Formation of Structure in a Viscous Universe.
Name: Carolina Martins de Siqueira Barbosa
Type: PhD thesis
Publication date: 04/05/2018
Advisor:
| Name | Role |
|---|---|
| Hermano Endlich Schneider Velten | Co-advisor * |
| Júlio César Fabris | Advisor * |
Examining board:
| Name | Role |
|---|---|
| Oliver Fabio Piattella | Internal Examiner * |
| Marcos Vinicius Borges Teixeira Lima | External Examiner * |
| Wiliam Santiago Hipolito Ricaldi | External Examiner * |
| Rudnei de Oliveira Ramos | External Examiner * |
| Hermano Endlich Schneider Velten | Co advisor * |
| Júlio César Fabris | Advisor * |
Summary: The cosmological standard model considers dark matter and dark energy, important components to explain observed phenomena in the Universe, contribute for about 95% of the total cosmic energy budget, while baryons and radiation with a small fraction of less than 5% of the total cosmic energy. Cold Dark Matter is considered to have equation of
state of zero pressure, however its nature is one of the greatest mysteries of cosmology, and assume a dust-like equation of state can be a mistake. Viscosities are constantly present in nature, and is natural to think that dark matter must also have viscous properties. In this
work we consider the study of a dark matter with viscous properties, which have a nonzero equation of state with negative pressure (since viscosities are dissipative mechanisms).
Two viscosities are considered here: bulk and shear. The main goal of this work is study how the inclusion of shear viscosity impacts on the structure formation. A secondary goal is to investigate the relation of shear viscosity with models of modified gravity, using a
phenomenological parametrization.
