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 ...

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 ...

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 ...

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 ...

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 ...

We study non-linear structure formation in the presence of dark energy. The influence of dark energy on the growth of large-scale cosmological structures is exerted both through its background effect on the expansion rate, ...

We study non-linear structure formation in the presence of dark energy. The influence of dark energy on the growth of large-scale cosmological structures is exerted both through its background effect on the expansion rate, ...

In this paper we describe in detail how to solve the problems of pre-inflationary cosmology within the holographic cosmology model of McFadden and Skenderis [1]. The solutions of the smoothness and horizon problems, the ...