162 research outputs found
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
Supersymmetric FRW model and the ground state of supergravity
In this work we construct the vacuum configuration of supergravity
interacting with homogeneous complex scalar matter fields. The corresponding
configuration is of the FRW model invariant under the local conformal
time supersymmetry, which is a subgroup of the four dimensional space-time
supersymmetry. We show, that the potential of the scalar matter fields is a
function of the K\"ahler potential and of the arbitrary parameter .
This parameter enumerates the vacuum states. The scalar matter potential
induces the spontaneous breaking of supersymmetry in supergravity. On the
quantum level our model is a specific supersymmetric quantum mechanics, which
admits quantum states in supergravity, and the states with zero energy are
described by the wave function of the FRW universe.Comment: 18 pages, Revtex, submitted to PR
Influencia de la fuente y el nivel de glicerina cruda en el pienso sobre los paráemtros productivos en pollos de 1 a 21 dĂas de edad.
Las cantidades de grasas y aceites destinadas a la producciĂłn de biodiesel han aumentado en los Ăşltimos años a nivel mundial (National Biodiesel Board, 2012). La glicerina cruda (Gly) es un subproducto de la industria del biodiesel que contiene cantidades variables de humedad, cenizas y glicerol. La Gly es una fuente atractiva de energĂa que se utiliza actualmente como sustituto parcial del grano de cereal en dietas para avicultura y otras
especies domĂ©sticas (Swiatkiewicz y Koreleski, 2009). Se estima que el nivel máximo de Gly a utilizar en piensos para broilers varĂa entre 5 y 10% (Cerrate et al., 2006). A estos niveles de inclusiĂłn, la Gly no presenta efecto negativo alguno sobre la salud o los parámetros productivos de las aves. Sin embargo, la calidad de las Gly comerciales varĂa en funciĂłn de su origen, composiciĂłn y proceso de obtenciĂłn. El objetivo de este estudio fue evaluar el efecto de la fuente y el nivel de glicerina cruda en el pienso sobre el rendimiento productivo en pollos de engorde de 1 a 21 dĂas de edad
Inluence of source and level of glycerin in the diet on growth performance, liver characteristics, and nturient digestibility in broilers from hatching to 21 days of age
The influence of source and level of inclusion of raw glycerin (GLYC) in the diet on growth performance, digestive traits, total tract apparent retention (TTAR), and apparent ileal digestibility of nutrients was studied in broilers from 1 to 21 d of age. There was a control diet based on corn and soybean meal and 8 additional diets that formed a 2 × 4 factorial with 2 sources of GLYC and 4 levels of inclusion (2.5, 5.0, 7.5, and 10%). The GLYC used were obtained from the same original batch of soy oil that was dried under different processing conditions and contained 87.5 or 81.6% glycerol, respectively. Type of processing of the GLYC did not affect any of the variables studied except DM and organic matter retention (P < 0.05) that was higher for the 87.5% glycerol diet. From d 1 to 21, feed conversion ratio (FCR) improved linearly (L, P ≤ 0.01) as the GLYC content of the diet increased, but ADG was not affected. On d 21, the relative weight (% BW) of the liver and the digestive tract increased (L, P < 0.01) as the level of GLYC in the diet increased, but lipid concentration in the liver was not affected. The TTAR of DM and organic matter increased quadratically (Q, P < 0.05) and the AMEn content of the diet increased linearly (L, P < 0.01) with increases in dietary GLYC. Also, the apparent ileal digestibility of DM (L, P < 0.05; Q, P = 0.07) and gross energy (L, P < 0.01) increased as the GLYC content of the diet increased. It is concluded that raw GLYC from the biodiesel industry can be used efficiently, up to 10% of the diet, as a source of energy for broilers from 1 to 21 d of age and that the energy content of well-processed raw GLYC depends primarily on its glycerol content
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
Twisted Covariant Noncommutative Self-dual Gravity
A twisted covariant formulation of noncommutative self-dual gravity is
presented. The formulation for constructing twisted noncommutative Yang-Mills
theories is used. It is shown that the noncommutative torsion is solved at any
order of the -expansion in terms of the tetrad and some extra fields of
the theory. In the process the first order expansion in for the
Pleba\'nski action is explicitly obtained.Comment: 23+1 pages, no figures, corrected typos, references and Appendix B is
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