Evolução top-hat hidrodinâmica em campos de velocidades peculiares primordiais

• Ano de defesa: 2012
• Autor(a) principal: Souza, Hidalyn Theodory Clemente Mattos de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Física; Física da Matéria Condensada; Astrofísica e Cosmologia; Física da Ionosfera
• Palavras-chave em Português: Cosmologia. Formação de estruturas primordiais. Mecanismos físicos de esfriamento do Universo primordial. Campos de velocidades primordiais. Energia escura. Matéria escura; Cosmology. Formation of primordial structures. Physical cooling mechanisms of the primordial Universe. Primordial velocities fields. Dark energy. Dark matter; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/16606

We investigate the cosmology of the vacuum energy decaying into cold dark matter according to thermodynamics description of Alcaniz & Lima. We apply this model to analyze the evolution of primordial density perturbations in the matter that gave rise to the first generation of structures bounded by gravity in the Universe, called Population III Objects. The analysis of the dynamics of those systems will involve the calculation of a differential equation system governing the evolution of perturbations to the case of two coupled fluids (dark matter and baryonic matter), modeled with a Top-Hat profile based in the perturbation of the hydrodynamics equations, an efficient analytical tool to study the properties of dark energy models such as the behavior of the linear growth factor and the linear growth index, physical quantities closely related to the fields of peculiar velocities at any time, for different models of dark energy. The properties and the dynamics of current Universe are analyzed through the exact analytical form of the linear growth factor of density fluctuations, taking into account the influence of several physical cooling mechanisms acting on the density fluctuations of the baryonic component of matter during the evolution of the clouds of matter, studied from the primordial hydrogen recombination. This study is naturally extended to more general models of dark energy with constant equation of state parameter in a flat Universe