Paper: astro-ph/0512605
Date: Sun, 25 Dec 2005 15:29:25 GMT (16kb)

Title: Structured FRW universe leads to acceleration: a non-perturbative
approach

Authors: Reza Mansouri
\\
We propose a model universe in the matter dominated phase described by a FRW
background with local inhomogeneities, like our local patch, grown out of the
primordial fluctuations. Our local patch consisting of different structures is
approximated as an inhomogeneous cosmic fluid described by a LTB metric
embedded in a background FRW universe. Within the exact general relativistic
formulation, the junction conditions for the only possible matching without a
thin shell at the boundary, neglected so far in the literature, constrains the
model in such a way that the luminosity distance-red shift relation mimics a
FRW universe with dark energy. Therefore, the dimming of SNIa is naturally
accounted for in such a {\it structured FRW} universe. The existence of the
overdense and the compensating underdense regions within the epoch of
transition at about $z = 0.5$, a consequence of the junction conditions,
explains naturally the late ISW effect and the suppression of low $l$
multipoles in CMB data. The no-go theorem does not apply here as the dynamics
of the inhomogeneous patch is compared with that of the FRW bulk. There is no
dark energy needed to interpret the acceleration. By using an exact formulation
of the general relativistic dynamics of structures in a homogeneous universe,
the claim is therefore confirmed that backreaction of cosmological
perturbations is the cause of the acceleration of the universe.

\\ ( http://arXiv.org/abs/astro-ph/0512605 , 16kb)