1.b Short Range Gravitational Theory

This research line is a collaboration with physicists of the University of Lyon (France),and is related to the possibility of modifications of the gravitational interaction at short distances. The existence of this new behaviour would entail a unification program, thanks to the massive spin-2 fields that would mediate Fermi-like gravitational forces. This theory would have consequences that are potentially observable in terrestrial or space laboratories. Some important effects are also to be expected in regions of high density, like the core of stars or the primordial high-temperature universe.

There is an issue to be solved without delay in order to proceed with this line, and that is the issue of the compatibility of the interaction of a spin 2 field with a Riemannian geometry of nonzero curvature. To solve this problem and bypass the difficulties pointed out by Aragones and Deser more than 20 years ago, we shall use the Fierz representation of a spin 2 field. We already have some preliminary results that suggest that this analysis can show a new way to solve the problem.