March 2008 arXiv papers — page 5

A. Lucotti, C. S. Casari, M. Tommasini, A. Li Bassi

Surface Enhanced Raman Spectroscopy (SERS) is exploited here to investigate the interaction of isolated sp carbon chains (polyynes) in a methanol solution with silver nanoparticles. Hydrogen-terminated polyynes show a strong interaction with silver colloids used as the SERS active medium revealing a chemical SERS effect. SERS spectra after mixing polyynes wi

Yoshiharu Maeno, Yukio Ohsawa

A new method is presented, that can help a person become aware of his or her unconscious preferences, and convey them to others in the form of verbal explanation. The method combines the concepts of reflection, visualization, and verbalization. The method was tested in an experiment where the unconscious preferences of the subjects for various artworks were

Kouji Ogawa, Hideki Ishihara, Hiroshi Kozaki, Hiroyuki Nakano

Stationary rotating strings can be viewed as geodesic motions in appropriate metrics on a two-dimensional space. We obtain all solutions describing stationary rotating strings in flat spacetime as an application. These rotating strings have infinite length with various wiggly shapes. Averaged value of the string energy, the angular momentum and the linear mo

Giorgio Torrieri, Boris Tomášik, Igor Mishustin

We describe a new scenario (first introduced in [G. Torrieri, B. Tomášik and I. Mishustin, Phys. Rev. C \textbf{77}, 034903 (2008)]) for freezeout in heavy ion collisions that could solve the lingering problems associated with the so-called HBT puzzle. We argue that bulk viscosity increases as $T$ approaches $T_c$. The fluid {then} becomes unstable against s

A. Alberti, V. V. Ivanov, G. M. Tino, G. Ferrari

The manipulation of matterwave represents a milestone in the history of quantum mechanics. It was at the basis of its experimental validation through the observation of diffraction of matter on crystals, as well as grating and Young's double-slit interference with electrons, neutron, atoms and molecules. More recently matterwave manipulation has become a

T. Sekihara, T. Hyodo, D. Jido

The electromagnetic mean squared radii, <r^2>_E and <r^2>_M, of Lambda(1405) are calculated in the chiral unitary model. We describe the excited baryons as dynamically generated resonances in the octet meson and octet baryon scattering. We evaluate values of <r^2>_E and <r^2>_M for the Lambda(1405) on the resonance pole and obtain their complex values. We al

Mathieu Bouville

Typical arguments against scientific misconduct generally fail to support current policies on research fraud: they may not prove wrong what is usually considered research misconduct and they tend to make wrong things that are not normally seen as scientific fraud, in particular honest errors. I also point out that sanctions are not consistent with the reason

Lianyi He, Pengfei Zhuang

We determine the critical Zeeman energy splitting for Fermi superfluidity at infinite s-wave scattering length according to the Monte Carlo and experimental results of the equations of state. Based on the universality hypothesis, we show that there exist two critical fields $H_{c1}$ and $H_{c2}$, between which a superfluid-normal mixed phase is energetically

Ke Liu, Nael Abu-Ghazaleh

Stateless geographic routing provides relatively good performance at a fixed overhead, which is typically much lower than conventional routing protocols such as AODV. However, the performance of geographic routing is impacted by physical voids, and localization errors. Accordingly, virtual coordinate systems (VCS) were proposed as an alternative approach tha

Renat A. Sultanov, Avas V. Khugaev, Dennis Guster

Results for quantum mechanical calculations of the integral cross sections and corresponding thermal rate coefficients for para-/ortho-H2+HD collisions are presented. Because of significant astrophysical interest in regard to the cooling of primodial gas the low temperature limit of para-/ortho-H2+HD is investigated. Sharp resonances in the rotational state-

R. J. Baxter

We consider the Ising model on a cylindrical lattice of L columns, with fixed-spin boundary conditions on the top and bottom rows. The spontaneous magnetization can be written in terms of partition functions on this lattice. We show how we can use the Clifford algebra of Kaufman to write these partition functions in terms of L by L determinants, and then fur

R. J. Baxter

We adapt our previous results for the ``partition function&#39;&#39; of the superintegrable chiral Potts model with open boundaries to obtain the corresponding matrix elements of e^{-αH}, where H is the associated hamiltonian. The spontaneous magnetization M_r can be expressed in terms of particular matrix elements of e^{-αH} S^r_1 \e^{-βH}, where S_1 is a d

Hamid Usefi

There have been gaps found in the proofs. The paper is withdrawn until further notice.

Robert N. Proctor, Philip Lah, Duncan A. Forbes, Matthew Colless

We present an analysis of the stellar populations in a sample of ~7000 galaxies from the 6dF Galaxy Survey (6dFGS). We derive ages and metallicities using stellar population models. We also derive dynamical masses and dynamical mass-to-light ratios by combining central velocity dispersions with global photometry in B, R and K bands. Together, these data allo

Guohong Li, Adina Luican, Eva Y. Andrei

We report low temperature high magnetic field scanning tunneling microscopy and spectroscopy of graphene flakes on graphite that exhibit the structural and electronic properties of graphene decoupled from the substrate. Pronounced peaks in the tunneling spectra develop with field revealing a Landau level sequence that provides a direct way to identify graphe

G. Catanzaro

Recent papers published in the last years contributed to resolve the enigma on the hypothetical Be nature of the hot pulsating star $β$ Cep. This star shows variable emission in the H$α$ line, typical for Be stars, but its projected rotational velocity is very much lower than the critical limit, contrary to what is expected for a typical Be star. The emissio

Greig A. Cowan, Graeme A. Stewart, Andrew Elwell

The start of data taking at the Large Hadron Collider will herald a new era in data volumes and distributed processing in particle physics. Data volumes of hundreds of Terabytes will be shipped to Tier-2 centres for analysis by the LHC experiments using the Worldwide LHC Computing Grid (WLCG). In many countries Tier-2 centres are distributed between a number

D. Blume

Motivated by the prospect of optical lattice experiments with two-component Fermi gases consisting of different atomic species such as Li and K, we calculate the energies for N fermions under harmonic confinement as a function of the mass- and trap-imbalance, i.e., as a function of the ratio between the masses and frequencies of species one and two, using mi

Ronald Benjamin, Ryoichi Kawai

We investigate the energetics of a Brownian motor driven by position dependent temperature, commonly known as the B{ü}ttiker-Landauer motor. Overdamped models (M=0) predict that the motor can attain Carnot efficiency. However, the overdamped limit ($M\to 0$), contradicts the previous prediction due to the kinetic energy contribution to the heat transfer. Usi

Richard M. Plotkin, Scott F. Anderson, Patrick B. Hall, Bruce Margon

We present a large sample of 501 radio-selected BL Lac candidates from the combination of the Sloan Digital Sky Survey (SDSS) Data Release 5 optical spectroscopy and from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) radio survey; this is one of the largest BL Lac samples yet assembled, and each object emerges with homogeneous data coverage

B. J. Smith, C. Struck, M. Hancock, M. L. Giroux

We present Spitzer infrared, GALEX UV, and SDSS and SARA optical images of the peculiar interacting galaxy pair Arp 285 (NGC 2856/4), and compare with a new numerical model of the interaction. We estimate the ages of clumps of star formation in these galaxies using population synthesis models, carefully considering the uncertainties on these ages. This syste

Fusayoshi J. Ohkawa

Kondo-lattice theory for the t-J model and a phenomenological theory based on it are developed to study superconductivity in the vicinity of the Mott metal-insulator transition. Since the quenching of magnetic moments by single-site quantum spin fluctuations or the Kondo effect is reduced by the opening of a superconducting gap, spin density wave (SDW) can a

Giuseppe D&#39;Aguanno, Nadia Mattiucci, Mark J. Bloemer

We find the analytical expression for the threshold intensity necessary to launch ultra-slow light pulses in a metamaterial with simultaneous cubic electric and magnetic nonlinearity. The role played respectively by the permittivity, the permeability, the electric cubic nonlinearity, the magnetic cubic nonlinearity and the pulse duration is clearly identifie

Jean Pradines

Reprint of a 1989 paper including minor corrections of misprints. Added comments (11 pages) about later related papers in the literature concerning comparison of Gabriel-Zisman calculus of (right) fractions and the use of generalized morphims in the sense of Haefliger-Skandalis-Hilsum for inverting differentiable equivalences between Lie groupoids.

Tudor D. Stanescu, Victor Galitski, H. D. Drew

Motivated by the recent experimental observation of quantum oscillations in the underdoped cuprates, we study the cyclotron and infrared Hall effective masses in an anisotropic Fermi liquid characterized by an angle-dependent quasiparticle residue Z_q, which models an arc-shaped Fermi surface. Our primary motivation is to explain the relatively large value o

Rajib Ganguly, Renyue Cen, Taotao Fang, Kenneth Sembach

We investigate the relationship between galaxies and metal-line absorption systems in a large-scale cosmological simulation with galaxy formation. Our detailed treatment of metal enrichment and non-equilibrium calculation of oxygen species allow us, for the first time, to carry out quantitative calculations of the cross-correlations between galaxies and O VI

Hilding R. Neilson, John B. Lester

An analytical derivation is presented for computing mass-loss rates of Cepheids by using the method of Castor, Abbott, & Klein (1975) modified to include a term for momentum input from pulsation and shocks generated in the atmosphere. Using this derivation, mass-loss rates of Cepheids are determined as a function of stellar parameters. When applied to a set

Asantha Cooray, Devdeep Sarkar, Paolo Serra

The cosmic microwave background (CMB) bispectrum is a well-known probe of the non-Gaussianity of primordial perturbations. Just as the intervening large-scale structure modifies the CMB angular power spectrum through weak gravitational lensing, the CMB primary bispectrum generated at the last scattering surface is also modified by lensing. We discuss the len

Deepshikha Shukla, Daniel R. Phillips, Eric Mortenson

We use nucleon-nucleon phase shifts obtained from experimental data, together with the chiral expansion for the long-distance part of the NN interaction, to obtain information about the short-distance piece of the NN potential that is at work in the 1S0 channel. We find that if the scale R that defines the separation between &#34;long-&#34; and &#34;short-&#

R. van Zon, S. S. Ashwin, E. G. D. Cohen

To describe short-time (picosecond) and small-scale (nanometre) transport in fluids, a Green&#39;s function approach was recently developed. This approach relies on an expansion of the distribution of single particle displacements around a Gaussian function, yielding an infinite series of correction terms. Applying a recent theorem [Van Zon and Cohen, J. Sta

J. E. Vaillancourt, C. D. Dowell, R. H. Hildebrand, L. Kirby

We have used the SHARP polarimeter at the Caltech Submillimeter Observatory to map the polarization at wavelengths of 350 and 450 micron in a ~2 x 3 arcmin region of the Orion Molecular Cloud. The map covers the brightest region of the OMC-1 ridge including the Kleinmann-Low (KL) nebula and the submillimeter source Orion-south. The ratio of 450-to-350 micron

Konstantine Zelator

In this paper, we investigate the one-variable equation, sinx+cosx+tanx+cotx+secx+cscx=n, where n is an integer. We prove that if n lies between(inclusively) -1 and 6; then the above equation has no real number solutions. While if n is greater than or equal to 7; or less than or equal to -2, then the said equation has a nonempty solution set which we describ

Lars Grant, Pietro A. Grassi, Seok Kim, Shiraz Minwalla

We formulate the problem of counting 1/16 BPS states of N = 4 Yang Mills theory as the enumeration of the local cohomology of an operator acting on holomorphic fields on C^2. We study aspects of the enumeration of this cohomology at finite N, especially for operators constructed only out of products of covariant derivatives of scalar fields, and compare our

Luc Lapointe, Yvan Le Borgne, Philippe Nadeau

We prove a previously conjectured closed form formula for the norm of the Jack polynomials in superspace with respect to a certain scalar product. The proof is mainly combinatorial and relies on the explicit expression in terms of admissible tableaux of the non-symmetric Jack polynomials. In the final step of the proof appears an identity on weighted sums of

D. P. DePonte, U. Weierstall, D. Starodub, K. Schmidt

As shown by Ganan-Calvo and co-workers, a free liquid jet can be compressed in iameter through gas-dynamic forces exerted by a co-flowing gas, obviating the need for a solid nozzle to form a microscopic liquid jet and thereby alleviating the clogging problems that plague conventional droplet sources of small diameter. We describe in this paper a novel form o

C. F. Berger, Z. Bern, L. J. Dixon, F. Febres Cordero

We present the first results from BlackHat, an automated C++ program for calculating one-loop amplitudes. The program implements the unitarity method and on-shell recursion to construct amplitudes. As input to the calculation, it uses compact analytic formulae for tree amplitudes for four-dimensional helicity states. The program performs all related computat

P. -A. Absil, P. Van Dooren

The two-sided Rayleigh quotient iteration proposed by Ostrowski computes a pair of corresponding left-right eigenvectors of a matrix $C$. We propose a Grassmannian version of this iteration, i.e., its iterates are pairs of $p$-dimensional subspaces instead of one-dimensional subspaces in the classical case. The new iteration generically converges locally cub

Amadeo Irigoyen

We deal with a problem of the reconstruction of any holomorphic function $f$ on the unit ball of $\mathbb{C}^2$ from its restricions on a union of complex lines. We give an explicit formula of Lagrange interpolation&#39;s type that is constructed from the knowledge of $f$ and its derivatives on these lines. We prove that this formula approximates any functio

Carl H. Albright

We show how models of neutrino masses and mixings can be differentiated on the basis of their predictions for $θ_{13}$ and lepton flavor violation in radiative charged lepton decays and $μ- e$ conversion. We illustrate the lepton flavor violation results for five predictive SO(10) SUSY GUT models and point out the relative importance of their heavy right-han

Vivian V. Franca, Klaus Capelle

We calculate the entanglement entropy of blocks of size x embedded in a larger system of size L, by means of a combination of analytical and numerical techniques. The complete entanglement entropy in this case is a sum of three terms. One is a universal x and L-dependent term, first predicted by Calabrese and Cardy, the second is a nonuniversal term arising

Eduardo Rojas, Alejandro Ayala, Adnan Bashir, Alfredo Raya

We study the dynamical generation of masses for fundamental fermions in quenched quantum electrodynamics, in the presence of magnetic fields of arbitrary strength, by solving the Schwinger-Dyson equation (SDE) for the fermion self-energy in the rainbow approximation. We employ the Ritus eigenfunction formalism which provides a neat solution to the technical

J. Schirmer, A. Dreuw

In a recent Comment (arXiv:0710.0018), Maitra, Burke, and van Leeuwen (MBL) attempt to refute our criticism of the foundations of TDDFT (see Phys. Rev. A 75, 022513 (2007)). However, their arguments miss the essence of our position. This is mainly due to an ambiguity concerning the meaning of the so-called mapping derivation of time-dependent Kohn-Sham equat

C. M. Lavelle, D. V. Baxter, A. Bogdanov, V. P. Derenchuk

The Low Energy Neutron Source (LENS) is an accelerator-based pulsed cold neutron facility under construction at the Indiana University Cyclotron Facility (IUCF). The idea behind LENS is to produce pulsed cold neutron beams starting with ~MeV neutrons from (p,n) reactions in Be which are moderated to meV energies and extracted from a small solid angle for use

P. A. Goddard, J. Singleton, P. Sengupta, R. D. McDonald

Pulsed-field magnetization experiments (fields $B$ of up to 85 T and temperatures $T$ down to 0.4 K) are reported on nine organic Cu-based two-dimensional (2D) Heisenberg magnets. All compounds show a low-$T$ magnetization that is concave as a function of $B$, with a sharp ``elbow&#39;&#39; transition to a constant value at a field $B_{\rm c}$. Monte-Carlo s

Mohamed Maghfoul

We define a group of relative differential K-characters associated with a smooth map between two smooth compact manifolds. We show that this group fits into a short exact sequence as in the non-relative case. Some secondary geometric invariants are expressed in this theory.

Simon P. Driver, Cristina C. Popescu, Richard J. Tuffs, Alister W. Graham

The dominant source of electromagnetic energy in the Universe today (over ultraviolet, optical and near-infrared wavelengths) is starlight. However, quantifying the amount of starlight produced has proven difficult due to interstellar dust grains which attenuate some unknown fraction of the light. Combining a recently calibrated galactic dust model with obse

J. Kalinowski, W. Kilian, J. Reuter, T. Robens

We consider NLO chargino production and decays at the ILC. For this, we present an NLO extension of the Monte Carlo Event Generator Whizard including the NLO production. For photonic corrections, we use both a fixed order and a resummation approach. The latter method evades the problem of negative event weights and automatically includes leading higher order

T. Roell, A. Seifahrt, R. Neuhäuser

We present our search program for substellar companions using high-precision relative astronomy. Due to its orbital motion around the star, an unseen substellar companion would produce a periodic &#34;wobble&#34; of the host star, which is the astrometric signal of the unseen companion. By measuring the separation between the components of stellar double and

Rainer Schmidt

In this work the charge transport properties of charge ordered (CO) La1-xCaxMnO3 (LCMO) (x= 0.55, 0.67) epitaxial thin films and polycrystals are discussed following the recent controversy of localised electron states vs. weakly or de- localised charge density wave (CDW) states in CO manganites. The transport properties were investigated by current vs. volta

Alexei Onatski

This paper extends the work of El Karoui [Ann. Probab. 35 (2007) 663--714] which finds the Tracy--Widom limit for the largest eigenvalue of a nonsingular $p$-dimensional complex Wishart matrix $W_{\mathbb{C}}(Ω_p,n)$ to the case of several of the largest eigenvalues of the possibly singular $(n<p)$ matrix $W_{\mathbb{C}}(Ω_p,n).$ As a byproduct, we extend al

Piotr Trocha, Józef Barnaś

Electronic transport through a triple quantum dot system, with only a single dot coupled directly to external leads, is considered theoretically. The model includes Coulomb correlations in the central dot, while such correlations in the two side-coupled dots are omitted. The infinite-U mean-field slave-boson approach is used to obtain basic transport charact

L. Deharveng, B. Lefloch, S. Kurtz, D. Nadeau

Aims: We wish to establish whether sequential star formation is taking place at the periphery of the Galactic HII region Sh2-212. Methods: We present CO millimetre observations of this region obtained at the IRAM 30-m telescope to investigate the distribution of associated molecular material. We also use deep JHK observations obtained at the CFHT to study th

Marco Polini, Andrea Tomadin, Reza Asgari, A. H. MacDonald

We outline a Kohn-Sham-Dirac density-functional-theory (DFT) scheme for graphene sheets that treats slowly-varying inhomogeneous external potentials and electron-electron interactions on an equal footing. The theory is able to account for the the unusual property that the exchange-correlation contribution to chemical potential increases with carrier density

Antoine Venaille, Joel Sommeria

Experimental results for the evolution of the probability distribution function (PDF) of a scalar mixed by a turbulence flow in a channel are presented. The sequence of PDF from an initial skewed distribution to a sharp Gaussian is found to be non universal. The route toward homogeneization depends on the ratio between the cross sections of the dye injector

C. Yang, B. N. J. Persson

We present a molecular dynamics study of the contact between a rigid solid with a randomly rough surface and an elastic block with a flat surface. The numerical calculations mainly focus on the contact area and the interfacial separation from small contact (low load) to full contact (high load). For small load the contact area varies linearly with the load a

Michele Ceriotti, Marco Bernasconi

We have studied diffusion pathways of a silyl radical adsorbed on the hydrogenated Si (100)-(2x1) surface by density-functional theory. The process is of interest for the growth of crystalline silicon by plasma-enhanced chemical vapor deposition. Preliminary searches for migration mechanisms have been performed using metadynamics simulations. Local minima an

W. J. Chaplin, T. Appourchaux, T. Arentoft, J. Ballot

We report on initial results from the first phase of Exercise 1 of the asteroFLAG hare and hounds. The asteroFLAG group is helping to prepare for the asteroseismology component of NASA&#39;s Kepler mission, and the first phase of Exercise 1 is concerned with testing extraction of estimates of the large and small frequency spacings of the low-degree p modes f

Andrew Ferstl, Nathan Moore

Without the use of cameras to record 2D motion and an appropriate analysis tool, creating a laboratory activity for students to experience the vector nature of momentum can be challenging. Even with appropriate measurement tools, it is difficult to predict the final velocities of the objects in the system unless you know the impact parameter. For accurately

Hirofumi Wada, Roland R. Netz

Using dynamic simulations and analytic methods, we study the elastic response of a helical filament subject to uniaxial tension over a wide range of bend and twist persistence length. A low-pitch helix at low temperatures exhibits a stretching instability and the force-extension curve consists of a sequence of spikes. At elevated temperature (i.e. small pers

Yang Li

We argue that the collinear factorization of the fragmentation functions in high energy nuclear collisions breaks down at transverse momenta $p_T \lesssim Q_s/g$ due to high parton densities in the colliding hadrons and/or nuclei. We find that gluon recombination dominates in that $p_T$ region. We calculate the inclusive cross-section for $π$ meson and nucle

M. Gervasi, A. Tartari, M. Zannoni, G. Boella

The contribution of the Unresolved Extragalactic Radio Sources to the diffuse brightness of the sky was evaluated using the source number - flux measurements available in literature. We first optimized the fitting function of the data based on number counts distribution. We then computed the brightness temperature at various frequencies from 151 MHz to 8440

Jan Essert

We prove homological stability for standard unitary groups over R, C and H and for general linear groups over skew-fields with infinite centre. We focus on the similarities and differences of these proofs. Both proofs are due to Chih-Han Sah (Homology of classical Lie groups made discrete I: Stability theorems and Schur multipliers. Comment. Math. Helv. 61(2

Tarek Ibrahim

We compute the one loop corrected effective Lagrangian for the neutralino-neutralino-neutral Higgs interactions $χ^{0}_{\ell} χ^{0}_kH^{0}_m$. The analysis completes the previous analyses where similar corrections were computed for the $\bar{f} f H^{0}_m$ couplings, where $f$ stands for Standard Model quarks and leptons and for the chargino-chargino-neutral

Marcelo Zimbres, Patricio S. Letelier

For stationary axially symmetric spacetimes we find a simple expression for the Lense-Thirring precession in terms of the Ernst potential. This expression is used to compute, in the weak field approximation, the major non-spherical contributions to the precession of a gyroscope orbiting the Earth. We reproduce previously known results and give a new estimati

Ellyn K. Baines, Harold A. McAlister, Theo A. ten Brummelaar, Nils H. Turner

Most exoplanets have been discovered via radial velocity studies, which are inherently insensitive to orbital inclination. Interferometric observations will show evidence of a stellar companion if it sufficiently bright, regardless of the inclination. Using the CHARA Array, we observed 22 exoplanet host stars to search for stellar companions in low-inclinati

Engelbert L. Schucking

The mantra about gravitation as curvature is a misnomer. The curvature tensor for a standard of rest does not describe acceleration in a gravitational field but the \underline{gradient} of the acceleration (e.g. geodesic deviation). The gravitational field itself (Einstein 1907) is essentially an accelerated reference system. It is characterized by a field o

S. Giacintucci, T. Venturi, G. Macario, D. Dallacasa

We present new high sensitivity observations of the radio relic in A521 carried out with the Giant Metrewave Radio Telescope at 327 MHz and with the Very Large Array at 4.9 and 8.5 GHz. We imaged the relic at these frequencies and carried out a detailed spectral analysis, based on the integrated radio spectrum between 235 MHz and 4.9 GHz, and on the spectral

S. M. Ageev, M. Cencelj, D. Repovš

We prove that Dranishnikov&#39;s $k$-dimensional resolution $d_k\colon μ^k\to Q$ is a UV$^{n-1}$-divider of Chigogidze&#39;s $k$-dimensional resolution $c_k$. This fact implies that $d_k^{-1}$ preserves $Z$-sets. A further development of the concept of UV$^{n-1}$-dividers permits us to find sufficient conditions for $d_k^{-1}(A)$ to be homeomorphic to the Nö

Henrik N. Latter, Gordon I. Ogilvie

This paper examines the onset of the viscous overstability in dense particulate rings. First, we formulate a dense gas kinetic theory that is applicable to the Saturnian system. Our model is essentially that of Araki and Tremaine (1986), which we show can be both simplified and generalised. Second, we put this model to work computing the equilibrium properti

Miklós Csörgõ, Barbara Szyszkowicz, Lihong Wang

Correction to The Annals of Statistics (2006) 34, 1013--1044 [URL: http://projecteuclid.org/euclid.aos/1151418250]

Taras Banakh, Dušan Repovš, Lyubomyr Zdomskyy

In this paper we answer the question of T. Banakh and M. Zarichnyi constructing a copy of the Fréchet-Urysohn fan $S_\w$ in a topological group $G$ admitting a functorial embedding $[0,1]\subset G$. The latter means that each autohomeomorphism of $[0,1]$ extends to a continuous homomorphism of $G$. This implies that many natural free topological group constr

M. Albert, T. Paul, N. Pavloff, P. Leboeuf

We consider dipole oscillations of a trapped dilute Bose-Einstein condensate in the presence of a scattering potential consisting either in a localized defect or in an extended disordered potential. In both cases the breaking of superfluidity and the damping of the oscillations are shown to be related to the appearance of a nonlinear dissipative flow. At sup

Umed H. Karimov, Dušan Repovš

Bredon has constructed a 2-dimensional compact cohomology manifold which is not homologically locally connected, with respect to the singular homology. In the present paper we construct infinitely many such examples (which are in addition metrizable spaces) in all remaining dimensions $n \ge 3$.

Yan Sun, Wenyang Zhang, Howell Tong

Longitudinal studies are often conducted to explore the cohort and age effects in many scientific areas. The within cluster correlation structure plays a very important role in longitudinal data analysis. This is because not only can an estimator be improved by incorporating the within cluster correlation structure into the estimation procedure, but also the

V. V. Ryazanov

A family of non-equilibrium statistical operators (NSO) is introduced which differ by the system lifetime distribution over which the quasi-equilibrium (relevant) distribution is averaged. This changes the form of the source in the Liouville equation, as well as the expressions for the kinetic coefficients, average fluxes, and kinetic equations obtained with

Rahul Basu, Debajyoti Choudhury, H. S. Mani

The dynamics of fermionic unparticles is developed from first principles. It is shown that any unparticle, whether fermionic or bosonic, can be recast in terms of a canonically quantized field, but with non-local interaction terms. We further develop a possible gauge theory for fermionic unparticles. Computing the consequent contribution of un-fermions to th

K. Rompicharla, D. I. Novita, Ping Chen, P. Boolchand

Modulated DSC measurements on bulk (Na2O)x(GeO2)1-x glasses show a sharp reversibility window in the 14% < x < 19% soda range, which correlates well with a broad global minimum in molar volumes. Raman and IR reflectance TO and LO mode frequencies exhibit anomalies between xc(1) = 14% (stress transition) and xc(2) = 19% (rigidity transition), with optical ela

H. J. Schreiber, N. B. Skachkov

The physical consequences of the relativistic and nonrelativistic approaches to describe the energy levels of electrons which propagate in a static homogeneous magnetic field are considered. It is shown that for a given strength of the magnetic field, the quantized energy levels of the electrons calculated by nonrelativistic and relativistic equations differ

Fei Zhan, Yuan Lin, Biao Wu

We discuss two approaches that are used frequently to describe quantum-classical hybrid system. One is the well-known mean-field theory and the other adopts a set of hybrid brackets which is a mixture of quantum commutators and classical Poisson brackets. We prove that these two approaches are equivalent.

Jiri Bicak, Joseph Katz, Donald Lynden-Bell

Linear perturbations of Friedmann-Robertson-Walker universes with any curvature and cosmological constant are studied in a general gauge without decomposition into harmonics. Desirable gauges are selected as those which embody best Mach&#39;s principle: in these gauges local inertial frames can be determined instantaneously via the perturbed Einstein field e

M. van den Broek, C. Van den Broeck

This paper provides some comprehensive calculations supporting the results in Phys. Rev. Lett. 100, 130601 (2008) [arXiv:0711.1758].

A. A. Andrianov, D. Espriu

We investigate the relation among slopes and intercepts of Regge trajectories for mesons of a given spin and different parities using large N_c arguments and the matching to perturbative QCD in the deep-Minkowski region. For spin-1 mesons of opposite parities we prove that: a) for large and increasing N_c, the scale Λ^{(V,A)} separating the resonance-dominat

Jiri Bicak, Bernd G. Schmidt

We investigate properties of solutions of the scalar wave equation and Maxwell&#39;s equations on Minkowski space with helical symmetry. Existence of local and global solutions with this symmetry is demonstrated with and without sources. The asymptotic properties of the solutions are analyzed. We show that the Newman--Penrose retarded and advanced scalars ex

Gábor J. Székely, Maria L. Rizzo, Nail K. Bakirov

Distance correlation is a new measure of dependence between random vectors. Distance covariance and distance correlation are analogous to product-moment covariance and correlation, but unlike the classical definition of correlation, distance correlation is zero only if the random vectors are independent. The empirical distance dependence measures are based o

N. R. Tanvir, A. J. Levan, E. Rol, R. L. C. Starling

Gamma-ray bursts are powerful probes of the early universe, but locating and identifying very distant GRBs remains challenging. We report here the discovery of the K-band afterglow of Swift GRB 060923A, imaged within the first hour post-burst, and the faintest so far found. It was not detected in any bluer bands to deep limits, making it a candidate very hig

Boncho P . Bonev, Michael J. Mumma, Hideyo Kawakita, Hitomi Kobayashi

Comet 73P-B/Schwassmann-Wachmann 3 was observed with IRCS/Subaru at geocentric distance of 0.074 AU on UT 10 May 2006. Multiple H2O emission lines were detected in non-resonant fluorescence near 2.9 microns. No significant variation in total H2O production rate was found during the (3 hour) duration of our observations. H2O rotational temperatures and ortho-

Andreas Leopold Knutsen, Angelo Felice Lopez

We study the existence of linear series on curves lying on an Enriques surface and general in their complete linear system. Using a method that works also below the Bogomolov-Reider range, we compute, in all cases, the gonality of such curves. We also give a new result about the positive cone of line bundles on an Enriques surface and we show how this relate

J. G. Esteve, Fernando Falceto

We continue the study of the assignment problem for a random cost matrix. We analyse the number of $k$-cycles for the solution and their dependence on the symmetry of the random matrix. We observe that for a symmetric matrix one and two-cycles are dominant in the optimal solution. In the antisymmetric case the situation is the opposite and the one and two-cy

Jacopo Stoppa

We show that a polarised manifold with a constant scalar curvature Kähler metric and discrete automorphisms is K-stable. This refines the K-semistability proved by S. K. Donaldson.

Andrey Novitsky

Electrodynamic spherical harmonic is a second rank tensor in three-dimensional space. It allows to separate the radial and angle variables in vector solutions of Maxwell&#39;s equations. Using the orthonormalization for electrodynamic spherical harmonic, a boundary problem on a sphere can be easily solved.

Cynthia Rudin, Robert E. Schapire, Ingrid Daubechies

We introduce a useful tool for analyzing boosting algorithms called the ``smooth margin function,&#39;&#39; a differentiable approximation of the usual margin for boosting algorithms. We present two boosting algorithms based on this smooth margin, ``coordinate ascent boosting&#39;&#39; and ``approximate coordinate ascent boosting,&#39;&#39; which are similar

Attila Szolnoki, Matjaz Perc

Evolutionary games are studied where the teaching activity of players can evolve in time. Initially all players following either the cooperative or defecting strategy are distributed on a square lattice. The rate of strategy adoption is determined by the payoff difference and a teaching activity characterizing the donor&#39;s capability to enforce its strate

Roberto Trotta

The application of Bayesian methods in cosmology and astrophysics has flourished over the past decade, spurred by data sets of increasing size and complexity. In many respects, Bayesian methods have proven to be vastly superior to more traditional statistical tools, offering the advantage of higher efficiency and of a consistent conceptual basis for dealing

Huijie Yang, Chuanyang Yin, Guimei Zhu, Baowen Li

The scaling properties of spectra of real world complex networks are studied by using the wavelet transform. It is found that the spectra of networks are multifractal. According to the values of the long-range correlation exponent, the Hust exponent $H$, the networks can be classified into three types, namely, $H>0.5$, $H=0.5$ and $H<0.5$. All real world net

V. L. Golo

The subject of this report is the dynamics of elastic system in conjunction with hydrogen bonds of the DNA. We draw attention to the draw-back of the familiar rod model of the DNA, and make a case of constructing models that could accommodate the intrinsic structure of the DNA. In this respect studying the interplay among the elastic system and the protons o

María Barbero-Liñán, Arturo Echeverrí a-Enríquez, David Martín de Diego, Miguel C. Muñoz-Lecanda

We present a unified geometric framework for describing both the Lagrangian and Hamiltonian formalisms of regular and non-regular time-dependent mechanical systems, which is based on the approach of Skinner and Rusk (1983). The dynamical equations of motion and their compatibility and consistency are carefully studied, making clear that all the characteristi

T. Venturi, S. Giacintucci, D. Dallacasa, R. Cassano

We present the results of the GMRT cluster radio halo survey. The main purposes of our observational project are to measure which fraction of massive galaxy clusters in the redshift range z=0.2--0.4 hosts a radio halo, and to constrain the expectations of the particle re--acceleration model for the origin of the non--thermal radio emission. We selected a com

Giovanni Bussi, Michele Parrinello

We show how to derive a simple integrator for the Langevin equation and illustrate how it is possible to check the accuracy of the obtained distribution on the fly, using the concept of effective energy introduced in a recent paper [J. Chem. Phys. 126, 014101 (2007)]. Our integrator leads to correct sampling also in the difficult high-friction limit. We also

Jerome Martin

Models where the accelerated expansion of our Universe is caused by a quintessence scalar field are reviewed. In the framework of high energy physics, the physical nature of this field is discussed and its interaction with ordinary matter is studied and explicitly calculated. It is shown that this coupling is generically too strong to be compatible with loca

L. Guilbert, J. P. Salvestrini, H. Hassan, M. D. Fontana

The combination of phase, intensity, and contrast effects during electrooptic modulation is theoretically and exper- imentally investigated. One consequence of this combination is the modification of the amplitude of the single-frequency signals which are commonly used as working points for electrooptic mod- ulators and for the measurements of the electroopt