January 2000 arXiv papers — page 11

Karn Kallio, Howard D. Trottier

A detailed study is made of four dimensional SU(2) gauge theory with static adjoint ``quarks'' in the context of string breaking. A tadpole-improved action is used to do simulations on lattices with coarse spatial spacings $a_s$, allowing the static potential to be probed at large separations at a dramatically reduced computational cost. Highly aniso

The OPAL collaboration, G. Abbiendi

Bose-Einstein correlations in pairs of charged kaons produced in a sample of 3.9 million hadronic Z0 decays have been measured with the OPAL experiment at LEP. Charged kaons were identified in the central tracking detector using their specific energy loss in the drift chamber gas. The correlation function was studied in two-jet events using a double ratio, f

The MACRO Collaboration

We present the measurement of two event samples induced by atmospheric $ν_μ$ of average energy $ \bar {E}_ν\sim 4 GeV$. In the first sample, the neutrino interacts inside the MACRO detector producing an upward-going muon leaving the apparatus. The ratio of the number of observed to expected events is $ 0.57 \pm0.05_{stat} \pm0.06_{syst} \pm0.14_{theor}$ with

Bruce J. King

Three types of high rate neutrino detectors for neutrino interaction physics at neutrino factories are discussed. High performance general-purpose detectors might collect event samples on the order of a billion events or more. This could greatly improve on existing analyses of neutrino interactions and also lead to new and important analysis topics including

Mayeul Arminjon

A simple example is given of the implementation of the usual method of asymptotic expansions for weak gravitational fields. A scalar, preferred-frame theory of gravitation is considered, but the method is general. Two kinds of asymptotic expansion are a priori possible: "post-Newtonian" (PN) or "post-Minkowskian", the latter allowing to accou

A. B. Batista, J. C. Fabris, R. de Sá Ribeiro

Analysing the Brans-Dicke solutions for the dust phase, we show that, for negative values of $ω$, they contain scenarios that display an initial subluminal expansion followed by an inflationary phase. We discuss these solutions with respect to the results of the observation of high redshif supernova as well as the age problem and structure formation. We stab

Stephane Fay

We use a conformal transformation to find solutions to the generalised scalar-tensor theory, with a coupling constant dependent on a scalar field, in an empty Bianchi type I model. We describe the dynamical behaviour of the metric functions for three different couplings: two exact solutions to the field equations and a qualitative one are found. They exhibit

C. A. Pickett, J. D. Zund

We present an elementary evaluation of the surface areas of the event horizon and stationary limit surface for an uncharged Kerr black hole. The latter appears not to have been previously given in the literature, and permits us to suggest new geometrical / physical interpretations of these areas.

M. V. Takook

The Wightman two-point function for the gravitational field in the linear approximation (the rank-2 ``massless'' tensor field) on de Sitter space has a pathological behaviour for large separated points (infrared divergence). This behaviour can be eliminated in the two-point function for the traceless part of this field if one chooses the Gupta-Bleule

Madhavan Varadarajan

We revisit the quantization of U(1) holonomy algebras using the abelian C* algebra based techniques which form the mathematical underpinnings of current efforts to construct loop quantum gravity. In particular, we clarify the role of ``smeared loops'' and of Poincare invariance in the construction of Fock representations of these algebras. This enabl

Joseph Y. Halpern, Gerhard Lakemeyer

Levesque introduced a notion of ``only knowing'', with the goal of capturing certain types of nonmonotonic reasoning. Levesque's logic dealt with only the case of a single agent. Recently, both Halpern and Lakemeyer independently attempted to extend Levesque's logic to the multi-agent case. Although there are a number of similarities in their

Anastassios Siarkos, Erich Runge, Roland Zimmermann

We present high-quality numerical calculations of the exciton center-of-mass dispersion for GaAs/AlGaAs quantum wells of widths in the range 2-20 nm. The k.p-coupling of the heavy- and light-hole bands is fully taken into account. An optimized center-of-mass transformation enhances numerical convergence. We derive an easy-to-use semi-analytical expression fo

Z. Zhai, C. Kusko, N. Hakim, S. Sridhar

We analyze microwave cavity perturbation methods, and show that the technique is an excellent, precision method to study the dynamic magnetic and dielectric response in the $GHz$ frequency range. Using superconducting cavities, we obtain exceptionally high precision and sensitivity for measurements of relative changes. A dynamic electromagnetic susceptibilit

I. E. Perakis, T. V. Shahbazyan

The dynamics of electrons and atoms interacting with intense and ultrashort optical pulses presents an important problem in physics that cuts across different materials such as semiconductors and metals. The currently available laser pulses, as short as 5 fs, provide a time resolution shorter than the dephasing and relaxation times in many materials. This al

Satya N. Majumdar, Supriya Krishnamurthy, Mustansir Barma

We study a lattice model where particles carrying different masses diffuse, coalesce upon contact, and also unit masses adsorb to a site with rate $q$ or desorb from a site with nonzero mass with rate $p$. In the limit $p=0$ (without desorption), our model reduces to the well studied Takayasu model where the steady-state single site mass distribution has a p

W. Knospe, L. Santen, A. Schadschneider, M. Schreckenberg

Although traffic simulations with cellular-automata models give meaningful results compared with empirical data, highway traffic requires a more detailed description of the elementary dynamics. Based on recent empirical results we present a modified Nagel-Schreckenberg cellular automaton model which incorporates both a slow-to-start and an anticipation rule,

R. J. Rivers, E. Kavoussanaki, G. Karra

Kibble and Zurek have provided a unifying causal picture for the appearance of topological defects like cosmic strings or vortices at the onset of phase transitions in relativistic QFT and condensed matter systems respectively. There is no direct experimental evidence in QFT, but in condensed matter the predictions are largely, but not wholly, supported in s

M. Filoche, B. Sapoval

A numerical study of the transfer across random fractal surfaces shows that their responses are very close to the response of deterministic model geometries with the same fractal dimension. The simulations of several interfaces with prefractal geometries show that, within very good approximation, the flux depends only on a few characteristic features of the

G. B. Arnold, R. A. Klemm

We calculate exactly the Josephson current for $c$-axis coherent tunneling between two layered superconductors, each with internal coherent tight-binding intra- and interlayer quasiparticle dispersions. Our results also apply when one or both of the superconductors is a bulk material, and include the usually neglected effects of surface states. For weak tunn

S. S. A. Razee, J. B. Staunton, B. Ginatempo, E. Bruno

Recently, we outlined a scheme to investigate the effects of compositional order on the magnetocrystalline anisotropy of alloys from a first-principles electronic structure point of view \{Phys. Rev. Lett. {\bf 83}, 5369 (1999)\} and showed that compositional order enhances the magnitude of magnetocrystalline anisotropy energy (MAE) of Co$_{0.5}$Pt$_{0.5}$ a

Christian von Ferber, Arben Jusufi, Christos N. Likos, Hartmut Lowen

We analyze the effective triplet interactions between the centers of star polymers in a good solvent. Using an analytical short distance expansion inspired by scaling theory, we deduce that the triplet part of the three-star force is attractive but only 11% of the pairwise part even for a close approach of three star polymers. We have also performed extensiv

P. Miller, J. K. Freericks

We formulate a fully self-consistent, microscopic model to study the retardation and correlation effects of the barrier within a Josephson junction. The junction is described by a series of planes, with electronic correlation included through a local self energy for each plane. We calculate current-phase relationships for various junctions, which include non

F. Venturini, U. Michelucci, T. P. Devereaux, A. P. Kampf

While the low frequency electronic Raman response in the superconducting state of the cuprates can be largely understood in terms of a d-wave energy gap, a long standing problem has been an explanation for the spectra observed in A_{1g} polarization orientations. We present calculations which suggest that the peak position of the observed A_{1g} spectra is d

F. Dominguez-Adame, I. Gomez, A. Avakyan, D. Sedrakyan

We present a model for alloys of compound semiconductors by introducing a one-dimensional binary random system where impurities are placed in one sublattice while host atoms lie on the other sublattice. The source of disorder is the stochastic fluctuation of the impurity energy from site to site. Although the system is one-dimensional and random, we demonstr

C. Godreche, J. M. Luck

We study the dynamics of ferromagnetic spin systems quenched from infinite temperature to their critical point. We show that these systems are aging in the long-time regime, i.e., their two-time autocorrelation and response functions and associated fluctuation-dissipation ratio are non-trivial scaling functions of both time variables. This is exemplified by

A. V. Kolesnikov, K. B. Efetov

Using the supersymmetry technique, we study the localization-delocalization transition in quasi-one-dimensional non-Hermitian systems with a direction. In contrast to chains, our model captures the diffusive character of carriers' motion at short distances. We calculate the joint probability of complex eigenvalues and some other correlation functions. We

D. Passerone, F. Ercolessi, F. Celestini, E. Tosatti

The large surface density changes associated with the (100) noble metals surface hex-reconstruction suggest the use of non-particle conserving simulation methods. We present an example of a surface Grand Canonical Monte Carlo applied to the transformation of a square non reconstructed surface to the hexagonally covered low temperature stable Au(100). On the

W. D. Heiss, D. S. McLachlan, C. Chiteme

The dielectric constant of a conductor-insulator mixture shows a pronounced maximum above the critical volume concentration. Further experimental evidence is presented as well as a theoretical consideration based on a phenomenological equation. Explicit expressions are given for the position of the maximum in terms of scaling parameters and the (complex) con

Shiping Feng, Feng Yuan, Weiqiang Yu

The c-axis charge dynamics of copper oxide materials in the underdoped and optimally doped regimes has been studied by considering the incoherent interlayer hopping. It is shown that the c-axis charge dynamics for the chain copper oxide materials is mainly governed by the scattering from the in-plane fluctuation, and the c-axis charge dynamics for the no-cha

T. Schneider, J. M. Singer

We outline the universal and finite temperature critical properties of the 3D-XY model, extended to anisotropic extreme type-II superconductors, as well as the universal quantum critical properties in 2D. On this basis we review: (i) the mounting evidence for 3D-XY behavior in optimally doped cuprate superconductors and the 3D to 2D crossover in the underdop

Barry M. McCoy

I review the revolutionary impact Rodney Baxter has had on statistical mechanics beginning with his solution of the 8 vertex model in 1971 and the invention of corner transfer matrices in 1976 to the creation of the RSOS models in 1984 and his continuing current work on the chiral Potts model.

A. B. Shick, W. E. Pickett, A. I. Liechtenstein

Multiple energy minima of the LDA+U energy functional are obtained for $γ$-Ce when it is implemented in a full potential, rotationally invariant scheme including spin-orbit coupling, and different starting local configurations are chosen. The lowest energy solution leads to a fully spin polarized 4f state and the lattice constant of $γ$-Ce. The higher energy

J. A. Gonzalo, M. I. Marques

Indirect but significative evidence (from fusion research data, and from the known 4He abundance) relevant to primordial nucleosynthesis is examined. It is shown that this evidence supports a change in cosmic equation of state at decoupling, compatible with Einstein&#39;s cosmological equations, from ROm T^4 aprox. cte (ROm=ROr) prior to decoupling (t<taf),

J. R. Gabel, F. C. Bruhweiler, D. M. Crenshaw, S. B. Kraemer

We present a study of available Hubble Space Telescope (HST) spectroscopic and imaging observations of the low ionization nuclear emission line region (LINER) galaxy NGC 1052. The WFPC2 imagery clearly differentiates extended nebular Halpha emission from that of the compact core. Faint Object Spectrograph (FOS) observations provide a full set of optical and

Pasquale Blasi

We calculate the distribution of electrons in clusters of galaxies, resulting from thermalization processes in the presence of stochastic acceleration due to plasma waves. We show that the electron distribution can deviate from a Maxwell-Boltzmann distribution, due to the effect of the stochastic energy gain, provided waves can be sustained against damping.

Roeland P. van der Marel

Globular clusters could harbor massive central black holes (BHs), just as galaxies do. So far, no unambiguous detection of a massive BH has been reported for any globular cluster. However, the dense core-collapsed cluster M15 seems to be a good candidate. I review the available photometric and kinematic data for this cluster. Both are consistent with a BH of

Jon Hakkila, Robert D. Preece, Geoffrey N. Pendleton

We introduce a definition of gamma-ray burst (GRB) duty cycle that describes the GRB&#39;s efficiency as an emitter; it is the GRB&#39;s average flux relative to the peak flux. This GRB duty cycle is easily described in terms of measured BATSE parameters; it is essentially fluence divided by the quantity peak flux times duration. Since fluence and duration a

Jon Hakkila, Timothy Giblin, Robert D. Preece

A possible relationship between the presence of a radio afterglow and gamma-ray burst spectral hardness is discussed. The correlation is marginally significant; the spectral hardness of the bursts with radio afterglows apparently results from a combination of the break energy Ebreak and the high-energy spectral index beta. If valid, this relationship would i

Jon Hakkila, Charles A. Meegan, Geoffrey N. Pendleton, Robert S. Mallozzi

The fluence duration bias causes fluences and durations of faint gamma-ray bursts to be systematically underestimated relative to their peak fluxes. Using Monte Carlo analysis, we demonstrate how this effect explains characteristics of structure of the fluence vs. 1024 ms peak flux diagram. Evidence of this bias exists in the BATSE fluence duration database,

X. Hernandez, Gerard Gilmore, David Valls-Gabaud

We use recent HST colour-magnitude diagrams of the resolved stellar populations of a sample of local dSph galaxies (Carina, LeoI, LeoII, Ursa Minor and Draco) to infer the star formation histories of these systems, $SFR(t)$. Applying a new variational calculus maximum likelihood method which includes a full Bayesian analysis and allows a non-parametric estim

M. E. van den Ancker, P. R. Wesselius, A. G. G. M. Tielens

We have studied molecular hydrogen emission in a sample of 21 YSOs using spectra obtained with the Infrared Space Observatory (ISO). H2 emission was detected in 12 sources and can be explained as arising in either a shock, caused by the interaction of an outflow from an embedded YSO with the surrounding molecular cloud, or in a PDR surrounding an exposed you

Jon Hakkila, David J. Haglin, Richard J. Roiger, Robert S. Mallozzi

The three gamma-ray burst (GRB) classes identified by statistical clustering analysis (Mukherjee et al. 1998) are examined using the pattern recognition algorithm C4.5 (Quinlan 1986). Although the statistical existence of Class 3 (intermediate duration, intermediate fluence, soft) is supported, the properties of this class do not need to arise from a distinc

R. Davies, M. Ward, H. Sugai

We present near infrared data on the luminous interacting system Mkn 266 (NGC 5256), comprising 2um continuum, and Br_gamma and 1-0S(1) emission line images, together with K-band spectra. We have fitted stellar templates to the continuum, allowing us to account for all the stellar features and hence detect even faint gas excitation emission lines, including

M. Salvati, R. Maiolino

Most of the energy of the X-ray background is contributed by sources with a hard X-ray spectrum, harder than the spectrum observed in nearby type 1 AGNs. The hard background contributors are conventionally identified with type 2 AGNs, obscured by circumnuclear matter both in the optical and in the soft X rays. However, preliminary results of identification p

Heinz Voelk

The diffuse Galactic gamma-ray background, as observed with EGRET on CGRO, exceeds the model predictions significantly above 1 GeV. This is particularly true for the inner Galaxy. We shall discuss here the contribution of the Galactic Cosmic Ray (GCR) sources, considered as unresolved, and in addition the possibility that the transport of the GCRs out of the

Katherine Blundell, Steve Rawlings

We compare two temporal properties of classical double radio sources: i) radiative lifetimes of synchrotron-emitting particles and ii) dynamical source ages. We discuss how these can be quite discrepant from one another, rendering use of the traditional spectral ageing method inappropriate: we contend that spectral ages give meaningful estimates of dynamical

Rennan Barkana, David Hogg, Abraham Loeb, Roger Blandford

The combination of deep exposures and high resolution offered by telescopes in space allows the detection of lensing over a wide range of source redshifts and lens masses. As an example, we model a lens candidate found in the southern Hubble Deep Field. The system consists of a source galaxy lensed into an arc, 0.9 arcseconds from an elliptical galaxy with a

C. S. Reynolds

Spectroscopy of the broad iron iron with ASCA and BeppoSAX has up opened the innermost regions of accreting black hole systems to detailed study. In this contribution, I discuss how observations with future X-ray missions will extend these studies and all us to observationally address issues which are currently only in the realm of the theorists. In particul

Renato A. Dupke, Raymond E. White

We present constraints on theoretical models of Type Ia SNe using spatially resolved ASCA X-ray spectroscopy of four galaxy clusters: Abell 496, Abell 2199, Abell 3571 & Perseus. All four clusters have central Fe abundance enhancements and an ensemble of abundance ratios are used to show that most of the Fe in the central regions of the clusters comes from S

J. C. Lopez

The bound state in the system of three protons and an electron (pppe) under a homogeneous strong magnetic field where the protons are situated in the vertices of an equilateral triangle perpendicular to the magnetic field lines is found. It is shown that for magnetic fields B = 10^11 - 4.414x10^13 G the potential energy curves as a function of the internucle

Thomas Schick

The Atiyah conjecture predicts that the L2-Betti numbers of a finite CW-complex with torsion-free fundamental group are integers. We show that the Atiyah conjecture holds (with an additional technical condition) for direct and inverse limits of directed systems of groups for which it is true. As a corollary it holds for residually torsion-free solvable group

E. V. Shuryak

General implications of existence of non-perturbative scales and hadronic sub-structure for high energy processes are discussed. We propose that the dependence of the cross section of $\bar q q$ dipoles on their size d should deviate from $d^2$ when d becomes comparable to substructure scale. Then we discuss Kharzeev-Levin pomeron model \cite{KL}, based on l

M. P. Nightingale, H. W. J. Bloete

We investigate aspects of universality of Glauber critical dynamics in two dimensions. We compute the critical exponent $z$ and numerically corroborate its universality for three different models in the static Ising universality class and for five independent relaxation modes. We also present evidence for universality of amplitude ratios, which shows that, a

Rosa Ramirez, Dino Risso, Rodrigo Soto, Patricio Cordero

A granular gas subjected to a permanent injection of energy is described by means of hydrodynamic equations derived from a moment expansion method. The method uses as reference function not a Maxwellian distribution $f_{\sf M}$ but a distribution $f_0 = Φf_{\sf M}$, such that $Φ$ adds a fourth cumulant $κ$ to the velocity distribution. The formalism is appli

S. L. Dubovsky, P. G. Tinyakov, I. I. Tkachev

Observation of clustering of ultra-high energy cosmic rays (UHECR) suggests that they are emitted by compact sources. Assuming small deflection of UHECR during the propagation, the statistical analysis of clustering allows to estimate the spatial density of the sources, h, including those which have not yet been observed directly. When applied to astrophysic

Miguel A. de Avillez

The results of a three-dimensional model for disk-halo interaction are presented here. The model considers explicitly the input of energy and mass by isolated a nd correlated supernovae in the disk. Once disrupted by the explosions, the disk never returns to its initial state. Instead it approaches a state where a thin HI disk is formed in the Galactic plane

Seiji Terashima

Recently Seiberg and Witten have proposed that noncommutative gauge theories realized as effective theories on D-brane are equivalent to some ordinary gauge theories. This proposal has been proved, however, only for the Dirac-Born-Infeld action in the approximation of neglecting all derivative terms. In this paper we explicitly construct general forms of the

Mikhail V. Medvedev

Abridged.-- We demonstrate that the radiation emitted by ultrarelativistic electrons in highly nonuniform, small-scale magnetic fields is different from synchrotron radiation if the electron&#39;s transverse deflections in these fields are much smaller than the beaming angle. A quantitative analytical theory of this radiation, which we refer to as jitter rad

S. Ying

The motivation for the development of a local finite density theory is discussed. One of the problems related to an instability in the baryon number fluctuation of the chiral symmetry breaking phase of the quark system in the local theory is shown to exist. Such an instability problem is removed by taking into account the statistical blocking effects for the

Yosuke Imamura

Via T-duality a theory of open strings on a D1-brane wrapped along a cycle of slanted torus is described by a U(1) gauge theory on a D2-brane in the B-field background. It is also known that there is another dual description of the D1-brane configuration by a non-commutative gauge theory on a D2-brane. Therefore, these two gauge theories on D2-branes are equ

Sergei V. Ketov

We use the manifestly N=2 supersymmetric, off-shell, harmonic (or twistor) superspace approach to solve the constraints implied by four-dimensional N=2 superconformal symmetry on the N=2 non-linear sigma-model target space, known as the special hyper-K&#34;ahler geometry. Our general solution is formulated in terms of a homogeneous (of degree two) function o

V. G. Bagrov, D. M. Gitman, A. Levin, V. B. Tlyachev

We study the impact of Aharonov-Bohm solenoid on the radiation of a charged particle moving in a constant uniform magnetic field. With this aim in view, exact solutions of Klein-Gordon and Dirac equations are found in the magnetic-solenoid field. Using such solutions, we calculate exactly all the characteristics of one-photon spontaneous radiation both for s

S. Parker, M. B. Plenio

It is commonly assumed that Shor&#39;s quantum algorithm for the efficient factorization of a large number $N$ requires a pure initial state. Here we demonstrate that a single pure qubit together with a collection of $log_2 N$ qubits in an arbitrary mixed state is sufficient to implement Shor&#39;s factorization algorithm efficiently.

Jean-Noel Roux

Some remarkable generic properties, related to isostaticity and potential energy minimization, of equilibrium configurations of assemblies of rigid, frictionless grains are studied. Isostaticity -the uniqueness of the forces, once the list of contacts is known- is established in a quite general context, and the important distinction between isostatic problem

Ram Brustein, Merav Hadad

Production of spin 1/2 fermions and gravitinos by the standard mechanism of amplification of quantum fluctuations during the dilaton-driven inflation phase in models of string cosmology is highly suppressed. Constraints on string cosmology models from gravitational production of gravitinos, contrary to expectations, are similar to constraints on other models

M. Yu. Kagan, K. I. Kugel, D. I. Khomskii

A simple model of charge ordering is considered. It is shown explicitly that at any deviation from half-filling ($n \neq 1/2$) the system is unstable with respect to phase separation into charge ordered regions with $n = 1/2$ and metallic regions with smaller electron or hole density. Possible structure of this phase-separated state (metallic droplets in a c

Hermann Nicolai, Jan Plefka

We present a simple derivation of the supersymmetric one-loop effective action of SU(2) Matrix theory by expressing it in a compact exponential form whose invariance under supersymmetry transformations is obvious. This result clarifies the one-loop exactness of the leading v^4 interactions and the absence of non-perturbative corrections.

Y. S. Myung, Gungwon Kang, H. W. Lee

We discuss the Randall-Sundrum (RS) choice for $h_{MN}$ in the brane-world. We begin with the de Donder gauge (transverse-tracefree) including scalar($h_{55}$), vector($h_{5μ}$) and tensor($h_{μν}$) in five dimensions for comparison. One finds that $h_{55}=0$ and $h_{5μ}=0$. This leads to the RS choice. It appears that the RS choice is so restrictive for the

Julian Lee, Koo-Chul Lee

We calculate the exact zeros of the partition function for a continuum system where the probability distribution for the order parameter is given by two asymmetric Gaussian peaks. When the positions of the two peaks coincide, the two separate loci of zeros which used to give first-order transition touch each other, with density of zeros vanishing at the cont

Sacha Davidson, Steen Hannestad, Georg Raffelt

We update the bounds on fermions with electric charge $εe$ and mass $m_ε$. For $m_ε\lsim m_e$ we find $10^{-15}\lsimε<1$ is excluded by laboratory experiments, astrophysics and cosmology. For larger masses, the limits are less restrictive and depend on $m_ε$. For milli-charged neutrinos, the limits are stronger, especially if the different flavors mix as sug

G. L. Granato, C. G. Lacey, L. Silva, A. Bressan

We present a new evolutionary model for the far-UV to sub-mm properties of the galaxy population. This combines a semi-analytic galaxy formation model based on hierarchical clustering (GALFORM) with a spectro-photometric code which includes dust reprocessing (GRASIL). The former provides the star formation and metal enrichment histories, together with the ga

J. S. B. Wyithe, E. L. Turner, R. L. Webster

The four bright images of the gravitationally lensed quasar Q2237+0305 are being monitored from the ground (eg. OGLE collaboration, Apache Point Observatory) in the hope of observing a high magnification event (HME). Over the past three seasons (1997-1999) the OGLE collaboration has produced microlensing light-curves with unprecedented coverage. These demons

J. S. B. Wyithe, E. L. Turner, R. L. Webster, E. Agol

The central regions of the gravitationally lensed quasar Q2237+0305 can be indirectly resolved on nano-arcsecond scales if viewed spectrophotometricly during a microlensing high magnification event (HME). Q2237+0305 is currently being monitored from the ground (eg. OGLE collaboration, Apache Point Observatory), with the goal, among others, of triggering grou

Chao-Shang Huang, Liao Wei

The constraints of electric dipole moments (EDMs) of electron and neutron on the parameter space in supergravity (SUGRA) models with nonuniversal gaugino masses are analyzed. It is shown that with a light sparticle spectrum, the sufficient cancellations in the calculation of EDMs can happen for all phases being order of one in the small tan$β$ case and all p

Martin Schmaltz, Witold Skiba

We propose Minimal Gaugino Mediation as the simplest known solution to the supersymmetric flavor and CP problems. The framework predicts a very minimal structure for the soft parameters at ultra-high energies: gaugino masses are unified and non-vanishing whereas all other soft supersymmetry breaking parameters vanish. We show that this boundary condition nat

X. M. Liu, G. J. Milburn

This paper has been withdrawn due to same as quant-ph/9908068

G. M. D&#39;Ariano, L. Maccone, M. G. A. Paris, M. F. Sacchi

We suggest a tunable optical device to synthesize Fock states and their superpositions starting from a coherent source. The scheme involves an avalanche triggering photodetector and a ring cavity coupled to a traveling wave through a cross-Kerr medium. Low quantum efficiency at the photodetector improves the synthesizing quality at the expense of reducing th

M. V. Ioffe, A. I. Neelov

The method of multidimensional SUSY Quantum Mechanics is applied to the investigation of supersymmetrical N-particle systems on a line for the case of separable center-of-mass motion. New decompositions of the superhamiltonian into block-diagonal form with elementary matrix components are constructed. Matrices of coefficients of these minimal blocks are show

Eric A. Galapon

It has always been believed that no self-adjoint and canonical time of arrival operator can be constructed within the confines of standard quantum mechanics. In this Letter we demonstrate the otherwise. We do so by pointing out that there is no a priori reason in demanding that canonical pairs form a system of imprimitivities. We then proceed to show that a

Slavnov D. A

It is shown that probabilistic treatment of quantum mechanics can be coordinated with causality of all physical processes. The physical interpretation of quantum-mechanical phenomena such as process of measurement and collapse of quantum state is given.

Zi-Yang Wang, Chuan-Wei Zhang, Chuan-Feng Li, Guang-Can Guo

We construct a Universal Quantum Entanglement Concentration Gate (QEC-Gate). Special times operations of QEC-Gate can transform a pure 2-level bipartite entangled state to nearly maximum entanglement. The transformation can attain any required fidelity with optimal probability by adjusting concentration step. We also generate QEC-Gate to the Schmidt decompos

Kevin A. Mitchell

We derive an effective Hamiltonian for a quantum system constrained to a submanifold (the constraint manifold) of configuration space (the ambient space) by an infinite restoring force. We pay special attention to how this Hamiltonian depends on quantities which are external to the constraint manifold, such as the external curvature of the constraint manifol

Jose Ignacio Usera

A coarse-grained quantum operator technique is used along with the formalism of Bohmian mechanics endowed with stochastic character at the quantum level in order to address some central issues in the quantum theory of measurement. A surprisingly simple picture of decoherence and EPR correlations emerges from its use.

C. Sean Bohun, F. I. Cooperstock

Detailed analysis of the coupled Dirac-Maxwell equations and the structure of their solutions is presented. Numerical solutions of the field equations in the case of spherical symmetry with negligible gravitational self-interaction reveal the existence of families of solitons with electric field dominance that are completely determined by the observed charge

S. A. Bass, A. Dumitru

We introduce a combined macroscopic/microscopic transport approach employing relativistic hydrodynamics for the early, dense, deconfined stage of the reaction and a microscopic non-equilibrium model for the later hadronic stage where the equilibrium assumptions are not valid anymore. Within this approach we study the dynamics of hot, bulk QCD matter, which i

Ana R. Bautista, Giampaolo Co&#39;, Antonio M. Lallena

The contribution of the spin-orbit interaction in Hartree-Fock calculations for closed shell nuclei is studied. We obtain explicit expressions for the finite range spin-orbit force. New terms with respect to the traditional spin-orbit expressions are found. The importance of the finite-range is analyzed. Results obtained with spin-orbit terms taken from real

Jen-Hsu Chang, Ming-Hsien Tu

We investigate the bi-Hamiltonian structures associated with constrained dispersionless modified KP hierarchies which are constructed from truncations of the Lax operator of the dispersionless modified KP hierarchy. After transforming their second Hamiltonian structures to those of Gelfand-Dickey type, we obtain the Poisson algebras of the coefficient functi

V. V. Yanovsky, A. V. Chechkin, D. Schertzer, A. V. Tour

We demonstrate that the Fokker-Planck equation can be generalized into a &#39;Fractional Fokker-Planck&#39; equation, i.e. an equation which includes fractional space differentiations, in order to encompass the wide class of anomalous diffusions due to a Levy stable stochastic forcing. A precise determination of this equation is obtained by substituting a Le

Predrag Cvitanovic

Spatio-temporally chaotic dynamics of a classical field can be described by means of an infinite hierarchy of its unstable spatio-temporally periodic solutions. The periodic orbit theory yields the global averages characterizing the chaotic dynamics, as well as the starting semiclassical approximation to the quantum theory. New methods for computing correcti

D. Ruelle

The Gaussian isokinetic and isoenergetic thermostats of Hoover and Evans are formally equivalent as remarked by Gallavotti, Rondoni and Cohen. But outside of equilibrium the fluctuations are uncontrolled and might break the equivalence. We show that equivalence is ensured if we consider an infinite system assumed to be ergodic under space translations.

John H. Van Drie

By considering the &#34;kinetic-energy&#34; term of the minimum principle for the Schrödinger equation as a measure of information, that minimum principle is viewed as a statistical estimation procedure, analogous to the manner in which Jaynes ({\it Phys. Rev.},{\bf 106}, 620, 1957) interpreted statistical mechanics. It is shown that the entropy formula of B

Vladimir F. Kovalev, Dmitrij V. Shirkov

The result from developing and applying the notions of functional self-similarity and the Bogoliubov renormalization group to boundary-value problems in mathematical physics during the last decade are reviewed. The main achievement is the regular algorithm for finding renormalization group-type symmetries using the contemporary theory of Lie groups of transf

A. Petermann

If, in some problems, one has to deal with the ``product&#39;&#39; of distributions $\rm f_i$ (also called generalized functions) $\rm\bar T = Π^m_{i=1} f_i$, this product has a priori no definite meaning as a functional $(\rm \bar T, ϕ) $ for $\rmϕ\in S$. But if $\rm x^{κ+1} Π^m_{i=1} f_i$ exists, whatever the associativity is between some powers $\rm r_i$

Mary Beth Ruskai, Elisabeth Werner

This paper presents a comprehensive study of a class of functions which approximate 1/|x| for large x but which are finite at the origin. These functions arise naturally in the study of atoms in strong magnetic fields where the so-called &#34;Landau states&#34; give rise to Gaussian integrals. Generalizations in which e^{-x^2} is replaced by e^{-x^p} are als

Anton Kast

We consider many-body problems in classical mechanics where a wide range of time scales limits what can be computed. We apply the method of optimal prediction to obtain equations which are easier to solve numerically. We demonstrate by examples that optimal prediction can reduce the amount of computation needed to obtain a solution by several orders of magni

James A. Mingo, Alexandru Nica

We consider the concept of a q-circular system, which is a deformation of the circular system from free probability, taking place in the framework of the so-called &#39;q-commutation relations&#39;. We show that certain averages of random unitaries in non-commutative tori behave asymptotically like a q-circular system.

Michael Eastwood, Roger Penrose

It is not commonly realized that the algebra of complex numbers can be used in an elegant way to represent the images of ordinary 3-dimensional figures, orthographically projected to the plane. We describe these ideas here, both using simple geometry and setting them in a broader context.

D. Toublan, J. J. M. Verbaarschot

We analyze the smallest Dirac eigenvalues by formulating an effective theory for the QCD Dirac spectrum. We find that in a domain where the kinetic term of the effective theory can be ignored, the Dirac eigenvalues are distributed according to a Random Matrix Theory with the global symmetries of the QCD partition function. The kinetic term provides informati

Li Jiang

We consider static U(1) monopole in non-commutative space. Up to the second order in the non-commutativity scale $θ$, we find no non-trivial corrections to the Dirac solution, the monopole mass remains infinite. We argue the same holds for any arbitrary higher order. Some speculation about the nature of non-commutative spacetime and its relation to the cosmo

Jose I. Illana

Assuming a light Higgs boson is discovered, its nature may remain unknown in case that no supersymmetric particles are found. The detection and study of heavier Higgs particles is then of great interest. For this purpose the Compton-collider option of a high energy e+e- linear collider is optimal both to produce Higgs bosons and to reveal their CP-parity. As