Bruno J. Barros
IA / FCUL

Abstract
Dark energy interactions are the main subject of this talk. Specifically, it will be exposed models where a canonical scalar field interacts with either dark matter or with classical electromagnetism. The phenomenology of the theories will be explored both at background and linear level, where we will identify the signatures of the coupling on observables such as the CMB, lensing and matter power spectra. The model predictions are tested against current cosmological observations in order to put bounds on the free parameters. In the context of dark matter interactions, we will briefly dive into the nonlinear regime by studying the spherical collapse of overdense regions. Since couplings to the electromagnetic sector may induce a variation of the fine structure constant, we will see how data from earth, astrophysical and early time probes constrain the quintessence interaction to Maxwell's theory. Finally we will talk about a 'quintessence medium' through which photons propagate

2023 March 29, 13:30

IA/U.Lisboa
Faculdade de Ciências da Universidade de Lisboa (C8.2.10)
Campo Grande,