Orador: Che-Yu Chen (National Taiwan University).
Data, hora e local: 3 de fevereiro de 2016, às 11h30m na sala de reuniões do Departamento de Matemática.
Resumo: The Eddington-inspired-Born-Infeld (EiBI) gravity, which is formulated within the Palatini formalism, is characterized by its ability to cure the Big Bang singularity in the very beginning of the Universe. We further analyze the EiBI phantom model, and investigate the possible avoidance or alleviation of other dark energy related singularities. We indeed found that most of the cosmological singularities of interest can be partially alleviated in the EiBI phantom model. Furthermore, we generalized the EiBI theory by adding a pure trace term to the determinant of the action. This amendment is the most general rank-two tensor composed of up to first order of the Riemann curvature. We found that this model allows the occurrence of primordial bounces and singularities that are smoother than the Big Bang. Most interestingly, for certain values of the parameter space, the Big Bang singularity can be followed naturally by an inflationary stage in a radiation dominated universe.
Funded by the Portuguese Government through the FCT – Fundação para a Ciência e a Tecnologia under the project UID/MAT/00212/2013
