Transform of Riccati equation of constant coefficients through fractional procedure

We use a particular fractional generalization of the ordinary differential equations that we apply to the Riccati equation of constant coefficients. By this means the latter is transformed into a modified Riccati equation with the free term expressed as a power of the independent variable which is of the same order as the order of the applied fractional derivative. We provide the solutions of the modified equation and employ the results for the case of the cosmological Riccati equation of FRW barotropic cosmologies that has been recently introduced by FaraoniComment: 7 pages, 2 figure

Iso-spectral potential and inflationary quantum cosmology

Using the factorization approach of quantum mechanics, we obtain a family of isospectral scalar potentials for power law inflationary cosmology. The construction is based on a scattering Wheeler-DeWitt solution. These iso-spectrals have new features, they give a mechanism to end inflation, as well as the possibility to have new inflationary epochs. The procedure can be extended to other cosmological models.Comment: 14 pages, 5 figure

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.

Faint Radio Sources in the NOAO Bootes Field. VLBA Imaging And Optical Identifications

As a step toward investigating the parsec-scale properties of faint extragalactic radio sources, the Very Long Baseline Array (VLBA) was used at 5.0 GHz to obtain phase-referenced images of 76 sources in the NOAO Booetes field. These 76 sources were selected from the FIRST catalog to have peak flux densities above 10 mJy at 5'' resolution and deconvolved major diameters of less than 3'' at 1.4 GHz. Fifty-five of these faint radio sources were identified with accretion-powered radio galaxies and quasars brighter than 25.5 mag in the optical I band. On VLA scales at 1.4 GHz, a measure of the compactness of the faint sources (the ratio of the peak flux density from FIRST to the integrated flux density from the NVSS catalog) spans the full range of possibilities arising from source-resolution effects. Thirty of the faint radio sources, or 39{sub -7}{sup +9}%, were detected with the VLBA at 5.0 GHz with peak flux densities above 6 {sigma} {approx} 2 mJy at 2 mas resolution. The VLBA detections occur through the full range of compactness ratios. The stronger VLBA detections can themselves serve as phase-reference calibrators, boding well for opening up much of the radio sky to VLBA imaging. For the adopted cosmology, the VLBA resolution corresponds to 17 pc or finer. Most VLBA detections are unresolved or slightly resolved but one is diffuse and five show either double or core-jet structures; the properties of these latter six are discussed in detail. Eight VLBA detections are unidentified and fainter than 25.5 mag in the optical I band; their properties are highlighted because they likely mark optically-obscured active nuclei at high redshift

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

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

Consumo de nutrientes de dietas contendo diferentes níveis de farelo de melancia forrageira (Citrullus lanatus cv. Citroides), em ovinos.

Utilizou-se 20 cordeiros, com idade média de seis meses e peso vivo médio de 11,2 kg (+- 1,2), submetidos a um delineamento experimental inteiramente casuaiizado, para determinar os consumos de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN) e carboidratos totais (CHOT). Cinco dietas contendo D1:80; D2:65; D3:50; D4:35 e D5:20% de farelo de melancia como conncentrado e feno de guandu taipeiro como volumoso, foram avaliadas. As análises estatísticas das variáveis estudadas foram interpretadas por análises de variância e de regressão os consumos de MS, MO, PB, CHOT e FDN, expressos em g/dia, apresentaram um comportamento quadrático (P<0,05) com o aumento do nível de farelo de melancia nas dietas, enquanto o consumo de EE não foi alterado. As diferentes proporções de farelo de melancia e feno de guandu taipeiro, utilizadas nas dietas não proporcionaram um consumo de nutrientes adequado para ovinos

Supersymmetric minisuperspace with non-vanishing fermion number

The Lagrangean of $N=1$ supergravity is dimensionally reduced to one (time-like) dimension assuming spatial homogeneity of any Bianchi type within class A of the classification of Ellis and McCallum. The algebra of the supersymmetry generators, the Lorentz generators, the diffeomorphism generators and the Hamiltonian generator is determined and found to close. In contrast to earlier work, infinitely many physical states with non-vanishing even fermion number are found to exist in these models, indicating that minisuperspace models in supergravity may be just as useful as in pure gravity.Comment: 4 page

Uso do farelo de melancia forrageira (Citrullus lanatus cv. Citroides) e do feno de guandu (Cajanus cajan (L.) Millspaugh cv. D1 Type.), em dietas para ovinos: digestibilidade de nutrientes.

Para se determinarem os coeficientes de digestibilidade da matéria seca (MS), matéria (MO), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN) e carboidratos totais (CHOT), foi realizado um ensaio de digestibilidade, utilizando-se cinco dietas contendo D1:80; D2:65; D3:50; 1)4:35 e D5:20% de farelo de melancia como concentrado e feno de guandu taipeiro como volumoso. Vinte cordeiros mestiços, com idade média de seis meses e peso vivo médio de 11,2 kg (+-1,2), foram submetidos a um delineamento inteiramente casualizado, com cinco tratamentos e quatro repetições. O nível de farelo de melancia forrageira na dieta influenciou linearmente a digestibilidade aparente da MO (62 a 54%) e dos CHOT (58 a 47%). A digestibilidade da PB teve um comportamento cúbico. Os níveis de concentrado não influenciaram a digestibilidade da MS, FDN e do EE. Pode-se concluir que os coeficientes de digestibilidade dos nutrientes das dietas, foram satisfatórios e próximos aos valores encontrados para algumas dietas e forrageiras utilizadas para ovinos, no semi-árido nordestino