5,743 research outputs found
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
The giant, horizontal and asymptotic branches of galactic globular clusters. I. The catalog, photometric observables and features
A catalog including a set of the most recent Color Magnitude Diagrams (CMDs)
is presented for a sample of 61 Galactic Globular Clusters (GGCs). We used this
data-base to perform an homogeneous systematic analysis of the evolved
sequences (namely, Red Giant Branch (RGB), Horizontal Branch (HB) and
Asymptotic Giant Branch (AGB)). Based on this analysis, we present: (1) a new
procedure to measure the level of the ZAHB (V_ZAHB) and an homogeneous set of
distance moduli obtained adopting the HB as standard candle; (2) an independent
estimate for RGB metallicity indicators and new calibrations of these
parameters in terms of both spectroscopic ([Fe/H]_CG97) and global metallicity
([M/H], including also the alpha-elements enhancement). The set of equations
presented can be used to simultaneously derive a photometric estimate of the
metal abundance and the reddening from the morphology and the location of the
RGB in the (V,B-V)-CMD. (3) the location of the RGB-Bump (in 47 GGCs) and the
AGB-Bump (in 9 GGCs). The dependence of these features on the metallicity is
discussed. We find that by using the latest theoretical models and the new
metallicity scales the earlier discrepancy between theory and observations
(~0.4 mag) completely disappears.Comment: 51 pages, 23 figures, AAS Latex, macro rtrpp4.sty included, accepted
by A
Born-Infeld electrostatics in the complex plane
The complex method to obtain 2-dimensional Born-Infeld electrostatic
solutions is presented in a renewed form. The solutions are generated by a
holomorphic seed that makes contact with the Coulombian complex potential. The
procedure is exemplified by solving the Born-Infeld multipolar configurations.
Besides, it is shown that the attractive force between two equal but opposite
charges is lower than its Coulombian partner; it decreases up to vanish when
the charges approach each other below a distance ruled by the Born-Infeld
constant.Comment: 15 pages, 4 figure
Horizontal-Branch Models and the Second-Parameter Effect. IV. The Case of M3 and Palomar 3
We present a detailed analysis of the "second-parameter pair" of globular
clusters M3 (NGC 5272) and Palomar 3. Our main results can be summarized as
follows: i) The horizontal-branch (HB) morphology of M3 is significantly bluer
in its inner regions (observed with the Hubble Space Telescope) than in the
cluster outskirts (observed from the ground), i.e., M3 has an internal second
parameter. Most plausibly the mass loss on the red giant branch (RGB) has been
more efficient in the inner than in the outer regions of the cluster. ii) The
dispersion in mass of the Pal 3 HB is found to be very small -- consistent with
zero -- and we argue that this is unlikely to be due to a statistical
fluctuation. It is this small mass dispersion that leads to the most apparent
difference in the HB morphologies of M3 and Pal 3. iii) The relative HB types
of M3 and Pal 3, as measured by mean colors or parameters involving the number
of blue, variable, and red HB stars, can easily be accounted for by a fairly
small difference in age between these clusters, of order 0.5-1 Gyr -- which is
in good agreement with the relative age measurement, based on the clusters'
turnoffs, by VandenBerg (2000).Comment: 20 pages, 12 figures, emulateapj5 style. The Astrophysical Journal,
in press. Figs. 1, 6, 9, 10 are in png format. The preprint (postscript
format) with full resolution (embedded) figures is available from
http://www.astro.virginia.edu/~mc6v
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