February 2000 arXiv papers — page 2

Ignazio Bombaci

Definitely, an affirmative answer to this question would have implications of fundamental importance for astrophysics (a new class of compact stars), and for the physics of strong interactions (deconfined phase of quark matter, and strange matter hypothesis). In the present work, we use observational data for the newly discovered millisecond X-ray pulsar SAX

B. Novosyadlyj, R. Durrer, S. Gottloeber, V. N. Lukash

The possibility of determining cosmological parameters on the basis of a wide set of observational data including the Abell-ACO cluster power spectrum and mass function, peculiar velocities of galaxies, the distribution of Ly-$α$ clouds and CMB temperature fluctuations is analyzed. Using a $χ^2$ minimization method, assuming $Ω_Λ+Ω_m =1$ and no contribution

F. Hoyle, T. Shanks, N. R. Tanvir

We investigate the reddening and Main Sequence fitted distances to eleven young, Galactic open clusters that contain Cepheids. Each cluster contains or is associated with at least one Cepheid variable star. Reddening to the clusters is estimated using the U-B:B-V colours of the OB stars and the distance modulus to the cluster is estimated via B-V:V and V-K:V

Wayne Hu

We review the theoretical implications of the past decade of CMB anisotropy measurements, which culminated in the recent detection of the first feature in the power spectrum, and discuss the tests available to the next decade of experiments. The current data already suggest that density perturbations originated in an inflationary epoch, the universe is spati

F. Durret, C. Adami, D. Gerbal, V. Pislar

We present a detailed analysis of the cluster of galaxies \a4. The optical data include a redshift catalogue of 466 galaxies, out of which 274 belong to the main cluster and a CCD photometric catalogue in a much smaller region, with 239 and 610 galaxies in the V and R bands respectively. The X-ray analysis is based on an image obtained with the ROSAT PSPC. B

K. -W. Chan, T. Onaka

We report the detection of a broad 22 microns emission feature in the Carina nebula H II region by the Infrared Space Observatory (ISO) Short Wavelength Spectrometer. The feature shape is similar to that of the 22 microns emission feature of newly synthesized dust observed in the Cassiopeia A supernova remnant. This finding suggests that both of the features

S W Ellingson, J D Bunton, J F Bell

Astronomers use the 1612 MHz OH spectral line emission as a unique window on properties of evolved stars, galactic dynamics, and putative proto-planetary disk systems around young stars. In recent years, experiments using this OH line have become more difficult because radio telescopes are very sensitive to transmissions from the GLONASS satellite system. Th

R D Ekers, J F Bell

We describe the nature of the interference challenges facing radio astronomy in the next decade. These challenges will not be solved by regulation only, negotiation and mitigation will become vital. There is no silver bullet for mitigating against interference. A successful mitigation approach is most likely to be a hierarchical or progressive approach throu

R D Ekers, J F Bell

Radio astronomy provides a unique window on the universe, allowing us to study: non-thermal processes (galactic nuclei, quasars, pulsars) at the highest angular resolution using VLBI, with low opacity. It is the most interesting wave band for SETI searches. To date it has yielded 3 Nobel prizes (microwave background, pulsars, gravitational radiation). There

D. Buzasi, J. Catanzarite, R. Laher, T. Conrow

We have used the star camera on the WIRE satellite to observe the K0 III star Alpha UMa, and we report the apparent detection of 10 oscillation modes. The lowest frequency mode is at 1.82 microhertz, and appears to be the fundamental mode. The mean spacing between the mode frequencies is 2.94 microhertz, which implies that all detected modes are radial. The

G. B. Cleaver, A. E. Faraggi, D. V. Nanopoulos, T. ter Veldhuis

The aim of superstring phenomenology is to develop the tools and methodology needed to confront string theory with experimental data. The first mandatory task is to find string solutions which reproduce the observable data. The subsequent goal is to extract potential signatures beyond the observable data. Recently, by studying exact flat directions of non-Ab

C. Alcock, R. A. Allsman, D. R. Alves, T. S. Axelrod

We present the microlensing optical depth towards the Galactic bulge based on the detection of 99 events found in our Difference Image Analysis (DIA) survey. This analysis encompasses three years of data, covering ~ 17 million stars in ~ 4 deg^2, to a source star baseline magnitude limit of V = 23. The DIA technique improves the quality of photometry in crow

Mark Windoloski

The spherical field formalism---a nonperturbative approach to quantum field theory---was recently introduced and applied to phi^4 theory in two dimensions. The spherical field method reduces a quantum field theory to a finite-dimensional quantum mechanical system by expanding field configurations in terms of spherical partial wave modes. We extend the formal

Sebastian de Haro, Kostas Skenderis, Sergey N. Solodukhin

We develop a systematic method for renormalizing the AdS/CFT prescription for computing correlation functions. This involves regularizing the bulk on-shell supergravity action in a covariant way, computing all divergences, adding counterterms to cancel them and then removing the regulator. We explicitly work out the case of pure gravity up to six dimensions

J. Gutowski, G. Papadopoulos

We propose a universal expression for the moduli metric of a class of four- and five-dimensional black holes which preserve at least four supersymmetries. These include the black holes that are associated with various intersecting branes in ten and eleven dimensions, the electrically charged black holes of N=2 D=5 and N=2 D=4 supergravities with any number o

Herbert Neuberger

A new, adiabatic phase choice is adopted for the overlap in the case of an infinite volume, noncompact abelian chiral gauge theory. This gauge choice obeys the same symmetries as the Brillouin-Wigner (BW) phase choice, and, in addition, produces a Wess-Zumino functional that is linear in the gauge variables on the lattice. As a result, there are no gauge vio

Yang Sun, Jing-ye Zhang, Mike Guidry, Jie Meng

Based on available experimental data, a new set of Nilsson parameters is proposed for proton-rich nuclei with proton or neutron numbers $28\leq N\leq 40$. The resulting single-particle spectra are compared with those from relativistic and non-relativistic mean field theories. Collective excitations in some even--even proton-rich nuclei in the upper $pf$ shel

A. Pinzul, A. Stern

We show how to map the Belavin-Polyakov instantons of the O(3)-nonlinear $σ-$model to a dual theory where they then appear as nontopological solitons. They are stationary points of the Euclidean action in the dual theory, and moreover, the dual action and the O(3)-nonlinear $σ-$model action agree on shell.

Alexander Strohmaier

We show that as soon as a linear quantum field on a stationary spacetime satisfies a certain type of hyperbolic equation, the (quasifree) ground- and KMS-states with respect to the canonical time flow have the Reeh-Schlieder property. We also obtain an analog of Borchers' timelike tube theorem. The class of fields we consider contains the Dirac field, th

F. Bonetto, D. Daems, J. L. Lebowitz

We study numerically and analytically the properties of the stationary state of a particle moving under the influence of an electric field $\bE$ in a two dimensional periodic Lorentz gas with the energy kept constant by a Gaussian thermostat. Numerically the current appears to be a continuous function of $\bE$ whose derivative varies very irregularly, possib

Stefano De Leo, Giuseppe Scolarici

We study the right eigenvalue equation for quaternionic and complex linear matrix operators defined in n-dimensional quaternionic vector spaces. For quaternionic linear operators the eigenvalue spectrum consists of n complex values. For these operators we give a necessary and sufficient condition for the diagonalization of their quaternionic matrix represent

Gregor Diezemann

Using non-linear response theory the time signals relevant for nonresonant spectral hole burning are calculated. The step-reponse function following the application of a high amplitude ac field (pump) and an intermediate waiting period is shown to be the sum of the equilibrium integrated response and a modification due to the preparation via ac irradiation.

E. F. Moreno, F. A. Schaposnik

We study the effective action associated to the Dirac operator in two dimensional non-commutative Field Theory. Starting from the axial anomaly, we compute the determinant of the Dirac operator and we find that even in the U(1) theory, a Wess-Zumino-Witten like term arises.

A. G. Akeroyd, A. Arhrib, E. Naimi

Full one-loop electroweak corrections to the on-shell decay $H^+ \to W^+A^0$ are computed in the framework of models with two Higgs doublets (THDM). Such a decay may be dominant for $H^{\pm}$ over a wide range of parameter space relevant at present and future colliders. We show that the corrections may approach 40% and in particular are sensitive to $λ_5$, w

S. Y. Choi, Manuel Drees, Jae Sik Lee

We compute one-loop corrections to the mass matrix of the neutral Higgs bosons of the Minimal Supersymmetric Standard Model with explicit CP violation. We use the effective potential method, allowing for arbitrary splitting between squark masses. We include terms O(g^2 h^2), where g and h stand for electroweak gauge and Yukawa couplings, respectively. Leadin

C. Duval, P. A. Horváthy

Taking advantage of the two-parameter central extension of the planar Galilei group, we construct a non relativistic particle model in the plane. Owing to the extra structure, the coordinates do not commute. Our model can be viewed as the non-relativistic counterpart of the relativistic anyon considered before by Jackiw and Nair. For a particle moving in a m

M. Nishi, H. Nakao, Y. Fujii, T. Masuda

Cu1-xMgxGeO3 undergoes a first-order phase transition at a critical concentration xc between an antiferromagnetic (AF) state on dimerized lattice (D-AF) and an AF Neel state on undistorted uniform lattice (U-AF). Previous magnetic susceptibility measurements showed xc = 0.023 while a recent neutron scattering study reported xc = 0.027 +- 0.001. The present c

S. A. Derev'anko, G. B. Tkachev, V. A. Yampol'skii

The nonlinear interaction of DC current flowing in a thin metal film with an external low-frequency AC electromagnetic field is studied theoretically. The nonlinearity is related to the influence of the magnetic field of the DC current and the magnetic field of the wave on the form of electron trajectories. This magnetodynamic mechanism of nonlinearity is th

Everett W. Howe

We provide a simple method of constructing isogeny classes of abelian varieties over certain fields $k$ such that no variety in the isogeny class has a principal polarization. In particular, given a field $k$, a Galois extension $\ell$ of $k$ of odd prime degree $p$, and an elliptic curve $E$ over $k$ that has no complex multiplication over $k$ and that has

S. Kasuya, M. Kawasaki

We study the formation of Q-balls which are made of flat directions that appear in the supersymmetric extension of the standard model in the context of gravity-mediated supersymmetry breaking. The full non-linear calculations for the dynamics of the complex scalar field are made. Since the scalar potential in this model is flatter than ϕ^2, we have found tha

Pawel Horodecki, Maciej Lewenstein, Guifré Vidal, Ignacio Cirac

We consider low rank density operators $\varrho$ supported on a $M\times N$ Hilbert space for arbitrary $M$ and $N$ ($M\leq N$) and with a positive partial transpose (PPT) $\varrho^{T_A}\ge 0$. For rank $r(\varrho) \leq N$ we prove that having a PPT is necessary and sufficient for $\varrho$ to be separable; in this case we also provide its minimal decomposit

Konrad Banaszek

We derive the maximum fidelity attainable for teleportation using a shared pair of d-level systems in an arbitrary pure state. This derivation provides a complete set of necessary and sufficient conditions for optimal teleportation protocols. We also discuss the information on the teleported particle which is revealed in course of the protocol using a non-ma

Andor Frenkel

In the existing expositions of the Karolyhazy model, quantum mechanical uncertainties are mimicked by classical spreads. It is shown how to express those uncertainties through entities of the future unified theory of general relativity and quantum theory.

I. Baumann, A. Breidenassel, C. Zühlke, A. Kasimov

The pressure shifts of the $3s4s^3S_1 \to 3s3p^3P_{0,1,2}$ transition of magnesium atoms immersed in superfluid helium have been measured at $(1.3\pm0.1 )$K between saturated vapour pressure and $24 $bar. The wavelength is blue shifted linearly by $(0.07\pm0.01) \frac{nm}{bar}$. This value can be satisfactorily described in the framework of the standard bubb

J. A. Jones

Liquid state nuclear magnetic resonance (NMR) techniques have produced some spectacular successes in the construction of small quantum computers, and NMR is currently by far the leading technology for quantum computation. There are, however, a number of significant problems with any attempt to scale up the technology to produce computers of any useful size.

Abhishek Agarwal, Pankaj Jain, Jagdish Rai

We consider the effect of spatial correlations on sources of polarized electromagnetic radiation. The sources, assumed to be monochromatic, are constructed out of dipoles aligned along a line such that their orientation is correlated with their position. In one representative example, the dipole orientations are prescribed by a generalized form of the standa

Jacek Dziarmaga

We estimate density of defects frozen into a biological Turing pattern which was turned on at a finite rate. A self-locking of gene expression in individual cells, which makes the Turing transition discontinuous, stabilizes the pattern together with its defects. A defect-free pattern can be obtained by spatially inhomogeneous activation of the genes.

D. M. Snyder

A number of issues related to measurement show that self-consistency is lacking in quantum mechanics as this theory has been generally understood. Each issue is presented as a point in this paper. Each point can be resolved by incorporating a cognitive component in quantum mechanics. Measurement in quantum mechanics involves the meaning of the physical circu

D. M. Snyder

Irreversibility is often considered to characterize measurements in quantum mechanics. Fundamental problems with this characterization are addressed. First, whether a measurement is made in quantum mechanics is an arbitrary decision on the part of the experimenter concerning how the experimental circumstances are structured. Second, how is irreversibility th

A. Abdesselam, J. Magnen, V. Rivasseau

We compute connected Green's functions of a Bosonic field theory with cutoffs by means of a ``minimal'' expansion which in a single move, interpolating a generalized propagator, performs the usual tasks of the cluster and Mayer expansion. In this way it allows a direct construction of the infinite volume or thermodynamic limit and it brings const

F. Bonetto, J. L. Lebowitz, L. Rey-Bellet

We present a selective overview of the current state of our knowledge (more precisely of ourignorance) regarding the derivation of Fourier's Law, ${\bf J}(\br) =-κ{\bf \nabla}T(\br)$; ${\bf J}$ the heat flux, $T$ the temperature and $κ$, the heat conductivity. This law is empirically well tested for both fluids and crystals, when the temperature varies s

Heberto del Rio Guerra

We construct examples of four dimensional manifolds with Spin$^c$-structures, whose moduli spaces of solutions to the Seiberg-Witten equations, represent a non-trivial bordism class of positive dimension, i.e. the Spin$^c$-structures are not induced by almost complex structures. As an application, we show the existence of infinitely many non-homeomorphic com

Alex Chigogidze

We show that complemented subspaces of uncountable products of Banach spaces are products of complemented subspaces of countable subproducts.

Alex Chigogidze

We show that a complemented subspace of a locally convex direct sum of an uncountable collection of Banach spaces is a locally convex direct sum of complemented subspaces of countable subsums. As a corollary we prove that a complemented subspace of a locally convex direct sum of arbitrary collection of $\ell_{1}(Γ)$-spaces is isomorphic to a locally convex d

Manuel González, Joaquín M. Gutiérrez

We introduce a weakened version of the Dunford-Pettis property, and give examples of Banach spaces with this property. In particular, we show that every closed subspace of Schreier's space $S$ enjoys it. As an application, we characterize the weak polynomial convergence of sequences, show that every closed subspace of $S$ has the polynomial Dunford-Petti

Martin Goldstern

If L is a complete ortholattice, f any partial function from L^n to L, then there is a complete ortholattice L* containing L as a subortholattice, and an ortholattice polynomial with coefficients in L* which represents f on L^n. Iterating this construction long enough yields a complete ortholattice in which every function can be interpolated by a polynomial

Dmitriy S. Kalyuzhniy

The explicit constructions of minimal isometric, and minimal unitary dilations of an arbitrary linear pencil of operators $T(λ)=T_0+λT_1$ consisting of contractions on a separable Hilbert space for $|λ|=1$, which generalize the classical constructions (the case $T_1=0$), are presented. In contrast to the classical case these dilations are essentially non-uni

H. -O. Georgii, V. Zagrebnov

In multitype lattice gas models with hard-core interaction of Widom--Rowlinson type, there is a competition between the entropy due to the large number of types, and the positional energy and geometry resulting from the exclusion rule and the activity of particles. We investigate this phenomenon in four different models on the square lattice: the multitype W

Peter Bouwknegt

We give some higher dimensional analogues of the Durfee square formula and point out their relation to dissections of multipartitions. We apply the results to write certain affine Lie algebra characters in terms of Universal Chiral Partition Functions.

Gaetano Fiore

Several Clifford algebras that are covariant under the action of a Lie algebra $g$ can be deformed in a way consistent with the deformation of $Ug$ into a quantum group (or into a triangular Hopf algebra) $U_qg$, i.e. so as to remain covariant under the action of $U_qg$. In this report, after recalling these facts, we review our results regarding the formal

Ritabrata Munshi

We prove that there is a one-to-one, bounded, holomorphic function on a region $Ω$ iff $S^{2} - Ω$ is not totally disconnected. This paper has been withdrawn by the author since Theorem 3 is incorrect.

S. Deser, D. Seminara

We compute the tree level 4-particle bosonic scattering amplitudes in D=11 supergravity. By construction, they are part of a linearized supersymmetry-, coordinate- and 3-form gauge-invariant. While this on-shell invariant is nonlocal, suitable SUSY-preserving differentiations turn it into a local one with correct dimension to provide a natural lowest (two-lo

Maximilian Kreuzer, Harald Skarke

Four dimensional reflexive polyhedra encode the data for smooth Calabi-Yau threefolds that are hypersurfaces in toric varieties, and have important applications both in perturbative and in non-perturbative string theory. We describe how we obtained all 473,800,776 reflexive polyhedra that exist in four dimensions and the 30,108 distinct pairs of Hodge number

A. A. Saharian

One of the most efficient methods to obtain the vacuum expectation values for the physical observables in the Casimir effect is based on the using the Abel-Plana summation formula. This allows to derive the regularized quantities by manifestly cutoff independent way and to present them in the form of strongly converging integrals. However the applications of

C. Ekstrand

A geometrical interpretation of the consistent and covariant chiral anomaly is done in the space-time respective Hamiltonian framework.

Nicolas Moeller, Washington Taylor

The tachyonic instability of the open bosonic string is analyzed using the level truncation approach to string field theory. We have calculated all terms in the cubic action of the string field theory describing zero-momentum interactions of up to level 20 between scalars of level 10 or less. These results are used to study the tachyon effective potential an

D. S. Berman

A comparison is made between the thermodynamics of weakly and strongly coupled Yang-Mills with fixed angular momentum. The free energy of the strongly coupled Yang-Mills is calculated by using a dual supergravity description corresponding to a rotating black hole in an Anti de Sitter (AdS) background. All thermodynamic quantities are shown have the same rati

T. Pisar, J. Rant, H. Zerrouki

A topological model in three dimensions is proposed. It combines the Chern-Simons action with a BFK-model which was investigated recently by the authors of hep-th/9906146. The finiteness of the model to all orders of perturbation theory is shown in the framework of algebraic renormalization procedure.

P. Baseilhac, S. Galice, P. Grangé, M. Rausch de Traubenberg

Multicomplex numbers of order n have an associated trigonometry (multisine functions with (n-1) parameters) leading to a natural extension of the sine-Gordon model. The parameters are constrained from the requirement of local current conservation. In two dimensions for n < 6 known integrable models (deformed Toda and non-linear sigma, pure affine Toda...) wi

Jun-Ichi Sumi, Wataru Souma, Ken-Ichi Aoki, Haruhiko Terao

The cutoff scheme dependence in the several formulations of the Exact Renormalization Group (ERG) is investigated. It is shown that the cutoff scheme dependence of the Wilsonian effective action is regarded as a certain coordinate transformation on the theory space. From this observation the Wilsonian effective actions are found to suffer from strong depende

Murat Gunaydin, Marco Zagermann

We give a detailed study of the critical points of the potentials of the simplest non-trivial N=2 gauged Yang-Mills/Einstein supergravity theories with tensor multiplets. The scalar field target space of these examples is SO(1,1)XSO(2,1)/SO(2). The possible gauge groups are SO(2)XU(1)_R and SO(1,1)XU(1)_R, where U(1)_R is a subgroup of the R-symmetry group S

Oliver DeWolfe, Daniel Z. Freedman

We study the coupled equations describing fluctuations of scalars and the metric about background solutions of N=8 gauged supergravity which are dual to boundary field theories with renormalization group flow. For the case of a kink solution with a single varying scalar, we develop a procedure to decouple the equations, and we solve them in particular exampl

Benoit Vanderheyden, Gordon Baym

We generalize the concept of conserving,Φ-derivable, approximations to relativistic field theories. Treating the interaction field as a dynamical degree of freedom, we derive the thermodynamical potential in terms of fully dressed propagators, an approach which allows us to resolve the entropy of a relativistic plasma into contributions from its interacting

Hans-Ulrich Martyn

A case study will be presented to investigate width effects in the precise determination of slepton masses at the e+e- TESLA Linear Collider.

Junji Hisano, Kiichi Kurosawa, Yasunori Nomura

Much heavier sfermions of the first-two generations than the other superparticles provide a natural explanation for the flavor and CP problems in the supersymmetric standard model (SUSY SM). However, the heavy sfermions may drive the mass squareds for the light third generation sfermions to be negative through two-loop renormalization group (RG) equations, b

Ernest Ma

With the particle content of the 27 representation of E_6, a skew left-right supersymmetric gauge model was proposed many years ago, with a variety of interesting phenomenological implications. The neutrino sector of this model offers a natural framework for obtaining small Majorana masses for nu_e, nu_mu, and nu_tau, with the added bonus of accommodating 2

A. Alexandru, Richard W. Haymaker

We study the configuration space of the Tomboulis $SO(3) \times Z(2)$ formulation with periodic boundary conditions. The dynamical variables are constrained by the required coincidence of Z(2) and SO(3) monopoles. We propose an update algorithm that satisfies the constraints and is straightforward to implement. We further prove that this it reaches all confi

M. Novello, V. A. De Lorenci, Luciane R. de Freitas, O. D. Aguiar

We examine the propagation of gravitational waves in the new field theory of gravitation recently proposed by Novello-De Lorenci-Luciane (NDL). This examination is done on a solvable case corresponding to a spherically symmetric static configuration. We show that in NDL theory the velocity of gravitational waves is lower than light velocity. We point out som

V. V. Kuznetsov, E. E. Mendez, E. T. Croke, X. Zuo

We have observed shot noise in the hopping conduction of two dimensional carriers confined in a p-type SiGe quantum well at a temperature of 4K. Moreover, shot noise is suppressed relative to its ``classical&#39;&#39; value 2eI by an amount that depends on the length of the sample and carrier density, which was controlled by a gate voltage. We have found a s

Fabrizio Lillo, Rosario N. Mantegna

We select the $n$ stocks traded in the New York Stock Exchange and we form a statistical ensemble of daily stock returns for each of the $k$ trading days of our database from the stock price time series. We study the ensemble return distribution for each trading day and we find that the symmetry properties of the ensemble return distribution drastically chan

Piotr Garbaczewski

Non-typical transport phenomena may arise when randomly driven particles remain in an active relationship with the environment instead of being passive. If we attribute to Brownian particles an ability to induce alterations of the environment on suitable space-time scales, those in turn must influence their further movement. In that case a general feedback m

R. Fletcher, V. M. Pudalov, A. D. B. Radcliffe, C. Possanzini

This letter reports thermopower and conductivity measurements through the metal-insulator transition for 2-dimensional electron gases in high mobility Si-MOSFET&#39;s. At low temperatures both thermopower and conductivity show critical behavior as a function of electron density which is very similar to that expected for an Anderson transition. In particular,

Yu. P. Stepanovsky, G. G. Sergeeva

We are discussing Schwinger&#39;idea that physical mechanism of sonoluminescence is a physical vacuum excitation. This theory was based on the assumption that the sudden change of the rate of bubble collapse leads to the jump of dielectric constant of the gas trapped inside the bubble. We show that the dependence of the dielectric constant on the gas density

Rosa Ramirez, Dino Risso, Patricio Cordero

Thermal convection is observed in molecular dynamic simulation of a fluidized granular system of nearly elastic hard disks moving under gravity, inside a rectangular box. Boundaries introduce no shearing or time dependence, but the energy injection comes from a slip (shear-free) thermalizing base. The top wall is perfectly elastic and lateral boundaries are

E. Abad, H. L. Frisch, G. Nicolis

We use a boolean cellular automaton model to describe the diffusion limited dynamics of the irreversible reaction A+A->A+S on a 1D lattice. We derive a set of equations for the dynamics of the empty interval probabilities from which explicit expressions for the particle concentration and the two-point correlation can be obtained. It is shown that the long ti

Anton Knigavko, Baruch Rosenstein

We explain 90 degree reorientation in the vortex lattice of borocarbide superconductors on the basis of a phenomenological extension of the nonlocal London model that takes full account of the symmetry of the system. We propose microscopic mechanisms that could generate the correction terms and point out the important role of the superconducting gap anisotro

Gregor Hackenbroich, Rafael A. Mendez

We show that tunneling through quantum dots can be completely dominated by states quantized on stable bouncing-ball orbits. The fingerprints of bouncing-ball tunneling are sequences of Coulomb blockade peaks with strongly correlated peak height and asymmetric peak line shape. Our results are in agreement with the striking correlations of peak height and tran

A. Pimenov, M. Biberacher, D. Ivannikov, A. Loidl

High-field antiferromagnetic-resonance (AFMR) spectra were obtained in the frequency range 60 GHz < ν< 700 GHz and for magnetic fields up to 8 T in twin-free single crystals of La_{0.95}Sr_{0.05}MnO_3. At low temperatures two antiferromagnetic modes were detected, which reveal different excitation conditions and magnetic field dependencies. No splitting of t

C. Bauer, S. Dietrich

Using an interface displacement model we calculate the shapes of nanometer-size liquid droplets on homogeneous cylindrical surfaces. We determine effective contact angles and line tensions, the latter defined as excess free energies per unit length associated with the two contact lines at the ends of the droplet. The dependences of these quantities on the cy

E. E. Tahiri, M. Tij, A. Santos

By means of the Direct Simulation Monte Carlo method, the Boltzmann equation is numerically solved for a gas of hard spheres enclosed between two parallel plates kept at different temperatures and subject to the action of a gravity field normal to the plates. The profiles of pressure, density, temperature and heat flux are seen to be quite sensitive to the v

P. Thomas, I. Varga, T. Lemm, J. E. Golub

Local ultrafast optical excitation of electron-hole pairs in disordered semiconductors provides the possibility to observe experimentally interaction-assisted propagation of correlated quantum particles in a disordered environment. In addition to the interaction driven delocalization known for the conventional single-band TIP-(two-interacting-particles)-prob

Ramin Golestanian

A path integral formulation is used to study the fluctuation-induced interactions between manifolds of arbitrary shape at large separations. It is shown that the form of the interactions crucially depends on the choice of the boundary condition. In particular, whether or not the Casimir interaction is pairwise additive is shown to depend on whether the ``met

O . P. Sushkov

In the present work we demonstrate that the spin columnar dimerized phase (conducting spin stripe liquid) is stable at doping $x_{c1} < x < x_{c2}$. At $x < x_{c1}$ the system undergoes phase transition to the Neel state, and at $x > x_{c2}$ it is Normal Fermi liquid. At t/J=3 the critical concentrations are $x_{c1}\approx 0.09$ and $x_{c2}\sim 0.36$. To pro

Slava V. Rotkin

A giant level shift, resulted from the interaction of an electron in a spherical quantum dot with zero--point oscillations of confined modes of the electric field, is divulged. The energy correction depends on the dot radius. This size scaling of the depolarisation effect is computed semiclassically. A change of the optical properties of the matrix surroundi

Bambi Hu, Baowen Li, Weng-ge Wang

We study a new statistics of wave functions in several chaotic and disordered systems: the random matrix model, band random matrix model, the Lipkin model, chaotic quantum billiard and the 1D tight-binding model. Both numerical and analytical results show that the distribution function of a generalized Riccati variable, defined as the ratio of components of

Nino Panagia

We consider some aspects of the evolution of massive stars which can only be elucidated by means of &#34;indirect&#34; observations, i.e. measurements of the effects of massive stars on their environments. We discuss in detail the early evolution of massive stars formed in high metallicity regions as inferred from studies of HII regions in external galaxies.

H. I. Teplitz, I. S. McLean, E. E. Becklin, D. F. Figer

Moderate resolution, near-IR spectroscopy of MS1512-cB58 is presented, obtained during commissioning of the the Near IR Spectrometer (NIRSPEC) on the Keck II telescope. The strong lensing of this z=2.72 galaxy by the foreground cluster MS1512+36 makes it the best candidate for detailed study of the rest-frame optical properties of Lyman Break Galaxies. A red

Pieter G. van Dokkum, Marijn Franx, Daniel Fabricant, Garth D. Illingworth

We present a study of 81 I selected, spectroscopically-confirmed members of the X-ray cluster MS1054-03 at z=0.83. Redshifts and spectral types were determined from Keck spectroscopy. Morphologies and accurate colors were determined from a large mosaic of HST WFPC2 images in F606W and F814W. Early-type galaxies constitute only 44% of this galaxy population.

S. W. Allen

We discuss the X-ray properties of the cooling flows in a sample of thirty highly X-ray luminous clusters of galaxies observed with the ASCA and ROSAT satellites. We demonstrate the need for multiphase models to consistently explain the spectral and imaging X-ray data for the clusters. The mass deposition rates of the cooling flows, independently determined

Juri Poutanen

Accreting black holes and neutron stars in their hard (low) state show not only very similar X/gamma-ray spectra but also that the behaviour of their light curves is quite similar which can be quantified as having similar power-density spectra and Fourier-frequency-dependent time/phase lags. Taken together this argues for a common mechanism of the X/gamma-ra

M. Joyce, P. W. Anderson, M. Montuori, L. Pietronero

The clustering of galaxies is well characterized by fractal properties, with the presence of an eventual cross-over to homogeneity still a matter of considerable debate. In this letter we discuss the cosmological implications of a fractal distribution of matter, with a possible cross-over to homogeneity at an undetermined scale R_{homo}. Contrary to what is

D. Schoenberner, T. Driebe, T. Bloecker

We employed recently computed evolutionary white-dwarf models with helium cores, supplemented by heavier models with carbon-oxygen cores, in order to investigate the ages of millisecond pulsar systems based on the cooling properties of the compact companions. Contrary to the behaviour of more massive white dwarfs, the evolutionary speed of low-mass white-dwa

Shoichi Yamada

With a view of applications to the simulations of supernova explosion and proto neutron star cooling, we derive the Boltzmann equations for the neutrino transport with the flavor mixing based on the real time formalism of the nonequilibrium field theory and the gradient expansion of the Green function. The relativistic kinematics is properly taken into accou

Zakir F. Seidov, P. I. Skvirsky

Gravitational potential and gravitational energy are presented in analytical form for homogeneous rectangular parallelepiped.

L. Van Waerbeke, Y. Mellier, T. Erben, J. C. Cuillandre

We report the detection of a significant (5.5 sigma) excess of correlations between galaxy ellipticities at scales ranging from 0.5 to 3.5 arc-minutes. This detection of a gravitational lensing signal by large-scale structure was made using a composite high quality imaging survey of 6300 arcmin^2 obtained at the Canada France Hawaii Telescope (CFHT) with the

S. Ayal, M. Livio, T. Piran

We study the long term evolution of a solar type star that is being disrupted by a super massive (10^6 solar mass) black hole. The evolution is followed from the disruption event, which turns the star into a long thin stream of gas, to the point where some of this gas returns to pericenter and begins its second orbit around the black hole. Following the evol

B. Galvan

This paper defines, on the Galilean space-time, the group of asymptotically Euclidean transformations (AET), which are equivalent to Euclidean transformations at space-time infinity, and proposes a formulation of nonrelativistic quantum mechanics which is invariant under such transformations. This formulation is based on the asymptotic quantum measure, which

R. F. Streater

We survey recent work on the Cramer-Rao inequality by Hasagawa and Petz; the notion of information manifold in infinite-dimensional Hilbert spaces is introduced, and the extension by Grasselli and the author to quadratic form perturbations is summarised.

R. F. Streater

We survey the development of probability from 1900, starting with Bachelier&#39;s theory of speculation. Fisher information appears in the theory of estimation. We touch on Brownian motion, and the Wiener integral. The Ito calculus, and its relation to to the heat equation, is mentioned. Quantum theory is introduced as a generalisation of probability, rather

Lee Rudolph

A necessary and sufficient condition for an oriented pretzel surface to be quasipositive yields an estimate for the slice genus of the boundary of an arbitrary oriented pretzel surface.