9,646 research outputs found
Operator ordering for generally covariant systems
The constraint operators belonging to a generally covariant system are found
out within the framework of the BRST formalism. The result embraces quadratic
Hamiltonian constraints whose potential can be factorized as a never null
function times a gauge invariant function. The building of the inner product
between physical states is analyzed for systems featuring either intrinsic or
extrinsic time.Comment: 4 pages. Talk given at the Third Conference on "Constrained Dynamics
and Quantum Gravity" held in Sardinia (Italy), September 1999. Journal
reference:Nucl. Phys. B (Proc. Suppl.) 88 (2000) 322-32
Statistics of cross sections of Voronoi tessellations
In this paper we investigate relationships between the volumes of cells of
three-dimensional Voronoi tessellations and the lengths and areas of sections
obtained by intersecting the tessellation with a randomly oriented plane. Here,
in order to obtain analytical results, Voronoi cells are approximated to
spheres. First, the probability density function for the lengths of the radii
of the sections is derived and it is shown that it is related to the Meijer
-function; its properties are discussed and comparisons are made with the
numerical results. Next the probability density function for the areas of cross
sections is computed and compared with the results of numerical simulations.Comment: 10 pages and 6 figure
Asteroids dimensions and the Truncated Pareto distribution
In this chapter first the statistics of the standard and truncated Pareto
distributions are derived and used to fit empirical values of asteroids
diameters from different families, namely, Koronis, Eos and Themis, and from
the Astorb database. A theoretical analysis is then carried out and two
possible physical mechanisms are suggested that account for Pareto tails in
distributions of asteroids diameter.Comment: 11 Pages and 6 figures. arXiv admin note: substantial text overlap
with arXiv:0804.030
Phase space path integral in curved space
Phase space path integral is worked out in a riemannian geometry, by
employing a prescription for the infinitesimal propagator that takes riemannian
normal coordinates and momenta on an equal footing. The operator ordering
induced by this prescription leads to the DeWitt curvature coupling in the
Schrodinger equation.Comment: 11 page
Path Integral and Solutions of the Constraint Equations: The Case of Reducible Gauge Theories
It is shown that the BRST path integral for reducible gauge theories, with
appropriate boundary conditions on the ghosts, is a solution of the constraint
equations. This is done by relating the BRST path integral to the kernel of the
evolution operator projected on the physical subspace.Comment: 10 pages Tex file, ULB-TH-94/0
On the Quantization of Reducible Gauge Systems
Reducible gauge theories with constraints linear in the momenta are
quantized. The equivalence of the reduced phase space quantization, Dirac
quantization and BRST quantization is established. The ghosts of ghosts are
found to play a crucial role in the equivalence proof.Comment: 41 pages, Plain Tex file, ULB-PMIF\92-07, GTCRG/92-0
Letter from Geraldine Ferraro to Laurence M. Wiig, YMCA International Institute for Peace
Letter from Geraldine Ferraro to Laurence M. Wiig, of the YMCA International Institute for Peace. Letter has handwritten notes.https://ir.lawnet.fordham.edu/vice_presidential_campaign_correspondence_1984_international/1359/thumbnail.jp
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