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Cosmological Fluctuations in Delta Gravity
(2023)
About 70% of the Universe is Dark Energy, but the physics community still does not know what it is. Delta gravity (DG) is an alternative theory of gravitation that could solve this cosmological problem. Previously, we ...
Evolution of density perturbations in decaying vacuum cosmology: the case of nonzero perturbations in the cosmological term
(Brasil, 2008)
We extend the results of a previous paper where a model of interacting dark energy, with a cosmological term decaying linearly with the Hubble parameter, is tested against the observed mass power spectrum. In spite of the ...
Cosmological models from string theory setups
(Universidade Estadual Paulista (Unesp), 2019-08-15)
Nesta tese, discutimos três modelos cosmológicos que são baseados direta ou indiretamente em ideias advindas de teoria das cordas. Depois de uma revisão geral de cosmologia em teoria das cordas, um resumo de cosmologia e ...
Inflationary perturbations in anisotropic, shear-free universes
(2012)
In this work, the linear and gauge-invariant theory of cosmological perturbations in a class of anisotropic and shear-free spacetimes is developed. After constructing an explicit set of complete eigenfunctions in terms of ...
Dark energy parametrizations and their effect on dark halos
(Iop Publishing Ltd, 2006-07-01)
There are a plethora of dark energy parametrizations that can fit current supernovae Ia data. However, these data are only sensitive to redshifts up to order one. In fact, many of these parametrizations break down at higher ...
Dark energy parametrizations and their effect on dark halos
(Iop Publishing Ltd, 2006-07-01)
There are a plethora of dark energy parametrizations that can fit current supernovae Ia data. However, these data are only sensitive to redshifts up to order one. In fact, many of these parametrizations break down at higher ...
Dark energy parametrizations and their effect on dark halos
(Iop Publishing Ltd, 2014)