O pré-aquecimento do universo: da ressonância paramétrica à turbulência

• Autor(a) principal: Crespo, José Antonio de Azevedo
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/12936
• topic: Cosmology; Preheating; Spectral Methods; Turbulence; Cosmologia; Pré-aquecimento; Métodos espectrais; Turbulência; CNPQ::CIENCIAS EXATAS E DA TERRA::ASTRONOMIA::ASTROFISICA EXTRAGALACTICA::COSMOLOGIA

Inflation can resolve a few problems of the Standard Model of Cosmology, while still preserving the successful from Big Bang model. In the simplest version, inflation is driven by a scalar field, the inflaton, which causes the universe to expand exponentially fast. Afterwards, the inflaton decays and reheating of the universe occurs. However, some authors suggest the existence of an intermediate phase, called preheating. The decay of the inflaton has a rich non-linear dynamics. In the first stage, the parametric resonance produces exponential growth in some modes. This changes the homogeneous inflaton dynamics, producing a restructuring the resonance charts of the equation of motion of the perturbative modes. Therefore, there is energy transfer to other modes, until the universe thermalize. This energy transfer is typical of a turbulent system. Since the evolution is non-linear, a implementation computational of numerical methods is convenient. In this context, spectral methods have proven to be an excellent tool for studying this kind of system. This thesis presents the results of the numerical scheme developed for the model with the quartic potential, that will be the basis for other studies to be undertaken. As shown, this scheme has proven to be extremely accurate and efficient.