant of the supersymmetric nonlinear sigma-model. Our estimate is based on a saddle-point anal
Massimo Giulietti, Gabor Korchmaros
We determine the semi-regular subgroups of the 2-transitive permutation groups PGL(2,n), PSL(2,n), PGU(3,n), PSU(3,n), Sz(n) and Ree(n) with n a suitable power of a prime number p.
Francois Henault
Several types of Wavefront Sensors (WFS) are nowadays available in the field of Adaptive Optics (AO). Generally speaking, their basic principle consists in measuring slopes or curvatures of Wavefront Errors (WFE) transmitted by a telescope, subsequently reconstructing WFEs digitally. Such process, however, does not seem to be well suited for evaluating co-ph
Reference grids of stellar models and oscillation frequencies: Data from the CESAM stellar evolution code and ADIPLS oscillation programme
astro-phYveline Lebreton, Eric Michel
We present grids of stellar models and their associated oscillation frequencies that have been used by the CoRoT Seismology Working Group during the scientific preparation of the CoRoT mission. The stellar models have been calculated with the CESAM stellar internal structure and evolution code while the oscillation frequencies have been obtained from the CES
Dominik Schatzmann, Martin Burkhart, Thrasyvoulos Spyropoulos
Despite a large amount of effort devoted in the past years trying to limit unsolicited mail, spam is still a major global concern. Content-analysis techniques and blacklists, the most popular methods used to identify and block spam, are beginning to lose their edge in the battle. We argue here that one not only needs to look into the network-related characte
Spin-wave mediated quantum corrections to the conductivity in thin ferromagnetic gadolinium films
cond-mat.dis-nnR. Misra, A. F. Hebard, K. A. Muttalib, P. Wolfle
We present a study of quantum corrections to the conductivity of thin ferromagnetic gadolinium films. In situ magneto-transport measurements were performed on a series of thin films with thickness d < 135A. For sheet resistances R0 < 4011 Ohm and temperatures T < 30K, we observe a linear temperature dependence of the conductivity in addition to the logarithm
T. Kono
The ATLAS trigger system is based on three levels of event selection that select the physics of interest from an initial bunch-crossing rate of 40 MHz. During nominal LHC operations at a luminosity of 10^34 cm^-2 s^-1, decisions must be taken every 25 ns with each bunch crossing containing about 23 interactions. The selections in the three trigger levels mus
M. Mapelli, B. Moore, E. Ripamonti, L. Giordano
Giant low surface brightness galaxies (GLSBs) have flat discs extending up to ~100 kpc. Their formation is a puzzle for cosmological simulations in the cold dark matter scenario. We suggest that GLSBs might be the final product of the evolution of collisional ring galaxies. In fact, our simulations show that, approximately 0.5-1.5 Gyr after the collision whi
Sylvain Lavallée, Christophe Reutenauer, Vladimir Retakh, Dominique Perrin
Given a matrix over a skew field fixing the column (1,...,1)^t, we give formulas for a row vector fixed by this matrix. The same techniques are applied to give noncommutative extensions of probabilistic properties of codes.
D. J. Bedingham
A simplified model of quantum electrodynamics involving a charged two-state system interacting with an electromagnetic field mode is examined. By extending the Schrodinger equation to include stochastic and nonlinear terms the dynamical process of quantum state reduction can be represented. A specific choice of modified Schrodinger dynamics is shown to resul
Montse Villar-Martin, Andrew Humphrey, Alejo Martinez-Sansigre, Miguel Perez-Torres
We have compared the optical emission line ratios of type 2 quasars from Zakamska et al. with standard AGN photoionization model predictions, Seyfert 2s, HII galaxies, and narrow line FRII radio galaxies. Moderate to high ionization narrow line radio galaxies and Seyfert 2s are indistinguishable from type 2 quasars based on their optical line ratios. The sta
M. van Leeuwen
We present selected recent results of multi-hadron correlation measurements in azimuth and pseudorapidity at intermediate and high \pt{} in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV, from the STAR experiment at RHIC. At intermediate \pt, measurements are presented that attempt to determine the origin of the associated near-side (small \dphi) yield at large
Alvio Renzini
The various scenarios proposed for the origin of the multiple, helium-enriched populations in massive globular clusters are critically compared to the relevant constraining observations. Among accretion of helium-rich material by pre-existing stars, star formation out of ejecta from massive AGB stars or from fast rotating massive stars, and pollution by Popu
A. C. D. van Enter, W. M. Ruszel
We consider planar rotors (XY spins) in $\mathbb{Z}^d$, starting from an initial Gibbs measure and evolving with infinite-temperature stochastic (diffusive) dynamics. At intermediate times, if the system starts at low temperature, Gibbsianness can be lost. Due to the influence of the external initial field, Gibbsianness can be recovered after large finite ti
J. R. Blundell, E. M. Terentjev
We present a revised theoretical study of the affine assumption applied to semiflexible networks. Drawing on simple models of semiflexible worm-like chains we derive an expression for the probability distribution of crosslink separations valid at all separations. This accounts for both entropic and mechanical filament stretching. From this we obtain the free
Steven B. Giddings, Michelangelo L. Mangano
In a recent note, arXiv:0808.1415, it was argued that a hypothetical metastable black hole scenario could pose collider risk not excluded by our previous study. We comment on inconsistency of this proposed scenario.
A novel method for measuring the extragalactic background light: Fermi application to the lobes of Fornax A
astro-phMarkos Georganopoulos, Rita M. Sambruna, Demosthenes Kazanas, Analia N. Cillis
We describe a new method for measuring the extragalactic background light (EBL) through the detection of $γ$-ray inverse Compton (IC) emission due to scattering of the EBL photons off relativistic electrons in the lobes of radio galaxies. Our method has no free physical parameters and is a powerful tool when the lobes are characterized by a high energy sharp
Siavash Ghabezloo, Jean Sulem, Sylvine Guédon, François Martineau
The effective stress law for the permeability of a limestone is studied experimentally by performing constant head permeability tests in a triaxial cell with different conditions of confining pressure and pore pressure. Test results have shown that a pore pressure increase and a confining pressure decrease both result in an increase of the permeability, and
Siavash Ghabezloo, Jean Sulem, Sylvine Guédon, Francçois Martineau
The poromechanical behaviour of hardened cement paste under isotropic loading is studied on the basis of an experimental testing program of drained, undrained and unjacketed compression tests. The macroscopic behaviour of the material is described in the framework of the mechanics of porous media. The poroelastic parameters of the material are determined and
Thomas R. Shemanske
As part of his work to develop an explicit trace formula for Hecke operators on congruence subgroups of $SL_2(\Z)$, Hijikata defines and characterizes the notion of a split order in $M_2(k)$, where $k$ is a local field. In this paper, we generalize the notion of a split order to $M_n(k)$ for $n>2$ and give a natural geometric characterization in terms of the
Numerical modelling of the effect of weathering on the progressive failure of underground limestone mines
physics.geo-phSiavash Ghabezloo, Ahmad Pouya
The observations show that the collapse of underground limestone mines results from a progressive failure due to gradual weathering of the rockmass. The following stages can be considered for the limestone weathering and degradation process in underground mines: condensation of the water on the roof of the gallery, infiltration of water in the porous rock, m
Cecilia B. M. H. Chirenti, Luciano Rezzolla
The ergoregion instability is known to affect very compact objects that rotate very rapidly and do not possess a horizon. We present here a detailed analysis on the relevance of the ergoregion instability for the viability of gravastars. Expanding on some recent results, we show that not all rotating gravastars are unstable. Rather, stable models can be cons
C. Weber, G. Barontini, J. Catani, G. Thalhammer
We report on the creation of heterospecies bosonic molecules, associated from an ultracold Bose-Bose mixture of 41K and 87Rb, by using a resonantly modulated magnetic field close to two Feshbach resonances. We measure the binding energy of the weakly bound molecular states versus the Feshbach field and compare our results to theoretical predictions. We obser
Henning Samtleben
The low-energy effective theories describing string compactifications in the presence of fluxes are so-called gauged supergravities: deformations of the standard abelian supergravity theories. The deformation parameters can be identified with the various possible (geometric and non-geometric) flux components. In these lecture notes we review the construction
Persistence in the zero-temperature dynamics of the $Q$-states Potts model on undirected-directed Barabási-Albert networks and Erdös-Rényi random graphs
cond-mat.stat-mechF. P. Fernandes, F. W. S. Lima
The zero-temperature Glauber dynamics is used to investigate the persistence probability $P(t)$ in the Potts model with $Q=3,4,5,7,9,12,24,64, 128$, $256, 512, 1024,4096,16384 $,..., $2^{30}$ states on {\it directed} and {\it undirected} Barabási-Albert networks and Erdös-Rényi random graphs. In this model it is found that $P(t)$ decays exponentially to zero
S. Kimura, M. Matsuda, T. Masuda, S. Hondo
From neutron diffraction measurements on a quasi-1D Ising-like Co$^{\rm 2+}$ spin compound BaCo$_{\rm 2}$V$_{\rm 2}$O$_{\rm 8}$, we observed an appearance of a novel type of incommensurate ordering in magnetic fields. This ordering is essentially different from the N{\' e}el-type ordering, which is expected for the classical system, and is caused by quan
Xiangjun Chen, Fang Wu, Mi Yan, Hai-Bei Li
Hyperconjugation is a basic conception of chemistry. Its straightforward effect is exhibited by the spatial delocalization characteristics of the electron density distributions or wavefunctions. Such effects on the electron wavefunctions of the highest-occupied molecular orbitals (HOMO) of two ethanol conformers are demonstrated with electron momentum spectr
Dimitra Kosta
Let X be a complete intersection of two hypersurfaces F_n and F_k in the projective space P^5 of degree n and k respectively with n >= k, such that the singularities of X are nodal and F_k is smooth. We prove that if the threefold X has at most (n+k-2)(n-1)-1 singular points, then it is factorial.
Sangtae Jeong
In this note we answer the question raised by D. Goss in [Applications of non-Archimedean integration to the $L$-series of $τ$-sheaves, {\em J. Number Theory,} 110 (2005), no. 1, 83--113] by proving that the group of locally analytic endomorphisms on the 1-units of a locally compact field of characteristic $p>0$ is isomorphic to the $p$-adic integers.
Victor Kryshkin
A method to search for dark matter by studying the interaction of accelerator beam particles with residual gas in dependence on gas pressure is proposed. The sensitivity of the method is estimated.
Jun Yin
The leading term of the ground state energy/particle of a dilute gas of bosons with mass $m$ in the thermodynamic limit is $2\pi \hbar^2 a \rho/m$ when the density of the gas is $\rho$, the interaction potential is non-negative and the scattering length $a$ is positive. In this paper, we generalize the upper bound part of this result to any interaction poten
Mass measurements in the vicinity of the rp-process and the nu p-process paths with JYFLTRAP and SHIPTRAP
nucl-exC. Weber, V. -V. Elomaa, R. Ferrer, C. Fröhlich
The masses of very neutron-deficient nuclides close to the astrophysical rp- and nu p-process paths have been determined with the Penning trap facilities JYFLTRAP at JYFL/Jyväskylä and SHIPTRAP at GSI/Darmstadt. Isotopes from yttrium (Z = 39) to palladium (Z = 46) have been produced in heavy-ion fusion-evaporation reactions. In total 21 nuclides were studied
Bernd Braunecker, Pascal Simon, Daniel Loss
The hyperfine interaction between the electron spin and the nuclear spins is one of the main sources of decoherence for spin qubits when the nuclear spins are disordered. An ordering of the latter largely suppresses this source of decoherence. Here we show that such an ordering can occur through a thermodynamic phase transition in two-dimensional (2D) Kondo-
Krzysztof Szczypiorski, Igor Margasinski, Wojciech Mazurczyk, Krzysztof Cabaj
The paper presents TrustMAS - Trusted Communication Platform for Multi-Agent Systems, which provides trust and anonymity for mobile agents. The platform includes anonymous technique based on random-walk algorithm for providing general purpose anonymous communication for agents. All agents, which take part in the proposed platform, benefit from trust and anon
David Bourqui
In the first part of this text, we define motivic Artin L-fonctions via a motivic Euler product, and show that they coincide with the analogous functions introduced by Dhillon and Minac. In the second part, we define under some assumptions a motivic Tamagawa number and show that it specializes to the Tamagawa number introduced by Peyre in the context of Mani
Melissa J. Dobbie, Brent L. Henderson, Don L. Stevens
Spatial designs for monitoring stream networks, especially ephemeral systems, are typically non-standard, `sparse' and can be very complex, reflecting the complexity of the ecosystem being monitored, the scale of the population, and the competing multiple monitoring objectives. The main purpose of this paper is to present a review of approaches to spatia
Valentin Kopchev, Petko Nedialkov, Georgy Petrov
Based on 2MASS J and Ks photometry for the open star clusters NGC 2383, NGC 2384,Pismis 6, Pismis 8 and using color magnitude diagrams with isochrones fit, we found an age of $\log ({age})$ = 8.3 (200 $\pm$ 6 Myr) for NGC 2383 and $\log ({age})$ = 6.9 (8 $\pm$ 6 Myr) for NGC 2384. For Pismis 6 and Pismis 8 we adopted a range of $\log ({age})$ = 6 - 7 (1 - 10
B. Lonetti, J. Kohlbrecher, L. Willner, J. K. G. Dhont
The linear and non-linear dynamic response to an oscillatory shear flow of giant wormlike micelles consisting of Pb-Peo block copolymers is studied by means of Fourier transform rheology. Experiments are performed in the vicinity of the isotropic-nematic phase transition concentration, where the location of isotropic-nematic phase transition lines is determi
AGILE detection of variable gamma-ray activity from the blazar S5 0716+714 in September-October 2007
astro-phA. W. Chen, F. D'Ammando, M. Villata, C. M. Raiteri
We report the gamma-ray activity from the intermediate BL Lac S5 0716+714 during observations acquired by the AGILE satellite in September and October 2007. These detections of activity were contemporaneous with a period of intense optical activity, which was monitored by GASP-WEBT. This simultaneous optical and gamma-ray coverage allows us to study in detai
Two-dimensional fluid with competing interactions exhibiting microphase separation: theory for bulk and interfacial properties
cond-mat.softA. J. Archer
Colloidal particles that are confined to an interface such as the air-water interface are an example of a two-dimensional fluid. Such dispersions have been observed to spontaneously form cluster and stripe morphologies in certain systems with isotropic pair potentials between the particles, due to the fact that the pair interaction between the colloids has c
Jinhua Shen, Tuanhui Zhou, Haisheng Ji, Na Wang
This Letter is to investigate the physics of a newly discovered phenomenon -- contracting flare loops in the early phase of solar flares. In classical flare models, which were constructed based on the phenomenon of expansion of flare loops, an energy releasing site is put above flare loops. These models can predict that there is a vertical temperature gradie
Christian Wozar, Tobias Kaestner, Bjoern H. Wellegehausen, Andreas Wipf
We study effective Polyakov loop models for SU(N) Yang-Mills theories at finite temperature. In particular effective models for SU(3) YM with an additional adjoint Polyakov loop potential are considered. The rich phase structure including a center and anti-center directed phase is reproduced with an effective model utilizing the inverse Monte-Carlo method. T
DaeKil Park, Sayatnova Tamaryan, Jin-Woo Son
The bipartite quantum teleportation with a three-qubit mixture of GHZ and W states as a quantum channel is discussed. When the quantum channel is a mixed state consisting of the GHZ state plus small perturbed W state, the entanglement of the channel becomes zero when the average fidelity $\bar{F}_{GHZ}$ is less than 0.775. This means that the mixed state can
A. Imerito, D. Coward, R. Burman, D. Blair
We compare the detection rates and redshift distributions of low-luminosity (LL) GRBs localized by Swift with those expected to be observed by the new generation satellite detectors on GLAST (now Fermi) and, in future, EXIST. Although the GLAST burst telescope will be less sensitive than Swift's in the 15--150 keV band, its large field-of-view implies th
Myles Hollander
Jayaram Sethuraman was born in the town of Hubli in Bombay Province (now Karnataka State) on October 3, 1937. His early years were spent in Hubli and in 1950 his family moved to Madras (now renamed Chennai). He graduated from Madras University in 1957 with a B.Sc. (Hons) degree in statistics and he earned his M.A. degree in statistics from Madras University
Daniel Commenges
We give an overview of statistical models and likelihood, together with two of its variants: penalized and hierarchical likelihood. The Kullback-Leibler divergence is referred to repeatedly, for defining the misspecification risk of a model, for grounding the likelihood and the likelihood crossvalidation which can be used for choosing weights in penalized li
A. Di Giacomo, L. Lepori, F. Pucci
We study monopoles and corresponding 't Hooft tensor in a generic gauge theory. This issue is relevant to the understanding of the color confinement in terms of dual symmetry.
M. E. Cluver, T. H. Jarrett, P. N. Appleton, R. C. Kraan-Korteweg
HIZOA J0836-43 is an extreme gas-rich ($M_{\rm{HI}}$=7.5$\times10^{10} M_{\sun}$) disk galaxy which lies hidden behind the strongly obscuring Vela region of the Milky Way. Utilizing observations from the {\it Spitzer Space Telescope}, we have found it to be a luminous infrared starburst galaxy with a star formation rate of $\sim 21 M_{\sun} \rm{yr^{-1}}$, ar
Jiao Wang, Antonio M. Garcia-Garcia
We investigate Anderson localization in a three dimensional (3d) kicked rotor. By a finite size scaling analysis we have identified a mobility edge for a certain value of the kicking strength $k = k_c$. For $k > k_c$ dynamical localization does not occur, all eigenstates are delocalized and the spectral correlations are well described by Wigner-Dyson statist
Coexistence of superconductivity and charge-density waves in a two-dimensional Holstein model at half-filling
cond-mat.supr-conS. Sykora, A. Hübsch, K. W. Becker
In one dimension the coupling of electrons to phonons leads to a transition from a metallic to a Peierls distorted insulated state if the coupling exceeds a critical value. On the other hand, in two dimensions the electron-phonon interaction may also lead to the formation of Cooper pairs. This competition of superconductivity and charge order (in conjunction
A. J. Archer, C. Ionescu, D. Pini, L. Reatto
We study the phase behaviour of a fluid composed of particles which interact via a pair potential that is repulsive for large inter-particle distances, is attractive at intermediate distances and is strongly repulsive at short distances (the particles have a hard core). As well as exhibiting gas-liquid phase separation, this system also exhibits phase transi
Fatemeh Ebrahimi
The anisotropy parameter of two-dimensional equilibrium clusters of site percolation process in long-range self-affine correlated structures are studied numerically. We use a fractional Brownian Motion(FBM) statistic to produce both persistent and anti-persistent long-range correlations in 2-D models. It is seen that self affinity makes the shape of percolat
Stephen M. Stigler
Karl Pearson played an enormous role in determining the content and organization of statistical research in his day, through his research, his teaching, his establishment of laboratories, and his initiation of a vast publishing program. His technical contributions had initially and continue today to have a profound impact upon the work of both applied and th
Vladimir B. Bokov
Measurement involves the determination of quantitative estimates of physical quantities from experiment, along with estimates of their associated uncertainties. Herewith an experimental system model is the key to extracting information from the experimental data. The measurement information obtained depends directly on the quality of the model. With this con
Massimo Giulietti, Gabor Korchmaros
We fill up a gap in Henn's proof concerning large automorphism groups of function fields of degree 1 over an algebraically closed field of positive characteristic.
Hiroyuki Abe, Yutaka Sakamura
We investigate 5-dimensional supergravity on S^1/Z_2 with a physical Z_2-odd vector multiplet, which yields an additional modulus other than the radion. We find additional terms in the 4-dimensional effective theory that are peculiar to the multi moduli case. Such terms can make the soft masses are non-tachyonic and almost flavor-universal at tree-level, in
Janos Englander
In this paper we prove that the center of mass of a supercritical branching-Brownian motion, or that of a supercritical super-Brownian motion tends to a limiting position almost surely, which, in a sense complements a result of Tribe on the final behavior of a critical super-Brownian motion. This is shown to be true also for a model where branching Brownian
D0 Collaboration, V. M. Abazov
We report on a search for the pair production of second generation scalar leptoquarks (LQ) in ppbar collisions at the center of mass energy sqrt(s)=1.96 TeV using a data set corresponding to an integrated luminosity of 1.0 fb-1 collected with the D0 experiment at the Fermilab Tevatron Collider. Topologies arising from the LQLQbar->muqnuq and LQLQbar->muqmuq
Arash Behzad, Mehdi Behzad, Cheryl E. Praeger
Nine variations of the concept of domination in a simple graph are identified as fundamental domination concepts, and a unified approach is introduced for studying them. For each variation, the minimum cardinality of a subset of dominating elements is the corresponding fundamental domination number. It is observed that, for each nontrivial connected graph, a
Coherent manipulation of nuclear spins in the breakdown regime of integer quantum Hall states
cond-mat.mes-hallMinoru Kawamura, Hiroyuki Takahashi, Yoshiaki Hashimoto, Shingo Katsumoto
We demonstrate a new method for electrical manipulation of nuclear spins utilizing dynamic nuclear polarization induced by quantum Hall effect breakdown. Nuclear spins are polarized and detected through the hyperfine interaction between a nuclear spin system and a two-dimensional electron system located at an interface of GaAs/AlGaAs single heterostructure.
Wendong Wang, Liqun Zhang
We obtained the $C^α$ continuity for weak solutions of a class of ultraparabolic equations with measurable coefficients of the form $${\partial_t u} = \partial_x(a(x,y,t)\partial_x u) +b_0(x,y,t)\partial_x u+b(x,y,t)\partial_y u,$$ which generalized our recent results on KFP equations.
Ma Luo, Chengguang Bao, Zhibing Li
Spin evolution of a mixture of two species of spin-1 Bose-Einstein condensates (Rb and Na) has been investigated beyond the mean field theory. Both analytical expression and numerical results on the populations of spin-components are obtained. The interference is found to depend on the initial states and the inter-species interaction sensitively. A number of
Coarse-graining stochastic biochemical networks: quasi-stationary approximation and fast simulations using a stochastic path integral technique
q-bio.MNN. A. Sinitsyn, Nicolas Hengartner, Ilya Nemenman
We propose a universal approach for analysis and fast simulations of stiff stochastic biochemical kinetics networks, which rests on elimination of fast chemical species without a loss of information about mesoscopic, non-Poissonian fluctuations of the slow ones. Our approach, which is similar to the Born-Oppenheimer approximation in quantum mechanics, follow
The Visual Orbit of the 1.1-day Spectroscopic Binary σ^2 Coronae Borealis from Interferometry at the CHARA Array
astro-phDeepak Raghavan, Harold A. McAlister, Guillermo Torres, David W. Latham
We present an updated spectroscopic orbit and a new visual orbit for the double-lined spectroscopic binary σ^2 Coronae Borealis based on radial velocity measurements at the Oak Ridge Observatory in Harvard, Massachusetts and interferometric visibility measurements at the CHARA Array on Mount Wilson. σ^2 CrB is composed of two Sun-like stars of roughly equal
Anomaly Mediation and Radius Stabilization by a Boundary Constant Superpotential in a Warped Space
hep-phNobuhito Maru, Norisuke Sakai, Nobuhiro Uekusa
We present a very simple model of the radius stabilization in a supersymmetric (SUSY) Randall-Sundrum model with a hypermultiplet and a boundary constant superpotential. A wide range of parameters where the anomaly mediation of SUSY breaking is dominated is found although there are many problematic bulk effects of SUSY breaking. A negative cosmological const
Alexander M. G. Cox, Jan K. Obłój
We consider model-free pricing of digital options, which pay out if the underlying asset has crossed both upper and lower barriers. We make only weak assumptions about the underlying process (typically continuity), but assume that the initial prices of call options with the same maturity and all strikes are known. Under such circumstances, we are able to giv
M. Mapelli, B. Moore, J. Bland-Hawthorn
It has long been known that a large fraction of disc galaxies are lopsided. We simulate three different mechanisms that can induce lopsidedness: flyby interactions, gas accretion from cosmological filaments and ram pressure from the intergalactic medium. Comparing the morphologies, HI spectrum and m=1 Fourier components, we find that all of these mechanisms
A priori Holder estimate, parabolic Harnack principle and heat kernel estimates for diffusions with jumps
math.PRZhen-Qing Chen, Takashi Kumagai
In this paper, we consider the following type of non-local (pseudo-differential) operators $\LL $ on $\R^d$: $$ \LL u(x) =\frac12 \sum_{i, j=1}^d \frac{\partial}{\partial x_i} (a_{ij}(x) \frac{\partial}{\partial x_j}) + \lim_{\eps \downarrow 0} \int_{\{y\in \R^d: |y-x|>\eps\}} (u(y)-u(x)) J(x, y) dy, $$ where $A(x)=(a_{ij}(x))_{1\leq i, j\leq d}$ is a measur