Speaker
Prof.
Julio Fabris
(Universidade Federal do Espirito Santo)
Description
The description of the present universe using a cosmological constant and cold dark matter is, in general, very successful. However, many problems appear at non-linear level, pointing possibly to the necessity of an extension of the cold dark matter paradigm. One of the possibilities in this sense is to introduce viscosity in the dark matter component. First we review the general properties of this viscous fluid, and the applications to cosmology. Later, it is analysed the effects of both bulk and shear viscosities on the perturbations,
relevant for structure formation in late time cosmology.
It is shown that shear viscosity can be as effective as the bulk viscosity
on suppressing the growth of perturbations and delaying the non-linear regime.
A statistical analysis of the shear and bulk viscous effects is performed
and some constraints on these viscous effects are given.
| Overview or Regular Talk? | Regular: 45 min. |
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Primary author
Prof.
Julio Fabris
(Universidade Federal do Espirito Santo)
Co-authors
Ms
Carolina Barbosa
(Universidade Federal do Espírito Santo)
Dr
Hermano Velten
(Universidade Federal do Espírito Santo)
Dr
Rudnei Ramos
(Universidade Estadual do Rio de Janeiro)
