Thesis

Modified Gravity theories: impact on cosmological observables and astrophysical implications.

• Call:

  PT-CERN Call 2022/1

• Academic Year:

  2022

• Domain:

  Astroparticle Physics

• Supervisor:

  Francisco Lobo

• Co-Supervisor:

  Noemi Frusciante

• Institution:

  FCUL (Universidade de Lisboa)

• Host Institution:

  IA - Instituto de Astrofísica e Ciências do Espaço

• Abstract:

  High precision cosmological probes seem to support the current standard cosmological model, ΛCDM. However, the most recent observations appear to reveal tensions between the theoretical predictions and observations. This provides the motivation to look beyond General Relativity (GR) in search for a fundamental theory of gravity. Modified Gravity theories (MG) attempt to solve these issues and minimise these tensions. With the advent of more precise cosmological probes, it’s worthy to explore the theoretical predictions and observational consequences of MG theories, to correctly interpret present and future data and thus filtering specific models. In this project, we propose to explore the fundamental nature of gravity by exploring several models of MG, namely interacting Dark Energy (DE), symmetric teleparallel gravity, higher dimension theories, and Horndeski models, by studying their phenomenology, cosmological and astrophysical implications in a model independent approach. This work will allow us to test the nature of gravity and provide tighter constraints on the models.