I study the Fock representations for a Dirac field given by the the different choices of creation and annihilation variables. This is done in the context of a perturbed flat cosmology that, in addition, is minimally coupled to fermionic perturbations. In our description, I use a canonical formulation for the entire system, formed by the underlying cosmological spacetime and all its...
We revisit Brans-Dicke type cosmologies. In the last years, this alternative has grown in popularity, because of the possibility it may explain cosmological data better than the current ΛCDM paradigm. Besides, as a difference from other scalar-tensor theories, we can assign a clear role to the variation of the scalar field through the cosmic history: a change in the effective Gravitational...
