299 research outputs found
Intermediate Inflation in the Jordan-Brans-Dicke Theory
We present an intermediate inflationary stage in a Jordan-Brans-Dicke theory.
In this scenario we analyze the quantum fluctuations corresponding to adiabatic
and isocurvature modes. The model is compared to that described by using the
intermediate model in Einstein General Relativity theory. We assess the status
of this model in light of the WMAP7 data.Comment: Proceedings of I CosmoSul - Cosmology and Gravitation in Southern
Cone (Rio de Janeiro, 2011). Eds: J. S. Alcaniz, S. Carneiro, L. P. Chimento,
S. del Campo, J. C. Fabris, J. A. S. Lima and W. Zimdah
Curvaton field and intermediate inflationary universe model
The curvaton in an intermediate inflationary universe model is studied. This
study has allowed us to find some interesting constraints on different
parameters that appear in the model.Comment: 16 pages, 2 figures, to appear in Physical Review
Two-fluid evolving Lorentzian wormholes
We investigate the evolution of a family of wormholes sustained by two matter
components: one with homogeneous and isotropic properties and another
inhomogeneous and anisotropic . The rate of expansion of these
evolving wormholes is only determined by the isotropic and homogeneous matter
component . Particularly, we consider a family of exact two-fluid
evolving wormholes expanding with constant velocity and satisfying the dominant
and the strong energy conditions in the whole spacetime. In general, for the
case of vanishing isotropic fluid and cosmological constant
the space expands with constant velocity, and for and the rate of expansion is determined by the cosmological constant. The
considered here two-fluid evolving wormholes are a generalization of single
fluid models discussed in previous works of the present authors [Phys.\ Rev.\ D
{\bf 78}, 104006 (2008); Phys.\ Rev.\ D {\bf 79}, 024005 (2009)].Comment: 8 pages, to be published in Phys. Rev
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