Interacting Dark Energy

Many cosmological models proposing an alternative to the cosmological constant have been analysed and compared with observational data, ranging from quintessence scalar field models in General Relativity to models based on modified theories of gravity. A less explored possibility is that dark energy (DE) interacts with dark matter (DM).

In this project we will build new interacting DE-DM models, in particular (at least initially) focusing on the case where DE is represented by a simple vacuum, assuming therefore that all the modifications of the standard LCDM model come from the interaction itself, following a phenomenological approach.

A first phase will be dedicated to building and analyzing the properties of the FLRW modes with numerical and dynamical systems techniques. In a second phase we will derive the relativistic perturbation equations describing the evolution of small inhomogeneities in these models. A third phase should implement these equations in existing numerical codes, which should be modified accordingly, in order to derive observational predictions of the models and constrain them with available data.