Gravastares e buracos negros como consequência da teoria da relatividade geral

• Autor(a) principal: Rocha, Pedro Senna
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal Fluminense (RIUFF)
• Texto Completo: https://app.uff.br/riuff/handle/1/18646
• topic: Buracos negros (Astronomia); Método numérico; Relatividade geral; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA

Dynamical models of prototype gravastars are constructed and studied. The three models presented in this work are the Visser and Wiltshire three layer gravastars, in which an infinitely thin spherical shell divides the hole spacetime in two regions. In the first model, it is studied the case where the equation of state of the thin shell is p = ½, the exterior spacetime is Schwarzschild and the internal region is de Sitter. In the second model, the thin shell are generalized by an equation of state p = (1 − °)¾, the exterior region is Schwarzschild and the interior region is de Sitter. In the third model, the thin shell has the same equation of state as the second model, the exterior is Schwarzschild and the interior is filled with an anisotropic dark energy fluid. It is found in all these models that in some cases they represent the bounded excursion stable gravastars, where the thin shell is oscillating between two finite radii, while in the other cases they collapse until the formation of black holes or normal stars. In the phase space, the region for both stable gravastars and bounded excursion gravastars is very small in comparison to that for black holes, although it is not completely empty. Therefore, although the existence of gravastars can not be completely excluded from current analysis, the opposite is not possible either, that is, even if gravastars exist, they do not exclude the existence of black holes, as proposed in the work of Mazur and Mottola.