Modelo cosmológico anisótropo con métrica Bianchi tipo I axisimétrica en coordenadas esféricas con constante cosmológica distinta de cero

Abstract

The anisotropic models are an alternative to explain the anomalies found in the Cosmic Microwave Back-ground (CMB) that are not explained from the Cosmological Standard Model. In this paper, because of the symmetry of the manifold and the results can be comparable with the results obtained with the Standard Model, we analyse an axisymmetric Bianchi type I model in spherical coordinates. At first, the solution was considered in vacuum with non-vanishing cosmological constant and secondly, an universe full of barotropic ideal fluid, especially dust and radiation, with vanishing cosmological constant was considered. It was found that the scale factors are proportional, which means that the scale of expansion, the components of the shear tensor, the anisotropy parameter and the deceleration parameter, considering fluid ideal, are indistinguishable from the isotropic case. Also, analysing the behaviour of null geodesics, the total area of the manifold and the cosmological redshift, we found that the universe described by this model is different to the one described by the Standard Model but we also found that the universe turns to isotropic model in some aspects.