November 2007 arXiv papers — page 2

Chi Hin Chan

This article is devoted to a regularity criteria for solutions of the Navier-Stokes equations in terms of regularity along the stream lines. More precisely, we prove that a suitable weak solution for the Navier-Stokes equations is regular under some constraint on the second derivative of |u| along the stream lines.

Ian J Leary

We give a lower bound for the exponent of certain elements in the integral cohomology of the total spaces of principal BC-bundles for C a finite cyclic group. As applications we give a proof of the theorem of A. Adem and H.-W. Henn that a p-group is elementary abelian if and only if its integral cohomology has exponent p, and we exhibit some infinite groups

David Conlon

We improve upon the lower bound for 3-colour hypergraph Ramsey numbers, showing, in the 3-uniform case, that \[r_3 (l,l,l) \geq 2^{l^{c \log \log l}}.\] The old bound, due to Erdős and Hajnal, was \[r_3 (l,l,l) \geq 2^{c l^2 \log^2 l}.\]

C. A. Linhares, A. P. C. Malbouisson, Y. W. Milla, I. Roditi

We consider the Euclidean $D$-dimensional $-λ|ϕ|^4+η|ϕ|^6$ ($λ,η>0 $) model with $d$ ($d\leq D$) compactified dimensions. Introducing temperature by means of the Ginzburg--Landau prescription in the mass term of the Hamiltonian, this model can be interpreted as describing a first-order phase transition for a system in a region of the $D$-dimensional space, l

David Conlon

We show that, for $n$ large, there must exist at least \[\frac{n^t}{C^{(1+o(1))t^2}}\] monochromatic $K_t$s in any two-colouring of the edges of $K_n$, where $C \approx 2.18$ is an explicitly defined constant. The old lower bound, due to Erdős \cite{E62}, and based upon the standard bounds for Ramsey's theorem, is \[\frac{n^t}{4^{(1+o(1))t^2}}.\]

E. Daddi, H. Dannerbauer, D. Elbaz, M. Dickinson

We present the first detection of molecular gas cooling CO emission lines from ordinary massive galaxies at z=1.5. Two sources were observed with the IRAM Plateau de Bure Interferometer, selected to lie in the mass-star formation rate correlation at their redshift, thus being representative of massive high-z galaxies. Both sources were detected with high con

S. Pascoli, S. T. Petcov

If future neutrino oscillation experiments show that the neutrino mass spectrum is with normal ordering, m1 < m2 < m3, and the searches for neutrinoless double beta-decay with sensitivity to values of the effective Majorana mass |<m>| > 0.01 eV give negative results, the next frontier in the quest for neutrinoless double beta-decay will correspond to |<m>| ~

M. Ahlers, H. Gies, J. Jaeckel, J. Redondo

Recently, the laser experiments BMV and GammeV, searching for light shining through walls, have published data and calculated new limits on the allowed masses and couplings for axion-like particles. In this note we point out that these experiments can serve to constrain a much wider variety of hidden-sector particles such as, e.g., minicharged particles and

Dalia Krieger, Narad Rampersad, Jeffrey Shallit

We give an O(n^3+n^2 t) time algorithm to determine whether an NFA with n states and t transitions accepts a language of polynomial or exponential growth. We also show that given a DFA accepting a language of polynomial growth, we can determine the order of polynomial growth in quadratic time.

Stefan Kraus, Thomas Preibisch, Keiichi Ohnaka

We study the geometry and the physical conditions in the inner (AU-scale) circumstellar region around the young Herbig Be star MWC 147 using long-baseline spectro-interferometry in the near-infrared (NIR K-band, VLTI/AMBER observations and PTI archive data) as well as the mid-infrared (MIR N-band, VLTI/MIDIobservations). The emission from MWC 147 is clearly

Leonhard Euler

E565 in the Enestrom index. Translated from the Latin original, &#34;De plurimis quantitatibus transcendentibus quas nullo modo per formulas integrales exprimere licet&#34; (1775). Euler does not prove any results in this paper. It seems to me like he is trying to develop some general ideas about special functions. He gives some examples of numbers he claims

Stuart Armstrong

Let $\mf{g}$ be any finite-dimensional Lie algebra with Killling form $B$. Let $\mf{h}$ be a subalgebra of $\mf{g}$ on which the Killing form is non degenerate. Then $\mf{h}$ is reductive.

Bruce W. Carney, David F. Gray, David Yong, David W. Latham

We report the results for rotational velocities, Vrot sin i, and macroturbulence dispersion, zeta(RT), for 12 metal-poor field red giant branch stars and 7 metal-poor field red horizontal branch stars. The results are based on Fourier transform analyses of absorption line profiles from high-resolution (R ~ 120,000), high-S/N (~ 215 per pixel) spectra obtaine

Longhai Li, Radford M. Neal

Bayesian classification and regression with high order interactions is largely infeasible because Markov chain Monte Carlo (MCMC) would need to be applied with a great many parameters, whose number increases rapidly with the order. In this paper we show how to make it feasible by effectively reducing the number of parameters, exploiting the fact that many in

T. Grange, R. Ferreira, G. Bastard

We calculate the lifetime of conduction band excited states in self-assembled quantum dots by taking into account LO-phonon-electron interaction and various anharmonic phonon couplings. We show that polaron relaxation cannot be accurately described by a semi-classical model. The contributions of different anharmonic decay channels are shown to depend strongl

Carlos A. Salgado

The reach of collider energies in heavy-ion collisions has profoundly changed our understanding of QCD under extreme conditions. I review some these new developments and comment on the properties of the produced medium as extracted from experimental data, as well as the exciting new opportunities which will be open at the LHC.

Carlos A. Salgado

We propose a new implementation of medium effects in jet structures in which a modification of the splitting function is included at every step in the typical final state parton shower. Although the main application of this new formalism will be at the LHC, it is interesting that, in the presence of a trigger bias to small number of splittings, non-trivial a

Thomas P. Kling, Simonetta Frittelli

We examine the accuracy of strong gravitational lensing determinations of the mass of galaxy clusters by comparing the conventional approach with the numerical integration of the fully relativistic null geodesic equations in the case of weak gravitational perturbations on Robertson-Walker metrics. In particular, we study spherically-symmetric, three-dimensio

W. J. de Wit, R. D. Oudmaijer, M. A. T. Groenewegen, M. G. Hoare

The paper investigates the milli-arcsecond scale structure of the present-day mass-loss of the post-Red Supergiant IRC+10420. We use three telescopes of the VLT Interferometer in combination with the AMBER near-infrared beam combiner to measure spectrally dispersed correlated fluxes in the K-band around the Br gamma transition. The resulting visibilities are

I. Belskaya, S. Bagnulo, K. Muinonen, M. A. Barucci

We investigate the surface characteristics of the large dwarf planet (136199) Eris. With the FORS1 instrument of the ESO VLT, we have obtained Bessell broadband R linear polarimetry and broadband V and I photometry. We have modelled the observations in terms of the coherent-backscattering mechanism to constrain the surface properties of the object. Polarimet

Alexey Mikaberidze, Ulf Saalmann, Jan M. Rost

Energy absorption of xenon clusters embedded in helium nanodroplets from strong femtosecond laser pulses is studied theoretically. Compared to pure clusters we find earlier and more efficient energy absorption in agreement with experiments. This effect is due to resonant absorption of the helium nanoplasma whose formation is catalyzed by the xenon core. For

C. A. Linhares, A. P. C. Malbouisson, I. Roditi

Starting from the complete Mellin representation of Feynman amplitudes for noncommutative vulcanized scalar quantum field theory, introduced in a previous publication, we generalize to this theory the study of asymptotic behaviours under scaling of arbitrary subsets of external invariants of any Feynman amplitude. This is accomplished for both convergent and

Christian Bartsch, Robin Steinigeweg, Jochen Gemmer

We investigate the occurrence of exponential relaxation in a certain class of closed, finite systems on the basis of a time-convolutionless (TCL) projection operator expansion for a specific class of initial states with vanishing inhomogeneity. It turns out that exponential behavior is to be expected only if the leading order predicts the standard separation

Diego Wisniacki, Gabriel G. Carlo

We study scarring phenomena in open quantum systems. We show numerical evidence that individual resonance eigenstates of an open quantum system present localization around unstable short periodic orbits in a similar way as their closed counterparts. The structure of eigenfunctions around these classical objects is not destroyed by the opening. This is expose

U. Mitra-Kraev, M. J. Thompson

We present meridional flow measurements of the Sun using a novel helioseismic approach for analyzing SOHO/MDI data in order to push the current limits in radial depth. Analyzing three consecutive months of data during solar minimum, we find that the meridional flow is as expected poleward in the upper convection zone, turns equatorward at a depth of around 4

H. F. Jones

Using the techniques of quasi-Hermitian quantum mechanics and quantum field theory we use a similarity transformation to construct an equivalent Hermitian Hamiltonian for the Lee model. In the field theory confined to the $V/Nθ$ sector it effectively decouples $V$, replacing the three-point interaction of the original Lee model by an additional mass term for

E. M. C. Abreu, A. Calil, L. S. Grigorio, M. S. Guimaraes

New actions in D=2 and D=3 are proposed that are dual equivalent to known theories displaying well defined chirality and helicity, respectively, along with a new interpolating action that maps continuously through the original dualities. The new chiral action in D=2 is a second-order theory displaying the chiral constraint dynamically while in D=3 the helici

Luciano Nicastro, Giorgio Calderone

In various astronomical projects it is crucial to have coordinates indexed tables. All sky optical and IR catalogues have up to 1 billion objects that will increase with forthcoming projects. Also partial sky surveys at various wavelengths can collect information (not just source lists) which can be saved in coordinate ordered tables. Selecting a sub-set of

A. A. Vladimirov

One proves that any everywhere defined constructive mapping from a complete metric space into a complete metric space which preserves the property of precompacity of subsets is locally uniformly continuous. This fact can be viewed as interpretation of L. E. J. Brower&#39;s fan theorem in terms of A. A. Markov&#39;s constructive analysis.

Maro Cvitan, Predrag Dominis Prester, Andrej Ficnar, Silvio Pallua

We review recent results on near-horizon static black hole solutions and entropy in R^2-corrected N=2 SUGRA in D=5, focusing on actions connected to heterotic string compactified on K3\times S^1. Comparison with \alpha'-perturbative results, results obtained by using simple Gauss-Bonnet R^2-correction, OSV conjecture and microscopic stringy description (for

Vyacheslav Shatokhin, Thomas Wellens, Cord Müller, Andreas Buchleitner

We survey recent progress achieved in understanding the impact of inelastic processes on coherent backscattering of light from cold atoms that are saturated by a powerful laser field.

Dietrich Burde, Karel Dekimpe, Sandra Deschamps

To any connected and simply connected nilpotent Lie group N, one can associate its group of affine transformations Aff(N). In this paper, we study simply transitive actions of a given nilpotent Lie group G on another nilpotent Lie group N, via such affine transformations. We succeed in translating the existence question of such a simply transitive affine act

S. Bucheler, D. Engel, J. Main, G. Wunner

The diffusion quantum Monte Carlo method is extended to solve the old theoretical physics problem of many-electron atoms and ions in intense magnetic fields. The feature of our approach is the use of adiabatic approximation wave functions augmented by a Jastrow factor as guiding functions to initialize the quantum Monte Carlo prodecure. We calcula te the gro

John M. Robinson

The entropy change of a (non-equilibrium) Markovian ensemble is calculated from (1) the ensemble phase density $p(t)$ evolved as iterative map, $p(t) = \mathbb{M}(t) p(t- Δt)$ under detail balanced transition matrix $\mathbb{M}(t)$, and (2) the invariant phase density $π(t) = \mathbb{M}(t)^{\infty} π(t) $. A virtual measurement protocol is employed, where va

Rainer Burghardt

A recently found interior for the Kerr metric is re-investigated by means of geometrical methods. A surface with nonholonomicity is matched to the surface of the exterior solution.

Rainer Burghardt

An exact solution of the Einstein field equations is proposed which represents a differentially rotating fluid. As this solution matches the exterior Kerr solution and reduces to the Schwarzschild interior solution by setting the rotational parameter to zero, it could serve as Kerr interior.

G. Boué, C. Adami, F. Durret, G. A. Mamon

We investigate the LF in the very relaxed cluster Abell 496. Our analysis is based on deep images obtained at CFHT with MegaPrime/MegaCam in four bands (ugri) covering a 1x1 deg2 region, which is centered on the cluster Abell 496 and extends to near its virial radius. The LFs are estimated by statistically subtracting a reference field taken as the mean of t

Olivier Leitner, Benoit Loiseau, Jean-Pierre Dedonder, Bruno El-Bennich

A short review on light scalar mesons is performed both in experiment and theory. A naive model, constrained by D branching ratios, is derived in order to make predictions on the wave functions of the $f_0(600)$ and $a_0(980)$ mesons. This leads us to compute transition form factors between the pseudoscalar $B$ and scalar mesons.

Pierre Nolin

We give a self-contained and detailed presentation of Kesten&#39;s results that allow to relate critical and near-critical percolation on the triangular lattice. They constitute an important step in the derivation of the exponents describing the near-critical behavior of this model. For future use and reference, we also show how these results can be obtained

F. Gelis

In this talk, I discuss some recent results obtained in Heavy Ion Collisions and what they tell us -- or what questions they raise -- about the physics of the system of quarks and gluons formed in these collisions.

H. B. Nersisyan, D. A. Osipyan, G. Zwicknagel

The electric microfield distribution (MFD) at an impurity ion is studied for two-component (TCP) electron-ion plasmas using molecular dynamics simulation and theoretical models. The particles are treated within classical statistical mechanics using an electron-ion Coulomb potential regularized at distances less than the de Broglie length to take into account

Jean-Alexandre Long, Philippe Cinquin, Jocelyne Troccaz, Sandrine Voros

PURPOSE: We have conducted experiments with an innovatively designed robot endoscope holder for laparoscopic surgery that is small and low cost. MATERIALS AND METHODS: A compact light endoscope robot (LER) that is placed on the patient&#39;s skin and can be used with the patient in the lateral or dorsal supine position was tested on cadavers and laboratory p

T. Suzuki, H. Bhang, J. Chiba, S. Choi

We have investigated correlations of coincident $ΛN$ pairs from the stopped $K^-$ reaction on ${}^4$He, and clearly observed $Λp$ and $Λn$ branches of the two-nucleon absorption process in the $ΛN$ invariant mass spectra. In addition, non-mesonic reaction channels, which indicate possible exotic signals for the formation of strange multibaryon states, have b

S. T. Chui, Z. F. Lin

We studied the response of a ferromagnet-insulator-normal metal tunnel structure under an external oscillating radio frequency (R.F.) magnetic field. The D. C. voltage across the junction is calculated and is found not to decrease despite the high resistance of the junction; instead, it is of the order of $μV$ to $100μV$, much larger than the experimentally

G. Li Causi, S. Antoniucci, E. Tatulli

AIMS: We have found that the interferometric visibilities of VLTI-AMBER observations, extracted via the standard reduction package, are significantly biased when faint targets are concerned. The visibility biases derive from a time variable fringing effect (correlated noise) appearing on the detector. METHODS: We have developed a method to correct this bias

Azi Lipshtat, Sudarshan P. Purushothaman, Ravi Iyengar, Avi Ma&#39;ayan

Representation of intracellular signaling networks as directed graphs allows for the identification of regulatory motifs. Regulatory motifs are groups of nodes with the same connectivity structure, capable of processing information. The bifan motif, made of two source nodes directly cross-regulating two target nodes, is an over-represented motif in a mammali

B. Tomasik, I. Melo, M. Gintner, S. Korony

We propose Kolmogorov-Smirnov test as a means for recognising event-by-event fluctuations of rapidity distributions in relativistic heavy ion collisions. Such fluctuations may be induced by the spinodal decomposition of the rapidly expanding system during the 1st order quark-hadron phase transition.

E. Dudas, Y. Mambrini, S. Pokorski, A. Romagnoni

In the recent years, phenomenological models of moduli stabilization were proposed, where the dynamics of the stabilization is essentially supersymmetric, whereas an O'Rafearthaigh supersymmetry breaking sector is responsible for the "uplift" of the cosmological constant to zero. We investigate the case where the uplift is provided by a Fayet-Iliopoulos sect

Amit P. S. Yadav, Eiichiro Komatsu, Benjamin D. Wandelt, Michele Liguori

In our recent paper (Yadav et al. 2007) we described a fast cubic (bispectrum) estimator of the amplitude of primordial non-Gaussianity of local type, f_{NL}, from a combined analysis of the Cosmic Microwave Background (CMB) temperature and E-polarization observations. In this paper we generalize the estimator to deal with a partial sky coverage as well as i

B. Tomasik, G. Torrieri, I. Melo, P. Bartos

Highly excited nuclear matter created in ultrarelativistic heavy-ion collisions possibly reaches the phase of quark deconfinement. It quickly cools down and hadronises. We explain that the process of hadronisation may likely be connected with disintegration into fragments. Observable signals of such a scenario are proposed.

Marcin Kacprowicz, Wojciech Wasilewski, Konrad Banaszek

We present a method for a complete characterization of a femtosecond ultraviolet pulse when a fundamental near-infrared beam is also available. Our approach relies on generation of second harmonic from the pre-characterized fundamental, which serves as a reference against which an unknown pulse is measured using spectral interference (SI). The characterizati

K. R. Ito, E. Seiler

We point out missing links in the recent paper by Tomboulis in which he claims a rigorous proof of quark confinement in 4D lattice gauge theory. We also discuss if it is possible to correct his proof.

Jan Friebe, André Pape, Matthias Riedmann, Karsten Moldenhauer

We report on a frequency measurement of the $(3s^2)^1S_0\to(3s3p)^3P_1$ clock transition of $^{24}$Mg on a thermal atomic beam. The intercombination transition has been referenced to a portable primary Cs frequency standard with the help of a femtosecond fiber laser frequency comb. The achieved uncertainty is $2.5\times10^{-12}$ which corresponds to an incre

Timo Weidl

We give an improvement of sharp Berezin type bounds on the Riesz means $\sum_k(Λ-λ_k)_+^σ$ of the eigenvalues $λ_k$ of the Dirichlet Laplacian in a domain if $σ\geq 3/2$. It contains a correction term of the order of the standard second term in the Weyl asymptotics. The result is based on an application of sharp Lieb-Thirring inequalities with operator value

Piotr Faliszewski

We study the concept of bribery in the situation where voters are willing to change their votes as we ask them, but where their prices depend on the nature of the change we request. Our model is an extension of the one of Faliszewski et al. [FHH06], where each voter has a single price for any change we may ask for. We show polynomial-time algorithms for our

O. Kochukhov, T. Ryabchikova, S. Bagnulo, G. Lo Curto

We have obtained time-resolved spectroscopic observations for a sample of 10 cool Ap stars using the ultra-stable spectrograph HARPS at the ESO 3.6-m telescope. The aim of our study was to search for low-amplitude oscillations in Ap stars with no or inconclusive evidence of pulsational variability. Here we report initial results of our investigation. We conf

M. S. Schöffler, J. Titze, L. Ph. H. Schmidt, T. Jahnke

Using the COLTRIMStechnique, scattering angle differential cross sections for single and double electron capture in collisions of protons and $He\sp{1,2+}$ projectiles with helium atoms for incident energies of $60-630 keV/u$ are measured. We also report new theoretical results obtained by means of four-body one-channel distorted wave models (CDW-BFS, CDW-BI

Ken Sekimoto

The energetics of the stochastic process has shown the balance of energy on the mesoscopic level. The heat and the energy defined there are, however, generally different from their macroscopic counterpart. We show that this discrepancy can be removed by adding to these quantities the reversible heat associated with the mesoscopic free energy.

Christian Corda

We show that from the R^{2} high order gravity theory it is possible to produce, in the linearized approch, particles which can be seen like massive modes of gravitational waves (GWs). The presence of the mass generates a longitudinal force in addition of the transverse one which is proper of the massless gravitational waves and the response an interferomete

G. Maciejewski, Ts. Georgiev, A. Niedzielski

The results of CCD photometric survey performed with the 90/180 cm Schmidt-Cassegrain Telescope of the Nicolaus Copernicus University Astronomical Observatory in Piwnice (Poland) and the 70/172 cm Schmidt Telescope of the National Astronomical Observatory (NAO) at Rozhen (Bulgaria) of the field of 1 Gyr old open cluster NGC 6939 are presented. Twenty two var

M. Gadella, J. Negro, G. P. Pronko, M. Santander

In this contribution, we discuss three situations in which complete integrability of a three dimensional classical system and its quantum version can be achieved under some conditions. The former is a system with axial symmetry. In the second, we discuss a three dimensional system without spatial symmetry which admits separation of variables if we use ellips

Melvin G. Hoare, Jose Franco

This chapter reviews progress in the field of massive star formation. It focuses on evidence for accretion and current models that invoke high accretion rates. In particular it is noted that high accretion rates will cause the massive young stellar object to have a radius much larger than its eventual main sequence radius throughout much of the accretion pha

M. L. Tong, Y. Zhang

The polarization vector (PV) of an electromagnetic wave (EW) will experience a rotation in a region of spacetime perturbed by gravitational waves (GWs). Based on this idea, Cruise&#39;s group has built an annular waveguide to detect GWs. We give detailed calculations of the rotations of the polarization vector of an EW caused by incident GWs from various dir

O. Kochukhov

We show that high-resolution observations of resolved Zeeman split lines can be used to obtain new constraints on the stellar magnetic field geometry. In particular, the contrast of the field strength distribution over the stellar surface can be deduced from the differential measurement of the second moment of the pi and sigma Zeeman components. Our analysis

O. Kochukhov, D. Shulyak

The atmospheric structure of chemically peculiar stars deviates from that of normal stars with similar fundamental parameters due to unusual chemistry, abundance inhomogeneities and the presence of strong magnetic field. These effects are not considered in the standard model atmospheres, possibly leading to large errors in the stellar parameter determination

Jeremy Shears, David Boyd, Steve Brady, Ian Miller

The variability of U1425-01208594 was recently discovered by Schmidtobreick et al, who suggested that it is a member of the delta Scuti family of pulsating stars. Photometry conducted by the authors revealed a period of 0.06695(8) d and a peak-to-peak amplitude of 0.014 mag.

O. Kochukhov

New observational techniques and sophisticated modelling methods has led to dramatic breakthroughs in our understanding of the interplay between the surface magnetism, atomic diffusion and atmospheric dynamics in chemically peculiar stars. Magnetic Doppler images, constructed using spectropolarimetric observations of Ap stars in all four Stokes parameters, r

Miles Gould

Given a symmetric operad $P$, and a signature (or generating sequence) $Φ$ for $P$, we define a notion of the &#34;categorification&#34; (or &#34;weakening&#34;) of $P$ with respect to $Φ$. When $P$ is the symmetric operad whose algebras are commutative monoids, with the standard signature, we recover the notion of symmetric monoidal categories. We then show

A. Sozzetti, S. Casertano, M. G. Lattanzi, A. Spagna

In this paper, we first summarize the results of a large-scale double-blind tests campaign carried out for the realistic estimation of the Gaia potential in detecting and measuring planetary systems. Then, we put the identified capabilities in context by highlighting the unique contribution that the Gaia exoplanet discoveries will be able to bring to the sci

Mikko Alava, John Ardelius, Erik Aurell, Petteri Kaski

We study the performance of stochastic local search algorithms for random instances of the $K$-satisfiability ($K$-SAT) problem. We introduce a new stochastic local search algorithm, ChainSAT, which moves in the energy landscape of a problem instance by {\em never going upwards} in energy. ChainSAT is a \emph{focused} algorithm in the sense that it considers

A. Sozzetti, G. Torres, D. W. Latham, B. W. Carney

We summarize the results of two experiments to address important issues related to the correlation between planet frequencies and properties and the metallicity of the hosts. Our results can usefully inform formation, structural, and evolutionary models of gas giant planets.

Maria Krawczyk, Dorota Sokolowska

Mass range of the charged Higgs boson in the 2HDM with explicit and spontaneous CP violation is discussed. Constraints on M_H+ in the CP conserving 2HDM(II) are shown.

J. F. Cariñena, A. M. Perelomov, M. F. Rañada, M. Santander

A nonpolynomial one-dimensional quantum potential representing an oscillator, that can be considered as placed in the middle between the harmonic oscillator and the isotonic oscillator (harmonic oscillator with a centripetal barrier), is studied. First the general case, that depends of a parameter $a$, is considered and then a particular case is studied with

Chun-Gang Ji, Wei-Ping Li, Pieter Moree

Let a(n,k) be the kth coefficient of the nth cyclotomic polynomial. The first two authors showed in part I that if m is a prime power and n and k range over the non-negative integers, then a(mn,k) assumes every integer value. Here this result is extended to the case where m is arbitrary. The proof use some properties of reciprocal cyclotomic polynomials (see

J. D. Vergados, S. H. Hansen, O. Host

We consider direct dark matter detection rates and investigate the difference between a standard Maxwell-Boltzmann velocity distribution and a &#34;realistic&#34; distribution like the ones extracted from numerical N-body simulations. Sizable differences are observed when such results are compared to the standard Maxwell-Boltzmann distribution. For a light t

Kang-Sin Choi, Tatsuo Kobayashi

We calculate couplings of arbitrary order from correlation functions among twisted strings, using conformal field theory. Twisted strings arise in heterotic string compactified on orbifolds yielding matter fields in the low energy limit. We calculate completely the classical and the quantum amplitude including normalization, up to a contribution from Kahler

Danil Doubochinski, Jonathan Tennenbaum

Einstein, De Broglie and others hoped that the schism between classical and quantum physics might one day be overcome by a theory taking into account the essential nonlinearity of elementary physical processes. However, neither their attempts, nor subsequent ones were able to supply a unifying principle that could serve as a starting-point for a coherent und

R. Adhikari, S. Succi

The notion of duality between the hydrodynamic and kinetic (ghost) variables of lattice kinetic formulations of the Boltzmann equation is introduced. It is suggested that this notion can serve as a guideline in the design of matrix versions of the lattice Boltzmann equation in a physically transparent and computationally efficient way.

X. Barcons

At low redshift (z<2), almost half of the baryons in the Universe are not found in bound structures like galaxies and clusters and therefore most likely reside in a Warm-Hot Intergalactic Medium (WHIM), as predicted by simulations. Attempts to detect WHIM filaments at cosmological distances in absorption towards bright background sources have yielded controv

Vasils Hatzopoulos, Henrik Jeldtoft Jensen

We investigate the evolution of cooperation on a non - growth network model with death/birth dynamics. Nodes reproduce under selection for higher payoffs in a prisoners dilemma game played between network neighbours. The mean field characteristics of the model are explored and an attempt is made to understand the size dependent behaviour of the model in term

Rok Zitko, Janez Bonca

We study the low-temperature transport properties of the systems of parallel quantum dots described by the N-impurity Anderson model. We calculate the quasiparticle scattering phase shifts, spectral functions and correlations as a function of the gate voltage for N up to 5. For any N, the conductance at the particle-hole symmetric point is unitary. For N >=

Roshanak Alimohammadi

There are various methods to analyze different kinds of data sets. Spatial data is defined when data is dependent on each other based on their respective locations. Spline and Kriging are two methods for interpolating and predicting spatial data. Under certain conditions, these methods are equivalent, but in practice they show different behaviors. Amount of

Juntao Song, Qing-feng Sun, Hua Jiang, X. C. Xie

The influence of electron-phonon interaction on the transmission phase shift of an electron passing through a quantum dot is investigated by using the scattering theory. The transmission phase versus the intra-dot level shows a serial of phonon-induced dips. These dips are highly sensitive to electron-phonon interaction strength $λ$, and they are much more p

Juntao Song, Qing-feng Sun, Jinhua Gao, X. C. Xie

The electron transport through a three-terminal single-molecular transistor (SMT) is theoretically studied. We find that the differential conductance of the third and weakly coupled terminal versus its voltage matches well with the spectral function versus the energy when certain conditions are met. Particularly, this excellent matching is maintained even fo

Yayoi Kinoshita, Koji Nishida, Kensuke Sakata, Ryuta Shinya

Let A be a commutative ring and I an ideal of A with a reduction Q. In this paper we give an upper bound on the reduction number of I with respect to Q, when a suitable family of ideals in A is given. As a corollary it follows that if some ideal J containing I satisfies J^2 = QJ, then I^{v + 2} = QI^{v + 1}, where v denotes the number of generators of J / I

Hideo Iwase, Dirk Englund, Jelena Vuckovic

We experimentally and theoretically investigate exciton-field coupling for the surface plasmon polariton (SPP) in waveguide-confined (WC) anti-symmetric modes of hexagonal plasmonic crystals in InP-TiO-Au-TiO-Si heterostructures. The radiative decay time of the InP-based transverse magnetic (TM)-strained multi-quantum well (MQW) coupled to the SPP modes is o

Gerald V. Dunne, Jin Hur, Choonkyu Lee, Hyunsoo Min

Our previously-developed calculational method (the partial wave cutoff method) is employed to evaluate explicitly scalar one-loop effective actions in a class of radially symmetric background gauge fields. Our method proves to be particularly effective when it is used in conjunction with a systematic WKB series for the large partial wave contribution to the

Palle E. T. Jorgensen, Myung-Sin Song

In this paper we offer a computational approach to the spectral function for a finite family of commuting operators, and give applications. Motivated by questions in wavelets and in signal processing, we study a problem about spectral concentration of integral translations of functions in the Hilbert space $L^{2}(\mathbb{R}^{n})$. Our approach applies more g

Sergiy Vasylkevych, Jerrold E. Marsden

This paper provides a precise sense in which the time t map for the Euler equations of an ideal fluid in a region in R^n (or a smooth compact n-manifold with boundary) is a Poisson map relative to the Lie-Poisson bracket associated with the group of volume preserving diffeomorphism group. This is interesting and nontrivial because in Eulerian representation,

S. Sarangi, P. K. Panda, S. K. Sahu, L. Maharana

We discuss a self-consistent method to calculate the properties of cold asymmetric nuclear matter which is dressed with isoscalar scalar pion condensates. The nucleon-nucleon interaction is mediated by these pion pairs, omega- and rho- mesons. The parameters of these interactions are evaluated self-consistently using the saturation properties of nuclear matt

T. T. Moon, S. A. Otero, L. L. Kiss

Combining visual observations of SR variables with measurements of them using a photoelectric photometer is discussed then demonstrated using data obtained for the bright, southern SR variable theta Aps. Combining such observations is useful in that it can provide a more comprehensive set of data by extending the temporal coverage of the light curve. Typical

Iddo Ben-Ari, Mathieu Merle, Alexander Roitershtein

We consider a nearest neighbor random walk on the one-dimensional integer lattice with drift towards the origin determined by an asymptotically vanishing function of the number of visits to zero. We show the existence of distinct regimes according to the rate of decay of the drift. In particular, when the rate is sufficiently slow, the position of the random

M. K. Olsen, A. S. Bradley

We investigate the quantum properties of the well-known process of sum frequency generation, showing that it is potentially a very useful source of non-classical states of the electromagnetic field, some of which are not possible with the more common techniques. We show that it can produce quadrature squeezed light, bright bichromatic entangled states and sy

Shijun Zheng

We obtain certain time decay and regularity estimates for 3D Schroedinger equation with a potential in the Kato class by using Besov spaces associated with Schroedinger operators.

Maxim Pospelov, Adam Ritz, Mikhail B. Voloshin

We consider a generic mechanism via which thermal relic WIMP dark matter may be decoupled from the Standard Model, namely through a combination of WIMP annihilation to metastable mediators with subsequent delayed decay to Standard Model states. We illustrate this with explicit examples of WIMPs connected to the Standard Model by metastable bosons or fermions

Alexander I. Milstein, Oleg P. Sushkov

We consider the extended 2D $t-t&#39;-t&#39;&#39;-J$ model at zero temperature. Parameters of the model corresponds to doping by holes. Using the low doping effective action we demonstrate that the system can 1) preserve the long range collinear antiferromagnetic order, 2) lead to a spin spiral state (static or dynamic), 3) lead to the phase separation insta

J. F. Muzy, E. Bacry, R. Baile, P. Poggi

In this paper we revisit an idea originally proposed by Mandelbrot about the possibility to observe ``negative dimensions&#39;&#39; in random multifractals. For that purpose, we define a new way to study scaling where the observation scale $τ$ and the total sample length $L$ are respectively going to zero and to infinity. This ``mixed&#39;&#39; asymptotic re

B. S. Zou

From recent study of properties of the lowest spin-parity $1/2^-$ baryons, $N^*(1535)$ and $Δ^*(1620)$, new pictures for the internal structure of the lowest $1/2^-$ baryon octet and decuplet are proposed. While the lowest $1/2^-$ baryon octet may have large diquark-diquark-antiquark component, the lowest $1/2^-$ baryon decuplet is proposed to have large vec

C. Foellmi, G. Koenigsberger, L. Georgiev, O. Toledano

We present the results of optical wavelength observations of the unusual SMC eclipsing binary system HD 5980 obtained in 1999 and 2004--2005. Radial velocity curves for the erupting LBV/WR object (star A) and its close WR-like companion (star B) are obtained by deblending the variable emission-line profiles of N IV and N V lines under the simplistic assumpti

Z. Fan, J. Ma, R. de Grijs, Y. Yang

Using metallicities from the literature, combined with the Revised Bologna Catalogue of photometric data for M31 clusters and cluster candidates (the latter of which is the most comprehensive catalogue of M31 clusters currently available, including 337 confirmed globular clusters -- GCs -- and 688 GC candidates), we determine 443 reddening values and intrins