June 2004 arXiv papers — page 5

Mohamed Laradji, P. B. Sunil Kumar

The dynamics of phase separation in multi-component bilayer fluid vesicles is investigated by means of large-scale dissipative particle dynamics. The model explicitly accounts for solvent particles, thereby allowing for the very first numerical investigation of the effects of hydrodynamics and area-to-volume constraints. We observed regimes corresponding to

Paul Anderson, Henrik Jeldtoft Jensen, L. P. Oliveira, Paolo Sibani

What features characterise complex system dynamics? Power laws and scale invariance of fluctuations are often taken as the hallmarks of complexity, drawing on analogies with equilibrium critical phenomena[1-3]. Here we argue that slow, directed dynamics, during which the system's properties change significantly, is fundamental. The underlying dynamics is

Subhasis Ghosh, Henny Halimun, Jaewon Choi, Saurabh Lodha

We present a simple and reliable method for making electrical contacts to small organic molecules with thiol endgroups. Nanometer-scale gaps between metallic electrodes have been fabricated by passing a large current through a lithographically-patterned Au-line with appropriate thickness. Under appropriate conditions, the passage of current breaks the Au-lin

J. F. Fernandez, J. J. Alonso

This is the reply to a Comment by I.S.Tupitsyn and P.C.E. Stamp (PRL v92,119701 (2004)) on a letter of ours (J.F.Fernandez and J.J.Alonso, PRL v91, 047202 (2003)).

C. Aku-Leh, J. Zhao, R. Merlin, J. Menendez

The anharmonic properties of the low-frequency E2 phonon in ZnO were measured using impulsive stimulated Raman scattering. At 5 K, the frequency and lifetime are (2.9787 +/- 0.0002) THz and (211 +/- 7) ps. The unusually long lifetime and the high accuracy in the determination of the frequency hold promise for applications in metrology, quantum computation an

E. Cappelluti, P. Paci, C. Grimaldi, L. Pietronero

Assessing the effective relevance of multiband effects in the fullerides is of fundamental importance to understand the complex superconducting and transport properties of these compounds. In this paper we investigate in particular the role of the multiband effects on the electron-phonon (el-ph) properties of the $t_{1u}$ bands coupled with the Jahn-Teller i

Salvo Rizzo, Andrea Rapisarda

We present an analysis of a time series of a wind strength measurements recorded at Florence airport in the period October 2002 - March 2003. The data were taken simultaneously by two runway head anemometers, located at a distance of 900 m, at a frequency of 3.3 10-3 Hz. The data show strong correlations over long time spans over a few tens of hours. We perf

Guilhem Semerjian

This thesis is devoted to the study of dynamical properties of diluted models. These are mean field statistical mechanics systems, but with finite local connectivity. Among other reasons, the interest for these models arises from their deep relationship with combinatorial optimization problems, random $K$-satisfiability for instance. Several analytical descr

Jean-Francois Berret

We review the experimental and theoretical results obtained during the past decade on the structure and rheology of wormlike micellar solutions. We focus on the linear and nonlinear viscoelasticity and emphasize the analogies with polymers. Based on a comprehensive survey of surfactant systems, the present study shows the existence of standard rheological be

H. Hoehler, N. Atodiresei, K. Schroeder, R. Zeller

In this paper we examine the electronic and geometrical structure of impurity-vacancy complexes in Si and Ge. Already Watkins suggested that in Si the pairing of Sn with the vacancy produces a complex with the Sn-atom at the bond center and the vacancy split into two half vacancies on the neighboring sites. Within the framework of density-functional theory w

R. Kosturek, K. Malarz

In this paper a simple (2+1) solid-on-solid model of the epitaxial films growth based on random deposition followed by breaking particle-particle lateral bonds and particles surface diffusion is introduced. The influence of the critical number of the particle-particle lateral bonds $z$ and the deposition rate on the surface roughness dynamics and possible su

R. Asgari, B. Davoudi, M. Polini, G. F. Giuliani

Motivated by a number of recent experimental studies we have revisited the problem of the microscopic calculation of the quasiparticle self-energy and many-body effective mass enhancement in a two-dimensional electron liquid. Our systematic study is based on the many-body local fields theory and takes advantage of the results of the most recent Diffusion Mon

M. C. Cross, A. Zumdieck, Ron Lifshitz, J. L. Rogers

We analyze a model for the synchronization of nonlinear oscillators due to reactive coupling and nonlinear frequency pulling motivated by the physics of arrays of nanoscale oscillators. We study the model for the mean field case of all-to-all coupling, deriving results for the onset of synchronization as the coupling or nonlinearity increase, and the fully l

J. M. Bao, A. V. Bragas, J. K. Furdyna, R. Merlin

A quantum-mechanical many-particle system may exhibit non-local behavior in that measurements performed on one of the particles can affect a second one that is far apart. These so-called entangled states are crucial for the implementation of quantum information protocols and gates for quantum computation. Here, we use ultrafast optical pulses and coherent pu

Michael Potthoff

For a system of correlated electrons, the Luttinger-Ward functional provides a link between static thermodynamic quantities on the one hand and single-particle excitations on the other. The functional is useful to derive several general properties of the system as well as for the formulation of thermodynamically consistent approximations. Its original constr

R. Pfeiffer, Ch. Kramberger, F. Simon, H. Kuzmany

A detailed investigation of the Raman response of the inner tube radial breathing modes (RBMs) in double-wall carbon nanotubes is reported. It revealed that the number of observed RBMs is two to three times larger than the number of possible tubes in the studied frequency range. This unexpected increase in Raman lines is attributed to a splitting of the inne

M. Ghaemi, M. Ghannadi, B. Mirza

A new finite-size scaling approach based on the transfer matrix method is developed to calculate the critical temperature of anisotropic two-layer Ising ferromagnet, on strips of r wide sites of square lattices. The reduced internal energy per site has been accurately calculated for the ferromagnetic case, with the nearest neighbor couplings Kx, Ky (where Kx

V. Bogomolov

The YBa2Cu3O8-x and NaxWO3 superconductors are treated not as an ionic compounds but rather as an arrays of atoms featuring both covalent and metallic bonding. We accept as particle radii the positions of the principal maxima in the radial distribution functions of the charge density, which are very close to the known covalent and metallic radii of atoms whi

A. Tajic, J. Tworzydlo, C. W. J. Beenakker

This paper was withdrawn by the authors. The purpose of this paper was to provide conclusive evidence for the Ehrenfest-time-independence of weak localization, by means of a computer simulation of the coherent backscattering peak on very large systems. (Two orders of magnitude larger than we could reach in cond-mat/0405122 by studying weak localization direc

P. K. Mishra, Sanjay Kumar, Yashwant Singh

We consider a model of self-avoiding walk on a lattice with on-site repulsion and an attraction for every vertex of the walk visited on the surface to study force-induced desorption of a linear polymer chain adsorbed on an attractive surface and use the exact enumeration technique for analyzing how the critical force for desorption $f_c(T)$ depends on the te

Hiroshi Shimahara

Effects of short-range correlations on the Coulomb screening, the phonons, and the pairing interactions are examined in electron-phonon systems. First, we derive a model Hamiltonian of Coulomb interactions which includes both the long-range part v_q and the short-range part U. It is found from the expression of the dielectric function that the strong on-site

Masaki Kawamura, Ryuji Tokunaga, Masato Okada

We previously reported the chaos induced by the frustration of interaction in a non-monotonic sequential associative memory model, and showed the chaotic behaviors at absolute zero. We have now analyzed bifurcation in a stochastic system, namely a finite-temperature model of the non-monotonic sequential associative memory model. We derived order-parameter eq

T. M. Stace, S. D. Barrett

We study the dynamics of a charge qubit, consisting of a single electron in a double well potential, coupled to a point-contact (PC) electrometer using the quantum trajectories formalism. In contrast with previous work, our analysis is valid for arbitrary source-drain bias across the PC, but is restricted to the sub-Zeno limit. We find that the dynamics is s

S. W. Chung, C. S. Tang, C. S. Chu, C. Y. Chang

We study the pumping effects, in both the adiabatic and nonadiabatic regimes, of a pair of \QTR{it}{finite} finger-gate array (FGA) on a narrow channel. Connection between the pumping characteristics and associated mechanisms is established. The pumping potential is generated by ac biasing the FGA pair. For a single pair (N=1) of finger gates (FG's), the

A. Blom, M. A. Odnoblyudov, I. N. Yassievich, K. -A. Chao

We present a unified approach for calculating the properties of shallow donors inside or outside heterostructure quantum wells. The method allows us to obtain not only the binding energies of all localized states of any symmetry, but also the energy width of the resonant states which may appear when a localized state becomes degenerate with the continuous qu

O. Loehmer, M. Kramer, T. Driebe, A. Jessner

We present results of timing measurements of the binary millisecond pulsar PSR J2145-0750. Combining timing data obtained with the Effelsberg and Lovell radio telescopes we measure a significant timing parallax of 2.0(6) mas placing the system at 500 pc distance to the solar system. The detected secular change of the projected semi-major axis of the orbit $\

Andreas A. Berlind, Michael R. Blanton, David W. Hogg, David H. Weinberg

We study the relationship between galaxy luminosity, color, and environment in a cosmological simulation of galaxy formation. We compare the predicted relationship with that found for SDSS galaxies and find that the model successfully predicts most of the qualitative features seen in the data, but also shows some interesting differences. Specifically, the si

Jacques Moret-Bailly

The reliable theory of the evolution of heavy stars predicts the existence of a type of neutron stars which accrete a cloud of dirty hydrogen (accretors). Although they are very small (some hundreds of kilometres), the accretors should be easily observable because the accretion raises the surface temperature over 1 000 000 K, but they are never detected. The

Michael R. Corbin, Kirk T. Korista, Nalaka Kodituwakku, Wolfram Freduling

The abundance of alpha-process elements such as magnesium and carbon relative to iron measured from the broad emission lines of QSOs can serve as a diagnostic of the star formation and chemical enrichment histories of their host galaxies. We investigate the relationship between Fe/Mg and Fe/C abundance ratios and the resulting Fe II / Mg II 2800A and Fe II /

Robert E. Rutledge

We describe an implementation of a semi-automated review system for the astrophysics literature. Registered users identify names under which they publish, and provide scores for individual papers of their choosing. Scores are held confidentially, and combined in a weighted average grade for each paper. The grade is divided among the co-authors as assigned cr

Dharam Vir Lal, A. Pramesh Rao

We have mapped the head-tail radio galaxy, 3C 129 at 240 and 610 MHz using the GMRT and studied the detailed morphology and spectral index variations in this object. This is the first attempt to observe a sample of head-tail sources at low frequencies. We find weak spectral steepening as we go away from the head along the jet. The Crosspiece has a spectral i

Guillermo Torres, Maciej Konacki, Dimitar D. Sasselov, Saurabh Jha

We report high-resolution spectroscopic follow-up observations of the faint transiting planet candidate OGLE-TR-33 (V = 14.7), located in the direction of the Galactic center. Small changes in the radial velocity of the star were detected that suggested initially the presence of a large planet or brown dwarf in orbit. However, further analysis revealed spect

S. S. Hasan, P. Ulmschneider

We aim to identify the physical processes which occur in the magnetic network of the chromosphere and which contribute to its dynamics and heating. Specifically, we study the propagation of transverse (kink) MHD waves which are impulsively excited in flux tubes through footpoint motions. When these waves travel upwards, they get partially converted to longit

P. Kervella, D. Segransan, V. Coude du Foresto

The interferometric data processing methods that we describe in this paper use a number of innovative techniques. In particular, the implementation of the wavelet transform allows us to obtain a good immunity of the fringe processing to false detections and large amplitude perturbations by the atmospheric piston effect, through a careful, automated selection

M. Almudena Prieto, K. Meisenheimer, Olivier Marco, Juha Reunanen

VLT J- to M\p-band adaptive optics observations of the Circinus Galaxy on parsec scales resolve a central bright Ks-band source with a FWHM size of 1.9 $\pm$ 0.6 pc. This source is only visible at wavelengths longward of 1.6 $μ$m and coincides in position with the peak of the [Si VII]~2.48 $μ$m coronal line emission. With respect to the peak of the central o

N. Ryde, M. J. Richter

We report on stellar Mg I emission at 12 um from alpha CMi (Procyon), a star slightly hotter than the Sun. Solar Mg I emission is well-known and its formation was successfully explained in detail by Carlsson et al. (1992). Here, for the first time, we compare synthetic spectra of the emission lines at 12 um with observations of a star other than the Sun. The

Frederick M. Walter, Guy S. Stringfellow, William H. Sherry, Angeliki Field Pollatou

We report on photometric (BVRIJHK) and low dispersion spectroscopic observations of V1647 Ori, the star that drives McNeil's Nebula, between 10 February and 7 May 2004. The star is photometrically variable atop a general decline in brightness of about 0.3-0.4 magnitudes during these 87 days. The spectra are featureless, aside from H-alpha and the Ca II i

C. Alard, S. Colombi

We propose to integrate the Vlasov-Poisson equations giving the evolution of a dynamical system in phase-space using a continuous set of local basis functions. In practice, the method decomposes the density in phase-space into small smooth units having compact support. We call these small units ``clouds'' and choose them to be Gaussians of elliptical

Jean-Loup Puget, Guilaine Lagache, Herve Dole

In recent years it became clear that a population of galaxies radiating most of their power in the far-infrared contribute an important part of the whole star formation activity in the universe. These galaxies emit up to 99% of their energy output in the infrared by dust. The optical properties of dust in galaxies are thus very important to understand this p

Ben Moore, Juerg Diemand, Joachim Stadel

We explore the region of influence of a galaxy cluster using numerical simulations of cold dark matter halos. Many of the observed galaxies in a cluster are expected to be infalling for the first time. Half of the halos at distances of one to two virial radii today have previously orbited through the cluster, most of them have even passed through the dense i

T. Antoni, KASCADE Collaboration

The flux of cosmic-ray induced single hadrons near sea level has been measured with the large hadron calorimeter of the KASCADE experiment. The measurement corroborates former results obtained with detectors of smaller size if the enlarged veto of the 304 m^2 calorimeter surface is encounted for. The program CORSIKA/QGSJET is used to compute the cosmic-ray f

S. Mieske, L. Infante, N. Benitez, D. Coe

The properties of Ultra Compact Dwarf (UCD) galaxy candidates in Abell 1689 (z=0.183) are investigated, based on deep high resolution ACS images. A UCD candidate has to be unresolved, have i<28 (M_V<-11.5) mag and satisfy color limits derived from Bayesian photometric redshifts. We find 160 UCD candidates with 22<i<28 mag. It is estimated that about 100 of t

Y. Q. Chen, P. E. Nissen, G. Zhao

Zn abundances, derived from a model atmosphere analysis of the 6362.35 A ZnI line, are presented for 44 thin disk, 10 thick disk and 8 halo dwarf stars in the metallicity range -1.0 [Fe/H] +0.2. It is found that [Zn/Fe] in thin disk stars shows a slight increasing trend with decreasing metallicity reaching a value [Zn/Fe] ~ +0.1 at [Fe/H] = -0.6. The thick d

Dharam Vir Lal

We have observed a sample of Seyfert (Sy) galaxies with the global Very Long Baseline Interferometry (VLBI) to test the predictions of the unification scheme for the Sy galaxies which hypothesises that Sys of Type 1 and of Type 2 constitute a single population of objects. If Sy 1 and Sy 2 galaxies differ only in the orientation of the axisymmmetric active nu

Pierantonio Cinzano, Cristopher D. Elvidge

We apply the sky brightness modelling technique introduced and developed by Roy Garstang to high-resolution DMSP-OLS satellite measurements of upward artificial light flux and to GTOPO30 digital elevation data in order to predict the brightness distribution of the night sky at a given site in the primary astronomical photometric bands for a range of atmosphe

Kiyotomo Ichiki, Kouji Nakamura

We investigate the cosmological evolution of gravitational waves in Friedman-Robertson-Walker brane world models embedded in a five dimensional anti de-Sitter spacetime. To predict the spectrum of stochastic gravitational background at present generated in the inflationary phase, we numerically calculate the evolution of gravitational waves according to the

Dharam Vir Lal, Prajval Shastri, Denise C. Gabuzda

We have obtained mas-scale resolution very long baseline interferometry (VLBI) images of a sample of Seyfert 1 and Seyfert 2 galaxies at 5 GHz (wavelength, $λ$ = 6 cm). The Seyferts of the two types were chosen to be matched in several orientation-independent properties, primarily in order to rigorously test predictions of the unified scheme. We detected all

Bing Zhang, Abraham Loeb

The binary J0737-3039 A & B includes two pulsars in a highly relativistic orbit. The pulsed radio flux from pulsar B brightens considerably during two portions of each orbit. This phenomenon cannot be naturally triggered by the illumination of $γ$-rays or X-rays from pulsar A or the bow shock around pulsar B. Instead, we explain these periodic flares quantit

Ahmad Idilbi, Xiangdong Ji, Jian-Ping Ma, Feng Yuan

The hadron-energy evolution (Collins and Soper) equation for all the leading-twist transverse-momentum and spin dependent parton distributions is derived in the impact parameter space. Based on the result, we present resummation formulas for the spin structure functions in the semi-inclusive deep inelastic scattering.

S. Hejazian, M. Mirzavaziri, M. S. Moslehian

Let $\mathcal A$ and $\mathcal B$ be two (complex) algebras. A linear map $ϕ:{\mathcal A}\to{\mathcal B}$ is called $n$-homomorphism if $ϕ(a_{1}... a_{n})=ϕ(a_{1})...ϕ(a_{n})$ for each $a_{1},...,a_{n}\in{\mathcal A}.$ In this paper, we investigate $n$-homomorphisms and their relation to homomorphisms. We characterize $n$-homomorphisms in terms of homomorphi

Jingfu Zhang, Wenzhang Liu, Zhiwei Deng, Zhiheng Lu

Quantum circuit network is a set of circuits that implements a certain computation task. Being at the center of the quantum circuit network, the multi-qubit controlled phase shift is one of the most important quantum gates. In this paper, we apply the method of modular structuring in classical computer architecture to quantum computer and give a recursive re

Bo-Yu Hou, Bo-Yuan Hou, Xiao-Hui Wang, Chuan-Hua Xiong

In this paper we interpret the hidden symmetry of the moduli space of IIB superstring on $AdS_{5}\times S^{5}$ in terms of the chiral embedding in $AdS_{5}$, which turns to be the $\mathbb{CP}^{3}$ conformal affine Toda model. We review how the position $μ$ of poles in the Riemann-Hilbert formulation of dressing transformation and how the value of loop param

Jingfu Zhang, Guilu Long, Zhiwei Deng, Wenzhang Liu

The quantum clock synchronization algorithm proposed by I. L. Chuang (Phys. Rev. Lett, 85, 2006(2000)) has been implemented in a three qubit nuclear magnetic resonance quantum system. The effective-pure state is prepared by the spatial averaging approach. The time difference between two separated clocks can be determined by reading out directly through the N

Ahmed Younes, Jon Rowe, Julian Miller

In this paper, we will define a quantum operator that performs the inversion about the mean only on a subspace of the system (Partial Diffusion Operator). This operator is used in a quantum search algorithm that runs in O(sqrt{N/M}) for searching an unstructured list of size N with M matches such that 1<= M<=N. We will show that the performance of the algori

Mohammed-Larbi Labbi

The Gauss-Bonnet curvature of order $2k$ is a generalization to higher dimensions of the Gauss-Bonnet integrand in dimension $2k$, as the usual scalar curvature generalizes the two dimensional Gauss-Bonnet integrand. In this paper, we evaluate the first variation of the integrals of these curvatures seen as functionals on the space of all Riemannian metrics

Shahid Hussain, Douglas W. McKay

High energy particle showers produce coherent Cherenkov radio emission in dense, radio-transparent media such as cold ice. Using PYTHIA and GEANT simulation tools, we make a comparative study among electromagnetic (EM) and hadronic showers initiated by single particles and neutrino showers initiated by multiple particles produced at the neutrino-nucleon even

J. D. McEwen, M. P. Hobson, A. N. Lasenby, D. J. Mortlock

A directional spherical wavelet analysis is performed to examine the Gaussianity of the WMAP 1-year data. Such an analysis is facilitated by the introduction of a fast directional continuous spherical wavelet transform. The directional nature of the analysis allows one to probe orientated structure in the data. Significant deviations from Gaussianity are det

Andre de Gouvea, Carlos Pena-Garay

We explore whether KamLAND and solar data may end up inconsistent when analyzed in terms of two-flavor neutrino oscillations. If this turned out to be the case, one would be led to conclude that there is more new physics, besides neutrino masses and mixing, in the leptonic sector. On the other hand, given that KamLAND and solar data currently agree when anal

J. C. Hidalgo, S. Mendoza

Self-similar solutions to the problem of a strong imploding relativistic shock wave are calculated. These solutions represent the relativistic generalisation of the Newtonian Gouderley-Landau-Stanyukovich problem of a strong imploding spherical shock wave converging to a centre. The solutions are found assuming that the pre-shocked flow has a uniform density

Sebastian F. Brandt, Hagen Kleinert, Axel Pelster

We set up a method for a recursive calculation of the effective potential which is applied to a cubic potential with imaginary coupling. The result is resummed using variational perturbation theory (VPT), yielding an exponentially fast convergence.

Seth Lloyd

This paper examines how black holes might compute in light of recent models of the black-hole final state. These models suggest that quantum information can escape from the black hole by a process akin to teleportation. They require a specific final state and restrictions on the interaction between the collapsing matter and the incoming Hawking radiation for

M. Dugic

We address the following criterion for quantifying the quantum information resources: classically simulable {\it vs.} classically non-simulable information processing. This approach gives rise to existence of a deeper level of quantum information processing--which we refer to as &#34;quantum communication channel&#34;. We particularly show, that following th

Lorenzo Iorio

In this paper we deal analytically with a version of the so called clock paradox in which the moving clock performs a circular motion of constant radius. The rest clock is denoted as (1), the rotating clock is (2), the inertial frame in which (1) is at rest and (2) moves is I and, finally, the accelerated frame in which (2) is at rest and (1) rotates is A. B

A. Ianni, P. Lombardi, G. Ranucci, O. Smirnov

The results of tests of more than 2200 ETL9351 type PMTs for the Borexino detector with the PMT test facility are presented. The PMTs characteristics relevant for the proper detector operation and modeling are discussed in detail.

O. J. E. Maroney

Landauer erasure seems to provide a powerful link between thermodynamics and information processing (logical computation). The only logical operations that require a generation of heat are logically irreversible ones, with the minimum heat generation being $kT \ln 2$ per bit of information lost. Nevertheless, it will be shown logical reversibility neither im

M. Ghaemi, G. A. Parsafar, M. Ashrafizaadeh

A new graphical method is developed to calculate the critical temperature of 2- and 3-dimensional Ising models as well as that of the 2-dimensional Potts models. This method is based on the transfer matrix method and using the limited lattice for the calculation. The reduced internal energy per site has been accurately calculated for different 2-D Ising and

Tatsuro Ito, Kenichiro Tanabe, Paul Terwilliger

Let $K$ denote a field, and let $V$ denote a vector space over $K$ with finite positive dimension. Consider a pair of linear transformations $A:V\to V$ and $A^*:V\to V$ that satisfy both conditions below: (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is diagonal, and the matrix representing $A^*$ is irreducible tridiagona

Paul Terwilliger

Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V\to V$ and $A^*:V\to V$ that satisfy both conditions below: (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is diagonal, and the matrix representing $A^*$ is irreducible tridiago

Paul C. Eklof, Alan H. Mekler, Saharon Shelah

We give a combinatorial equivalent to the existence of a non-free hereditarily separable group of cardinality aleph_1. This can be used, together with a known combinatorial equivalent of the existence of a non-free Whitehead group, to prove that it is consistent that every Whitehead group is free but not every hereditarily separable group is free. We also sh

Saharon Shelah

This paper deals with variety of problems in pcf theory and infinitary combinatorics. We look at normal filters and prc, measures of the size of [lambda]^{<kappa}, pcf-inaccessibility, entangled orders (and narrow Boolean Algebras), measuring prod_{i<kappa}f(i) by a family of ideals and a family of sequences <B_i:i<kappa> with |B_i|<mu_i, and finally we deal

Thomas H. Geisser

We show that the cyclotomic trace map for smooth varieties over number rings can be interpreted as a regulator map and hence are related to special values of $ζ$-functions.

Francois Bergeron, Francois Lamontagne

The purpose of this paper is to give an explicit description of the irreducible decomposition of the multigraded S_n-module of coinvariants of S_n x S_n. Many of the results presented can be extended to analogous questions for other finite reflection group.

A. Mallios, E. E. Rosinger

In an earlier paper of the authors it was shown that the sheaf theoretically based recently developed abstract differential geometry of the first author can in an easy and natural manner incorporate singularities on arbitrary closed nowhere dense sets in Euclidean spaces, singularities which therefore can have arbitrary large positive Lebesgue measure. As al

Tobias J. Hagge

We show that every knot type admits a pair of diagrams that cannot be made identical without using Reidemeister Omega_2-moves. We also show that our proof is compatible with known results for the other move types, in the sense that every knot type admits a pair of diagrams that cannot be made identical without using all of the move types.

Enrico Deotto

Various aspects of Supersymmetry in 1-dimensional systems are analyzed.

Radhey Shyam

We investigate the associated strangeness Lambda K+ and Sigma0 K+ productions in proton-proton collisions within an effective Lagrangian model. The initial interaction between the two nucleons is modeled by the exchange of pi, rho, omega, and sigma mesons and the strangeness production proceeds via excitations of N*(1650), N*(1710), and N*(1720) baryonic res

CDF Collaboration, D. Acosta

We present the results of a search for doubly-charged Higgs bosons (H+/-+/-) decaying to dileptons using ~240/pb of ppbar collision data collected by the CDF II experiment at the Fermilab Tevatron. In our search region, given by same-sign dilepton mass m_ll&#39; > 80 GeV/c^2 (100 GeV/c^2 for dielectron channel), we observe no evidence for doubly-charged Higg

Somdeb Lahiri

We show, that a simple generalization of the Deferred Acceptance Procedure with firms proposing due to Gale and Shapley(1962), yeild outcomes for a two-sided contract choice problem, which necessarily belong to the core and are Weakly Pareto Optimal for firms. Under additional assumptions: (a) given any two distinct workers, the set of yields acheivable by a

M. Poggio, G. M. Steeves, R. C. Myers, N. P. Stern

Spin dynamics of optically excited electrons confined in asymmetric coupled quantum wells are investigated through time resolved Faraday rotation experiments. The inter-well coupling is shown to depend on applied electric field and barrier thickness. We observe three coupling regimes: independent spin precession in isolated quantum wells, incoherent spin tra

Akira Endo, Yasuhiro Iye

We have uncovered a new class of small amplitude magnetoresistance oscillation in unidirectional lateral superlattice (ULSL). The oscillation is observed in a low-field regime, typically |B| =< 0.03 T, as small undulation on top of well-known positive magnetoresistance background. Positions of maxima of the oscillation shift to lower field side with the incr

Satoshi Nishimoto, Florian Gebhard, Eric Jeckelmann

We study the Hubbard model at half band-filling on a Bethe lattice with infinite coordination number in the paramagnetic insulating phase at zero temperature. We use the dynamical mean-field theory (DMFT) mapping to a single-impurity Anderson model with a bath whose properties have to be determined self-consistently. For a controlled and systematic implement

M. Ghaemi, G. A. Parsafar

A new algebraic method is developed to reduce the size of the transfer matrix of Ising and three-state Potts ferromagnets, on strips of width r sites of square and triangular lattices. This size reduction has been set up in such a way that the maximum eigenvalues of both the reduced and original transfer matrices became exactly the same. In this method we wr

M. Ghaemi, B. Mirza, G. A. Parsafar

A numerical method based on the transfer matrix method is developed to calculate the critical temperature of two-layer Ising ferromagnet with a weak inter-layer coupling. The reduced internal energy per site has been accurately calculated for symmetric ferromagnetic case, with the nearest neighbor coupling K1 = K2 = K (where K1 and K2 are the nearest neighbo

S. Bravina, N. Morozovsky, E. A. Eliseev, E. Cattan

The comparative investigation of pyroelectric response modulation frequency dependences of structures of &#34;polar active film-Si substrate&#34; type based on PZT and PVDF and of structures of &#34;polar active film - buffer layer - Si substrate&#34; type based on PZT and porous silicon (por-Si) has been carried out. By photopyroelectric modulation method t

Mitchell C. Begelman, Annalisa Celotti

We argue that the observed `accretion rate gap&#39; - between black holes in radio-loud active galactic nuclei (AGN) accreting at close to the Eddington limit and those accreting at considerably lower rates - can be explained in terms of the adiabatic inflow-outflow (ADIOS) scenario for radiatively inefficient accretion. Whenever the accretion rate falls bel

Dharam Vir Lal, A. Pramesh Rao

We present radio maps of the head-tail radio galaxy, 3C 129 at 240 and 610 MHz using the Giant Metrewave Radio Telescope. We have studied in detail the morphology of the source and the distribution of spectral index over the object. We find large-scale spectral steepening along the jet away from the core. Using synchrotron spectral ageing theory, we infer th

Mason A. Porter, P. G. Kevrekidis

We consider the Gross-Pitaevskii (GP) equation in the presence of periodic and quasiperiodic superlattices to study cigar-shaped Bose-Einstein condensates (BECs) in such potentials. We examine spatially extended wavefunctions in the form of modulated amplitude waves (MAWs). With a coherent structure ansatz, we derive amplitude equations describing the evolut

O. Iguchi, Y. Sota, T. Tatekawa, A. Nakamichi

We study the velocity distribution in spherical collapses and cluster-pair collisions by use of N-body simulations. Reflecting the violent gravitational processes, the velocity distribution of the resultant quasi-stationary state generally becomes non-Gaussian. Through the strong mixing of the violent process, there appears a universal non-Gaussian velocity

Damir Becirevic, Svjetlana Fajfer, Sasa Prelovsek

We discuss the recent experimental observation which suggested that the mass difference between the scalar and pseudoscalar heavy-light mesons is larger for the non-strange states than for the strange ones. After computing the chiral corrections in the heavy quark limit we show that, contrary to experiment, the mass difference in the non-strange case should

Guo-Zhu Liu

We study confinement of matter fields in the effective compact (2+1)-dimensional QED theory of high-$T_{c}$ superconductors. It is shown that the monopole configurations do not affect the propagator of gauge potential $a_μ$. Based on this result, we found that: chiral symmetry breaking and confinement take place simultaneously in the antiferromagnetic state;

Hideaki Kudoh, Yasunari Kurita

We reinvestigate the thermodynamics of black objects (holes and strings) in four-dimensional braneworld models that are originally constructed by Emparan, Horowitz and Myers based on the anti-de Sitter (AdS) C-metric. After proving the uniqueness of slicing the AdS C-metric, we derive thermodynamic quantities of the black objects by means of the Euclidean fo

F. H. Jafarpour, S. R. Masharian

We analytically investigate a 1d branching-coalescing model with reflecting boundaries in a canonical ensemble where the total number of particles on the chain is conserved. Exact analytical calculations show that the model has two different phases which are separated by a second-order phase transition. The thermodynamic behavior of the canonical partition f

Shoju Kudaka, Shuichi Matsumoto

We find a quantum mechanical formulation of proper time for spin 1/2 particles within the framework of the Dirac theory. It is shown that an operator corresponds to the rate of the proper time and that the operator contains terms which oscillate with a very high frequency. We deduce, as an effect of these terms, the existence of an interference between the m

Jens U. Noeckel, Richard K. Chang

An overview is provided over the physics of dielectric microcavities with non-paraxial mode structure; examples are microdroplets and edge-emitting semiconductor microlasers. Particular attention is given to cavities in which two spatial degrees of freedom are coupled via the boundary geometry. This generally necessitates numerical computations to obtain the

Richard Fitzpatrick, Francois L Waelbroeck

The dynamics of a propagating magnetic island interacting with a resistive wall or a static external magnetic perturbation is investigated using two-fluid, drift-MHD theory in slab geometry. In both cases, the island equation of motion is found to take exactly the same form as that predicted by single-fluid MHD theory. Three separate ion polarization terms a

Richard Fitzpatrick, Francois L. Waelbroeck

A set of reduced, 2-D, two-fluid, drift-MHD equations is derived. Using these equations, a complete and fully self-consistent solution is obtained for an isolated magnetic island propagating through a slab plasma with uniform but different ion and electron fluid velocities. The ion and electron fluid flow profiles around the island are uniquely determined, a

David H. Foster, Jens U. Noeckel

Micro-domes based on a combination of metallic and dielectric multilayer mirrors are studied using a fully vectorial numerical basis-expansion method that accurately accounts for the effects of an arbitrary Bragg stack and can efficiently cover a large range of dome shapes and sizes. Results are examined from three different viewpoints: (i) the ray-optics li

T. Berdyyeva, C. D. Woodworth, I. Sokolov

We describe a novel application of atomic force microscopy (AFM) to directly visualize cytoskeletal fibers in human foreskin epithelial cells. The nonionic detergent Triton X-100 in a low concentration was used to remove the membrane, soluble proteins, and organelles from the cell. The remaining cytoskeleton can then be directly visualized in either liquid o

Kartik Srinivasan, Paul E. Barclay, Matthew Borselli, Oskar Painter

We review a novel method for characterizing both the spectral and spatial properties of resonant cavities within two-dimensional photonic crystals (PCs). An optical fiber taper serves as an external waveguide probe whose micron-scale field is used to source and couple light from the cavity modes, which appear as resonant features in the taper&#39;s wavelengt

N. Jachowicz, K. Vantournhout, J. Ryckebusch, K. Heyde

We study neutrino-induced nucleon knockout from nuclei. Expressions for the induced polarization are derived within the framework of the independent-nucleon model and the non-relativistic plane-wave approximation. Large dissimilarities in the nucleon polarization asymmetries are observed between neutrino- and antineutrino-induced processes. These asymmetries