Spatial Periodicity of Galaxy Number Counts, CMB Anisotropy, and SNIa Hubble Diagram Based on the Universe Accompanied by a Non-Minimally Coupled Scalar Field

We have succeeded in establishing a cosmological model with a non-minimally coupled scalar field $\phi$ that can account not only for the spatial periodicity or the {\it picket-fence structure} exhibited by the galaxy $N$-$z$ relation of the 2dF survey but also for the spatial power spectrum of the cosmic microwave background radiation (CMB) temperature anisotropy observed by the WMAP satellite. The Hubble diagram of our model also compares well with the observation of Type Ia supernovae. The scalar field of our model universe starts from an extremely small value at around the nucleosynthesis epoch, remains in that state for sufficiently long periods, allowing sufficient time for the CMB temperature anisotropy to form, and then starts to grow in magnitude at the redshift $z$ of $\sim 1$, followed by a damping oscillation which is required to reproduce the observed picket-fence structure of the $N$-$z$ relation. To realize such behavior of the scalar field, we have found it necessary to introduce a new form of potential $V(\phi)\propto \phi^2\exp(-q\phi^2)$, with $q$ being a constant. Through this parameter $q$, we can control the epoch at which the scalar field starts growing.Comment: 19 pages, 18 figures, Accepted for publication in Astrophysics & Space Scienc

The Strong Energy Condition and the S-Brane Singularity Problem

Recently it has been argued that, because tachyonic matter satisfies the Strong Energy Condition [SEC], there is little hope of avoiding the singularities which plague S-Brane spacetimes. Meanwhile, however, Townsend and Wohlfarth have suggested an ingenious way of circumventing the SEC in such situations, and other suggestions for actually violating it in the S-Brane context have recently been proposed. Of course, the natural context for discussions of [effective or actual] violations of the SEC is the theory of asymptotically deSitter spacetimes, which tend to be less singular than ordinary FRW spacetimes. However, while violating or circumventing the SEC is necessary if singularities are to be avoided, it is not at all clear that it is sufficient. That is, we can ask: would an asymptotically deSitter S-brane spacetime be non-singular? We show that this is difficult to achieve; this result is in the spirit of the recently proved "S-brane singularity theorem". Essentially our results suggest that circumventing or violating the SEC may not suffice to solve the S-Brane singularity problem, though we do propose two ways of avoiding this conclusion.Comment: 13 pages, minor corrections and improvements, references adde

Quantization of the interior Schwarzschild black hole

We study a Hamiltonian quantum formalism of a spherically symmetric space-time which can be identified with the interior of a Schwarzschild black hole. The phase space of this model is spanned by two dynamical variables and their conjugate momenta. It is shown that the classical Lagrangian of the model gives rise the interior metric of a Schwarzschild black hole. We also show that the the mass of such a system is a Dirac observable and then by quantization of the model by Wheeler-DeWitt approach and constructing suitable wave packets we get the mass spectrum of the black hole.Comment: 12 pages, 1 figure, revised versio

Plant extracts as a natural treatment against the fish ectoparasite Neobenedenia sp. (Monogenea: Capsalidae)

The toxicity of water-ethanol extracts of garlic (Allium sativum), ginger (Zingiber officinale), basil (Ocimum basilicum), bitter chaparro (Castela tortuousa), onion (Allium cepa) and papaya (Carica papaya) against adults, eggs and oncomiracidia of Neobenedenia spp. parasites was examined. Parasites were exposed to continuous immersion and treated as follows: extracts were tested at three dilutions: 1:10, 1:50 and 1:100 made with filtered seawater (35 g l(-1)); ethanol (70%) was evaluated at the same dilutions of 1:10 (7% ethanol), 1:50 (1.4% ethanol) and 1:100 (0.07% ethanol) and a seawater (35 g l(-1)) control. The antiparasitic effect was measured on: (1) adult survival, egg production and time to detachment from the culture vessel; (2) egg development and cumulative egg hatching; and (3) oncomiracidia survival. All three dilutions of ginger and dilutions 1:100 and 1:50 of basil extract reduced adult survival in vitro, time to detachment from the surface of the culture vessel, egg production and oncomiracidia survival. Bitter chaparro extract reduced adult egg production and oncomiracidia survival. Hatching success was significantly reduced (P < 0.05) in basil extract (1:100) to 86.6% compared to the seawater control (100%). Dilutions 1:10 of ginger and basil exhibited the highest impact on the biological parameters of Neobenedenia sp. Our study demonstrates that water-ethanol extracts of ginger, basil and bitter chaparro are toxic against Neobenedenia sp. life stages

Peripheral brain-derived neurotrophic factor (BDNF) as a biomarker in bipolar disorder: a meta-analysis of 52 studies

FSW - Self-regulation models for health behavior and psychopathology - ou