November 2007 arXiv papers — page 4
Showing 301–400 of 5,016 papers
Complete Set of Commuting Symmetry Operators for the Klein-Gordon Equation in Generalized Higher-Dimensional Kerr-NUT-(A)dS Spacetimes
hep-thArtur Sergyeyev, Pavel Krtous
We consider the Klein-Gordon equation in generalized higher-dimensional Kerr-NUT-(A)dS spacetime without imposing any restrictions on the functional parameters characterizing the metric. We establish commutativity of the second-order operators constructed from the Killing tensors found in arXiv:hep-th/0612029 and show that these operators, along with the fir
James B. Hartle, S. W. Hawking, Thomas Hertog
We consider the no-boundary proposal for homogeneous isotropic closed universes with a cosmological constant and a scalar field with a quadratic potential. In the semi-classical limit, it predicts classical behavior at late times if the initial scalar field is more than a certain minimum. If the classical late time histories are extended back, they may be si
Jacob S. Christiansen, Barry Simon, Maxim Zinchenko
We consider Jacobi matrices whose essential spectrum is a finite union of closed intervals. We focus on Szego's theorem, Jost solutions, and Szego asymptotics for this situation. This announcement describes talks the authors gave at OPSFA 2007.
Ricardo N. Oliveira, Said N. Sidki
The second author introduced notions of weak permutability and commutativity between groups and proved the finiteness of a group generated by two weakly permutable finite groups. Two groups H,K weakly commute provided there exists a bijection f: H -> K which fixes the identity element and such that h commutes with its image h^f for all h in H. The present pa
E. Abadoglu, H. Gumral
We reduced the problem of constructing bi-Hamiltonian structure in three dimensions to the solution of a Riccati equation in moving coordinates of Serret-Frenet frame. We then show that either the linearly independent solutions of the corresponding second order equation or the normal vectors of the moving frame imply two compatible Poisson structures.
Alexander S. Silbergleit, Robert V. Wagoner
We demonstrate that the corotation resonance affects only some non-axisymmetric g-mode oscillations of thin accretion disks, since it is located within their capture zones. Using a more general (weaker radial WKB approximation) formulation of the governing equations, such g-modes, treated as perfect fluid perturbations, are shown to formally diverge at the p
C. -H. Zhang, Yogesh N. Joglekar
We investigate the ground state of a balanced electron-hole system in the quantum Hall regime using mean-field theory and obtain a rich phase diagram as a function of interlayer distance d and the filling factor within a layer. We identify an excitonic condensate phase, an excitonic supersolid phase, as well as uncorrelated Wigner crystal states. We find tha
Christopher Ticknor
We explore the impact of the short range interaction on the scattering of ground state polar molecules, and study the transition from a weak to strong dipolar scattering over an experimentally reasonable range of energies and electric field values. In the strong dipolar limit, the scattering scales with respect to a dimensionless quantity defined by mass, in
An Overdensity of i-dropouts Among A Population of Excess Field Objects in the Virgo Cluster
astro-phHaojing Yan, Nimish Hathi, Rogier Windhorst
Using a set of deep imaging data obtained by the ACS on the HST shortly after its deployment, Yan, Windhorst & Cohen (2003) found a large number of F775W-band dropouts (i-dropouts), which are consistent with being galaxies at z~6. The surface density of i-dropouts thus derived, however, is an order of magnitude higher than those subsequent studies found in o
B. C. Wilhite, R. J. Brunner, C. J. Grier, D. P. Schneider
Repeat scans by the Sloan Digital Sky Survey (SDSS) of a 278 square degree stripe along the Celestial equator have yielded an average of over 10 observations each for nearly 8,000 spectroscopically confirmed quasars. Over 2500 of these quasars are in the redshift range such that the CIV emission line is visible in the SDSS spectrum. Utilising the width of th
Eduardo D. Sontag
This note discusses a theoretical issue regarding the application of the "Modular Response Analysis" method to quasi-steady state (rather than steady-state) data.
Construction of the discrete breathers and a simple physical interpretation of their existence
nlin.PSG. M. Chechin, G. S. Dzhelauhova
We present a simple numerical method for the discrete breather construction based on the idea of the pair synchronization of the particles involved in the breather vibration. It can be used for obtaining exact breather solutions in nonlinear Hamiltonian lattices of different types. We illustrate the above method using chains of the coupled Duffng oscillators
Ian J. Leary
We compute the integral cohomology rings of a family of 3-groups. As a corollary, we exhibit, for each n greater than or equal to 5, a pair of groups of order 3^n whose integral cohomology rings are isomorphic.
Ian J. Leary
For each prime p, we exhibit pairs of p-groups all of whose integral cohomology groups are isomorphic. The method used involves very little calculation. The groups are exhibited as kernels of homomorphisms from a compact Lie group G to U(1), and the main result is that kernels of `similar' elements of Hom(G,U(1)) have isomorphic integral cohomology group
Jianmin Tao, Sergei Tretiak, Jian-Xin Zhu
It is known that the adiabatic approximation in time-dependent density functional theory usually provides a good description of low-lying excitations of molecules. In the present work, the capability of the adiabatic nonempirical meta-generalized gradient approximation (meta-GGA) of Tao, Perdew, Staroverov, and Scuseria (TPSS) to describe atomic and molecula
Han Peters
We define and study when a polynomial mapping has a local or global time average. We conjecture that a polynomial f in the complex plane has a time average near a point z if and only if z is eventually mapped into a Siegel-disc of f. We prove that the conjecture holds generically, namely for those polynomials whose iterates have the maximal number of critica
Ian J. Leary
We consider the Lyndon-Hochschild-Serre spectral sequence with mod-p coefficients for a central extension with kernel cyclic of order a power of p and arbitrary discrete quotient group. For this spectral sequence the second and third differentials are known, and we give a description for the fourth differential. Using this result we deduce a similar formula
Clues to the Origin of the Mass-Metallicity Relation: Dependence on Star Formation Rate and Galaxy Size
astro-phSara L. Ellison, David R. Patton, Luc Simard, Alan W. McConnachie
We use a sample of 43,690 galaxies selected from the Sloan Digital Sky Survey Data Release 4 to study the systematic effects of specific star formation rate (SSFR) and galaxy size (as measured by the half light radius, r_h) on the mass-metallicity relation. We find that galaxies with high SSFR or large r_h for their stellar mass have systematically lower gas
Ian J Leary, Nobuaki Yagita
For each odd prime p, we exhibit p-groups G of p-rank two such that (suitably defined) Chern classes of unitary representations of G fail to generate the following rings: 1. The even degree integral cohomology of G; 2. The final page of the Atiyah-Hirzebruch spectral sequence for G; 3. The Brown-Peterson generalized cohomology of G. It follows that these gro
Ian J. Leary
We determine the mod-p cohomology rings of an infinite family of p-groups, for odd primes p, with cyclic derived subgroups. Our method involves embedding the groups in a compact Lie group of dimension one, and was suggested by P. H. Kropholler and J. Huebschmann.
Paul Lasky, Anthony Lun
We provide a covariant derivation of plasma physics coupled to gravitation by utilizing the 3+1 formulation of general relativity, including a discussion of the Lorentz force law. We then reduce the system to the spherically symmetric case and show that all regions of the spacetime can be represented in a single coordinate system, thus revoking the need for
S. M. Soskin, R. Mannella, O. M. Yevtushenko
We develop a new approach to the theoretical treatment of the separatrix chaos, using a special analysis of the separatrix map. The approach allows us to describe boundaries of the separatrix chaotic layer in the Poincaré section and transport within the layer. We show that the maximum which the width of the layer in energy takes as the perturbation frequenc
Ian J Leary
We determine the integral cohomology rings of an infinite family of p-groups, for odd primes p, with cyclic derived subgroups. Our method involves embedding the groups in a compact Lie group of dimension one, and was suggested by P H Kropholler and J Huebschmann.
Chandra Chekuri, Nitish Korula
Orienteering is the following optimization problem: given an edge-weighted graph (directed or undirected), two nodes s,t and a time limit T, find an s-t walk of total length at most T that maximizes the number of distinct nodes visited by the walk. One obtains a generalization, namely orienteering with time-windows (also referred to as TSP with time-windows)
H. Brunner, N. Cappelluti, G. Hasinger, X. Barcons
The Lockman Hole field represents the sky area of lowest Galactic line-of-sight column density N_H=5.7X10^19 cm^-2. It was observed by the XMM-Newton X-ray observatory in 18 pointings for a total of 1.16 Msec (raw EPIC pn observing time) constituting the deepest XMM-Newton exposure so far. We present a catalogue of the X-ray sources detected in the central 0
D. S. O'Brien
Many sets of polarization evolution equations have been suggested to describe the method of polarization buildup by spin filtering in storage rings. In this paper a generic system of polarization evolution equations describing spin filtering is derived and solved, then we compare and contrast this system to other descriptions of spin filtering appearing in t
C. M. Hull, R. A. Reid-Edwards
String compactifications with T-duality twists are revisited and the gauge algebra of the dimensionally reduced theories calculated. These reductions can be viewed as string theory on T-fold backgrounds, and can be formulated in a `doubled space' in which each circle is supplemented by a T-dual circle to construct a geometry which is a doubled torus bundle o
Shadyar Farhangfar
We have performed four-probe electrical transport measurements on solitary highly crystalline wires of semimetallic bismuth with aspect ratios up to 60 at room and at cryogenic temperatures. By proper choice of the substrate material and the film deposition parameters, lithographic wires with lateral dimensions of down to one single grain, $\sim 250$ nm, wer
Brian D. Storey, Lee R. Edwards, Mustafa Sabri Kilic, Martin Z. Bazant
The current theory of alternating-current electro-osmosis (ACEO) is unable to explain the experimentally observed flow reversal of planar ACEO pumps at high frequency (above the peak, typically 10-100 kHz), low salt concentration (1-1000 $μ$M), and moderate voltage (2-6 V), even if taking into account Faradaic surface reactions, nonlinear double-layer capaci
Fulvio Melia
Based on dramatic observations of the CMB with WMAP and of Type Ia supernovae with the Hubble Space Telescope and ground-based facilities, it is now generally believed that the Universe's expansion is accelerating. Within the context of standard cosmology, the Universe must therefore contain a third `dark' component of energy, beyond matter and radia
Ilkka Norros, Eero Saksman
Let S(t,t') be the sigma-algebra generated by the differences X(s)-X(s) with s,s' in the interval(t,t'), where (X_t) is the fractional Brownian motion process with Hurst index H between 0 and 1. We prove that for any two distinct t and t' the sigma-algebras S(t-a,t+a) and S(t'-a,t'+a) are asymptotically independent as a tends to 0. We
The circumstellar medium around a rapidly rotating, chemically homogeneously evolving, possible gamma-ray burst progenitor
astro-phAllard Jan van Marle, Norbert Langer, Sung-Chul Yoon, Guillermo Garcia-Segura
Rapidly rotating, chemically homogeneously evolving massive stars are considered to be progenitors of long gamma-ray bursts. We present numerical simulations of the evolution of the circumstellar medium around a rapidly rotating 20 Msol star at a metallicity of Z=0.001. Its rotation is fast enough to produce quasi-chemically homogeneous evolution. While conv
Yiguang Yan, Joel Koplik
The two-dimensional pressure driven flow of non-Newtonian power-law fluids in self-affine fracture channels at finite Reynolds number is calculated. The channels have constant mean aperture and two values $ζ$=0.5 and 0.8 of the Hurst exponent are considered. The calculation is based on the lattice-Boltzmann method, using a novel method to obtain a power-law
Sergey Mashchenko, James Wadsley, H. M. P. Couchman
Dwarf galaxies pose significant challenges for cosmological models. In particular, current models predict a dark matter density that is divergent at the center, in sharp contrast with observations which indicate an approximately constant central density core. Energy feedback, from supernova explosions and stellar winds, has been proposed as a major factor sh
J. A. Cazares, H. Garcia-Compean, V. S. Manko
The Emparan-Teo non-extremal black dihole solution is reparametrized using Komar quantities and the separation distance as arbitrary parameters. We show how the potential $A_3$ can be calculated for the magnetic analogs of this solution in the Einstein-Maxwell and Einstein-Maxwell-dilaton theories. We also demonstrate that, similar to the extreme case, the e
Properties of newly formed dust by SN2006jc based on near-to-mid infrared observation with AKARI
astro-phI. Sakon, T. Wada, Y. Ohyama, D. Ishihara
We present our latest results on near- to mid- infrared observation of SN2006jc at 200 days after the discovery using the Infrared Camera (IRC) on board $AKARI$. The near-infrared (2--5$μ$m) spectrum of SN2006jc is obtained for the first time and is found to be well interpreted in terms of the thermal emission from amorphous carbon of 800$\pm 10$K with the m
B. Bellomo, R. Lo Franco, G. Compagno
A procedure to obtain the dynamics of $N$ independent qudits ($d$-level systems) each interacting with its own reservoir, for any arbitrary initial state, is presented. This is then applied to study the dynamics of the entanglement of two qubits, initially in an extended Werner-like mixed state with each of them in a zero temperature non-Markovian environmen
Sidney van den Bergh
Traditionally globular clusters and dwarf spheroidal galaxies have been distinguished by using one or more of the following criteria: (1) mass, (2) luminosity, (3) size, (4) mass-to-light ratio and (5) spread in metallicity. However, a few recently discovered objects show some overlap between the domains in parameter space that are occupied by galaxies and c
R. Palmer, J. Scott Berg, R. Fernow, J. C. gallardo
It has been observed \cite{break} that breakdown in an 805 MHz pill-box cavi ty occurs at much lower gradients as an external axial magnetic field is inc reased. This effect was not observed with on open iris cavity. It is propose d that this effect depends on the relative angles of the magnetic and maximu m electric fields: parallel in the pill-box case; at
Enhanced high-energy neutrino emission from choked gamma-ray bursts due to meson and muon acceleration
astro-phHylke B. J. Koers, Ralph A. M. J. Wijers
It has been suggested that a potentially large fraction of supernovae could be accompanied by relativistic outflows that stall below the stellar surface. In this letter we point out that internal shocks that are believed to accelerate protons to very high energies in these flows will also accelerate secondary mesons and muons. As a result the neutrino spectr
Discovery of exceptional points in the Bose-Einstein condensation of gases with attractive 1/r-interaction
nlin.CDHolger Cartarius, Jörg Main, Günter Wunner
The extended Gross-Pitaevskii equation for the Bose-Einstein condensation of gases with attractive 1/r-interaction has a second solution which is born together with the ground state in a tangent bifurcation. At the bifurcation point both states coalesce, i.e., the energies and the wave functions are identical. We investigate the bifurcation point in the cont
Deuteron form factors in chiral effective theory: regulator-independent results and the role of two-pion exchange
nucl-thM. Pavon Valderrama, A. Nogga, E. Ruiz Arriola, D. R. Phillips
We evaluate the deuteron charge, quadrupole, and magnetic form factors using wave functions obtained from chiral effective theory ($χ$ET) when the potential includes one-pion exchange, chiral two-pion exchange, and genuine contact interactions. We study the manner in which the results for form factors behave as the regulator is removed from the $χ$ET calcula
L. S. Geng, E. Oset, L. Roca, J. A. Oller
Recent studies based on unitary chiral perturbation theory (U$χ$PT) found that the low-lying axial vector mesons can be dynamically generated due to the interaction of the pseudoscalar octet of the pion and the vector nonet of the rho. In particular, two poles in the second Riemann sheet have been associated to the nominal $K_1(1270)$ resonance. In this talk
Marcos Alvarez, Paul P. Martin
Guided by consideration of problems in 2 and 3 dimensional lattice model computation, we are led to define a number of new categories, and functors between these categories and the partition category, culminating in the introduction of two categories generalising the Temperley-Lieb category. We show how to compute practically in these categories, by giving a
S. D. Yoon, C. Vittoria, V. G. Harris, A. Widom
Employing a new experimental technique to measure magnetoelectric response functions, we have measured the magnetoelectric effect in composite films of nano granular metallic iron in anatase titanium dioxide at temperatures below 50 K. A magnetoelectric resistance is defined as the ratio of a transverse voltage to bias current as a function of the magnetic f
Dejan Stokic, Rudolf Hanel, Stefan Thurner
As a model for gene and protein interactions we study a set for molecular catalytic reactions. The model is based on experimentally motivated interaction network topologies, and is designed to capture some key statistics of gene expression statistics. We impose a non-linearity to the system by a boundary condition which guarantees non-negative concentrations
M. Gliozzi, L. Foschini, R. M. Sambruna, F. Tavecchio
Aims: We investigate the origin of X-rays and the nature of accretion flow in 4 LINERs hosted by radio galaxies, namely NGC1692, PKS0625-35, 3C88, 3C444, recently observed with XMM. Methods: We combine the results from the time-averaged spectral analysis with model-independent information from X-ray temporal and spectral variability analyses, and with additi
T. Pechacek, V. Karas
Hot spots residing on the surface of an accretion disc have been considered as a model of short-term variability of active galactic nuclei. In this paper we apply the theory of random point processes to model the observed signal from an ensemble of randomly generated spots. The influence of general relativistic effects near a black hole is taken into account
Marco Pappagallo
Recent measurements of hadronic branching fractions of D and Ds mesons, performed by the BaBar and Belle experiments at the asymmetric e+e- B factories colliders PEP II and KEKB, are reviewed.
Fabien Robineau, Nicolas Vuillerme, Jean-Pierre Orliaguet, Yohan Payan
Many applications use electrostimulation of the human skin to provide tactile sensation. The effect of electrotactile stimulations were studied on a 6x6 matrix of tactile electrodes placed on the anterior part of the tongue. The liminary threshold with continuous or discontinuous waveform and patterns with 2 or 4 electrodes was investigated. The result sugge
Silvia Onofrei
A locally truncated geometry with diagram of type affine E7 is studied. One considers a parapolar space, locally of type A_{7,4}, which is subject to an extra axiom. A covering of this space is constructed; it is proved that this covering space is a rank 6, residually connected, locally truncated diagram geometry which is a homomorphic image of a truncated b
N. B. Perkins, M. D. Nunez-Regueiro, B. Coqblin, J. R. Iglesias
We present theoretical results for the underscreened Kondo lattice model with localized S=1 spins coupled to a conduction band through a Kondo coupling, $J_K$, and interacting among them ferromagnetically. We use a fermionic representation for the spin operators and expand the Hamiltonian in terms of bosonic fields. For large values of $J_K$, we obtain a fer
B. I. Ermolaev, M. Greco, S. I. Troyan
The explicit expressions describing the structure function g_1 at arbitrary x and Q^2 are obtained. In the first place, they combine the well-known DGLAP expressions for g_1 with the total resummation of leading logarithms of x, which makes possible to cover the kinematic region of arbitrary x and large Q^2. In order to cover the small-Q^2 region the shift Q
George Rawitscher
A spectral integral method (IEM) for solving the two-body Schroedinger equation in configuration space is generalized to the calculation of the corresponding T-matrix. It is found that the desirable features of the IEM, such as the economy of mesh-points for a given required accuracy, are carried over also to the solution of the T-matrix. However the algorit
Path-Integral Renormalization Group Treatments for Many-Electron Systems with Long-Range Repulsive Interactions
cond-mat.str-elMasashi Kojo, Kikuji Hirose
A practical algorithm for many-electron systems based on the path-integral renormalization group (PIRG) method is proposed in the real-space finite-difference (RSFD) approach. The PIRG method, developed for investigating strongly correlated electron systems, has been successfully applied to some models such as Hubbard models. However, to apply this method to
Stefan Vehoff, Dieter E. A. Nuernberger, Christian A. Hummel, Wolfgang J. Duschl
We used MIDI, the mid-infrared interferometric instrument of the VLTI, to observe the massive protostellar candidate IRS 9A, located at a distance of about 7 kpc at the periphery of the NGC 3603 star cluster. Our ongoing analysis shows that MIDI almost fully resolves the object on all observed baselines, yet below 9 $μ$m we detect a steep rise of the visibil
Generalized Galitskii approach for the vertex function of a Fermi gas with resonant interaction
cond-mat.otherA. Vagov, H. Schomerus, A. Shanenko
We present a generalized Galitskii approach for the Bethe-Salpeter equation for the two-particle vertex function of a Fermi system with resonant interaction by accounting for the resonant state in the scattering potential and utilizing the universal form of the resonant scattering amplitude. The procedure can be carried out both for the normal as well as for
Ben Davies, Don F. Figer, Casey J. Law, Rolf-Peter Kudritzki
We present new high-resolution near-IR spectroscopy and OH maser observations to investigate the population of cool luminous stars of the young massive Galactic cluster RSGC1. Using the 2.293\micron CO-bandhead feature, we make high-precision radial velocity measurements of 16 of the 17 candidate Red Supergiants (RSGs) identified by Figer et al. We show that
Stefano Nicotri
I present a brief review of results obtained both in open and hidden charm spectroscopy, discussing the interpretation of $D_{sJ}(2860)$, $D_{sJ}(2700)$ and X(3872).
S. Loth, M. Wenderoth, K. Teichmann, R. G. Ulbrich
Autocompensated Si-doped GaAs is studied with cross-sectional scanning tunneling spectroscopy (X-STS). The local electronic contrasts of substitutional Si(Ga) donors and Si(As) acceptors under the (110) cleavage plane are imaged with high resolution. Si(Ga) donor atoms exhibit radially symmetric contrasts. Si(As) acceptors have anisotropic features. The anis
Boris Filippov, Serge Koutchmy
A close association between eruptive prominences and CMEs, both slow and fast CMEs, was reported in many studies. Sometimes it is possible to follow the material motion starting from the prominence (filament) activation to the CME in the high corona. Remnants of the prominence were found in the bright core of CMEs. However, detailed comparisons of the two ph
S. Yu. Igashov, V. A. Rodin, M. H. Urin, A. Faessler
A version of the pn-continuum-QRPA is outlined and applied to describe the Gamow-Teller strength distributions for $ββ$-decaying open-shell nuclei. The calculation results obtained for the pairs of nuclei $^{116}$Cd-Sn and $^{130}$Te-Xe are compared with available experimental data.
Microlensing search for extrasolar planets: observational strategy, discoveries and implications
astro-phArnaud Cassan, Takahiro Sumi, Daniel Kubas
Microlensing has proven to be a valuable tool to search for extrasolar planets of Jovian- to Super-Earth-mass planets at orbits of a few AU. Since planetary signals are of very short duration, an intense and continuous monitoring is required. This is achieved by ground-based networks of telescopes (PLANET/RoboNET, microFUN) following up targets, which are id
Prasenjit Sen
Electronic and magnetic structure of $(100)$ films of K and Cs are calculated within the plane-wave projector augmented wave (PAW) formalism of the density functional theory (DFT) using both local spin density approximation (LSDA) and the PW91 generalized gradient approximation (GGA). Only a 6 layer Cs film is found to have a ferromagnetic (FM) state which i
Razvan Tudor Radulescu
Miniaturization is a hallmark of modern technologies. Notably, this feature has not spared molecular biology and its potential applications. Towards developing more effective therapeutics against cancer, studies began to explore more than a decade ago how natural tumor suppression could be translated into antineoplastic drugs. To this end, investigators focu
Magnetoelastic and thermal effects in the BiMn2O5 lattice: a high-resolution x-ray diffraction study
cond-mat.mtrl-sciE. Granado, M. S. Eleoterio, A. F. Garcia-Flores, J. A. Souza
High-resolution synchrotron x-ray diffraction measurements were performed on single crystalline and powder samples of BiMn2O5. A linear temperature dependence of the unit cell volume was found between T_{N}=38$ K and 100 K, suggesting that a low-energy lattice excitation may be responsible for the lattice expansion in this temperature range. Between T* ~ 65
Christian de Ronde
In this article we discuss the problem of finding an interpretation of quantum mechanics which provides an objective account of physical reality. In the first place we discuss the problem of interpretation and analyze the importance of such an objective account in physics. In this context we present the problems which arise when interpreting the quantum wave
Aavishkar A. Patel
Grover's database search algorithm is the optimal algorithm for finding a desired object from an unsorted collection of items. Although it was discovered in the context of quantum computation, it is simple and versatile enough to be implemented using any physical system that allows superposition of states, and several proposals have been made in the lite
N. Ozdemir
A spherically symmetric charged ideal fluid solution of Einstein field equation is given in the presence of the cosmological constant and two well known example of this type of solution is presented. If the matter is confined in a region, the exterior spacetime is considered as RN-de Sitter (Reissner-Nordstrom de Sitter) and to complete solution matching con
Martin Kohls
Let K be an algebraically closed field. For a graded K-Algebra R, we write cmdef R:=dim R -depth R. We show that for each reductive group G (over K) which is not linearly reductive, there exists a faithful G-module V such that cmdef K[\sum_i=1^k V]^G >= k-2 for all k. We will give such a V explicitly.
Jean-Yves Brua
This paper concerns the estimation of the regression function at a given point in nonparametric heteroscedastic models with Gaussian noise or with noise having unknown distribution. In the two cases an asymptotically efficient kernel estimator is constructed for the minimax absolute error risk.
Laurence Gaume, Yoël Forterre
Background : The carnivorous plants of the genus Nepenthes, widely distributed in the Asian tropics, rely mostly on nutrients derived from arthropods trapped in their pitcher-shaped leaves and digested by their enzymatic fluid. The genus exhibits a great diversity of prey and pitcher forms and its mechanism of trapping has long intrigued scientists. The slip
L. Herrera
We explore the possible physical consequences derived from the fact that the only static and asymptotically-flat vacuum space-time possessing a regular horizon is the Schwarzschild solution (Israel theorem). If small deviations from the Schwarzschild metric are described by means of exact solutions to Einstein equations (as it should be), then for very compa
T. Schneider, A. A. Serga, B. Leven, B. Hillebrands
We demonstrate the functionality of spin-wave logic XNOR and NAND gates based on a Mach-Zehnder type interferometer which has arms implemented as sections of ferrite film spin-wave waveguides. Logical input signals are applied to the gates by varying either the phase or the amplitude of the spin waves in the interferometer arms. This phase or amplitude varia
A. Vallenari
We discuss the young population of stars and clusters in the Magellanic Clouds. We present the discovery of pre-main sequence candidates in the nebula N~11 in the Large Magellanic Clouds using HST ACS photometry. The comparison of the Colour-Magnitude diagram with pre-main sequence tracks and the presence of Spitzer objects YSO I and II suggest that the star
Increase of Thermal Resistance Between a Nanostructure and a Surface due to Phonon Multireflections
physics.class-phS. Volz, P. -O. Chapuis
The thermal resistance between a nanostructure and a half-body is calculated in the framework of particle-phonons physics. The current models approximate the nanostructure as a thermal bath. We prove that the multireflections of heat carriers in the nanostructure significantly increase resistance in contradiction with former predictions. This increase depend
Nicolas Bouleau, Jean-Yves Girard, Alain Louveau
These five lectures on undecidability were given to students with a good level in mathematics but with no special knowledge on logic. The first conference presents the formalization of mathematics with a short historical survey, the language of first order predicates and the axioms of set theory. The second and third lectures explain the incompleteness pheno
J. S. Urquhart, M. G. Hoare, S. L. Lumsden, R. D. Oudmaijer
Here we describe the Red MSX Source (RMS) survey which is the largest, systematic, galaxy-wide search for massive young stellar objects (MYSOs) yet undertaken. Mid-IR bright point sources from the MSX satellite survey have been followed-up with ground-based radio, millimetre, and infrared observations to identify the contaminating sources and characterise th
Alan G. B. Lauder
We present experimental evidence to support the widely held belief that one half of all elliptic curves have infinitely many rational points. The method used to gather this evidence is a refinement of an algorithm due to the author which is based upon rigid and crystalline cohomology.
Hendrik Weimer, Günter Mahler
We consider a two-level atom interacting with a single mode of the electromagnetic field in a cavity within the Jaynes-Cummings model. Initially, the atom is thermal while the cavity is in a coherent state. The atom interacts with the cavity field for a fixed time. After removing the atom from the cavity and applying a laser pulse the atom will be in a therm
B. A. H. Huisman, P. G. Bolhuis, A. Fasolino
We report Monte Carlo simulations of the self-assembly of supramolecular polymers based on a model of patchy particles. We find a first-order phase transition, characterized by hysteresis and nucleation, toward a solid bundle of polymers, of length much greater than the average gas phase length. We argue that the bundling transition is the supramolecular equ
Quantum and classical multiple scattering effects in spin dynamics of cavity polaritons
cond-mat.mes-hallM. M. Glazov, L. E. Golub
The transport properties of exciton-polaritons are studied with allowance for their polarization. Both classical multiple scattering effects and quantum effects such as weak localization are taken into account in the framework of a generalized kinetic equation. The longitudinal-transverse (TE-TM) splitting of polariton states which plays role analogous to th
Delia Ionescu-Kruse
We describe the physical hypotheses underlying the derivation of an approximate model of water waves. For unidirectional surface shallow water waves moving over an irrotational flow as well as over a non-zero vorticity flow, we derive the Camassa-Holm equation by an interplay of variational methods and small-parameter expansions.
Theory of fluorescence correlation spectroscopy at variable observation area for two-dimensional diffusion on a meshgrid
cond-mat.stat-mechNicolas Destainville
It has recently been proposed, with the help of numerical investigations, that fluorescence correlation spectroscopy at variable observation area can reveal the existence of a meshgrid of semi-permeable barriers hindering the two-dimensional diffusion of tagged particles, such as plasmic membrane constituents. We present a complete theory confirming and acco
Marc Kesseböhmer, Bernd O. Stratmann
In this paper we give non-trivial applications of the thermodynamic formalism to the theory of distribution functions of Gibbs measures (devil's staircases) supported on limit sets of finitely generated conformal iterated function systems in $\R$. For a large class of these Gibbs states we determine the Hausdorff dimension of the set of points at which t
Ady Stern
The dichotomy between fermions and bosons is at the root of many physical phenomena, from metallic conduction of electricity to super-fluidity, and from the periodic table to coherent propagation of light. The dichotomy originates from the symmetry of the quantum mechanical wave function to the interchange of two identical particles. In systems that are conf
A high resolution scintillating fiber tracker with SiPM readout for the PEBS experiment
physics.ins-detH. Gast, R. Greim, T. Kirn, G. Roper Yearwood
Using thin scintillating fibers with Silicon Photomultiplier (SiPM) readout a mo dular high-resolution charged-particle tracking detector has been designed. The fiber modules consist of 2 x 5 layers of 128 round multiclad scintillating fiber s of 0.250mm diameter. The fibers are read out by four SiPM arrays (8mm x 1mm) e ach on either end of the module.
David T. F. Weldrake, Daniel D. R. Bayliss
We have conducted a wide-field photometric survey in a single 52'x52' field towards the Lupus Galactic Plane in an effort to detect transiting Hot Jupiter planets. The planet Lupus-TR-3b was identified from this work. The dataset also led to the detection of 494 field variables, all of which are new discoveries. This paper presents an overview of the
Delia Ionescu-Kruse
We describe the physical hypothesis in which an approximate model of water waves is obtained. For an irrotational unidirectional shallow water flow, we derive the Camassa-Holm equation by a variational approach in the Lagrangian formalism.
Juraj Boháčik, Peter Prešnajder
We discuss the problem of an effective descriptions of the phase transition phenomena in the pure gluodynamics in SU(2) symmetric QCD. We choose the method of calculation following the conjecture that the infrared sector of the theory possesses the same confinement characteristic as the full theory. We show, that analytic descriptions of this phenomena is be
Alex E. Bernardini
We propose a generalized way to formally obtain the gauge invariance of the kinetic part of a field Lagrangian over which a gauge transformation ruled by an $SU(n)_{U} \otimes SU(m)_{V}$ coupling symmetry is applied. As an illustrative example, we employ such a formal construction for reproducing the standard model Lagrangian. This generalized formulation is
Martin Schlichenmaier, Oleg K. Sheinman
Lax operator algebras were introduced by Krichever and Sheinman as a further development of I.Krichever's theory of Lax operators on algebraic curves. These are almost-graded Lie algebras of current type. In this article local cocycles and associated almost-graded central extensions are classified. It is shown that in the case that the corresponding fini
L. Leon Chen, Christian Beck
We introduce a superstatistical model for the progression statistics of malignant cancer cells. The metastatic cascade is modeled as a complex nonequilibrium system with several macroscopic pathways and inverse-chi-square distributed parameters of the underlying Poisson processes. The predictions of the model are in excellent agreement with observed survival
Daniela Alic, Carles Bona, Carles Bona-Casas
We present a new numerical dissipation algorithm, which can be efficiently used in combination with centered finite-difference methods. We start from a formulation of centered finite-volume methods for Numerical Relativity, in which third-order space accuracy can be obtained by employing just piecewise-linear reconstruction. We obtain a simplified version of
Proceedings to the 10th Workshop 'What Comes Beyond the Standard Models', Bled, July 17. - 27., 2007, Slovenia
hep-phD. Bennett, G. Bregar, M. Breskvar, V. V. Dvoeglazov
Contents: 1. Finestructure Constants at the Planck Scale from Multiple Point Principle (D.L.Bennett, L.V. Laperashvili and H.B. Nielsen) 2. Random Dynamics in Starting Levels (D. Bennett, A. Kleppe in H.B. Nielsen), 3. Families of Quarks and Leptons and Their Mass Matrices from the Approach Unifying Spins and Charges: Prediction for the Fourth Family (G. Bre
Marco Castrillon Lopez, Mark J. Gotay, Jerrold E. Marsden
We show how to "concatenate" variational principles over different bases into one over a single base, thereby providing a unified Lagrangian treatment of interacting systems. As an example we study a Klein-Gordon field interacting with a mesically charged particle. We employ our method to give a novel group-theoretic derivation of the kinetic stress-
Cristina Zambon
In this talk some classical and quantum aspects concerning a special kind of integrable defect - called a jump-defect - will be reviewed. In particular, recent results obtained in an attempt to incorporate this defect in the affine Toda field theories, in addition to the sine-Gordon model, will be presented.
Reply to the Comment on "Influence of protons on the capture of electrons by the nuclei of 7Be in the Sun"
astro-phV. B. Belyaev, M. Tater, E. Truhlik
We show that the arguments against our paper raised by B. Davids et al. are either irrelevant or incorrect.
P. Degroote, D. Bodewits, M. Reyniers
The appearance of folding ion rays in cometary comae is still not very well understood, so our aim is to gain more insight into the role of the local solar wind in the formation of these structures. Comet C/2004 Q2 (Machholz) was intensively monitored during its closest approach to Earth (January 2005) with the CCD camera Merope mounted on the Flemish 1.2m M
Romesh K. Kaul
Holst action containing Immirzi parameter for pure gravity is generalised to the supergravity theories. Supergravity equations of motion are not modified by such generalisations, thus preserving supersymmetry. Dependence on the Immirzi parameter does not emerge in the classical equations of motion. This is in contrast with the recent observation of Perez and