3-Form Cosmology: Phantom Behaviour, Singularities and Interactions

Abstract

Abstract:The latest cosmological observations by the Planck collaboration (and combined with others) are compatible with a phantom-like behaviour (w < −1) for the dark energy equation of state that drives the current acceleration of the Universe. With this mindset, we look into models where dark energy is described by a 3-form field minimally coupled to gravity. When compared to a scalar field, these models have the advantage of more naturally accommodating a cosmological-constant and phantom-like behaviours. We show how the latter happens for a fairly general class of positive-valued potentials, and through a dynamical system approach, we find that in such cases the 3-form field leads the Universe into a Little Sibling of the Big Rip singular event into the future. In this work, we explore the possibility of avoiding such singularity via an interaction in the dark sector between cold dark matter and the 3-form field. For the kind of interactions considered, we deduce a condition for replacing the LSBR by a late time de Sitter phase. For specific examples of interactions that meet this condition, we look for distinctive imprints in the statefinder hierarchy {S 3(1) ; S 4 (1) }, {S 3 (1) ; S 5 (1) }, and in the growth rate of matter, (z), through the composite null diagnostic (CND).

Scalaron tunneling and the fate of antisymmetric tensor fields in F(R) gravity

“…However the axion field we discussed in the above section is a dual of the antisymmetric KR field which can also act as a possible source of spacetime torsion [3], unlike to the class of axion discussed in the earlier literature in the context of dark matter [68][69][70]. Further in [71], a massive three-form field has been used to explain the dark energy epoch of the present Universe. This is different in comparison to our present paper where we deal with the massless KR field.…”