Probing the Nature of Dark Energy

Ten years after its discovery, the accelerated expansion of the Universe has obtained a great observational support from several independent cosmological measurements. On the other hand, its fundamental origin remains a complete mystery and a rich variety of models have been proposed to explain it, ranging from a simple cosmological constant to modifications of gravity. The exotic energy component that produces this behaviour is generically known as Dark Energy. My research consists in the phenomenologic al study of different dark energy models, obtaining predictions and testing them against several sets of cosmological data. A complementary perspective is as well pursued by analysing the relevant astronomical observations to find their usefulness. The lo ng term goal is to find a strategy to determine the physics behind the cosmic acceleration; specially the search for parameters that can distinguish modified gravity from other forms of dark energy. The work at the Institute of Theoretical Astrophysics w ould focus in scalar field models derived from disformal transformations. These have proven to encompass a large class of scalar field models and represent a very general approach. The specific aim is to confront predictions of these theoretical models a gainst cosmological observations including Supernovae, Cosmic Microwave Radiation and Galaxies distributions. The research stay at the ITA in the University of Oslo would significantly propel the aforementioned project by allowing direct collaboration wi th Dr. David Mota and profiting from his expertise in theoretical cosmology. Furthermore, access to the TITAN computer cluster would provide the computational resources necessary to pursuit this research line.