2005/12/25 by Reza Mansouri, Mansouri, Reza
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #Cosmology and Gravitation Theories #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #High Energy Physics - Theory (hep-th)
paper · pdf · doi:10.48550/arxiv.astro-ph/0512605
openalex publication_date 2005/12/25 · openalex created_date 2022/10/03 · openalex updated_date 2026/07/28
We propose a model universe in the matter dominated phase described by a FRW\nbackground with local inhomogeneities, like our local patch, grown out of the\nprimordial fluctuations. Our sub-horizon local patch consisting of different\nstructures is approximated as an inhomogeneous cosmic fluid described by a LTB\nmetric embedded in a background FRW universe, in which the observer could be\nlocated anywhere. Within the exact general relativistic formulation, the\njunction conditions for the only possible matching without a thin shell at the\nboundary, neglected so far in the literature, constrains the model in such a\nway that the luminosity distance-red shift relation mimics a FRW universe with\ndark energy. Therefore, the dimming of SNIa is accounted for in such a it\nstructured FRW universe. We have also calculated the exact general\nrelativistic backreaction term and shown how it influences the global Hubble\nparameter and the effective density of the cosmic fluid By using an exact\nformulation of the general relativistic dynamics of structures in a homogeneous\nuniverse, the claim is therefore stressed that the backreaction of cosmological\nperturbations leads to an apparent dimming of the cosmological distances.\n