April 2003 arXiv papers — page 5

Michael J. Fromerth, Johann Rafelski

We quantify the limits on quark-antiquark mass differences imposed by the neutral kaon mass system. In particular, we find that an upper limit to the mass difference of 10^{-3} eV exists if mass differences across quark flavors are uncorrelated. In the upcoming antihydrogen experiments this limit on quark mass difference would allow a measurement of electron

S. Brian Edgar, Ola Wingbrant

It is known that some results for spinors, and in particular for superenergy spinors, are much less transparent and require a lot more effort to establish, when considered from the tensor viewpoint. In this paper we demonstrate how the use of dimensionally dependent tensor identities enables us to derive a number of 4-dimensional identities by straightforwar

Abhay Ashtekar, Olaf Dreyer, Jacek Wisniewski

Using ideas employed in higher dimensional gravity, non-expanding, weakly isolated and isolated horizons are introduced and analyzed in 2+1 dimensions. While the basic definitions can be taken over directly from higher dimensions, their consequences are somewhat different because of the peculiarities associated with 2+1 dimensions. Nonetheless, as in higher

Ran Raz

Recent results established exponential lower bounds for the length of any Resolution proof for the weak pigeonhole principle. More formally, it was proved that any Resolution proof for the weak pigeonhole principle, with $n$ holes and any number of pigeons, is of length $Ω(2^{n^ε})$, (for a constant $ε= 1/3$). One corollary is that certain propositional form

Russell Impagliazzo

We survey recent developments in the study of probabilistic complexity classes. While the evidence seems to support the conjecture that probabilism can be deterministically simulated with relatively low overhead, i.e., that $P=BPP$, it also indicates that this may be a difficult question to resolve. In fact, proving that probabilistic algorithms have non-tri

Uriel Feige

An NP-hard combinatorial optimization problem $Π$ is said to have an {\em approximation threshold} if there is some $t$ such that the optimal value of $Π$ can be approximated in polynomial time within a ratio of $t$, and it is NP-hard to approximate it within a ratio better than $t$. We survey some of the known approximation threshold results, and discuss th

Sanjeev Arora

We survey a collective achievement of a group of researchers: the PCP Theorems. They give new definitions of the class \np, and imply that computing approximate solutions to many \np-hard problems is itself \np-hard. Techniques developed to prove them have had many other consequences.

I. Schnell, G. Czycholl, R. C. Albers

The ab-initio many-body method suggested in the preceding paper is applied to the 3d transition metals Fe, Co, Ni, and Cu. We use a linearized muffin-tin orbital calculation to determine Bloch functions for the Hartree one-particle Hamiltonian, and from these obtain maximally localized Wannier functions. Within this Wannier basis all relevant one-particle an

E. Cizmar, J. -H. Park, S. J. Gamble, B. H. Ward

The thermodynamic and magnetic properties of MnCl3(C12H8N2), have been studied down to 2 K. The material is an S = 2 antiferromagnetic linear chain that undergoes long-range ordering to a canted antiferromagnetic state at 23 K. The comparison of magnetic data from polycrystalline samples with the results of specific heat measurements using a pressed pellet o

I. Schnell, G. Czycholl, R. C. Albers

We propose a new, alternative method for ab-initio calculations of the electronic structure of solids, which has been specifically adapted to treat many-body effects in a more rigorous way than many existing ab-initio methods. We start from a standard band-structure calculation for an effective one-particle Hamiltonian approximately describing the material o

W. Janke, P. -E. Berche, C. Chatelain, B. Berche

We report on large-scale Monte Carlo simulations of the three-dimensional 4-state Potts ferromagnet subject to quenched, random bond dilution. For small dilutions the rather strong first-order phase transition of the pure system is found to persist, whereas for larger dilutions the theoretically expected softening to a continuous transition is confirmed. The

Isadore Rudnick, Joseph Rudnick

We show that a viscoelastic dispersion relation for shear waves in normal $^{3}$He at low temperatures follows directly from the Landau theory of normal Fermi liquids. This theoretical result is in accord with the experimental observations of propagating high frequency shear waves that identify normal $^{3}$He as a viscoelastic substance.

Peter J. Chupas, Xiangyun Qiu, Jonathan C. Hanson, Peter L. Lee

An image plate (IP) detector coupled with high energy synchrotron radiation was used for atomic pair distribution function (PDF) analysis, with high probed momentum transfer \Qmax $\leq 28.5$ \RAA from crystalline materials. Materials with different structural complexities were measured to test the validity of the quantitative data analysis. Experimental res

K. Malarz, J. Czaplicki, B. Kawecka-Magiera, K. Kulakowski

Two kinds of evolving trees are considered here: the exponential trees, where subsequent nodes are linked to old nodes without any preference, and the Barabási--Albert scale-free networks, where the probability of linking to a node is proportional to the number of its pre-existing links. In both cases, new nodes are linked to $m=1$ nodes. Average node-node d

Falko Ziebert, Walter Zimmermann

The biopolymers actin and microtubules are often in an ongoing assembling/disassembling state far from thermal equilibrium. Above a critical density this leads to spatially periodic patterns, as shown by a scaling argument and in terms of a phenomenological continuum model, that meets also Onsager's statistical theory of the nematic--to--isotropic transi

M. E. Gehm, S. L. Hemmer, K. M. O'Hara, J. E. Thomas

We derive the elastic collision rate for a harmonically-trapped Fermi gas in the extreme unitarity limit where the s-wave scattering cross section is $σ(k) =4π/k^2$, with $\hbar k$ the relative momentum. The collision rate is given in the form $Γ=γI(T/T_F)$--the product of a universal collision rate $γ=k_B T_F/(6 π\hbar)$ and a dimensionless function of the

W. Vincent Liu, Frank Wilczek

In a recent paper [cond-mat/0303185], Wu and Yip presented calculations that they interpreted as indicating an instability of the interior gap phase -- a new, hybrid superfluid-normal state of matter that we proposed in [PRL 90, 047002 (2003)]. Here we observe that their interpretation does not apply to the situations of most physical interest. Their instabi

X. Zotos

Based on numerical simulations, a study of the high temperature, finite frequency, thermal conductivity $κ(ω)$ of spin-1/2 ladders is presented. The exact diagonalization and a novel Lanczos technique are employed.The conductivity spectra, analyzed as a function of rung coupling, point to a non-diverging $dc-$limit but to an unconventional low frequency beha

A. Cano, A. P. Levanyuk

The present communication is a critical examination of two points relevant to the surface phase transitions of Pb and Sn overlayers on Ge(111). One is connected with the reading of the reported structural data, which lead to some consequences of paramount importance but overlooked up to now. The other point is the seeming contradiction in what concerns to th

Y. Ono, K. Sano

We study a two-band Hubbard model using the dynamical mean-field theory combined with the exact diagonalization method. At the electron density $n=2$, a transition from a band-insulator to a correlated semimetal occurs when the on-site Coulomb interaction $U$ is varied for a fixed value of the charge-transfer energy $Δ$. At low temperature, the correlated se

I. Kuryliszyn-Kudelska, T. Wojtowicz, X. Liu, J. K. Furdyna

High-field magnetic measurements performed with the use of magnetooptical Kerr effect (MOKE) in the polar configuration as well as high-field and low-field magnetotransport studies were carried out on Ga1-xMnxAs epilayers grown by low temperature molecular beam epitaxy, and subsequently annealed under various conditions. The structural investigations by mean

D. K. Sunko, S. Barisic

The effect of antiferromagnetic (AF) correlations is studied in the framework of the three-band (Emery) model, with respect to experiments in BSCCO. We study the pseudogap regime with a central peak. Detailed dispersions of quasiparticle peaks show that one can simultaneously fit Fermi surfaces and ARPES leading-edge energy scales. The band parameter regime

Kazuhiro Sano, Yoshiaki Ono

The multi-orbital Hubbard model in one dimension is studied using the numerical diagonalization method. Due to the effect of the crystal-field splitting $Δ$, the fully polarized ferromagnetism which is observed in the strong coupling regime becomes unstable against the partially polarized ferromagnetism when the Hund's rule coupling $J$ is smaller than a

Carlos Frontera, Diego Rubí, José Navarro, José Luis García-Muñoz

By means of high resolution neutron powder diffraction at low temperature we have characterized the structural details of $\rm La_{x}Sr_{2-x}FeMoO_6$ ($0\leq {\rm x}\leq 0.5$) and $\rm Ca_{x}Sr_{2-x}FeMoO_6$ ($0\leq {\rm x}\leq 0.6$) series of compounds. This study reveals a similar variation of the mean bond-angle \FeOMo in both series. In contrast, the mea

Beom Jun Kim, H. Hong, M. Y. Choi

We consider atoms interacting each other through the topological structure of a complex network and investigate lattice vibrations of the system, the quanta of which we call {\em netons} for convenience. The density of neton levels, obtained numerically, reveals that unlike a local regular lattice, the system develops a gap of a finite width, manifesting ext

Z. Toroczkai, G. Korniss, M. A. Novotny, H. Guclu

We consider massively parallel discrete event simulations where the communication topology among the processing elements is a complex graph. In the case of regular topologies we review recent results on virtual time horizon management. First we analyze the computational scalability of the conservative massively parallel update scheme for discrete event simul

N. Sandler, H. Maei, J. Kondev

Spatial correlations of occupation probabilities, if their decay is not too fast, can change the critical exponents for classical percolation. From numerical studies of electron dynamics in the lowest Landau level (LLL) we demonstrate the quantum analog of this effect. Similar to classical percolation, we find that the extended Harris criterion applies to lo

Liat Ein-Dor, Remi Monasson

We study the dynamics of a backtracking procedure capable of proving uncolourability of graphs, and calculate its average running time T for sparse random graphs, as a function of the average degree c and the number of vertices N. The analysis is carried out by mapping the history of the search process onto an out-of-equilibrium (multi-dimensional) surface g

T. C. G. Reusch, M. Wenderoth, L. Winking, N. Quaas

Scanning Tunnelling Spectroscopy of GaAs(110):Au Schottky contacts in cross-sectional configuration has been used to investigate the in-depth properties of the space charge layer as well as the interface region with nanometer resolution.

Xiao Hu, Masashi Tachiki

B-T phase diagram and phase transitions of interlayer Josephson vortices are investigated. For magnetic fields above a critical value, we find a Kosterlitz-Thouless (KT) type intermediate phase characterized by in-plane two-dimensional, quasi long-range orders (QLROs) of vortex alignment and superconductivity. The transformation to high-temperature normal ph

N. J. Turner, J. M. Stone, J. H. Krolik, T. Sano

We examine the small-scale dynamics of black hole accretion disks in which radiation pressure exceeds gas pressure. Local patches of disk are modeled by numerically integrating the equations of radiation MHD in the flux-limited diffusion approximation. The shearing-box approximation is used, and the vertical component of gravity is neglected. Magneto-rotatio

A. K. H. Kong, R. Di Stefano

We report the results of XMM-Newton observations for an especially luminous supersoft X-ray source (SSS) with bolometric luminosity of 10^39 erg/s in the spiral galaxy NGC 300. The source was detected as a SSS in 1992 and disappeared in subsequent X-ray observations. The source was active again during recent XMM-Newton observations. It appeared to be very so

David M. Smith

Observations of the central radian of the Galaxy by the Reuven Ramaty High Energy Solar Spectroscopy Imager (RHESSI) have yielded a high-resolution measurement of the 1809 keV line from 26Al, detected at 11 sigma significance in nine months of data. The RHESSI result for the width of the cosmic line is 2.03 (+0.78, -1.21) keV FWHM. The best fit line width of

John H. Schwarz

The first part of this report gives a very quick sketch of how string theory concepts originated and evolved during its first 25 years (1968-93). The second part presents a somewhat more detailed discussion of the highlights of the past decade. The final part discusses some of the major problems that remain to be solved.

Dirk Petry

An improved way of taking off-source data for background determination in Cherenkov telescope observations is proposed. Generalizing the traditional concept of taking on-source/off-source observations of equal duration (e.g. 30 minutes ON followed by 30 minutes OFF), Faster Background Determination (FBD) permits an off-source observation with the same zenith

Michael Kappes, Juergen Kerp, Philipp Richter

The Lockman Hole is well known as the region with the lowest neutral atomic hydrogen colum density on the entire sky. We present an analysis of the soft X-ray background radiation towards the Lockman Hole using ROSAT all-sky survey data. This data is correlated with the Leiden/Dwingeloo survey (Galactic HI 21cm-line emission) in order to model the soft X-ray

R. Barnard, J. P. Osborne, U. Kolb, K. N. Borozdin

Four XMM-Newton X-ray observations of the central region of the Andromeda Galaxy (M31) have revealed an X-ray source that varies in luminosity over \~1--3, 10^{38} erg s^{-1} between observations and also displays significant variability over time-scales of a few hundred seconds. The power density spectra of lightcurves obtained in the 0.3--10 keV energy ban

M. Bellazzini, R. Ibata, F. R. Ferraro, V. Testa

We use infrared Color Magnitude Diagrams from the 2-Micron All-Sky Survey (2MASS) to search for stars belonging to the tidal stream of the Sagittarius dwarf spheroidal galaxy (Sgr dSph) around selected Galactic globular clusters. Statistically significant detections are presented for the cases of Pal 12 and NGC 4147, strongly supporting the idea that these c

R. Cornelisse, J. J. M. in 't Zand, F. Verbunt, E. Kuulkers

We present an overview of BeppoSAX Wide Field Cameras observations of the nine most frequent type-I X-ray bursters in the Galactic center region. Six years of observations (from 1996 to 2002) have amounted to 7 Ms of Galactic center observations and the detection of 1823 bursts. The 3 most frequent bursters are GX 354-0 (423 bursts), KS 1731-260 (339) and GS

Oktay H. Guseinov, Askin Ankay, Aytap Sezer, Sevinc O. Tagieva

In this work, we have constructed a relation between the surface brightness ($Σ$) and diameter (D) of Galactic C- and S-type supernova remnants (SNRs). In order to calibrate the $Σ$-D dependence, we have carefully examined some intrinsic (e.g. explosion energy) and extrinsic (e.g. density of the ambient medium) properties of the remnants and, taking into acc

V. Holzwarth, M. Schuessler

Observations of magnetically active close binaries with orbital periods of a few days reveal the existence of starspots at preferred longitudes (with respect to the direction of the companion star). We numerically investigate the non-linear dynamics and evolution of magnetic flux tubes in the convection zoneof a fast-rotating component of a close binary syst

F. Courbin

The determination of the Hubble parameter H_0 is probably one of the most important applications of quasar lensing. The method, based on the measurement of the so-called ``time-delay'' between the lensed images of distant sources, e.g., quasars, and on detailed mass modeling of the potential well responsible for the multiple images, yields an accurac

V. Holzwarth, M. Schuessler

Surface reconstructions of active close binary stars based on photometric and spectroscopic observations reveal non-uniform starspot distributions, which indicate the existence of preferred spot longitudes (with respect to the companion star). We consider the equilibrium and linear stability of toroidal magnetic flux tubes in close binaries to examine whethe

J. M. Cordes, N. D. R. Bhat, T. H. Hankins, M. A. McLaughlin

We analyze the Crab pulsar at ten frequencies from 0.43 to 8.8 GHz using data obtained at the Arecibo Observatory. Giant pulses occur only in the main and interpulse components manifest from radio frequencies to gamma-ray energies. Individual giant pulses reach brightness temperatures of at least $10^{32}$K in our data, which do not resolve the narrowest pul

T. R. Kendall, W. J. de Wit, J. L. Yun

We have performed intermediate resolution (R = 5000), high signal-to-noise H-band spectroscopy of a small, initial sample of three massive embedded young stellar objects (YSOs), using VLT/ISAAC. The sample has been selected from sources characterised in previous literature as being likely of OB spectral type, to be unambiguously associated with bright (H < 1

David Elbaz, Catherine J. Cesarsky

The cosmic infrared background (CIRB) is a record of a large fraction of the emission of light by stars and galaxies over time. The bulk of this emission has been resolved by the Infrared Space Observatory camera. The dominant contributors are bright starburst galaxies with redshift z ~ 0.8; that is, in the same redshift range as the active galactic nuclei r

Sushan Konar, Arnab R. Choudhury

Recently, we have proposed a model for the screening of the magnetic field of an accreting neutron star by the accreted material flowing from the polar regions towards the equator and sinking there underneath the surface (Choudhuri & Konar). In this model it was assumed that the flow pattern remained stationary over time. However, as the surface magnetic fie

B. T. Draine

This review surveys the observed properties of interstellar dust grains: the wavelength-dependent extinction of starlight, including absorption features, from UV to IR; optical luminescence; IR emission; microwave emission; optical, UV, and X-ray scattering by dust; and polarization of starlight and of infrared emission. The relationship between presolar gra

B. T. Draine

Nine lectures reviewing the astrophysics of dust in interstellar clouds. Topics include: (1) Summary of observational evidence concerning interstellar dust: broadband extinction, scattering of starlight, polarization of starlight, spectroscopy of dust, IR and FIR emission, and depletions of grain-forming elements. (2) Optics of interstellar dust grains: diel

M. Maio, L. Baldacci, G. Clementini, C. Greco

We briefly review our photometric and spectroscopic study of RR Lyrae variable stars in the bar of the Large Magellanic Cloud (LMC), that allowed us to reconcile the so-called &#34;short&#34; and &#34;long&#34; distance moduli of the LMC on the value mod_LMC=18.51 +/- 0.085 mag. Then we present preliminary results from the photometric study of a 33&#39; x 34

Demianski, Doroshkevich

We investigate the mass functions of different elements of the Large Scale Structure -- walls, pancakes, filaments and clouds -- and the impact of transverse motions -- expansion and/or compression -- on their statistical characteristics. Using the Zel&#39;dovich theory of gravitational instability we show that the mass functions of all structure elements ar

Luis Dieulefait

We prove the following uniformity principle: if one of the Galois representations in the family attached to a genus two Siegel cusp form of weight $k>3$, &#34;semistable&#34; and with multiplicity one, is reducible (for an odd prime $p$),then all the representations in the family are reducible. This, combined with Serre&#39;s conjecture (which is now a theor

M. Demiański, A. G. Doroshkevich

We present a new method of measuring the power spectrum of initial perturbations to an unprecedently small scale of $\sim$ 10$h^{-1}$ kpc. We apply this method to a sample of 4500 Ly-$α$ absorbers and recover the cold dark matter (CDM) like power spectrum at scales $\geq 300h^{-1}$kpc with a precision of $\sim$ 10%. However at scales $\sim 10 - 300 h^{-1}$kp

Mitsuru Kakizaki, Yoshiteru Ogura, Fumitaka Shima

The triplet Higgs model, which is an extension of the standard model with a weak-scale triplet Higgs boson, is capable of generating small neutrino masses naturally. We investigate lepton flavor violation mediated by the triplet Higgs boson. We stress that various neutrino mass patterns could be distinguished by measuring the lepton flavor violating processe

Han Zhu, Xin-Ran Wang, Jian-Yang Zhu

In network evolution, the effect of aging is universal: in scientific collaboration network, scientists have a finite time span of being active; in movie actors network, once popular stars are retiring from stage; devices on the Internet may become outmoded with techniques developing so rapidly. Here we find in citation networks that this effect can be repre

S. B. Pandey, G. C. Anupama, R. Sagar, D. Bhattacharya

We determine Johnson $B,V$ and Cousins $R,I$ photometric CCD magnitudes for the afterglow of GRB 021211 during the first night after the GRB trigger. The afterglow was very faint and would have been probably missed if no prompt observation had been conducted. A fraction of the so-called ``dark&#39;&#39; GRBs may thus be just ``optically dim&#39;&#39; and req

Mang Feng, Irene D&#39;Amico, Paolo Zanardi, Fausto Rossi

A potential scheme is proposed for realizing a two-qubit quantum gate in semiconductor quantum dots. Information is encoded in the spin degrees of freedom of one excess conduction electron of each quantum dot. We propose to use two lasers, radiation two neighboring QDs, and tuned to blue detuning with respect to the resonant frequencies of individual exciton

P. Zinn-Justin, J. -B. Zuber

Virtual links are generalizations of classical links that can be represented by links embedded in a ``thickened&#39;&#39; surface $Σ\times I$, product of a Riemann surface of genus $h$ with an interval. In this paper, we show that virtual alternating links and tangles are naturally associated with the $1/N^2$ expansion of an integral over $N\times N$ complex

Luis Dieulefait

In a previous article, we have proved a result asserting the existence of a compatible family of Galois representations containing a given crystalline irreducible odd two-dimensional representation. We apply this result to establish new cases of the Fontaine-Mazur conjecture, namely, an irreducible Barsotti-Tate $λ$-adic 2-dimensional Galois representation u

Luis Dieulefait

We prove that any abelian surface defined over $\Q$ of $GL_2$-type having quaternionic multiplication and good reduction at 3 is modular. We generalize the result to higher dimensional abelian varieties with ``sufficiently many endomorphisms&#34;.

Luis Dieulefait

We give a method to solve generalized Fermat equations of type $x^4 + y^4 = q z^p$, for some prime values of $q$ and every prime $p$ bigger than 13. We illustrate the method by proving that there are no solutions for $q= 73, 89$ and 113.

Melvyn B. Nathanson

For the quantum integer [n]_q = 1+q+q^2+... + q^{n-1} there is a natural polynomial multiplication such that [mn]_q = [m]_q \otimes_q [n]_q. This multiplication is given by the functional equation f_{mn}(q) = f_m(q) f_n(q^m), defined on a sequence {f_n(q)} of polynomials such that f_n(0)=1 for all n. It is proved that if {f_n(q)} is a solution of this functi

Jonathan Gratus

A one parameter set of noncommutative complex algebras is given. These may be considered deformation quantisation algebras. The commutative limit of these algebras correspond to the algebra of polynomial functions over a manifold or variety. The topology of the manifold or variety depends on the parameter, varying from nothing, to a point, a sphere, a certai

A. Guillin, R. Liptser

We establish large deviation principle (LDP) for the family of vector-valued random processes $(X^ε,Y^ε),ε\to 0$ defined as $$ X^ε_t=\frac{1}{ε^κ}\int_0^t H(ξ^ε_s,Y^ε_s)ds, dY^ε_t=F(ξ^ε_t,Y^ε_t)dt+ Dε^{1/2-κ}G(ξ^ε_t,Y^ε_t)dW_t,$$ where $W_t$ is Wiener process and $ξ^ε_t$ is fast ergodic diffusion. We show that, under $κ<{1/2}$ or less and Veretennikov-Khasmi

Luis Dieulefait

We prove two results concerning the generalized Fermat equation $x^4+y^4=z^p$. In particular we prove that the First Case is true if $p \neq 7$.

Srdjan Vukmirovic

The pseudo-Riemannian manifold $M=(M^{4n},g), n \geq 2$ is para-quaternionic K\&#34; ahler if $hol(M) \subset sp(n, \RR) \oplus sp(1, \RR).$ If $hol(M) \subset sp(n, \RR),$ than the manifold $M$ is called para-hyperK\&#34; ahler. The other possible definitions of these manifolds use certain parallel para-quaternionic structures in $\End (TM),$ similarly to t

Claus Gerhardt

We prove that the mean curvature $τ$ of the slices given by a constant mean curvature foliation can be used as a time function, i.e. $τ$ is smooth with non-vanishing gradient.

Claus Gerhardt

The existence of closed hypersurfaces of prescribed curvature in semi-riemannian manifolds is proved provided there are barriers.

Graham D. Kribs

A simple argument based on an SU(3) gauged horizontal symmetry is presented that connects the explanation for three generations of matter with the existence of a triplet of right-handed neutrinos. This rationale for right-handed neutrinos is analogous to, but completely independent of, grand unification or extra universal dimensions. A brief discussion of th

G. Duplancic, B. Nizic

We present a generally applicable reduction formalism which makes it possible to express an arbitrary tensor and scalar one-loop Feynman integral, with N external lines and massless propagators, in terms of a basic set of eight fundamental scalar Feynman integrals with 2, 3, and 4 external lines, for arbitrary external kinematics. The formalism is particular

C. Bouchiat

After a summary of the basic three neutrino oscillation formalism we review briefly our present empirical knowledge of the oscillation parameters and conclude that the 2-neutrinos model is adequate to describe the survival probability of the electronic neutrino P(nue->nue). Then we proceed to the evaluation of P(nue->nue) relative to the antineutrinos emitte

M. Guidal, S. Bouchigny, J. -P. Didelez, C. Hadjidakis

We discuss the relations between Generalized Parton Distributions (GPDs) and nucleon resonances. We first briefly introduce the concept of &#34;transition&#34; GPDs. Then we discuss a straightforward application to the modelization of the N-$Δ$ magnetic transition form factor. Finally, we discuss the experimental aspects of the subject and present first prel

G. X. Peng, U. Lombardo, M. Loewe, H. C. Chiang

We present a novel treatment for calculating the in-medium quark condensates. The advantage of this approach is that one does not need to make further assumptions on the derivatives of model parameters with respect to the quark current mass. The normally accepted model-independent result in nuclear matter is naturally reproduced. The change of the quark cond

Jutta Luettmer-Strathmann

When a temperature gradient is applied to a polymer solution, the polymer typically migrates to the colder regions of the fluid as a result of thermal diffusion (Soret effect). However, in recent thermodiffusion experiments on poly(ethylene-oxide) (PEO) in a mixed ethanol/water solvent it is observed that for some solvent compositions the polymer migrates to

Pierre Le Doussal, Kay Joerg Wiese, Pascal Chauve

We study elastic systems such as interfaces or lattices, pinned by quenched disorder. To escape triviality as a result of ``dimensional reduction&#39;&#39;, we use the functional renormalization group. Difficulties arise in the calculation of the renormalization group functions beyond 1-loop order. Even worse, observables such as the 2-point correlation func

Michael Bachmann, Wolfhard Janke

We present a temperature-independent Monte Carlo method for the determination of the density of states of lattice proteins that combines the fast ground-state search strategy of the nPERM chain growth and multicanonical reweighting for sampling the complete energy space. Since the density of states contains all energetic information of a statistical system,

Rudolf A. Roemer, Philipp Cain

We review recent applications of the real-space renormalization group (RG) approach to the integer quantum Hall (QH) transition. The RG approach, applied to the Chalker-Coddington network model, reproduces the critical distribution of the power transmission coefficients, i.e., two-terminal conductances, P_c(G), with very high accuracy. The RG flow of P(G) at

Igor Ya. Erukhimovich, Yaroslav V. Kudryavtsev

An extended generalization of the dynamic random phase approximation (DRPA) for L-component polymer systems is presented. Unlike the original version of the DRPA, which relates the (LxL) matrices of the collective density-density time correlation fumctions and the corresponding susceptibilities of polymer concentrated systems to those of the tracer macromole

Y. C. Chung, M. Heiblum, Y. Oreg, V. Umansky

Fractionally charged quasiparticles in edge states, are expected to condense to a chiral Luttinger liquid (CLL). We studied their condensation by measuring the conductance and shot noise due to an artificial backscatterer embedded in their path. At sufficiently low temperatures backscattering events were found to be strongly correlated, producing a highly no

M. H. Ernst, R. Brito

Analytic solutions $F(v,t)$ of the nonlinear Boltzmann equation in $d$-dimensions are studied for a new class of dissipative models, called inelastic repulsive scatterers, interacting through pseudo-power law repulsions, characterized by a strength parameter $ν$, and embedding inelastic hard spheres ($ν=1$) and inelastic Maxwell models ($ν=0$). The systems a

I. Felner, E. Galstyan, V. P. S. Awana, E. Takayama-Muromachi

RuY1.5Ce0.5Sr2Cu2O10, is not superconducting (SC) and orders magnetically at TM =152 K. The Ru moment at 5K is 0.75 mB. Ferromagnetic hysteresis loops are observed below Tirr= 100 K. At 100 K, the remanent magnetization (Mrem) and the coercive field (HC) become zero. Surprisingly, at Tirr <T< TM a reappearance of antiferromagnetic (AFM) hysteresis loops are

Han Zhu, Jian-Yang Zhu

In spin-lattice models with order parameter conserved, we generalize the idea of spin diffusion incorporating a variety factors as possible driving forces, including the external field and the temperature. The Kawasaki dynamics in the Gaussian model and the one-dimensional Ising model are studied. The Gaussian model is rigorously treated and the critical exp

S. Calchi Novati, Ph. Jetzer, G. Scarpetta, Y. Giraud-Heraud

We report the final analysis of a search for microlensing events in the direction of the Andromeda galaxy, which aimed to probe the MACHO composition of the M31 halo using data collected during the 1998-99 observational campaign at the MDM observatory. In a previous paper, we discussed the results from a first set of observations. Here, we deal with the comp

S. B. Pandey, D. K. Sahu, G. C. Anupama, D. Bhattacharya

The supernova SN 2002ap was discovered in the outer regions of the nearby spiral M74 on January 29.4 UT. Early photometric and spectroscopic observations indicate the supernova belongs to the class of Ic hypernova. Late time (After JD 2452500) light curve decay slopes are similar to that of the hypernovae SN 1997ef and SN 1998bw. We present here the $BVRI$ p

M. Göckeler, R. Horsley, D. Pleiter, P. E. L. Rakow

We perform a quenched lattice calculation of the first moment of twist-two generalized parton distribution functions of the proton, and assess the total quark (spin and orbital angular momentum) contribution to the spin of the proton.

Philipp Hagler, John Negele, Dru Renner, Wolfram Schroers

Calculation of moments of generalized parton distributions in lattice QCD requires more powerful techniques than those previously used to calculate moments of structure functions. Hence, we present a novel approach that exploits the full information content from a given lattice configuration by measuring an overdetermined set of lattice observables to provid

D. Sornette, W. -X. Zhou

We present a systematic algorithm testing for the existence of collective self-organization in the behavior of agents in social systems, with a concrete empirical implementation on the Dow Jones Industrial Average index (DJIA) over the 20th century and on Hong Kong Hang Seng composite index (HSI) since 1969. The algorithm combines ideas from critical phenome

Vladimir V. Kudryashov, Yulian V. Vanne

The independent solutions of the one-dimensional Schrödinger equation are approximated by means of the explicit summation of the leading constituent WKB series. The continuous matching of the particular solutions gives the uniformly valid analytical approximation to the wave functions. A detailed numerical verification of the proposed approximation is perfor

Mario Rabinowitz

This paper is written to provide an insight into the physics and engineering that go into power delivery of the future. Topics covered are Fault Current Limiters (FCL) including Superconducting FCL and Emission Limited FCL; Lightning and Restoration Preparedness; Compressed-Gas-Insulated Delivery; Evaporative Cooling Delivery; Advanced Delivery Technologies

Ji Luo, Chuang Zhang, Bo Liu

By concern of compression of charge density field, the corrected Lorentz force formula and consequent inference is presented. And further radiation frequency property of an individual charge density field in magnetic dipole is analyzed respectively for radiant property of the charged particle and the emitted electromagnetic wave transfer property between the

Matthew B. Kennel, Michael Buhl

A symbolic analysis of observed time series data requires making a discrete partition of a continuous state space containing observations of the dynamics. A particular kind of partition, called ``generating&#39;&#39;, preserves all dynamical information of a deterministic map in the symbolic representation, but such partitions are not obvious beyond one dime

Stjepan Meljanac, Dragutin Svrtan

In this paper we study a collections of operators $a(k)$ satisfying the &#34;$q_{kl} $-canonical commutation relations&#34; $a(k)a^{+}(l)-q_{kl}a^{+}(l)a(k) =δ_{kl} $ (corresponding for $q_{kl}=q$ to Greenberg (infinite) statistics, for $q=\pm 1$ to classical Bose and Fermi statistics).We show that $n!\times n!$ matrices $A_{n}(\{q_{kl}\})$ of scalar product

Stjepan Meljanac, Dragutin Svrtan

In this Colloqium Lecture (by one of the authors (D.S)) a thorough presentation of the authors&#39; research on the subjects, stated in the title, is given. By quite laborious mathematics it is explained how one can handle systems in which each Heisenberg commutation relation is deformed separately. For Hilbert space realizability a detailed determinant comp

Stjepan Meljanac, Ante Perica, Dragutin Svrtan

In this paper we consider energy operator (a free Hamiltonian), in the second-quantized approach, for the multiparameter quon algebras: $a_{i}a_{j}^{\dagger}-q_{ij}a_{j}^{\dagger}a_{i} = δ_{ij}, i,j\in I$ with $(q_{ij})_{i,j\in I}$ any hermitian matrix of deformation parameters. We obtain an elegant formula for normally ordered (sometimes called Wick-ordered

Christian Pauly

We construct families of quartic and cubic hypersurfaces through a canonical curve, which are parametrized by an open subset in a Grassmannian and a Flag variety respectively. Using G. Kempf&#39;s cohomological obstruction theory, we show that these families cut out the canonical curve and that the quartics are birational (via a blowing-up of a linear subspa

Vasantha W. B. Kandasamy

Generally, in any human field, a Smarandache Structure on a set A means a weak structure W on A such that there exists a proper subset B contained in A which is embedded with a stronger structure S. These types of structures occur in our everyday life, that&#39;s why we study them in this book. Thus, as a particular case: A Smarandache semigroup is a semigro

Gregory F. Lawler, Wendelin Werner

We define a natural conformally invariant measure on unrooted Brownian loops in the plane and study some of its properties. We relate this measure to a measure on loops rooted at a boundary point of a domain and show how this relation gives a way to ``chronologically add Brownian loops&#39;&#39; to simple curves in the plane.

Anton Deitmar

A Lefschetz formula is given that relates loops in a regular finite graph to traces of a certain representation. As an application the poles of the Ihara/Bass zeta function are expressed as dimensions of global section spaces of locally constant sheaves.

Vyacheslav Futorny, Alexander Molev, Serge Ovsienko

We study Harish-Chandra representations of Yangian for gl(2). We prove an analogue of Kostant theorem showing that resterited Yangians for gl(2) are free modules over certain maximal commutative subalgebras. We also study the categories of generic Harish-Chandra modules, describe their simple modules and indecomposable modules in tame blocks.

H. Casini, R. Montemayor, Luis F. Urrutia

The construction of dual theories for linearized gravity in four dimensions is considered. Our approach is based on the parent Lagrangian method previously developed for the massive spin-two case, but now considered for the zero mass case. This leads to a dual theory described in terms of a rank two symmetric tensor, analogous to the usual gravitational fiel