Mimetic gravity description of loop quantum cosmology: reinterpreting the bounce and inflation from a curvature perspective

• Ano de defesa: 2019
• Autor(a) principal: Eunice Valtânia de Jesus Bezerra
• Orientador(a): Oswaldo Duarte Miranda
• Banca de defesa: Carlos Alexandre Wuensche de Souza, Tobias Frederico, Wayne Leonardo Silva de Paula, Marco André Ferreira Dias
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Instituto Nacional de Pesquisas Espaciais (INPE)
• Programa de Pós-Graduação: Programa de Pós-Graduação do INPE em Astrofísica
• País: BR
• Link de acesso: http://urlib.net/sid.inpe.br/mtc-m21c/2019/04.17.16.57

The physics of the early universe remains a mystery to cosmologists. The primordial universe is within energy scales in which the quantum gravity effects may play a significant role. A consistent quantum gravity theory would be composed with the best elements from general relativity and quantum field theory. In our work, we focus on Loop Quantum Gravity (LQG) or being more specific, we are interested in its cosmological counterpart, called Loop Quantum Cosmology (LQC), at the effective level. The results coming from Effective LQC are promising, mainly, the replacement of the initial singularity by a bounce. On the other hand, there is a very powerful approach known as Mimetic Gravity (MG) that can also produce a bounce. The original theory was not built with this purpose, but it was generalized and became capable of reproducing different cosmological evolutionary scenarios. Above all, Langlois et al. (2017) constructed a MG description of LQC in which the Effective LQC dynamics was reproduced. In particular, we explore the treatment employed to obtain the cosmological evolution in a curved Friedmann-Robertson- Walker space-time and the curvature potential presented in it. We build our own formulation reinterpreting the curvature potential role, at the same time, we emphasize its direct relation with matter. After, we apply the developed formalism to Higgs inflationary scenario, taking advantage of the intrinsic relation between the Higgs field and curvature. Moreover, we discuss the primordial gravitational waves and its essential role as fundamental proofs to validate any cosmological model whose aim is to describe the primordial universe dynamics.