Ψ=We±Φ\rm \Psi= W e^{\pm \Phi} quantum cosmological solutions for Class A Bianchi Models

We find solutions for quantum Class A Bianchi models of the form $\rm \Psi=W e^{\pm \Phi}$ generalizing the results obtained by Moncrief and Ryan in standard quantum cosmology. For the II and IX Bianchi models there are other solutions $\rm \tilde\Phi_2$, $\rm \tilde\Phi_9$ to the Hamilton-Jacobi equation for which $\rm \Psi$ is necessarely zero, in contrast with solutions found in supersymmetric quantum cosmology.Comment: 15 pages, Late

Generalized information entropies depending only on the probability distribution

Systems with a long-term stationary state that possess as a spatio-temporally fluctuation quantity $\beta$ can be described by a superposition of several statistics, a "super statistics". We consider first, the Gamma, log-normal and $F$-distributions of $\beta$. It is assumed that they depend only on $p_l$, the probability associated with the microscopic configuration of the system. For each of the three $\beta-$distributions we calculate the Boltzmann factors and show that they coincide for small variance of the fluctuations. For the Gamma distribution it is possible to calculate the entropy in a closed form, depending on $p_l$, and to obtain then an equation relating $p_l$ with $\beta E_l$. We also propose, as other examples, new entropies close related with the Kaniadakis and two possible Sharma-Mittal entropies. The entropies presented in this work do not depend on a constant parameter $q$ but on $p_l$. For the $p_l$-Gamma distribution and its corresponding $B_{p_l}(E)$ Boltzmann factor and the associated entropy, we show the validity of the saddle-point approximation. We also briefly discuss the generalization of one of the four Khinchin axioms to get this proposed entropy.Comment: 13 pages, 3 figure

Time and "angular" dependent backgrounds from stationary axisymmetric solutions

Backgrounds depending on time and on "angular" variable, namely polarized and unpolarized $S^1 \times S^2$ 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 $D$-branes, $iD$-branes allows one to find $S$-brane solutions. Simple models have been constructed by means of analytic continuation of the Schwarzchild and the Kerr metrics. The possibility of studying the $i$-Gowdy models obtained here is outlined with an eye toward seeing if they could represent some kind of generalized $S$-branes depending not only on time but also on an ``angular'' variable.Comment: 24 pages, 5 figures, corrected typos, references adde

Classical and quantum time dependent solutions in string theory

Using the ontological interpretation of quantum mechanics in a particular sense, we obtain the classical behaviour of the scale factor and two scalar fields, derived from a string effective action for the FRW time dependent model. Besides, the Wheeler-DeWitt equation is solved exactly. We speculate that the same procedure could also be applied to S-branes.Comment: 11 pages, To appear in Int. J. Mod. Phys.

Características químicas de la carne de búfalos en un sistema de alimentación de autoconsumo

The exploitation of buffaloes is presented as an alternative for meat production in the northeast region of Argentina, as it adapts to special agroecological conditions due to the flooding of the land, the presence of low digestible pastures and ectoparasites in which cattle are not always expresses its maximum potentiality. In order to study the quality of post-weaning buffaloes meat from 12 to 15 months of age and with an average weight of 380 kg, the composition of the feed supplied by self-consumption system was studied as a strategic supplementation to achieve the slaughter weight and chemical composition of meat, as well as of the fatty acids present in intramuscular fat by gas chromatography. The meat values found were 28.09% DM, 71.91% humidity, 23.69% CP, 1.94% EE and 1.23% ash. With regard to fatty acids, values of 18.59% saturated and 81.4% unsaturated were found, among the latter being 77.34% monounsaturated and 4% polyunsaturated, concluding that buffalo meat is nutritionally healthy and productively profitable for the region.La explotación de búfalos se presenta como una alternativa de producción de carne en la región nordeste de Argentina, por adaptarse a condiciones agroecológicas especiales debido al anegamiento del terreno, la presencia de pastos de baja digestibilidad y de ectoparásitos en las que no siempre el ganado vacuno expresa su máxima potencialidad. Con la finalidad de estudiar la calidad de carne de bubillos post-destete de 12 a 15 meses de edad y de pesos promedio de 380 kg se estudió la composición del alimento suministrado por sistema de autoconsumo como suplementación estratégica para lograr el peso de faena, la composición química de la carne, como así también de los ácidos grasos presentes en la grasa intramuscular mediante cromatografía gaseosa. Los valores encontrados en la carne fueron de 28,09% de MS, 71,91% de humedad, 23,69% de PB, 1,94% de EE y 1,23% de cenizas. Con respecto a los ácidos grasos se hallaron valores de 18,59% de saturados y de 81,4% de insaturados, destacándose dentro de estos últimos un 77,34 % de monoinsaturados y de 4% de poliinsaturados, concluyendo que la carne de búfalo es nutricionalmente saludable y productivamente rentable para la región

Noncommutative Quantum Cosmology

We propose a model for noncommutative quantum cosmology by means of a deformation of minisuperspace. For the Kantowski-Sachs metric we are able to find the exact wave function. We construct wave packets and show that new quantum states that ``compete'' to be the most probable state appear, in clear contrast with the commutative case. A tunneling process could be possible among these states.Comment: 5 pages, 5 figures, revtex4 file, major style changes, to be published in PR

Towards a Gravitational Analog to S-duality in Non-abelian Gauge Theories

For non-abelian non-supersymmetric gauge theories, generic dual theories have been constructed. In these theories the couplings appear inverted. However, they do not possess a Yang-Mills structure but rather are a kind of non-linear sigma model. It is shown that for a topological gravitational model an analog to this duality exists.Comment: LaTeX, 14 pages, no figures, minor correction

Quantum states on supersymmetric minisuperspace with a cosmological constant

Spatially homogeneous models in quantum supergravity with a nonvanishing cosmological constant are studied. A class of exact nontrivial solutions of the supersymmetry and Lorentz constraints is obtained in terms of the Chern-Simons action on the spatially homogeneous 3-manifold, both in Ashketar variables where the solution is explicit up to reality conditions, and, more concretely, in the tetrad-representation, where the solutions are given as integral representations differing only by the contours of integration. In the limit of a vanishing cosmological constant earlier exact solutions for Bianchi type IX models in the tetrad-representation are recovered and additional asymmetric solutions are found.Comment: 14 pages, late

Noncommutative Topological Half-flat Gravity

We formulate a noncommutative description of topological half-flat gravity in four dimensions. BRST symmetry of this topological gravity is deformed through a twisting of the usual BRST quantization of noncommutative gauge theories. Finally it is argued that resulting moduli space of instantons is characterized by the solutions of a noncommutative version of the Plebanski's heavenly equation.Comment: 12+1 pages, revtex4, no figure

Quantum Cosmology of Generalized Two--Dimensional Dilaton Gravity Models

The quantum cosmology of two-dimensional dilaton-gravity models is investigated. A class of models is mapped onto the constrained oscillator-ghost-oscillator model. A number of exact and approximate solutions to the corresponding Wheeler-DeWitt equation are presented. A wider class of minisuperspace models that can be solved in this fashion is identified. Supersymmetric extensions to the induced gravity theory and the bosonic string theory are then considered and closed-form solutions to the associated quantum constraints are derived. The possibility of applying the third-quantization procedure to two-dimensional dilaton-gravity is briefly discussed.Comment: 28 pages, late