April 2009 arXiv papers — page 39

Ng. Ibohal, Ngangbam Ishwarchandra, K. Yugindro Singh

In this paper we present an exact solution of Einstein's fields equations describing dark matter possessing dark energy with negative pressure and energy equation of state parameter having minus sign.

Bruce C. Berndt, Atul Dixit

In 'The Lost Notebook and Other Unpublished Papers' of Ramanujan are present some manuscripts of Ramanujan in the handwriting of G. N. Watson which are 'copied from loose papers'. We present a proof of a beautiful formula of Ramanujan in one of these manuscripts, namely a transformation formula involving the Gamma function and Riemann Zeta fu

Matthew R DePies, Craig J Hogan

A new candidate source of gravitational radiation is described: the nearly-perfect harmonic series from individual loops of cosmic string. It is argued that theories with light cosmic strings give rise to a population of numerous long-lived stable loops, many of which cluster gravitationally in galaxy halos along with the dark matter. Each cosmic string loop

S. M. Huang, Y. Tokura, H. Akimoto, K. Kono

We investigated the electron transport property of the InGaAs/GaAs double quantum dots, the electron g-factors of which are different from each other. We found that in a magnetic field, the resonant tunneling is suppressed even if one of the Zeeman sublevels is aligned. This is because the other misaligned Zeeman sublevels limit the total current. A finite b

Naomichi Hatano, Tatsuro Kawamoto, Joshua Feinberg

We provide probabilistic interpretation of resonant states. This we do by showing that the integral of the modulus square of resonance wave functions (i.e., the conventional norm) over a properly expanding spatial domain is independent of time, and therefore leads to probability conservation. This is in contrast with the conventional employment of a bi-ortho

K. -S. Kim, C. Pepin

We develop the quantum Boltzman equation approach for the Kondo breakdown quantum critical point, involved with two bands for conduction electrons and localized fermions. Particularly, the role of vertex corrections in transport is addressed, crucial for non-Fermi liquid transport of temperature linear dependence. Only one band of spinons may be considered f

Todd A. Oliynyk

We show that for two dimensional manifolds M with negative Euler characteristic there exists subsets of the space of smooth Riemannian metrics which are invariant and either parabolic or backwards-parabolic for the 2nd order RG flow. We also show that solutions exists globally on these sets. Finally, we establish the existence of an eternal solution that has

Yasunobu Uchiyama, Takaaki Tanaka, Tadayuki Takahashi, Koji Mori

We observed PSR B1259-63, a young non-accreting pulsar orbiting around a Be star SS 2883, eight times with the Suzaku satellite in 2007, to characterize the X-ray emission arising from the interaction between a pulsar relativistic wind and Be star outflows. The X-ray spectra showed a featureless continuum in 0.6-10 keV, modeled by a power law with a wide ran

Stanislav Smirnov

We introduce canonical antisymmetric quasiconformal maps, which minimize the quasiconformality constant among maps sending the unit circle to a given quasicircle. As an application we prove Astala's conjecture that the Hausdorff dimension of a $k$-quasicircle is at most $1+k^2$.

Grzegorz Chimczak, Ryszard Tanaś

We propose a protocol of the long-distance atomic state teleportation via cavity decay, which allows for high-fidelity teleportation even with currently available optical cavities. The protocol is based on the scheme proposed by Bose \emph{et al.} [Phys. Rev. Lett. {\textbf{83}}, 5158 (1999)] but with one important modification: it employs non-maximally-enta

J. Melbourne, S. Bussman, K. Brand, V. Desai

A simple optical to mid-IR color selection, R-[24] > 14, i.e. f_nu(24) / f_nu(R) > 1000, identifies highly dust obscured galaxies (DOGs) with typical redshifts of z~2 +/- 0.5. Extreme mid-IR luminosities (L_{IR} > 10^{12-14}) suggest that DOGs are powered by a combination of AGN and star formation, possibly driven by mergers. In an effort to compare their ph

Oleg Pikhurko

Let c(G) be the smallest number of edges we have to test in order to determine an unknown acyclic orientation of the given graph G in the worst case. For example, if G is the complete graph on n vertices, then c(G) is the smallest number of comparisons needed to sort n numbers. We prove that c(G)\le (1/4+o(1))n^2 for any graph G on n vertices, answering in t

Navin Goyal, Luis Rademacher

We show that learning a convex body in $\RR^d$, given random samples from the body, requires $2^{Ω(\sqrt{d/\eps})}$ samples. By learning a convex body we mean finding a set having at most $\eps$ relative symmetric difference with the input body. To prove the lower bound we construct a hard to learn family of convex bodies. Our construction of this family is

Yaming Yu

An asymptotic series in Ramanujan's second notebook (Entry 10, Chapter 3) is concerned with the behavior of the expected value of $ϕ(X)$ for large $λ$ where $X$ is a Poisson random variable with mean $λ$ and $ϕ$ is a function satisfying certain growth conditions. We generalize this by studying the asymptotics of the expected value of $ϕ(X)$ when the dist

Pawel Hitczenko, Svante Janson

In this paper we use a probabilistic approach to derive the expressions for the characteristic functions of basic statistics defined on permutation tableaux. Since our expressions are exact, we can identify the distributions of basic statistics (like the number of unrestricted rows, the number of rows, and the number of 1s in the first row) exactly. In all t

P. Viana Almeida, N. C. Santos, C. Melo, M. Ammler-von Eiff

The recently discovered coeval, moving groups of young stellar objects in the solar neighborhood represent invaluable laboratories to study recent star formation and to search for high metallicity stars which can be included in future exo-planet surveys. In this study we derived through an uniform and homogeneous method stellar atmospheric parameters and abu

W. Adam

The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracke

Don Colladay, Patrick McDonald

The one-loop renormalizability of the electroweak sector of the Standard Model Extension with Lorentz violation is studied. Functional determinants are used to calculate the one-loop contributions of the higgs, gauge bosons and fermions to the one-loop effective action. The results are consistent with multiplicative renormalization of the SME coupling consta

J. M. Rathborne, A. M. Johnson, J. M. Jackson, R. Y. Shah

The Boston University-Five College Radio Astronomy Observatory (BU-FCRAO) Galactic Ring Survey (GRS) of 13 CO (1-0) emission covers Galactic longitudes 18 deg < l < 55.7 deg and Galactic latitudes |b| <= 1 deg. Using the SEQUOIA array on the FCRAO 14m telescope, the GRS fully sampled the 13 CO Galactic emission (46 arcsec angular resolution on a 22 arcsec gr

J. M. F. Bassalo, P. T. S. Alencar, A. Nassar, M. Cattani

In this work we study the Ramsauer-Townsend effect.First, we use the Quantum Mechanical Formalism of Schrodinger. After, it is calculated with the Quantum Mechanical Formalism of de Broglie-Bohm. In this case, we use the Kostin equation, taking into account the energy dissipation of the electrons scattered by sharp edged potential wells.

Jerome K Vanclay

Empirical observations suggest that in pure even-aged forests, the mean diameter of forest trees (D, diameter at breast height, 1.3 m above ground) tends to remain a constant proportion of stand height (H, average height of the largest trees in a stand) divided by the logarithm of stand density (N, number of trees per hectare): D = beta (H-1.3)/Ln(N). Thinni

Mark W. Keller, A. B. Kos, T. J. Silva, W. H. Rippard

We measure oscillator phase from the zero crossings of the voltage vs. time waveform of a spin torque nanocontact oscillating in a vortex mode. The power spectrum of the phase noise varies with Fourier frequency $f$ as $1/f^2$, consistent with frequency fluctuations driven by a thermal source. The linewidth implied by phase noise alone is about 70 % of that

Andreas Johann Raab

In the first part of our generalized ergodic theory we introduced Cantor-systems, when we managed to prove the generalized ergodic theorem 3.3. The first component of a Cantor-system is a group of the flow and its second component is a set of sets covering the phase-space. Now we continue and we first come across the resistence of the term of metric sensitiv

Yumi Choi, Tomotsugu Goto, Suk-Jin Yoon

Strong Balmer absorption lines and the lack of Ha and [OII] emission lines signify that E+As are post-starburst systems. Recent studies suggest that E+As may undergo the transition from the `blue cloud&#39; to the `red sequence&#39; and eventually migrate to red sequence ETGs. An observational validation of this scenario is to identify the intervening galaxy

Jay D. Sau, S. R. Leslie, D. M. Stamper-Kurn, Marvin L. Cohen

Recent experimental studies of $^{87}$Rb spinor Bose Einstein condensates have shown the existence of a magnetic field driven quantum phase transition accompanied by structure formation on the ferromagnetic side of the transition. In this theoretical study we examine the dynamics of the unstable modes following the transition taking into account the effects

Zakirjon Kanokov, Juern W. P. Schmelzer, Avazbek K. Nasirov

An analysis of a variety of existing experimental data leads to the conclusion on the existence of a resonance mechanism allowing weak magnetic fields to affect biological processes. These fields may either be static magnetic fields comparable in magnitude with the magnetic field of the earth or weak ultra-low frequency time-dependent fields. So far, a gener

Semeon Bogatyi, Jan Fricke, Elena Kudryavtseva

Let M and N be two closed (not necessarily orientable) surfaces, and f a continuous map from M to N. By definition, the minimal multiplicity MMR[f] of the map f denotes the minimal integer k having the following property: f can be deformed into a map g such that the number |g^{-1}(c)| of preimages of any point c in N under g is at most k. We calculate MMR[f]

Guillaume Vincent, Orfan Zahraa

Heterogeneous photocatalysis is an interesting alternative for the purification, decontamination and smell abatment of air. In the present work, the photocatalytic oxidation of 2-butanone (MEK : methyl ethyle ketone) is investigated, this low molecular mass product being the source of serious smell pollution. The influence of light and of the pollutant conce

Jérôme Jaffré, Amel Sboui

For a two-phase (liquid-gas) two-component (water-hydrogen) system in porous media we discuss the formulation of the possible dissolution of hydrogen in the liquid phase. We show how Henry&#39;s law fits in a phase diagram. Then the problem is formulated as a set of nonlinear partial differential equations with complementarity constraints.

Anne Bauval, Daciberg L Goncalves, Claude Hayat, Maria Herminia de Paula Leite Mello

Starting with an O(2)-principal fibration over a closed oriented surface F_g, g>=1, a 2-fold covering of the total space is said to be special when the monodromy sends the fiber SO(2) = S^1 to the nontrivial element of Z_2. Adapting D Jonhson&#39;s method [Spin structures and quadratic forms on surfaces, J London Math Soc, 22 (1980) 365-373] we define an act

Arian Maleki

There is a recent surge of interest in developing algorithms for finding sparse solutions of underdetermined systems of linear equations $y = Φx$. In many applications, extremely large problem sizes are envisioned, with at least tens of thousands of equations and hundreds of thousands of unknowns. For such problem sizes, low computational complexity is param

M. Brozos-Vazquez, P. Gilkey, S. Nikcevic

We study geometric realization questions of curvature in the affine, Riemannian, almost Hermitian, almost para Hermitian, almost hyper Hermitian, almost hyper para Hermitian, Hermitian, and para Hermitian settings. We also express questions in Ivanov-Petrova geometry, Osserman geometry, and curvature homogeneity in terms of geometric realizations.

Christoph A. Stephan

In this publication we will implement the inverse Seesaw mechanism into the noncommutative framework on the basis of the AC-extension of the Standard Model. The main difference to the classical AC model is the chiral nature of the AC fermions with respect to a U(1) extension of the Standard Model gauge group. It is this extension which allows us to couple th

Ahmad Ali, Melih Turgut

In this work, notion of a slant helix is extended to space E$^n$. Necessary and sufficient conditions to be a slant helix in the Euclidean $n-$space are presented. Moreover, we express some integral characterizations of such curves in terms of curvature functions.

Bjoern Grohmann

A new 4-pass Key-Agreement Protocol is presented. The security of the protocol mainly relies on the existence of a (polynomial-computable) One-Way-Function and the supposed computational hardness of solving a specific system of equations.

M. Schoeck, S. Els, R. Riddle, W. Skidmore

As part of the conceptual and preliminary design processes of the Thirty Meter Telescope (TMT), the TMT site testing team has spent the last five years measuring the atmospheric properties of five candidate mountains in North and South America with an unprecedented array of instrumentation. The site testing period was preceded by several years of analyses se

Apostolos Pilaftsis

This is a brief review on the scenario of baryogenesis through leptogenesis. Leptogenesis is an appealing scenario that may relate the observed baryon asymmetry in the Universe to the low-energy neutrino data. In this review talk, particular emphasis is put on recent developments on the field, such as the flavourdynamics of leptogenesis and resonant leptogen

Aaron Parsons, Dan Werthimer, Donald Backer, Tim Bastian

Time-to-science is an important figure of merit for digital instrumentation serving the astronomical community. A digital signal processing (DSP) community is forming that uses shared hardware development, signal processing libraries, and instrument architectures to reduce development time of digital instrumentation and to improve time-to-science for a wide

Bernd A. Berg, Hao Wu

We study the performance of MPI checkerboard code for SU(3) lattice gauge theory as function of the number of MPI processes, which run in parallel on an identical number of CPU cores. Computing platforms explored are a small PC cluster at FSU and the Cray at NERSC.

Thomas Baird, Yi Lin

Consider an effective Hamiltonian torus action $T\times M \to M$ on a topologically twisted,generalized complex manifold $M$ of dimension $2n$. We prove that the $rank(T) \leq n-2$ and that the topological twisting survives Hamiltonian reduction. We then construct a large new class of such actions satisfying $rank(T) = n-2$, using a surgery procedure on tori

Grigori G. Amosov, Vladimir I. Man&#39;ko

We investigate the dependence of the center-of-mass tomogram of a system with many degrees of freedom $N$ on the Planck constant $\hbar $. It is shown that to use the central limit theorem under taking the limit $N\to +\infty $ one should keep the energy of the system to be constant. In the case, the resulting distribution is Gaussian if the initial distribu

Boris Baeumer, Mark M. Meerschaert, Erkan Nane

Zolotarev proved a duality result that relates stable densities with different indices. In this paper, we show how Zolotarev duality leads to some interesting results on fractional diffusion. Fractional diffusion equations employ fractional derivatives in place of the usual integer order derivatives. They govern scaling limits of random walk models, with pow

Manuel Nunez-Regueiro

Examination of the electrical resistivities of iron pnictides shows that they can be accounted by conduction by polarons. Their activation energies show a linear behaviour with the critical temperatures of the spin density waves (SDW), T*, as both vary with pressure. The slope matches the ratio SDW gap to T*, while the intercept can be related to the transit

Yanier Crespo, Alessandro Laio, Giuseppe E. Santoro, Erio Tosatti

We present a history-dependent Monte Carlo scheme for the efficient calculation of the free-energy of quantum systems, inspired by the Wang-Landau sampling and metadynamics method. When embedded in a path integral formulation, it is of general applicability to a large variety of Hamiltonians. In the two-dimensional quantum Ising model, chosen here for illust

Brian Jackson, Rory Barnes, Richard Greenberg

The distribution of the orbits of close-in exoplanets shows evidence for on-going removal and destruction by tides. Tides raised on a planet&#39;s host star cause the planet&#39;s orbit to decay, even after the orbital eccentricity has dropped to zero. Comparison of the observed orbital distribution and predictions of tidal theory show good qualitative agree

V. Soma, P. Bozek

We calculate thermodynamic quantities in symmetric nuclear matter within the self-consistent Green&#39;s functions method including three-body forces. The thermodynamic potential is computed directly from a diagrammatic expansion, implemented with the CD-Bonn and Nijmegen nucleon-nucleon potentials and the Urbana three-body forces. We present results for ent

Laurianne Vagharchakian, Frederic Restagno, Liliane Leger

In order to characterize very weak adhesive surfaces, we have developed a quantitative test inspired by the Johnson, Kendall, and Roberts adhesion test for soft adhesives, which relies on the formation and then the rupture of a capillary bridge between the surface to be tested and a liquid bath. Both the shape and the kinetics of breakage of the capillary br

Carolin B. Braeuninger, Marco Cirelli

We study the fluxes of anti-deuterons that could be produced by annihilations in the galactic halo of Dark Matter particles with multi-TeV mass and a large annihilation cross section, as indicated by the recent PAMELA results. The model of Minimal Dark Matter (MDM) is an example in this category. We find that the fluxes are well within the reach of planned e

Xiao-Peng Chen, Li-Yan Wu, Yuan-Ling Ye

Let $(X, \{w_j \}_{j=1}^m, \{p_j \}_{j=1}^m)$ ($2 \leq m < \infty$) be a contractive iterated function system (IFS), where $X$ is a compact subset of ${\Bbb{R}}^d$. It is well known that there exists a unique nonempty compact set $K$ such that $K=\bigcup_{j=1}^m w_j(K)$. Moreover, the Ruelle operator on $C(K)$ determined by the IFS $(X, \{w_j \}_{j=1}^m, \{p

Jennifer Hatchell, Michael M. Dunham

Molecular outflows provide an alternative method of identifying protostellar cores, complementary to recent mid-infrared studies. Continuing our studies of Perseus, we investigate whether all Spitzer-identified protostars, and particularly those with low luminosities, drive outflows, and if any new protostellar cores (perhaps harbouring low-mass sources) can

Miloje M. Rakocevic

It is presented that the positions of amino acids within Genetic Code Table follow from strict their physical and chemical properties as well as from a pure formal determination by the Golden mean.

P. V. Shevchenko

An efficient conditioning technique, the so-called Brownian Bridge simulation, has previously been applied to eliminate pricing bias that arises in applications of the standard discrete-time Monte Carlo method to evaluate options written on the continuous-time extrema of an underlying asset. It is based on the simple and easy to implement analytic formulas f

Subhash Kak

We provide textual evidence on divisibility and primality in the ancient Vedic texts of India. Concern with divisibility becomes clear from the listing of all the fifteen pairs of divisors of the number 720. The total number of pairs of divisors of 10,800 is also given. The motivation behind finding the divisors was the theory that the number of divisors of

Gheorghe Mihai

General physics approach is applied to analysis of power components in electrical systems under sinusoidal and non-sinusoidal conditions. Physical essence of active, reactive and distorting powers are determinate. It is shown that the all three powers are the different aspects of the same physical phenomenon: mechanical action per time of Coulomb forces or i

Patricia Reynaud-Bouret, Vincent Rivoirard

In this paper, we deal with the problem of calibrating thresholding rules in the setting of Poisson intensity estimation. By using sharp concentration inequalities, oracle inequalities are derived and we establish the optimality of our estimate up to a logarithmic term. This result is proved under mild assumptions and we do not impose any condition on the su

Shuqin Zhong, Zhi Ma, Yajie Xu, Xing Lv

This paper studies the construction for quantum codes with parameters $((n,K,d))_{p}$ by use of an \textit{n}-variable logic function with APC distance $d&#39;\ge 2$ over ${\rm {\mathbb F}}_{p} $, where $d$ is related to $d&#39;$. We obtain $d\le d&#39;$ and the maximal $K$ for all $d=d&#39;-k$, $0\le k\le d&#39;-2$. We also discuss the basic states and the

P. Selvelli, A. Cassatella, R. Gilmozzi, R. Gonzalez-Riestra

By various methods, we obtained L$_{disk}$ $\sim$ 70 L$_{\odot}$ and $\dot{M}$ $\sim$1.1 $\times$ 10$^{-8}$ M$_{\odot}$yr$^{-1}$. These values were about twice as high in the pre-1966-outburst epoch. This allowed the first direct estimate of the total mass accreted before outburst, M$_{accr}$=$\dot{M}_{pre-OB}$ $\cdot Δ$t, and its comparison with the critica

Jaime Sanudo, Ricardo Lopez-Ruiz

In this work, the calculation of a statistical measure of complexity and the Fisher-Shannon information is performed for all the atoms in the periodic table. Non-relativistic and relativistic cases are considered. We follow the method suggested in [C.P. Panos, N.S. Nikolaidis, K. Ch. Chatzisavvas, C.C. Tsouros, arXiv:0812.3963v1] that uses the fractional occ

Jaeyoo Choy, Hahng-Yun Chu, Min Kyu Kim

Let $M$ be a manifold with a volume form $ω$ and $f : M \to M$ be a diffeomorphism of class $\mathcal{C}^1$ that preserves $ω$. In this paper, we do \textit{not} assume $f$ is $\mathcal{C}^1$-generic. We have two main themes in the paper: (1) the chain recurrence; (2) relations among recurrence points, homoclinic points, shadowability and hyperbolicity. For

Kimberly Hopkins

In this paper we formulate a conjecture which partially generalizes the Gross-Kohnen-Zagier theorem to higher weight modular forms. For f in S_k(N) satisfying certain conditions, we construct a map from the Heegner points of level N to a complex torus defined by f. We define higher weight analogues of Heegner divisors on this torus. We conjecture they all li

O. Bienaymé

We define new potential-density pairs and examine the impact of the potential flattening on the vertical velocity ellipsoid tilt, $δ$. By means of numerical integrations and analytical calculations, we estimate $δ$ in a variety of galactic potentials. We show that at 1 kpc above the Galactic plane at the solar radius, $δ$ can differ by 5 degrees, depending o

L. -W. Siu, J. W. Holt, T. T. S. Kuo, G. E. Brown

We study the equation of state for symmetric nuclear matter using a ring-diagram approach in which the particle-particle hole-hole ($pphh$) ring diagrams within a momentum model space of decimation scale $Λ$ are summed to all orders. The calculation is carried out using the renormalized low-momentum nucleon-nucleon (NN) interaction $V_{low-k}$, which is obta

Diego Carrascal, Lucas Fernandez-Seivane, Jaime Ferrer

We present a theoretical study of the magnetic properties of dicyclopentadienyl metallocene and phthalocyanine molecules, that contain the transition metal atoms M = Fe, Co, Ni, Cu, Zn, Ir, Pt and Au. Our most important prediction is that gold and copper molecules are magnetic. We find that the magnetism of these molecules is fairly unconventional: the gold

Partha Goswami

A momentum space, mean field d-density wave (DDW) Hamiltonian is investigated self-consistently. The pseudo-gapped(PG)state of YBCO is assumed to correspond to the pure DDW state. A relation between thermodynamic potential of the system and certain spectral weight functions is established. This yields an expression for entropy in DDW state in the absence of

Stefan Ohm, Christopher van Eldik, Kathrin Egberts

In recent years, Imaging Atmospheric Cherenkov Telescopes (IACTs) have discovered a rich diversity of very high energy (VHE, > 100 GeV) gamma-ray emitters in the sky. These instruments image Cherenkov light emitted by gamma-ray induced particle cascades in the atmosphere. Background from the much more numerous cosmic-ray cascades is efficiently reduced by co

Mark Demers, Paul Wright, Lai-Sang Young

We study the billiard map corresponding to a periodic Lorentz gas in 2-dimensions in the presence of small holes in the table. We allow holes in the form of open sets away from the scatterers as well as segments on the boundaries of the scatterers. For a large class of smooth initial distributions, we establish the existence of a common escape rate and norma

M. Guedel

Magnetically active stars are the sites of efficient particle acceleration and plasma heating, processes that have been studied in detail in the solar corona. Investigation of such processes in young stellar objects is much more challenging due to various absorption processes. There is, however, evidence for violent magnetic energy release in very young stel

Sovan Mitra

This paper formed part of a preliminary research report for a risk consultancy and academic research. Stochastic Programming models provide a powerful paradigm for decision making under uncertainty. In these models the uncertainties are represented by a discrete scenario tree and the quality of the solutions obtained is governed by the quality of the scenari

Luca Fanelli, Andoni Garcia

In space dimension $n\geq3$, we consider the magnetic Schrödinger Hamiltonian $H=-(\nabla-iA(x))^2$ and the corresponding Schrödinger equation i\partial_tu+Hu=0. We show some explicit examples of potentials $A$, with less than Coulomb decay, for which any solution of this equation cannot satisfy Strichartz estimates, in the whole range of Schrödinger admissi

Olja Panić, Michiel R. Hogerheijde, David Wilner, Chunhua Qi

We study the distribution and physical properties of molecular gas in the disc around the T Tauri star IM Lup on scales close to 200 AU. We investigate how well the gas and dust distributions compare and work towards a unified disc model that can explain both gas and dust emission. 12CO, 13CO, and C18O J=2-1 line emission, as well as the dust continuum at 1.

Vicent J. Martinez, Virginia Trimble

We review the present status of cosmological discoveries and how these confirm our modern cosmological model, but at the same time we try to focus on its weaknesses and inconsistencies with an historical perspective, and foresee how the on-going big cosmological projects may change in the future our view of the universe.

Francisco M. Fernandez

We show that a simple and straightforward rational approximation to the Thomas-Fermi equation provides the slope at origin with unprecedented accuracy and that relatively small Padé approximants are far more accurate than more elaborate approaches proposed recently by other authors. We consider both the Thomas-Fermi equation for isolated atoms and for atoms

S. N. Filippov, V. I. Man&#39;ko

Using the irreducible tensor-operator technique, we establish the relation between different forms of spin tomograms. Quantizer and dequantizer operators are presented in simple explicit forms and are specified for the low-spin states. The kernel of the star-product is evaluated for qubits and qutrits and its connection with a generic formula is found.

Alberto Rosso, Pierre Le Doussal, Kay Joerg Wiese

We calculate numerically the sizes S of jumps (avalanches) between successively pinned configurations of an elastic line (d=1) or interface (d=2), pulled by a spring of (small) strength m^2 in a random-field landscape. We obtain strong evidence that the size distribution, away from the small-scale cutoff, takes the form P(S) = p(S/S_m) <S>/S_m^2, where S_m:=

Andreas Kurcz, Antonio Capolupo, Almut Beige

Sonoluminescence occurs when tiny bubbles rilled with noble gas atoms are driven by a sound wave. Each cycle of the driving field is accompanied by a collapse phase in which the bubble radius decreases rapidly until a short but very strong light flash is emitted. The spectrum of the light corresponds to very high temperatures and hints at the presence of a h

Nicolas Champagnat, Pierre-Emmanuel Jabin

We study existence and uniqueness for the classical dynamics of a particle in a force field in the phase space. Through an explicit control on the regularity of the trajectories, we show that this is well posed if the force belongs to the Sobolev space $H^{3/4}$.

M. Hundertmark, F. V. Hessman, S. Dreizler

We investigate the chance of detecting proto-planetary or debris disks in stars that induce microlensing events (lenses). The modification of the light curves shapes due to occultation and extinction by the disks as well as the additional gravitational deflection caused by the additional mass is considered. The magnification of gravitational microlensing eve

Jorge Casares

X-ray binaries are excellent laboratories to study collapsed objects. On the one hand, transient X-ray binaries contain the best examples of stellar-mass black holes while persistent X-ray binaries mostly harbour accreting neutron stars. The determination of stellar masses in persistent X-ray binaries is usually hampered by the overwhelming luminosity of the

Bai-Ni Guo, Feng Qi

In the paper, after reviewing the history, background, origin, and applications of the functions $\frac{b^{t}-a^{t}}{t}$ and $\frac{e^{-αt}-e^{-βt}}{1-e^{-t}}$, we establish sufficient and necessary conditions such that the special function $\frac{e^{αt}-e^{βt}}{e^{λt}-e^{μt}}$ are monotonic, logarithmic convex, logarithmic concave, 3-log-convex and 3-log-co

A. F. Bliss, D. M. Worrall, M. Birkinshaw, S. S. Murray

PKS J2310-437 is an AGN with bright X-ray emission relative to its weak radio emission and optical continuum. It is believed that its jet lies far enough from the line of sight that it is not highly relativistically beamed. It thus provides an extreme test of AGN models. We present new observations aimed at refining the measurement of the source&#39;s proper

F. Bagarello

In a previous paper we have proven that any multi-resolution analysis of $L^2(\R)$ produces, for even values of the inverse filling factor and for a square lattice, a single-electron wave function of the lowest Landau level (LLL) which, together with its (magnetic) translated, gives rise to an orthonormal set in the LLL. We have also discussed the inverse co

David Nowak

Cryptographic primitives are fundamental for information security: they are used as basic components for cryptographic protocols or public-key cryptosystems. In many cases, their security proofs consist in showing that they are reducible to computationally hard problems. Those reductions can be subtle and tedious, and thus not easily checkable. On top of the

Ji-Haeng Huh, Jihn E. Kim, Bumseok Kyae

Based on the Z_{12-I} orbifold compactification of the heterotic string theory, we construct a flipped-SU(5) model with three families of the standard model matter and ingredients for dynamical supersymmetry breaking. The doublet-triplet splittings in the Higgs representations 5_{-2} and \bar{5}_{2} are achieved by the couplings 10_{1}10_{1}5_{-2} and \bar{1

R. B. G. Kramer, A. V. Silhanek, J. Van de Vondel, B. Raes

A direct visualization of the flux distribution in a Pb film covering a five-fold Penrose array of Co dots is obtained by mapping the local field distribution with a scanning Hall probe microscope. We demonstrate that stable vortex configurations can be found for fields H~0.8H_1, H_1 and 1.6H_1, where H_1 corresponds to one flux quantum per pinning site. The

Ralf Launhardt

Searching for extrasolar planets by direct detection is extremely challenging for current instrumentation. Indirect methods, that measure the effect of a planet on its host star, are much more promising and have indeed led to the discovery of nearly all extrasolar systems known today. While the most successful method thus far is the radial velocity technique

Nguyen Tien Quang, Nguyen Thu Thuy, Che Thi Kim Phung

There are different categorizations of the definition of a {\it ring} such as {\it Ann-category} (see N. T. Quang [6]), {\it ring category} (see M. Kapranov and V.Voevodsky [2]),... The main result of this paper is to prove that every axiom of the definition of a {\it ring category}, without the axiom $x_{0}=y_{0},$ can be deduced from the axiomatics of an {

R. Angeloni, S. Ciroi, P. Marigo, M. Contini

MASYS is the AKARI spectroscopic survey of Symbiotic Stars in the Magellanic Clouds, and one of the European Open Time Observing Programmes approved for the AKARI (Post-Helium) Phase-3. It is providing the first ever near-IR spectra of extragalactic symbiotic stars. The observations are scheduled to be completed in July 2009.

K. Morita, K. Morimoto, D. Kaji, H. Haba

Decay properties of an isotope $^{266}$Bh and its daughter nucleus $^{262}$Db produced by the $^{248}$Cm($^{23}$Na, 5\textit{n}) reaction were studied by using a gas-filled recoil separator coupled with a position-sensitive semiconductor detector. $^{266}$Bh was clearly identified from the correlation of the known nuclide, $^{262}$Db. The obtained decay prop

G. Cynolter, E. Lendvai, G. Pocsik

We calculate the oblique electroweak corrections and confront them with the experiments in a composite Higgs version of the standard model. A vector-like weak doublet and a singlet fermion are added to the standard model without elementary Higgs. Due to quartic coupling there is a mixing between the components of the new fields triggering electroweak symmetr

Mats Lindroos, Bob McElrath, Christopher Orme, Thomas Schwetz

We propose a method to measure the neutrino mass kinematically using beams of ions which undergo beta decay. The idea is to tune the ion beam momentum so that in most decays, the electron is forward moving with respect to the beam, and only in decays near the endpoint is the electron moving backwards. Then, by counting the backward moving electrons one can o

Hongwei Yu, N. F. Svaiter, L. H. Ford

We treat the effects of compactified spatial dimensions on the propagation of light in the uncompactified directions in the context of linearized quantum gravity. We find that the flight times of pulses can fluctuate due to modification of the graviton vacuum by the compactification. In the case of a five dimensional Kaluza-Klein theory, the mean variation i

Maria Evelina Rossi, Leila Sharifan

Let I be a homogeneous ideal in a polynomial ring P over a field. By Macaulay&#39;s Theorem, there exists a lexicographic ideal L=Lex(I) with the same Hilbert function as I. Peeva has proved that the Betti numbers of P/I can be obtained from the graded Betti numbers of P/L by a suitable sequence of consecutive cancellations. We extend this result to any idea

Norio Nawata

Noncommutative tori with real multiplication are the irrational rotation algebras that have special equivalence bimodules. Y. Manin proposed the use of noncommutative tori with real multiplication as a geometric framework for the study of abelian class field theory of real quadratic fields. In this paper, we consider the Cuntz-Pimsner algebras constructed by

Kwamiwi Mawussi, Sylvain Lavernhe, Claire Lartigue

The paper deals with associating the optimal machining strategy to a given pocket geometry, within the context of High-Speed Machining (HSM) of aeronautical pockets. First we define different classes of pocket features according to geometrical criteria. Following, we propose a method allowing to associate a set of capable tools to the features. Each capable

Christophe Tournier, Sylvain Lavernhe, Claire Lartigue

Manufacturing of free form parts relies on the calculation of a tool path based on a CAD model, on a machining strategy and on a given numerically controlled machine tool. In order to reach the best possible performances, it is necessary to take into account a maximum of constraints during tool path calculation. For this purpose, we have developed a surface

Bosiljka Tadić, Marija Mitrović

We study high-density traffic of information packets on sparse modular networks with scale-free subgraphs. With different statistical measures we distinguish between the free flow and congested regime and point out the role of modules in the jamming transition. We further consider correlations between traffic signals collected at each node in the network. Th

Norio Nawata, Yasuo Watatani

We introduce the fundamental group ${\mathcal F}(A)$ of a unital simple $C^*$-algebra $A$ with a unique normalized trace. We compute fundamental groups ${\mathcal F}(A)$ of several nuclear or non-nuclear $C^*$-algebras $A$. K-theoretical obstruction enables us to compute the fundamental group easily. Our study is essentially based on the computation of Picar

Nicolae Bogdan Mandache

Anomalous delta-type interactions, of both electric and magnetic nature, are introduced between the overlapping peripheral structures of the nucleons, which may explain the spin-triplet deuteron state and the absence of other nucleon-nucleon bound states.

Stefan Weinzierl

This article gives the perturbative NNLO results for the most commonly used event shape variables associated to three-jet events in electron-positron annihilation: Thrust, heavy jet mass, wide jet broadening, total jet broadening, C parameter and the Durham three-to-two jet transition variable. In addition the NNLO results for the jet rates corresponding to

Sylvain Lavernhe, Christophe Tournier, Claire Lartigue

After presenting the main difficulties related to machining 5 axes machining within the context of HSM, we present a surface model of 5-axis trajectories allowing taking into account geometrical and kinematical constraints. This model is integrated in an optimization scheme in order to maximize the productivity while ensuring the expected geometrical quality