7,793 research outputs found
Self-dual formulations of d=3 gravity theories in the path-integral framework
We study the connection, at the quantum level, between d=2+1 dimensional
self-dual models with actions of growing (from first to fourth) order,
governing the dynamics of helicity +2 (or -2) massive excitations. We obtain
identities between generating functionals of the different models using the
path-integral framework, this allowing to establish dual maps among relevant
vacuum expectation values. We check consistency of these v.e.v.'s with the
gauge invariance gained in each mapping.Comment: 26 pages. LaTeX. Minor changes. Published in Int. J Modern Phys. A;
http://www.worldscinet.com/ijmp
Correlations and realistic interactions in doubly closed shell nuclei
We review the latest variational calculations of the ground state properties
of doubly closed shell nuclei, from C to Pb, with semirealistic
and realistic two- and three-nucleon interactions. The studies are carried on
within the framework of the correlated basis function theory and integral
equations technique, with state dependent correlations having central and
tensor components. We report results for the ground state energy, one- and
two-body densities and static structure functions. For O and Ca
we use modern interactions and find that the accuracy of the method is
comparable to that attained in nuclear matter with similar hamiltonians, giving
nuclei underbound by 2 MeV/A. The computed Coulomb sums are in complete
agreement with the latest analysis of the experimental data.Comment: 11 Latex pages, 2 ps figures. Talk delivered at the 10th
International Conference on Recent Progress In Many-Body Theories, Seattle
1999. To appear in "Advances in Quantum Many-Body Theory", vol.3, World
Scientifi
Analysis of Jovian decametric data: Study of radio emission mechanisms
The Voyager 1 and Voyager 2 Planetary Radio Astronomy Experiments (PRA) have produced the finest set of Jovian decametric radio emission data ever obtained. Jovian decametric L-burst and S-burst arcs were characterized and the data reconciled with models for the radio emission geometry and mechanisms. The first major results involve comparisons of the distribution of arc separations with longitudes. The identification and analyses of systematic variations in the PRA data have yielded interesting results, but only the most obvious features of the data were examined. Analyses of the PRA data were extended with the use of new 6-Sec formats that are more sensitive to the S-bursts
Massive Gauge Axion Fields
A gauge invariant formulation for the massive axion is considered. The axion
acquires mass through a topological term which couples a (pseudo)scalar and a
third rank antisymmetric tensor. Duality, local and canonical equivalences with
the non-gauge invariant proposal are established. The supersymmetric version of
the gauge invariant model is constructed.Comment: Final version. New references adde
A Symmetry Adapted Approach to Molecular Spectroscopy: The Anharmonic Oscillator Symmetry Model
We apply the Anharmonic Oscillator Symmetry Model to the description of
vibrational excitations in and molecules. A
systematic procedure can be used to establish the relation between the
algebraic and configuration space formulations, by means of which new
interactions are found in the algebraic model, leading to reliable
spectroscopic predictions. We illustrate the method for the case of -triatomic molecules and the Be-cluster.Comment: 12 pages, invited talk at XIX Oaxtepec Symposium on Nuclear Physics,
January 199
Robust ab initio calculation of condensed matter: transparent convergence through semicardinal multiresolution analysis
We present the first wavelet-based all-electron density-functional
calculations to include gradient corrections and the first in a solid. Direct
comparison shows this approach to be unique in providing systematic
``transparent'' convergence, convergence with a priori prediction of errors, to
beyond chemical (millihartree) accuracy. The method is ideal for exploration of
materials under novel conditions where there is little experience with how
traditional methods perform and for the development and use of chemically
accurate density functionals, which demand reliable access to such precision.Comment: 4 pages, 3 figures, 4 tables. Submitted to Phys. Rev. Lett. (updated
to include GGA
- …