August 2001 arXiv papers — page 22

Ivo Souza, Nicola Marzari, David Vanderbilt

We present a method for obtaining well-localized Wannier-like functions (WFs) for energy bands that are attached to or mixed with other bands. The present scheme removes the limitation of the usual maximally-localized WFs method (N. Marzari and D. Vanderbilt, Phys. Rev. B 56, 12847 (1997)) that the bands of interest should form an isolated group, separated b

Kerry Kuehn, Sarabjit Mehta, Haiying Fu, Edgar Genio

We report new measurements in four cells of the thermal boundary resistance $R$ between copper and $^4$He below but near the superfluid-transition temperature $T_λ$. For $10^{-7} \leq t \equiv 1 - T/T_λ\leq 10^{-4}$ fits of $R = R_0 t^{x_b} + B_0$ to the data yielded $x_b \simeq 0.18$, whereas a fit to theoretical values based on the renormalization-group th

Takuya Yamano

We present the effect of regulations on self-organized market by using biological model of Bak-Sneppen in higher dimensions. This study extends the idea of Cuniberti et.al. The higher-dimensional description of the market suffices less effect of regulation than that of lower one.

A. Bianchi, R. Movshovich, M. Jaime, J. D. Thompson

We present the results of the specific heat and AC magnetic susceptibility measurements of $CeIr_{1-x}Rh_xIn_5$ for x from 0 to 0.5. As x is increased from 0 both quantities reflect the competition between two effects. The first is a suppression of superconductivity below the bulk transition temperature of T$_c = 0.4$ K, which is due to the pair breaking eff

Chris Hillman, H. W. Jiang

Electrically detected electron spin resonance (ESR) is used to study the hyperfine interaction of the two-dimensional electrons and the nuclei of the host lattice in a GaAs/AlGaAs heterostructure. Under the microwave and radio- frequency double excitations, we have observed that the ESR line can be pinned in a very narrow range of magnetic field - in the vic

Yogesh N. Joglekar, Allan H. MacDonald

We present a microscopic theory of ground-state spectral function of bilayer quantum Hall systems that includes interactions between Hartree-Fock quasiparticles and quantum fluctuations of the order parameter field. The collective modes in these systems are properly described only when fluctuations in direct and exchange particle-hole channels are taken into

Anatoly Spitkovsky, Yuri Levin, Greg Ushomirsky

We analyze the global hydrodynamic flow in the ocean of an accreting, rapidly rotating, non-magnetic neutron star in an LMXB during a type I X-ray burst. Our analysis takes into account the rapid rotation of the star and the lift-up of the burning ocean during the burst. We find a new regime for spreading of a nuclear burning front, where the flame is carrie

Robert L. Oldershaw

Sahu et al. recently reported tentative evidence for a large population of "free-floating" planetary-mass objects in a nearby globular cluster. If verified, this discovery is consistent with a prediction that the galactic dark matter has a substantial planetary-mass component.

N. M. McClure-Griffiths, John M. Dickey, B. M. Gaensler, A. J. Green

We report the discovery of two new large HI shells in the direction of the Coalsack nebula. Both shells were observed with the Parkes Radio Telescope as part of the Southern Galactic Plane Survey. The largest shell, GSH 304-00-12, is at a distance of ~1.2 kpc and has derived physical dimensions of 280 x 200 pc. The second shell, GSH 305+01-24, is at a distan

Oleg Y. Gnedin

The existence of quasars at redshift z > 5 indicates that supermassive black holes were present since the very early times. If they grew by accretion, the seeds of mass ~ 10^5 Msun must have formed at z ~ 9. These seed black holes may result from the collapse and dissipation of primordial gas during the early stages of galaxy formation. I discuss the effects

Brad K. Gibson, Yeshe Fenner, Sarah T. Maddison, Daisuke Kawata

Motivated by the apparent order-of-magnitude discrepancy between the observed number of Local Group satellite galaxies, and that predicted by Lambda-CDM hierarchical clustering cosmologies, we explore an alternate suggestion - perhaps the missing satellites are not actually ``missing'', but are instead ``in disguise''. The disguise we conside

M. M. Aggarwal

Results on transverse mass spectra of neutral pions measured at central rapidity are presented for impact parameter selected 158$\cdot A$ GeV Pb + Pb, and Pb + Nb collisions. The distributions cover the range $0.5 \mathrm{GeV}/c^{2} \le m_{T} - m_{0} \le 4 \mathrm{GeV}/c^{2}$. The change of the spectral shape with centrality is studied in detail. In going fr

B. Militzer, D. M. Ceperley, J. D. Kress, J. D. Johnson

We calculate the equation of state of dense deuterium with two ab initio simulations techniques, path integral Monte Carlo and density functional theory molecular dynamics, in the density range of 0.67 < rho < 1.60 g/cc. We derive the double shock Hugoniot and compare with the recent laser-driven double shock wave experiments by Mostovych et al. [1]. We find

Hong-Jian He, Christopher T. Hill, T. Tait

We present a complete study of the vacuum structure of Top Quark Seesaw models of the Electroweak Symmetry Breaking, including bottom quark mass generation. Such models emerge naturally from extra dimensions. We perform a systematic gap equation analysis and develop an improved broken phase formulation for including exact seesaw mixings. The composite Higgs

Xiaohui Fan, Vijay K. Narayanan, Robert H. Lupton, Michael A. Strauss

We present the results from a survey of i-dropout objects selected from ~1550 deg^2 of multicolor imaging data from the Sloan Digital Sky Survey, to search for luminous quasars at z>5.8. Objects with i*-z*>2.2 and z*<20.2 are selected, and follow-up J band photometry is used to separate L and T type cool dwarfs from high-redshift quasars. We describe the dis

D. Kharzeev, E. Levin

We derive a simple analytical scaling function which embodies the predictions of high density QCD on the energy, centrality, rapidity, and atomic number dependences of hadron multiplicities in nuclear collisions. Both centrality and rapidity dependences of hadron multiplicity in $Au-Au$ collisions as measured at RHIC at $\sqrt{s}= 130 {GeV}$ are well describ

B. Aubert

We have studied the B^+/- --> J/psi pi^+/- and B^+/- --> J/psi K^+/- decays using a 20.7 fb-1 data set collected with the BABAR detector. We observe a signal of 51+/-10 B^+/- --> J/psi pi^+/- events and determine the ratio BF(B^+/- --> J/psi pi^+/-)/BF(B^+/- --> J/psi K^+/-) to be [3.91 +/- 0.78 (stat.) +/- 0.19 (syst.)]%. The CP-violating charge asymmetries

Marco Bruni, Cristiano Germani, Roy Maartens

We investigate how braneworld gravity affects gravitational collapse and black hole formation by studying Oppenheimer-Snyder-like collapse on a Randall-Sundrum type brane. Without making any assumptions about the bulk, we prove a no-go theorem: the exterior spacetime on the brane cannot be static, which is in stark contrast with general relativity. We also c

M. Fabbrichesi, M. Piai, G. Tasinato

It has been recently shown that the requirement of anomaly cancellation in a (non-supersymmetric) six-dimensional version of the standard model fixes the field content to the known three generations. We discuss the phenomenological consequences of the cancellation of the local anomalies: the strong CP problem is solved and the fundamental scale of the theory

A. C. Carter, A. J. Bray, M. A. Moore

We introduce the technique of aspect-ratio scaling to study the scale-dependence of interfacial energies in Ising spin glasses, and we show how one can use it to determine the stiffness exponent $θ$ in a clean way, with results that are independent of the domain-wall-forcing boundary conditions imposed on the system. In space dimension d=2 we obtain $θ= -0.2

J. A. F. Heimel, A. De Martino

We study the dynamics of the `batch&#39; minority game with market-impact correction using generating functional techniques to carry out the quenched disorder average. We find that the assumption of weak long-term memory, which one usually makes in order to calculate ergodic stationary states, breaks down when the persistent autocorrelation becomes larger th

Evgeny Podkletnov, Giovanni Modanese

The detection of apparent anomalous forces in the vicinity of high-Tc superconductors under non equilibrium conditions has stimulated an experimental research in which the operating parameters of the experiment have been pushed to values higher than those employed in previous attempts. The results confirm the existence of an unexpected physical interaction.

A. Dedes, H. K. Dreiner, U. Nierste

We analyse the rare decay mode B_s -> mu^+ mu^- in the minimal supergravity scenario (mSUGRA). We find a strong correlation with the muon anomalous magnetic moment (g-2)_mu. An interpretation of the recently measured excess in (g-2)_mu in terms of mSUGRA corrections implies a substantial supersymmetric enhancement of the branching ratio Br(B_s -> mu^+ mu^-):

T. Gorin, T. H. Seligman

In a complex scattering system with few open channels, say a quantum dot with leads, the correlation properties of the poles of the scattering matrix are most directly related to the internal dynamics of the system. We may ask how to extract these properties from an analysis of cross sections. In general this is very difficult, if we leave the domain of isol

J. D. Franson, Michelle M. Donegan

The quantum-mechanical state vector is not directly observable even though it is the fundamental variable that appears in Schrodinger&#39;s equation. In conventional time-dependent perturbation theory, the state vector must be calculated before the experimentally-observable expectation values of relevant operators can be computed. We discuss an alternative f

Sander van Smaalen, Peter Daniels, Lukas Palatinus, Reinhard K. Kremer

High-resolution X-ray diffraction data show that the low-temperature superstructure of alpha-NaV2O5 has an F-centered orthorhombic 2a x 2b x 4c superlattice. A structure model is proposed, that is characterized by layers with zigzag charge order on all ladders and stacking disorder, such that the averaged structure has space group Fmm2. This model is in acco

P. Merlatti

We study the enhancon mechanism for fractional D-branes in conifold and orbifold backgrounds and show how it can resolve the repulson singularity of these geometries. In particular we show that the consistency of the excision process requires that the interior space be not empty. In the orbifold case, we exploit the boundary state formalism to obtain an expl

O. Entin-Wohlman, A. Aharony, Y. Imry, Y. Levinson

Aharonov-Bohm mesoscopic solid-state interferometers yield a conductance which contains a term $\cos(ϕ+β)$, where $ϕ$ relates to the magnetic flux. Experiments with a quantum dot on one of the interfering paths aim to relate $β$ to the dot&#39;s intrinsic Friedel transmission phase, $α_1$. For closed systems, which conserve the electron current (unitarity),

Jes Madsen

Finite lumps of color-flavor locked strange quark matter (CFL-strangelets) are significantly more stable than strangelets without color-flavor locking for wide ranges of parameters, increasing the likelihood of strangelet metastability, or even absolute stability beyond some minimum baryon number $A_{min}$. Whereas bulk CFL strange quark matter is electrical

Zafar Ahmed

We propose that the real spectrum and the orthogonality of the states for several known complex potentials of both types, PT-symmetric and non-PT-symmetric can be understood in terms of currently proposed $η$-pseudo-Hermiticity (Mostafazadeh, quant-ph/0107001) of a Hamiltonian, provided the Hermitian linear automorphism, $η$, is introduced as $e^{-θp}$ which

Jouni Kallunki, Joachim Krug, Miroslav Kotrla

The meander instability of a vicinal surface growing under step flow conditions is studied within a solid-on-solid model. In the absence of edge diffusion the selected meander wavelength agrees quantitatively with the continuum linear stability analysis of Bales and Zangwill [Phys. Rev. B {\bf 41}, 4400 (1990)]. In the presence of edge diffusion a local inst

O. Lisovyy

We derive determinant representations and nonlinear differential equations for the scaled 2-point functions of the 2D Ising model on the cylinder. These equations generalize well-known results for the infinite lattice (Painlevé III equation and the equation for the $τ$-function of Painlevé V).

R. N. Faustov, A. P. Martynenko

The correction to the hydrogen-deuterium isotope shift due to the proton and deuteron polarizability is evaluated on the basis of modern experimental data on the structure functions of inelastic lepton-nucleus scattering. The numerical value of this contribution is equal 63\pm 12 Hz.

V. V. Flambaum, J. S. M. Ginges

Parity and time invariance violating (P,T-odd) nuclear forces produce P,T-odd nuclear moments. In turn, these moments can induce electric dipole moments (EDMs) in atoms through the mixing of electron wavefunctions of opposite parity. The nuclear EDM is screened by atomic electrons. The EDM of an atom with closed electron subshells is induced by the nuclear S

J. Takeya, Yoichi Ando, Seiki Komiya, X. F. Sun

The thermal conductivity κis measured in a series of La_{2-x}Sr_{x}CuO_{4} (x = 0 - 0.22) single crystals down to 90 mK to elucidate the evolution of the residual electronic thermal conductivity κ_{res}, which probes the extended quasiparticle states in the d-wave gap. We found that κ_{res}/T grows smoothly, except for a 1/8 anomaly, above x = 0.05 and shows

Yoichi Ando, Kouji Segawa

Magnetoresistance (MR) in the a-axis resistivity of untwinned YBa_{2}Cu_{3}O_{y} single crystals is measured for a wide range of doping (y = 6.45 - 7.0). The y-dependence of the in-plane coherence length ξ_{ab} estimated from the fluctuation magnetoconductance indicates that the superconductivity is anomalously weakened in the 60-K phase; this gives evidence

Yoichi Ando, Kouji Segawa, Seiki Komiya, A. N. Lavrov

We investigate the manifestation of the stripes in the in-plane resistivity anisotropy in untwinned single crystals of La_{2-x}Sr_{x}CuO_{4} (x = 0.02 - 0.04) and YBa_{2}Cu_{3}O_{y} (y = 6.35 - 7.0). It is found that both systems show strongly temperature-dependent in-plane anisotropy in the lightly hole-doped region and that the anisotropy in YBa_{2}Cu_{3}O

A. Atoyan, C. D. Dermer

An important radiation field for photomeson neutrino production in blazars is shown to be the radiation field external to the jet. Assuming that protons are accelerated with the same power as electrons and injected with a -2 number spectrum, we predict that km^2 neutrino telescopes will detect about 1-to-several neutrinos per year from flat spectrum radio qu

E. W. Piotrowski, J. Sladkowski

We continue the analysis of quantum-like description of markets and economics. The approach has roots in the recently developed quantum game theory and quantum computing. The present paper is devoted to quantum English auction which are a special class of quantum market games. The approach allows to calculate profit intensities for various possible strategie

Alessandra Gatti, Stefano Mancini

We consider the hexagonal pattern forming in the cross-section of an optical beam produced by a Kerr cavity, and we study the quantum correlations characterizing this structure. By using arguments related to the symmetry broken by the pattern formation, we identify a complete scenario of six-mode entanglement. Five independent phase quadratures combinations,

Michal Horodecki, Pawel Horodecki, Ryszard Horodecki, Debbie Leung

We derive the general formula for the capacity of a noiseless quantum channel assisted by an arbitrary amount of noisy entanglement. In this capacity formula, the ratio of the quantum mutual information and the von Neumann entropy of the sender&#39;s share of the noisy entanglement plays the role of mutual information in the completely classical case. A cons

T. -S. Park, L. E. Marcucci, R. Schiavilla, M. Viviani

Using effective field theory, we calculate the S-factor for the hep process in a totally parameter-free formulation. The transition operators are organized according to chiral counting, and their matrix elements are evaluated using the realistic nuclear wave functions obtained in the correlated-hyperspherical-harmonics method. Terms of up to next-to-next-to-

P. Moskal, H. -H. Adam, A. Budzanowski, T. Goetz

A method of measuring the close to threshold meson production in neutron-neutron collisions is described where the momenta of the colliding neutrons can be determined with the accuracy obtainable for the proton-proton reaction. The technique is based on the double quasi-free nn --> nn X^0 reaction, where deuterons are used as a source of neutrons

I. Reichwein, U. Werthenbach, G. Zech

Groove chambers with different pitch and gap height have been tested. Gas amplifications of the order of a few times 10$^{3}$ have been obtained. Combining a groove structure with a GEM pre-amplification foil a gas gain of 10$^{5}$ was reached. The device is robust and can be produced at low cost in large sizes by a laser technique.

D. Korotkin

In these notes we solve a class of Riemann-Hilbert (inverse monodromy) problems with quasi-permutation monodromy groups which correspond to non-singular branched coverings of $\CP1$. The solution is given in terms of Szegö kernel on the underlying Riemann surface. In particular, our construction provides a new class of solutions of the Schlesinger system. We

Corrado Mascia, Kevin Zumbrun

Combining pointwise Green&#39;s function bounds obtained in a companion paper [MZ.2] with earlier, spectral stability results obtained in [HuZ], we establish nonlinear orbital stability of small amplitude viscous shock profiles for the class of dissipative symmetric hyperbolic-parabolic systems identified by Kawashima [Kaw], notably including compressible Na

Joaquim Roe

We study the geometry of the varieties of clusters X_r introduced by Kleiman in the 70&#39;s, showing that for every Enriques diagram D of r vertices the subset Cl(D) of the clusters with Enriques diagram D is locally closed. We study also the relative positions of the subvarieties Cl(D), showing that they do not form a stratification and giving criteria for

N. Aizawa

Simple extensions of peripheric extended twists, introduced recently by Lyakhovsky and Del Olmo, are presented. Explicit form of twisting elements are given and it is shown that the new twists as well as peripheric extended twists are suitable to deform inhomogeneous Lie algebras such as isu(n), iso(n), (1+n) dimensional Schroedinger algebras and Poincare al

Chris Harvey-Fros

We introduce Wilson&#39;s, or Polchinski&#39;s, exact renormalization group, and review the Local Potential Approximation as applied to scalar field theory. Focusing on the Polchinski flow equation, standard methods are investigated, and by choosing restrictions to some sub-manifold of coupling constant space we arrive at a very promising variational approxi

D. S. Gorbunov, V. A. Rubakov, S. M. Sibiryakov

We study tensor perturbations in a model with inflating Randall--Sundrum-type brane embedded in five-dimensional anti-de Sitter (adS$_5$) bulk. In this model, a natural {\it in}-vacuum of gravitons is the vacuum defined in static adS$_5$ frame. We show that this vacuum is, in fact, the same as the {\it in}-vacuum defined in the frame with de Sitter (dS$_4$)

Boyu Hou, Yongqiang Wang, Zhanying Yang, Ruihong Yue

By constructing close one cochain density ${Ω^1}_{2n}$ in the gauge group space we get WZW effective Lagrangian on high dimensional non-commutative space.Especially consistent anomalies derived from this WZW effective action in non-commutative four-dimensional space coincides with those by L.Bonora etc.

T. G. Steele

QCD sum-rules are related to an integral of a hadronic spectral function, and hence must satisfy integral inequalities which follow from positivity of the spectral function. Development of these Holder inequalities and their application to the Laplace sum-rule for pions lead to a lower bound on the average of the non-strange 2 GeV light-quark masses in the M

K. Splittorff, D. Toublan, J. J. M. Verbaarschot

We study QCD with two colors and quarks in the fundamental representation at finite baryon density in the limit of light quark masses. In this limit the free energy of this theory reduces to the free energy of a chiral Lagrangian which is based on the symmetries of the microscopic theory. In earlier work this Lagrangian was analyzed at the mean field level a

Ralf Kuhn, Michael Meyer-Hermann, Ralf Schützhold

We review the results of our previous publication [Phys. Rev. D63, 116001 (2001); hep-ph/0012226] in the light of recent calculations and comments.

D. Bodeker, M. Laine

We discuss the effective action for QCD gauge fields at finite temperatures and densities, obtained after integrating out the hardest momentum scales from the system. We show that a non-vanishing baryon density induces a charge conjugation (C) odd operator to the gauge field action, proportional to the chemical potential. Even though it is parametrically sma

S. Moch, J. A. M. Vermaseren, M. Zhou

We review recent developments in the calculation of deep-inelastic structure functions to next-to-next-to leading order in perturbative QCD. We discuss the impact of these corrections on the determination of the strong coupling alpha_s and the parton distributions.

G. K. Leontaris, A. Prikas, A. Spanou, N. D. Tracas

In various supersymmetric extensions of the Standard Model there appear non-topological solitons due to the existence of U(1) global symmetries associated with Baryon and/or Lepton quantum numbers. Trilinear couplings (A-terms) in the scalar potential break explicitly the U(1) invariance. We investigate numerically the stability of these objects in the case

A. I. Sanda

We point out that time dependent study of four decay modes $B^0(t)\to \Dbar K_S$, $B^0(t)\to D K_S$ $\Bbar^0(t)\to \Dbar K_S$, and $\Bbar^0(t)\to D K_S$ allows us to measure $\sin(ϕ_1-ϕ_2)$ - contrary to previously obtained result that it measures $\sin(2ϕ_1+ϕ_3)$. The time dependent study of $B_s^0(t)\to D^\pm_sK^\mp$, and the study of $B^-\to K^-(D,\Dbar)\

V. Del Duca, W. Kilgore, C. Oleari, C. Schmidt

Real emission corrections to Higgs production via gluon fusion, at order alpha_s^4, lead to a Higgs plus two-jet final state. We present the calculation of these scattering amplitudes, as induced by top-quark triangle-, box- and pentagon-loop diagrams. These diagrams are evaluated analytically for arbitrary top mass m_t. We study the renormalization and fact

Erik Dvergsnes, Per Osland, Nurcan Ozturk

We discuss Bremsstrahlung induced by graviton exchange in proton-proton interactions at hadronic colliders, resulting from gg\to G\to μ^+μ^-γ. Both the ADD and RS scenarios are discussed. Due to the coupling of the graviton to two photons, the cross section has a new kinematical singularity for hard photons. Thus, graviton-induced Bremsstrahlung tends to yie

Kiwoon Choi, Kyuwan Hwang, Wan Young Song

In supersymmetric models with nonzero Majorana neutrino mass, the sneutrino and antisneutrino mix, which may lead to same sign dilepton signals in future collider experiments. We point out that the anomaly-mediated supersymmetry breaking scenario has a good potential to provide an observable rate of such signals for the neutrino masses suggested by the atmos

Yu-Bing Dong, T. Morii, T. Yamanishi

We propose a new formula for extracting the polarized gluon distribution from the large-$p_T$ light hadron pair production for semi-inclusive processes in polarized deep inelastic scattering. In general, a large-$p_T$ hadron pair is produced via photon-gluon fusion(PGF) and QCD Compton at the lowest order of QCD. The PGF gives us a direct information on $Δg$

U. Nierste

If tan beta is large, supersymmetric QCD corrections can become large, putting naive perturbation theory into doubt. I show how these tan-beta-enhanced corrections can be controlled to all orders in alpha_s tanbeta. The result is shown for the decays H^+ -> t b-bar and b -> s gamma.

Andrei Alexandru, Richard W. Haymaker

We show that gauge invariant definition of thin, thick and hybrid center vortices, defined by Kovacs and Tomboulis on SO(3) x Z(2) configurations, can also be defined in SU(2). We make this connection using the freedom of choosing a particular SU(2) representative of SO(3). We further show that in another representative the Tomboulis σ- ηthin vortices are P

Stephen Sharpe, Noam Shoresh

This paper completes the argument that lattice simulations of partially quenched QCD can provide quantitative information about QCD itself, with the aid of partially quenched chiral perturbation theory. A barrier to doing this has been the inclusion of $Φ_0$, the partially quenched generalization of the $η&#39;$, in previous calculations in the partially que

Steven G. Harris, Robert J. low

What is the shape of space in a spacetime? One way of addressing this issue is to consider edgeless spacelike submanifolds of the spacetime. An alternative is to foliate the spacetime by timelike curves and consider the quotient obtained by identifying points on the same timelike curve. In this article we investigate each of these notions and obtain conditio

Robert J Low

A wave-front in a space-time $\cal M$ is a family of null geodesics orthogonal to a smooth spacelike two-surface in $\cal M$; it is of some interest to know how a wave-front can fail to be a smoothly immersed surface in $\cal M$. In this paper we see that the space of null geodesics $\cal N$ of $\cal M$, considered as a contact manifold, provides a natural s

S G Ghosh, A Beesham

We investigate the occurrence and nature of a naked singularity in the gravitational collapse of an inhomogeneous dust cloud described by higher dimensional Tolman-Bondi space-times. The naked singularities are found to be gravitationally strong in the sense of Tipler. Higher dimensions seem to favour black holes rather than naked singularities.

R. S. Markiewicz

Meingast, et al. suggest that in YBCO the pseudogap is associated with preformed pairs. It is shown that in underdoped cuprates there is evidence for two pseudogaps, and superconducting fluctions terminate at the smaller pseudogap.

Colin Denniston, J. M. Yeomans

We report on a novel method of dynamically controlling the boundary conditions at the surface of a nematic liquid crystal using a surface flexoelectric effect. By moving the surface directors we show that one is able to manipulate defects which lie near the surface. This can be used to produce switching of a nematic liquid crystal device between two states w

M. V. Fistul, S. Flach, A. Benabdallah

We present a theoretical study of inhomogeneous dynamic (resistive) states in a single plaquette consisting of three Josephson junctions. Resonant interactions of such a breather state with electromagnetic oscillations manifest themselves by resonant current steps and voltage jumps in the current-voltage characteristics. An externally applied magnetic field

M. V. Simkin, J. Olness

We use a renormalization group method, similar to that developed for random spin chains, to infer information about the layouts of cellular wireless networks.

A. Dulcic, D. Paar, M. Pozek, G. V. M. Williams

We report magnetic field dependent magnetization and microwave impedance measurements on a MgB2 superconductor prepared by high pressure synthesis. We find that the upper critical field is linearly dependent on temperature near Tc and the dc irreversibility field exponent is ~1.4. The microwave data display an excess surface resistance below Tc which is neit

J. -B. Fouet, M. Mambrini, P. Sindzingre, C. Lhuillier

Exact diagonalizations of the spin-1/2 Heisenberg model on the checkerboard lattice have been performed for sizes up to N=36 in the full Hilbert space and N=40 in the restricted subspace of first neighbor dimers. This antiferromagnet does not break SU(2) symmetry and displays long range order in 4-spin S=0 plaquettes. Both the symmetry properties of the spec

J. Kwapien, S. Drozdz, F. Gruemmer, F. Ruf

The correlation matrix formalism is used to study temporal aspects of the stock market evolution. This formalism allows to decompose the financial dynamics into noise as well as into some coherent repeatable intraday structures. The present study is based on the high-frequency Deutsche Aktienindex (DAX) data over the time period between November 1997 and Sep

V. R. Shaginyan

The effect of a quantum phase transition associated with the appearance of the fermion condensate in an electron liquid on the properties of superconductors is considered. It is shown that the electron system in both superconducting and normal states exhibits characteristic features of a quantum protectorate after the point of this fermion-condensation quant

S. Miyashita, N. Nagaosa

Motivated by the experimental observations of resonant tunnelings in the systems with half-integer spin, such as V$_{15}$ and Mn$_4$, we study the mechanism of adiabatic change of the magnetization in systems with the time-reversal symmetry. Within the time-reversal symmetric models, effects of several types of perturbations are investigated. Although tunnel

M. Moskalets, M. Buttiker

Pumping of charge in phase-coherent mesoscopic systems due to the out-of-phase modulation of two parameters has recently found considerable interest. We investigate the effect of inelastic processes on the adiabatically pumped current through a two terminal mesoscopic sample. We find that the loss of coherence does not suppress the pumped charge but rather a

A. A. Sahakyan, S. K. Nikoghosyan, G. N. Yeritsyan

By means of small magnetic field ac susceptibility measurement at 10 kHz we found that the real and imaginary parts of ceramic $YBa_2Cu_3O_ x$ susceptibility in presence of the external low frequency field close to 0.1 Hz exhibit frequency dependence. The wide maximum of hysteresis losses and {\color{black} the exponential dependence} of the {\color{black} e

E. Reister, M. Mueller, K. Binder

We investigate how the dynamics of a single chain influences the kinetics of early stage phase separation in a symmetric binary polymer mixture. We consider quenches from the disordered phase into the region of spinodal instability. On a mean field level we approach this problem with two methods: a dynamical extension of the self consistent field theory for

K. Ivanova, M. Ausloos, T. Ackerman, H. N. Shirer

Specific aspects of time series analysis are discussed. They are related to the analysis of atmospheric data that are pertinent to clouds. A brief introduction on some of the most interesting topics of current research on climate/weather predictions is given. Scaling properties of the liquid water path in stratus clouds are analyzed to demonstrate the applic

C. Kawabata, N. Hayashi, F. Ono

The diboride materials MB2 (M = Mg, Be, Pb, etc.) are discussed on the basis of the 3D Josephson junction array (JJA) model due to Kawabata-Shenoy-Bishop, in terms of the B-B layers in the diborides analogous to the Cu-O ones in the cuprates. We propose a possibility of superconducting materials with the MgB2-type structure which exhibit higher critical temp

Alexander V. Zhukov

I predict the existence of internal spatial currents in a {\it single} macroscopic quantum system, namely in trapped dilute-gas at sufficiently low temperatures, when a Bose-Einstein condensation occurs. The spatial profiles of the wavefunctions of low-lying states in such a system are different due to the inhomogeneity, caused by an asymmetry of external tr

Hsiao-Wen Chen, Jason X. Prochaska, Kenneth M. Lanzetta

We present a detailed analysis of the chemical abundances, ionization state, and origin of a partial Lyman limit system (N(HI) ~ 10^{16} cm^{-2}) at low redshift (z=0.167 towards PKS0405-1219). We also present the first estimate of the total baryons in extended gaseous envelopes around galaxies based on a simple photoionization model for the Lya absorbers. W

S. V. Lebedev, J. P. Chittenden, F. N. Beg, S. N. Bland

We present first results of astrophysically relevant experiments where highly supersonic plasma jets are generated via conically convergent flows. The convergent flows are created by electrodynamic acceleration of plasma in a conical array of fine metallic wires (a modification of the wire array Z-pinch). Stagnation of plasma flow on the axis of symmetry for

E. L. Martin, M. R. Zapatero Osorio, D. Barrado y Navascues, V. J. S. Bejar

We present K-band photometry and low-resolution near-infrared spectroscopy from 1.44 to 2.45 micron of isolated planetary-mass candidate members in the sigma Orionis cluster found by Zapatero Osorio et al. The new data have been obtained with NIRC at the Keck I telescope. All of our targets, except for one, are confirmed as likely cluster members. Hence, we

Anita L. Cochran, William D. Cochran

We report on high spectral resolution observations of comet C/1999 S4 (LINEAR) obtained at McDonald Observatory in June and July 2000. We report unequivocal detections of the O (1S) and O (1D) metastable lines in emission in the cometary spectrum. These lines are well separated from any telluric or cometary emission features. We have derived the ratio of the

Patrick McDonald

The correlation between Lyman-alpha absorption in the spectra of quasar pairs can be used to measure the transverse distance scale at z~2, which is sensitive to the cosmological constant (Omega_Lambda) or other forms of vacuum energy. Using Hydro-PM simulations, I compute the three-dimensional power spectrum of the Lyman-alpha forest flux, P_F(k,mu), from wh

N. A. Bond, C. W. Churchill, J. C. Charlton, S. S. Vogt

We present HIRES/Keck profiles of four extremely strong (W_r > 1.8 A) Mg II absorbers at 1 < z < 2. The profiles display a common kinematic structure, having a sharp drop in optical depth near the center of the profile and strong, black-bottomed absorption on either side. This ``symmetric-inverted&#39;&#39; structure, with a velocity spread of several hundre

A. A. Cole

We present the Two Micron All Sky Survey (2MASS) (J-K, K) color-magnitude diagram for the region within 1 degree of the center of the Sagittarius dwarf spheroidal galaxy. Using the slope of the red giant branch (RGB), we determine a mean metallicity for the main stellar population of [Fe/H] = -0.5 +/-0.2. The Sagittarius RGB possesses a blue tail that overla

Angela V. Olinto, Pasquale Blasi, Craig Tyler

Weakly interacting massive particles (WIMPs) remain the strongest candidates for the dark matter in the Universe. If WIMPs are the dark matter, they will form galactic halos according to the hierarchical clustering observed in N-body simulations. Cold dark matter (CDM) simulations show that large dark matter structures such as galactic and cluster halos are

Christopher W. Mauche, Edward L. Robinson

Using EUV photometry obtained with the Extreme Ultraviolet Explorer (EUVE) satellite and UBVR optical photometry obtained with the 2.7-m telescope at McDonald Observatory, we have detected quasi-coherent oscillations (so-called ``dwarf nova oscillations&#39;&#39;) in the EUV and optical flux of the dwarf nova SS Cygni during its 1996 October outburst. There

Daniel Wolf Savin

Many of the fundamental questions in astrophysics can be addressed using spectroscopic observations of photoionized cosmic plasmas. However, the reliability of the inferred astrophysics depends on the accuracy of the underlying atomic data used to interpret the collected spectra. In this paper, we review some of the most glaring atomic data needs for better

J. P. Osborne, K. N. Borozdin, S. P. Trudolyubov, W. C. Priedhorsky

We present the results of a study of the variability of X-ray sources in the central 30&#39; of the nearby Andromeda Galaxy (M31) based on XMM Performance Verification observations. Two observations of this field, with a total exposure time of about 50 ks, were performed in June and December of 2000. We found 116 sources brighter than a limiting luminosity o

Jochen M. Braun

In this contribution I will present the current status of our project of stellar population analyses and spatial information of both Magellanic Clouds (MCs). The Magellanic Clouds - especially the LMC with its large size and small depth (<300pc) - are suitable laboratories and testing ground for theoretical models of star formation. With distance moduli of 1

Joan Najita, Edwin A. Bergin, Joel N. Ullom

We examine the ability of stellar X-rays to desorb molecules from grains in outer protoplanetary disks. In particular, we consider the possibility of spot heating by X-rays and examine its effectiveness, compared to whole grain heating by X-rays, in sustaining a gas phase abundance of CO. As found in previous studies, whole grain heating is effective only fo

Victor Galitski, K. M. Kuzanyan, D. D. Sokoloff

We investigate symmetry properties of the solar magnetic field in the framework of the linear Parker&#39;s migratory dynamo model. We show that the problem can be mapped onto the well-known quantum-mechanical double-well problem. Using the WKB approximation, we construct analytical solutions for the dipole and quadrupole configurations of the generated magne

P. Cinzano, F. Falchi, C. D. Elvidge

We present the first World Atlas of the zenith artificial night sky brightness at sea level. Based on radiance calibrated high resolution DMSP satellite data and on accurate modelling of light propagation in the atmosphere, it provides a nearly global picture of how mankind is proceeding to envelope itself in a luminous fog. Comparing the Atlas with the U.S.

Alberto D. Bolatto, Joshua D. Simon, Adam Leroy, Leo Blitz

We have obtained ~100 pc resolution CO and ~60 pc resolution Halpha observations of the dwarf spiral galaxy NGC 4605. We use them to derive a high resolution rotation curve and study the central density profile of NGC 4605&#39;s dark matter halo. We find that these observations do not agree with the predictions of most high resolution Cold Dark Matter calcul

Peter N. Meisinger, Michael C. Ogilvie

We develop exact, simple closed form expressions for partition functions associated with relativistic bosons and fermions in odd spatial dimensions. These expressions, valid at high temperature, include the effects of a non-trivial Polyakov loop and generalize well-known high temperature expansions. The key technical point is the proof of a set of Bessel fun