312 research outputs found
Non-Abelian Born-Infeld theory without the square root
A non-Abelian Born-Infeld theory is presented. The square root structure that
characterizes the Dirac-Born-Infeld (DBI) action does not appear. The procedure
is based on an Abelian theory proposed by Erwin Schr\"{o}dinger that, as he
showed, is equivalent to Born-Infeld theory. We briefly mention other possible
similar proposals. Our results could be of interest in connection with string
theory and possible extensions of well known physical results in the usual
Born-Infeld Abelian case.Comment: 9 pages, no figures, revtex
Bianchi Cosmologies: New Variables and a Hidden Supersymmetry
We find a supersymmetrization of the Bianchi IX cosmology in terms of
Ashtekar's new variables. This provides a framework for connecting the recent
results of Graham and those of Ryan and Moncrief for quantum states of this
model. These states are also related with the states obtained particularizing
supergravity for a minisuperspace. Implications for the general theory are also
briefly discussed.Comment: 15 Pages, RevTex, NSF-ITP-93-9
quantum cosmological solutions for Class A Bianchi Models
We find solutions for quantum Class A Bianchi models of the form generalizing the results obtained by Moncrief and Ryan in
standard quantum cosmology. For the II and IX Bianchi models there are other
solutions , to the Hamilton-Jacobi
equation for which is necessarely zero, in contrast with solutions
found in supersymmetric quantum cosmology.Comment: 15 pages, Late
Oscillatons formed by non linear gravity
Oscillatons are solutions of the coupled Einstein-Klein-Gordon (EKG)
equations that are globally regular and asymptotically flat. By means of a
Legendre transformation we are able to visualize the behaviour of the
corresponding objects in non-linear gravity where the scalar field has been
absorbed by means of the conformal mapping.Comment: Revtex file, 6 pages, 3 eps figure; matches version published in PR
Time and "angular" dependent backgrounds from stationary axisymmetric solutions
Backgrounds depending on time and on "angular" variable, namely polarized and
unpolarized Gowdy models, are generated as the sector inside
the horizons of the manifold corresponding to axisymmetric solutions. As is
known, an analytical continuation of ordinary -branes, -branes allows
one to find -brane solutions. Simple models have been constructed by means
of analytic continuation of the Schwarzchild and the Kerr metrics. The
possibility of studying the -Gowdy models obtained here is outlined with an
eye toward seeing if they could represent some kind of generalized -branes
depending not only on time but also on an ``angular'' variable.Comment: 24 pages, 5 figures, corrected typos, references adde
WKB-type Approximation to Noncommutative Quantum Cosmology
In this work, we develop and apply the WKB approximation to several examples
of noncommutative quantum cosmology, obtaining the time evolution of the
noncommutative universe, this is done starting from a noncommutative quantum
formulation of cosmology where the noncommutativity is introduced by a
deformation on the minisuperspace variables. This procedure gives a
straightforward algorithm to incorporate noncommutativity to cosmology and
inflation.Comment: Revtex4, 6 pages, no figure
Vector Mosquito Surveillance Using Centers For Disease Control and Prevention Autocidal Gravid Ovitraps In San Antonio, Texas
Mosquito surveillance in large urban areas of the southern USA that border Mexico has become increasingly important due to recent transmission of Zika virus and chikungunya virus in the Americas as well as the continued threat of dengue and West Nile viruses. The vectors of these viruses, Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus, co-occur in residential areas, requiring vector control entities to deploy several different trap types, often expensive and labor-intensive, to surveil these ecologically different species. We evaluated the use of a single trap type, the US Centers for Disease Control and Prevention autocidal gravid ovitraps (AGOs), to monitor all 3 vector species across residential neighborhoods in San Antonio, TX, over 12 wk (epiweeks 24–35). Mosquito abundance was highest early in our surveillance period (epiweek 25) and was driven largely by Cx. quinquefasciatus. The AGOs collected significantly more Cx. quinquefasciatus than both Aedes species, with more Ae. aegypti collected than Ae. albopictus. The average number of Ae. aegypti captured per trap was consistent across most neighborhoods except for 2 areas where one had significantly the highest and the other with the lowest mosquitoes collected per trap. The average number of Ae. albopictus captured per trap varied with no clear pattern, and Cx. quinquefasciatus were trapped most often near forested hill country neighborhoods. These results indicate that AGOs are appropriate for detecting and tracking the relative abundance of Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus across a large and diverse urban landscape over time and therefore may be an inexpensive and streamlined option for vector surveillance programs in large cities
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