Principal Investigator
Francisco S. N. Lobo

Abstract
In the high-energy astroparticle physics regime, modified gravity could shed light on several outstanding problems in particle physics, such as the nature of dark matter since its thermal production in the early universe may give rise to a relic density of the same order of magnitude of the present dark matter density. Particularly relevant in these scenarios could be the role played by modified gravity, as these theories predict a thermal evolution of the universe different with respect to one based on GR. More precisely, modified gravity predicts a modification/amplification of the expansion rate of the universe with respect to standard cosmology so that the thermal relics decouple with larger relic abundances. As a consequence, the correct value of the relic abundance comes out from larger annihilation cross-sections. Other fundamental issues in the framework of modified gravity are related to the origin of the matter-antimatter asymmetry in the universe and Leptogenesis, as the matter-antimatter asymmetry in the Universe is still an open problem of the particle physics and cosmology. Furthermore, mixing fields, vacuum fluctuations, neutrino oscillations, WIMPS, gravitational waves and the absolute value of the neutrino mass could be important tools to probe modified gravity. These issues will be explored in this project.

The ultimate goal of the proposed research program is to devise viable modified gravity models that pass local tests, explain the dynamics of the Universe and be consistent with constraints from high-energy astroparticle physics, and thus offer a window into understanding the perplexing nature of the dynamics of the Universe and of gravity itself.

Start
1 September 2020
End
31 August 2023

Funding Institution
Fundação para a Ciência e a Tecnologia