September 2000 arXiv papers — page 6

T. Maihara, F. Iwamuro, H. Tanabe, T. Taguchi

Deep near-infrared images of a blank 2'x2' section of sky near the Galactic north pole taken by Subaru Telescope are presented. The total integration times of the J and K' bands are 12.1 hours and 9.7 hours, resulting in 5-sigma limiting magnitudes of 25.1 and 23.5 mag, respectively. The numbers of sources within these limiting magnitudes found w

A. L. Roy, A. S. Wilson, J. S. Ulvestad, E. J. M. Colbert

We have used the Very Long Baseline Array at 5 GHz to image the nucleus of NGC 1068 at two epochs separated by 2.92 yr. No relative motion was detected between the high brightness-temperature knots within components NE and C relative to the nuclear component S1, placing an upper limit of 0.075 c on the relative component speeds at distances of 21 pc and 43 p

A. D. Dolgov, P. D. Naselsky, I. D. Novikov

We discuss the hypothesis that the cosmological baryon asymmetry and entropy were produced in the early Universe by the primordial black hole (PBHs) evaporation.

R. N. Manchester

There are many reasons why it is important to increase the number of known pulsars. Not only do pulsar searches continue to improve statistical estimates of, for example, pulsar birthrates, lifetimes and the Galactic distribution, but they continue to turn up interesting and, in some cases, unique individual pulsars. In the early days of pulsar astronomy, th

Stephen P. Maran, George Sonneborn, Chun S. J. Pun, Peter Lundqvist

Two-dimensional spectra of Supernova 1987A were obtained on 1998 November 14-15 (4282 days after outburst) with the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST). The slit sampled portions of the inner circumstellar ring at the east and west ansae as well as small sections of both the northern and southern outer rings.

Oleg Tchernyshyov

The physics of a parity anomaly, potentially observable in a narrow-gap semiconductor, is revisited. Fradkin, Dagotto, and Boyanovsky have suggested that a Hall current of anomalous parity can be induced by a Peierls distortion on a domain wall. I argue that a perturbation inducing the parity anomaly must break the time reversal symmetry, which rules out the

Shang-Yung Wang

The quantum kinetics of photons is studied directly in real time by implementing the dynamical renormalization group. In contrast to conventional approach, the dynamical renormalization group method consistently includes off-shell (energy non-conserving) effects and accounts for time-dependent collisional kernel. To lowest order we find that in the relaxatio

James T. Liu, H. Sati

It has recently been shown that the Randall-Sundrum brane-world may be obtained from an appropriate doubled D3-brane configuration in type IIB theory. This corresponds, in five dimensions, to a sphere compactification of the original IIB theory with a non-trivial breathing mode supporting the brane. In this paper, we shall study the supersymmetry of this red

S. Kadlecek, J. Sebby, R. Newell, T. G. Walker

We demonstrate a new method for non-destructive imaging of laser-cooled atoms. This spatial heterodyne technique forms a phase image by interfering a strong carrier laser beam with a weak probe beam that passes through the cold atom cloud. The figure of merit equals or exceeds that of phase-contrast imaging, and the technique can be used over a wider range o

Zurab Berezhiani, Leonida Gianfagna, Maurizio Giannotti

A new possibility for solving the strong CP-problem is suggested,which assumes that apart of the ordinary world of observable particles described by standard model, there exits a mirror sector of particles and two sectors share the same Peccei-Quinn symmetry realized {\it a là} Weinberg-Wilczek model. The mirror gauge group is completely analogous to that of

P. Ramadevi, Tapobrata Sarkar

We explicitly show that the new polynomial invariants for knots, upto nine crossings, agree with the Ooguri-Vafa conjecture relating Chern-Simons gauge theory to topological string theory on the resolution of the conifold.

S. M. Lietti, A. A. Natale, C. G. Roldao, R. Rosenfeld

We investigate the sensitivity of the heavy ion mode of the LHC to anomalous Higgs boson couplings to photons, H-photon-photon, through the analysis of the processes photon photon to b anti-b and photon photon to photon photon in peripheral heavy ion collisions. We suggest cuts to improve the signal over background ratio and determine the capability of LHC t

J. C. Fabris, A. M. Pelinson, I. L. Shapiro

In the very early Universe matter can be described as a conformal invariant ultra-relativistic perfect fluid, which does not contribute, on classical level, to the evolution of the isotropic and homogeneous metric. However, in this situation the vacuum effects of quantum matter fields become important. The vacuum effective action depends, essentially, on the

Debashis Ghoshal, Ashoke Sen

It has been shown recently that the background independent open string field theory provides an exact description of the tachyon condensation on unstable D-branes of bosonic string theory. In this analysis the overall normalisation of the action was chosen so that it reproduces the conjectured relations involving tachyon condensation. In this paper we fix th

J. Houdayer, F. Krzakala, O. C. Martin

We numerically extract large-scale excitations above the ground state in the 3-dimensional Edwards-Anderson spin glass with Gaussian couplings. We find that associated energies are O(1), in agreement with the mean field picture. Of further interest are the position-space properties of these excitations. First, our study of their topological properties show t

Daniela Zanon

We consider noncommutative {\cal N}=4 supersymmetric U(N) Yang-Mills theory. Using the {\cal N}=1 superfield formalism and the background field method we compute one-loop four point contributions to the effective action and compare the result with the field theory limit from open string amplitudes in the presence of a constant B-field.

Betti Hartmann, Burkhard Kleihaus, Jutta Kunz

We construct monopole solutions in SU(2) Einstein-Yang-Mills-Higgs theory, carrying magnetic charge n. For vanishing and small Higgs selfcoupling, these multimonopole solutions are gravitationally bound. Their mass per unit charge is lower than the mass of the n=1 monopole. For large Higgs selfcoupling only a repulsive phase exists.

S. F. King, M. Oliveira

We analyse a supersymmetric string-inspired model of all fermion masses and mixing angles based on the Pati-Salam $SU(4)\times SU(2)_L \times SU(2)_R$ gauge group supplemented by a $U(1)_X$ flavour symmetry. The model involves third family Yukawa unification and predicts the top mass and the ratio of the vacuum expectation values $\tan β$. The model also pro

J. C. Collins, F. Hautmann

We address the problem of decomposing graphs in perturbative QCD into terms associated with particular regions. Motivated by asking how to incorporate next-to-leading order (NLO) QCD corrections in parton-shower algorithms, we require that: (a) The integrand for the hard part is to be integrable even if the corrections are applied to a process that is not in

Silvia Anjos

In this paper we discuss the topology of the symplectomorphism group of a product of two 2-dimensional spheres when the ratio of their areas lies in the interval (1,2]. More precisely we compute the homotopy type of this symplectomorphism group and we also show that the group contains two finite dimensional Lie groups generating the homotopy. A key step in t

Hongsong Chou

We generalize the derivation of dynamo coefficient $α$ of Field et al (1999) to include the following two aspects: first, the de-correlation times of velocity field and magnetic field are different; second, the magnetic Prandtl number can be arbitrary. We find that the contributions of velocity field and magnetic field to the $α$ effect are not equal, but af

Alexei Tsygvintsev

We study the planar three-body problem and prove the absence of a complete set of complex meromorphic first integrals in a neighborhood of the Lagrangian solution.

Simon A. King

We introduce a numerical isomorphism invariant p(T) for any triangulation T of S^3. Although its definition is purely topological (inspired by the bridge number of knots), p(T) reflects the geometric properties of T. Specifically, if T is polytopal or shellable then p(T) is `small' in the sense that we obtain a linear upper bound for p(T) in the number n

Gilad Perez

We present a model based on an O(3) flavor symmetry and a minimal extension of the scalar sector to induce hierarchical breaking, O(3) -> O(2) -> SO(2) -> nothing. The model naturally accounts for all the known lepton parameters and yields various interesting predictions for others: (i) Neutrinos are nearly degenerate, m_ν\sim 0.1 eV; (ii) The solar neutrino

Theodore E. Liolios

Two models are presented for the description of the electron screening effects that appear in laboratory nuclear reactions at astrophysical energies. The two-electron screening energy of the first model agrees very well with the recent LUNA experimental result for the break-up reaction $% He3(He3,2p)He^{4}$, which so far defies all available theoretical mode

C. W. Gardiner, A. S. Bradley

We compute an approximate set of longitudinal quasiparticle modes for a hydrogen condensate as produced in the MIT experiments. An expansion in quasiparticles using a simple one-dimensional Bogoliubov picture shows however that at the high temperatures (\approx 44muK) and in the very shallow trap employed (omega_z = 2π\times 10.2Hz) the contribution to the d

J. Kluson

In this paper we would like to show that from N non-BPS D0-branes in type IIB theory we can obtain all BPS and non-BPS D-branes through the tachyon condensation in the large N limit.

Sz. Farkas, Z. Kurucz, M. Weiner

A great number of problems of relativistic position in quantum mechanics are due to the use of coordinates which are not inherent objects of spacetime, cause unnecessary complications and can lead to misconceptions. We apply a coordinate-free approach to rule out such problems. Thus it will be clear, for example, that the Lorentz covariance of position, requ

Christopher A. Fuchs, Kurt Jacobs

In this paper we give a new way to quantify the folklore notion that quantum measurements bring a disturbance to the system being measured. We consider two observers who initially assign identical mixed-state density operators to a two-state quantum system. The question we address is to what extent one observer can, by measurement, increase the purity of his

Kim J. Bostroem

Based on the concept of many-letter theory, an observable is defined measuring the raw quantum information content of single messages. A general characterization of quantum codes using the Kraus representation is given. Compression codes are defined by their property of decreasing the expected raw information content of a given message ensemble. Lossless qua

C. J. Erickson, D. Levron, W. Happer, S. Kadlecek

Resonances in the magnetic decoupling curves for the spin relaxation of dense alkali-metal vapors prove that much of the relaxation is due to the spin-axis interaction in triplet dimers. Initial estimates of the spin-axis coupling coefficients for the dimers are 290 MHz for Rb; 2500 MHz for Cs.

V. I. Korobov

The recently reported precise experimental determination of the dipole polarizability of the H_2^+ molecular ion ground state [P.L. Jacobson, R.A. Komara, W.G. Sturrus, and S.R. Lundeen, Phys. Rev. A 62, 012509 (2000)] reveals a discrepancy between theory and experiment of about 0.0007a_0^3, which has been attributed to relativistic and QED effects. In prese

Miklos Gyulassy

QCD predicts the existence of a new partonic Yukawa phase above a critical temperature $T_c\sim 150$ MeV. I review some of the key observables which will be used in heavy ion reactions to search for this new phase at RHIC. Systematics of collective observables ($N_{ch},E_\perp)$, flow patterns, meson interferometry, jet quenching, and $J/ψ$ suppression are d

F. Gabbiani

The phase shifts for the higher partial waves in the spin quartet and doublet channel of nd scattering are presented at next-to-leading and next-to-next-to-leading order in an effective field theory in which pions are integrated out. The results agree with both phase shift analyses and potential model calculations.

Damian H. Zanette, Susanna C. Manrubia

A stochastic model for the evolution of a growing population is proposed, in order to explain empirical power-law distributions in the frequency of family names as a function of the family size. Preliminary results show that the predicted exponents are in good agreement with real data. The evolution of family-name distributions is discussed in the frame of v

Bruno Eckhardt, Siegfried Grossmann, Detlef Lohse

We interpret measurements of the Reynolds number dependence of the torque in Taylor-Couette flow by Lewis and Swinney [Phys. Rev. E 59, 5457 (1999)] and of the pressure drop in pipe flow by Smits and Zagarola, [Phys. Fluids 10, 1045 (1998)] within the scaling theory of Grossmann and Lohse [J. Fluid Mech. 407, 27 (2000)], developed in the context of thermal c

Andrey Tsiganov

We discuss some special classes of canonical transformations of the extended phase space, which relate integrable systems with a common Lagrangian submanifold. Various parametric forms of trajectories are associated with different integrals of motion, Lax equations, separated variables and action-angles variables. In this review we will discuss namely these

Justin Sawon

Rozansky and Witten proposed a 3-dimensional sigma-model whose target space is a hyperkähler manifold. They conjectured that this theory has an associated TQFT, with Hilbert spaces given by certain cohomology groups of the hyperkähler manifold. On the other hand, there is a certain modified TQFT constructed by Murakami and Ohtsuki using the universal quantum

Gabriel Nagy

We prove that the value of the quasi-trace on an idempotent element in a AW*-factor of type II_1 is the same as the dimension of its left (or right) support.

Martin Schlichenmaier

In this lecture results on the Berezin-Toeplitz quantization of arbitrary compact quantizable Kaehler manifolds are presented. These results are obtained in joint work with M. Bordemann and E. Meinrenken. The existence of the Berezin-Toeplitz deformation quantization is also covered. Recent results obtained in joint work with A. Karabegov on the asymptotic e

Alexei Tsygvintsev

We study the planar three-body problem and prove the absence of a complete set of complex meromorphic first integrals in a neighborhood of the Lagrangian solution. We use the Ziglin's method and study the monodromy group of the corresponding normal variational equations.

Rachel Taillefer

In this paper, we compute the cyclic homology of the Taft algebras and of their Auslander algebras. Given a Hopf algebra $Λ,$ the Grothendieck groups of projective $Λ-$modules and of all $Λ-$modules are endowed with a ring structure, which in the case of the Taft algebras is commutative (\cite{C2}, \cite{G}). We also describe the first Chern character for th

Yoshio Uwano

In the series of papers [1-4], the inverse problem of the Birkhoff-Gustavson normalization was posed and studied. To solve the inverse problem, the symbolic-computing program named ANFER (Algorithm of Normal Form Expansion and Restoration) is written up, with which a new aspect of the Bertrand and Darboux integrability condition is found \cite{Uwano2000}. In

Robert Friedman, John W. Morgan

Given a del Pezzo surface of degree d between 1 and 6, possibly with rational double points, we construct a "tautological" holomorphic G-bundle over X, where G is a reductive group which is an appropriate conformal form of the simply connected complex linear group whose coroot lattice is isomorphic to the primitive cohomology of the minimal resolutio

Stefan Kebekus

Let X be a complex Fano-manifolds with second Betti-number 1 which carries a contact structure. It follows from previous work that such a manifold can always be covered by lines. Thus, it seems natural to consider the geometry of lines in greater detail. In this brief note we show that if x in X is a general point, then all lines through x are smooth. If X i

M. Porrati, A. Starinets

We discuss various aspect of the holographic correspondence between 5-d gravity and 4-d field theory. First of all, we describe deformations of N=4 Super Yang-Mills (SYM) theories in terms of 5-d gauged supergravity. In particular, we describe N=0 and N=1 deformations of N=4 SYM to confining theories. Secondly, we describe recent proposals for the holographi

Emil Nissimov, Svetlana Pacheva

This work consist of two interrelated parts. First, we derive massive gauge-invariant generalizations of geometric actions on coadjoint orbits of arbitrary (infinite-dimensional) groups $G$ with central extensions, with gauge group $H$ being certain (infinite-dimensional) subgroup of $G$. We show that there exist generalized ``zero-curvature'' repres

Jan Plefka

We derive the vertex operators that are expected to govern the emission of the massless d=11 supermultiplet from the supermembrane in the light cone gauge. Our results immediately imply the linear coupling of matrix theory to an arbitrary supergravity background to all orders in anticommuting coordinates. Finally we address the definition of n-point tree lev

S. J. Gates,, M. T. Grisaru, M. E. Knutt, S. Penati

We use the method of Banerjee, Banerjee and Mitra and minimal homotopy paths to compute the consistent gauge anomaly for several superspace models of SSYM coupled to matter. We review the derivation of the anomaly for N=1 in four dimensions and then discuss the anomaly for two-dimensional models with (2,0) supersymmetry.

Akira Kokado, Gaku Konisi, Takesi Saito

The Dirac quantization is performed for the constrained system of the open string with different charges located at both ends in the constant background B field. Noncommutativity reveals to commutators [X, X], [P, P] and also [X,P] at both ends of the string. We consider a dependence on the change of the "cyclotron frequency" of the charged string. T

M. Cvetic, H. Lu, C. N. Pope

We present a systematic study of a new type of consistent ``Brane-world Kaluza-Klein Reduction,'' which describe fully non-linear deformations of co-dimension one objects that arise as solutions of a large class of gauged supergravity theories in diverse dimensions, and whose world-volume theories are described by ungauged supergravities with one hal

Manoelito M de Souza

The physical meaning and the geometrical interpretation of causality implementation in classical field theories are discussed. Local causality are kinematical constraints dynamically implemented via solutions of the field equations, but in a limit of zero-distance from the field sources part of these constraints carries a dynamical content that explains old

J. Dias de Deus, R. Ugoccioni

We show that the Dual String Model with fusion leads, in heavy ion collisions, to strict saturation of the particle (pseudo-)rapidity density, normalised to the number of participant nucleons, as that number increases. Asymptotically, as the centre-of-mass energy goes to infinity with the number of participants fixed, this density approaches the nucleon-nucl

A. Barducci, R. Casalbuoni, R. Gatto, G. Pettini

The ratio of the sigma mass to the pion mass at finite temperatures and densities provides for a quantitative signal of chiral symmetry breaking. We calculate this ratio by using an extension to finite chemical potential of the field theoretic composite operator formalism as applied to QCD. The calculation is limited to regions of the phase diagram where onl

L. Silvestrini

After briefly reviewing the status of epsilon'/epsilon in the Standard Model, I discuss SUSY contributions to epsilon'/epsilon, K^+ to pi^+ nu bar nu, K_L to pi^0 nu bar nu and K_L to pi^0 e^+ e^-. While in the simplest case of the MSSM with Minimal Flavour Violation the main effect is a suppression of these transitions with respect to the Standard M

F. Benatti, R. Floreanini

In the framework of open quantum systems, the propagation of polarized photons can be effectively described using quantum dynamical semigroups. These extended time-evolutions induce irreversibility and dissipation. Planned, high sensitive experiments, both in the laboratory and in space, will be able to put stringent bounds on these non-standard effects.

Mario Atance, Barbara Schrempp

In the framework of the low energy chiral Lagrangian renormalization group equations for the couplings are investigated up to order p^6 -- as well for SU(2)xSU(2) as for SU(3)xSU(3) chiral symmetry. Infrared attractive fixed points for ratios of O(p^4) couplings are found, which turn out to agree with the values determined from experiment in a surprisingly l

Afanasiev, NA49 collaboration

We present the first measurement of fluctuations from event to event in the production of strange particles in collisions of heavy nuclei. The ratio of charged kaons to charged pions is determined for individual central Pb+Pb collisions. After accounting for the fluctuations due to detector resolution and finite number statistics we derive an upper limit on

Aleph, CDF, Delphi, L3

Combined results on b-hadron lifetimes, b-hadron production rates, B^0_d - \bar{B^0_d} and B^0_s -\bar{B^0_s} oscillations, the decay width difference between the mass eigenstates of the B^0_s -\bar{B^0_s} system, and the values of the CKM matrix elements | V_cb | and \Vert V_ub | are obtained from published and preliminary measurements available in Summer 9

V. Skalsky

In the standard model of universe the increase in mass of our observed expansive Universe is explained by the assumption of emerging the matter objects on the horizon (of the most remote visibility). However, the physical analysis of the influence of this assumption on the velocity of matter objects shows unambiguously that this hypothetical assumption contr

H. Arthur Weldon

A general formulation of spinor fields in Riemannian space-time is given without using vierbeins. The space-time dependence of the Dirac matrices required by the anticommutation relation {γ_μ,γ_ν}=2g_{μν} determines the spin connection. The action is invariant under any local spin base transformations in the 32 parameter group Gl(4,c) and not just under loca

Carlos F Sopuerta

The imposition of symmetries or special geometric properties on submanifolds is less restrictive than to impose them in the full space-time. Starting from this idea, in this paper we study irrotational dust cosmological models in which the geometry of the hypersurfaces generated by the fluid velocity is flat, which supposes a relaxation of the restrictions i

David D. Song, Elizabeth Winstanley

We consider the generalized second law of black hole thermodynamics in the light of quantum information theory, in particular information erasure and Landauer's principle (namely, that erasure of information produces at least the equivalent amount of entropy). A small quantum system outside a black hole in the Hartle-Hawking state is studied, and the qua

T. Dereli, O. Sarioglu

We obtain a general class of exact solutions to topologically massive gravity with or without a negative cosmological constant. In the first case, we show that the solution is supersymmetric and asymptotically approaches the extremal BTZ black hole solution, while in the latter case it goes to flat space-time.

Marshall Bern, David Eppstein

We give algorithms for computing the regression depth of a k-flat for a set of n points in R^d. The running time is O(n^(d-2) + n log n) when 0 < k < d-1, faster than the best time bound for hyperplane regression or for data depth.

A. Mitsutake, Y. Okamoto

We propose a new method for the determination of the weight factor for the simulated tempering method. In this method a short replica-exchange simulation is performed and the simulated tempering weight factor is obtained by the multiple-histogram reweighting techniques. The new algorithm is particularly useful for studying frustrated systems with rough energ

Eldon G. Emberly, George Kirczenow

We present a self-consistent method for the evaluation of the electronic current flowing through a multi-terminal molecular wire. The method is based on Buttiker- Landauer theory which relates the current to one-electron scattering probabilities. The scattering problem is solved using a tight-binding form for Schroedinger&#39;s equation that incorporates a s

Toru Sakai, Olivier Cepas, Timothy Ziman

The direct electron spin resonance (ESR) absorption between a singlet ground state and the triplet excited states of spin gap systems is investigated. Such an absorption, which is forbidden by the conservation of the total spin quantum number in isotropic Hamiltonians, is allowed by the Dzyaloshinskii-Moriya interaction. We show a selection rule in the prese

R. Shankar

Luttinger&#39;s contributions abound in different parts of many-body physics. Here I review the ones that appear when one uses the Renormalization Group (RG) to study the subject: the Luttinger Liquid, Luttinger&#39;s Theorem (on the volume of the Fermi surface) and the Kohn-Luttinger Theorem on the superconducting instability of all metals as one approaches

N. Schorghofer, D. H. Rothman

We investigate the consequences of fluid flowing on a continuous surface upon the geometric and statistical distribution of the flow. We find that the ability of a surface to collect water by its mere geometrical shape is proportional to the curvature of the contour line divided by the local slope. Consequently, rivers tend to lie in locations of high curvat

D. Boese, M. Lischka, L. E. Reichl

We study the conductance properties of a straight two-dimensional quantum wire with impurities modeled by $s$-like scatterers. Their presence can lead to strong inter-channel coupling. It was shown that such systems depend sensitively on the number of transverse modes included. Based on a poor man&#39;s scaling technique we include the effect of higher modes

Reinhold Brueckner

Concerning renormalisation group theory applied to phase transitions, we examine the value of positive numerical and analytical evidence, the divergent short-wavelength behaviour of classical free fields and the absence of UV-divergences in quantum field theories with proper mathematical handling. We conclude as to the inadequacy of the conceptual and mathem

Philipp Schoffel, Martin H. Muser

Two methods are proposed to evaluate the second-order elastic constants of quantum mechanically treated solids. One method is based on path-integral simulations in the (NVT) ensemble using an estimator for elastic constants. The other method is based on simulations in the (NpT) ensemble exploiting the relationship between strain fluctuations and elastic cons

Rudolf A. Roemer, Michael Schreiber, Thomas Vojta

We review some of the recent results on two-interacting particles (TIP) in low-dimensional disordered quantum models. Special attention is given to the mapping of the problem onto random band matrices. In particular, we construct two simple, seemingly closely related examples for which an analogous mapping leads to incorrect results. We briefly discuss possi

Andre G. Moreira, Roland R. Netz

Similarly and highly charged plates in the presence of multivalent counter ions attract each other, leading to electrostatically bound states. Using Monte-Carlo simulations we obtain the inter-plate pressure in the global parameter space. The equilibrium plate separation, where the pressure changes from attractive to repulsive, exhibits a novel unbinding tra

Andre G. Moreira, Roland R. Netz

The Poisson-Boltzmann approach gives asymptotically exact counter-ion density profiles around charged objects in the weak-coupling limit of low valency and high temperature. In this paper we derive, using field-theoretic methods, a theory which becomes exact in the opposite limit of strong coupling. Formally, it corresponds to a standard virial expansion. Lo

A. J. F. de Souza, F. G. B. Moreira, J. R. L. de Almeida

In this work a site diluted antiferromagntic Ising model in the FCC lattice is studied by Monte Carlo simulation. At low temperatures, we find that as the external field is increased the transition from the antiferromagnetic phase to the superantiferromagnetic one occurs through an intermediate phase which is not present in the undiluted system. This new pha

Christian Fuchs, Ralph v. Baltz

The Lloyd model is extended to the exciton problem in quasi one-dimensional structures to study the interplay between the Coulomb attraction and disorder scattering. Within this model the averaging and resummation of the locator series can be performed analytically. As an application, the optical absorption in quantum box wires is investigated. Without elect

Philippe Bourges

The relevance of magnetism for the mechanism responsible for high-temperature superconductivity remains an open and still interesting issue. The observation by inelastic neutron scattering of strong antiferromagnetic dynamical correlations in superconducting cuprates is discussed in relation to the unusual physical properties of the cuprates as well as in re

Sankar Das Sarma, Eugene Demler

We discuss and review recent advances in our understaning of quantum Hall systems where additional quantum numbers associated with spin and/or layer (pseudospin) indices play crucial roles in creating exotic quantum phases. Among the novel quantum phases we discuss are the recently discovered canted antiferromagnetic phase, the spontaneous interlayer coheren

Hal Tasaki

We derive quantum analogues of Jarzynski&#39;s relations, and discuss two applications, namely, a derivation of the law of entropy increase for general compound systems, and a preliminary analysis of heat transfer between two quantum systems at different temperatures. We believe that the derivation of the law of entropy increase is new and of importance.

Jason Melbourne, Ata Sarajedini, Andrew Layden, Donald H. Martins

We present CCD photometry for the Galactic globular cluster NGC 4833. Our BVI color magnitude diagrams (CMD) extend from above the red giant branch (RGB) tip to several magnitudes below the main sequence turnoff. The principal sequences of the cluster show the effects of differential reddening. We have created a local extinction map, consistent with IRAS and

S. Casassus, P. F. Roche

Can the distribution of warm-dust compositions in IR-bright galactic disk PNe be linked to the underlying stellar population? The PNe with warm dust emission represent a homogeneous population, which is presumably young and minimally affected by a possible dependence of PN lifetime on progenitor mass. The sample in paper I thus allows testing the predictions

S. Casassus, P. F. Roche, D. K. Aitken, C. H. Smith

We investigate the galactic disk distribution of a sample of planetary nebulae characterised in terms of their mid-infrared spectral features. The total number of galactic disk PNe with 8-13mum spectra is brought up to 74 with the inclusion of 24 new objects, whose spectra we present for the first time. 54 PNe have clearly identified warm dust emission featu

J. T. Armstrong, Tyler E. Nordgren, M. E. Germain, Arsen R. Hajian

We have measured the diameters of the Cepheid variables delta Cephei (18 nights) and eta Aquilae (11 nights) with the Navy Prototype Optical Interferometer. The primary results of these observations are the mean angular diameters <theta(LD)> of these Cepheids: 1.520 +/- 0.014 milliseconds of arc (mas) for delta Cep and 1.69 +/- 0.04 mas for eta Aql. We also

Luis F. Miranda, Jose M. Torrelles, Martin A. Guerrero, Roberto Vazquez

We present narrow-band optical images, VLA-A 3.6 cm continuum and H92alpha emission line data and high resolution long-slit [N II] spectra of Hu 2-1. The formation of Hu 2-1 appears dominated by anisotropic mass ejection during the late AGB stage of its progenitor and by variable, ``precessing&#39;&#39; collimated bipolar outflows during the proto-PN and/or

Jacqueline Fischer

Far-infrared spectroscopy obtained with the ISO LWS has shown that there is strong variation (more than 2 orders of magnitude) in the [C II]/FIR ratios in galaxies extending from blue compact dwarfs, to normal and starburst galaxies, down to elliptical and ultraluminous galaxies (ULIGs). The variation in the relative [C II] 158 micron line strength has been

Matthias Bartelmann

Full-sky microwave surveys like the upcoming Planck satellite mission will detect of order 10^4 galaxy clusters through their thermal Sunyaev-Zel&#39;dovich effect. I investigate the properties of the gravitationally lensing subsample of these clusters. The main results are: (1) The combined sample comprises >~70% of the complete sample. (2) It is confined t

H. Dahle

Deep two-color imaging of 40 clusters of galaxies with the NOT and the University of Hawaii 2.24-m telescope is used to measure the weak gravitational shear acting on faint background galaxies. From this, maps of the projected cluster mass distribution are constructed, and the cluster masses are measured within circular apertures of up to ~3 Mpc/h. The resul

N. Thatte, M. Tecza, R. Genzel

We report on the discovery of a double nucleus in M 83, based on measurements of the line of sight velocity distribution of stars observed at near infrared wavelengths with the VLT ISAAC spectrograph. We observe two peaks separated by 2.7&#34; in the velocity dispersion profile of light from late-type stars measured along a slit 0.6&#34; wide, centered on th

E. Battaner, E. Florido, A. Guijarro

Magnetic fields are considered to be dominant when $ε_{B}\geqε_{K}$, being $ε_{B}=B^{2}/8π$ the magnetic energy density and $ε_{K}=1/2 ρθ^{2}$ the rotation energy density, for a conventional moderate B= 1 $μ$G. They are considered to be negligible when $ε_{B}<ε_{K}$ for $B\sim 10 μ$G. With no assumption and no theoretical calculation, we show that magnetic f

M. Sasaki, F. Haberl, W. Pietsch

During the operational phase of the ROSAT satellite between 1990 and 1998 the X-ray telescope pointed 71 times to the Small Magellanic Cloud (SMC) for observations with the High Resolution Imager (HRI), covering a field of 5 deg x 5 deg. From this data a catalogue of 121 discrete X-ray sources was derived. By cross-correlating the source catalogue with the S

A. Caccianiga, T. Maccacaro, A. Wolter, R. Della Ceca

We present the results on the cosmological evolution of BL Lac objects as derived from a statistically complete sample of 44 BL Lacs selected from the X-ray bright tail of the REX survey. With this sample, we have investigated the cosmological properties of BL Lacs taking into account the radio, optical and X-ray limits. We infer that no evolution is clearly

P. J. Outram, Fiona Hoyle, T. Shanks

We investigate the effect of redshift-space distortions in the power spectrum parallel and perpendicular to the observer&#39;s line of sight, P(k_par,k_perp), using the optically selected Durham/UKST Galaxy Redshift Survey. On small, non-linear scales anisotropy in the power-spectrum is dominated by the galaxy velocity dispersion; the `Finger of God&#39; eff

Norbert Straumann

After a short history of the $Λ$-term it is explained why the (effective) cosmological constant is expected to obtain contributions from short-distance physics, corresponding to an energy at least as large as the Fermi scale. The actual tiny value of the cosmological constant by particle physics standards represents, therefore, one of the deepest mysteries o

Jean-Paul Kneib

Multiple images, giant arcs, Einstein cross, fold, cusp, lip, caustics, critical lines, sources, mapping, time delay, arclets, weak shear, magnification bias, depletion, ellipticities, polarization, smearing, convergence, kernel, mass reconstruction, sub-structure, dark halos, natural telescope, amplification, distant galaxies, faintest sources ... This is a

Chueng-Ryong Ji, Ho-Meoyng Choi

We discuss a necessary nonvalence contribution in timelike exclusive processes. Following a Schwinger-Dyson type of approach, we relate the nonvalence contribution to an ordinary light-front wave function that has been extensively tested in the spacelike exclusive processes. A complicate four-body energy denominator is exactly cancelled in summing the light-

Martin Maul

In this paper hadroproduction of charmonium states in polarized pp collisions is discussed. A thermal picture for the gluonic cloud of comovers is given making contact between the formalism and the measured unpolarized cross sections. The experimentally observed non-polarization of the final J/psi states leads to the consequence that no correlations between

Sergei V. Ketov

The holographic correspondence between 2d, N=2 quantum field theories and classical 4d, N=2 supergravity coupled to hypermultiplet matter is proposed. The geometrical constraints on the target space of the 4d, N=2 non-linear sigma-models in N=2 supergravity background are interpreted as the exact renormalization group flow equations in two dimensions. Our ge

V. V&#39;yurkov, L. Y. Gorelik

A novel implementation of a charge based quantum computer is proposed. There is no charge transfer during calculation, therefore, uncontrollable entanglement between qubits due to long-range Coulomb forces is suppressed. High-speed computation with 1ps per an operation looks as feasible.