Bouncing cosmology with Generalized Proca theories

Bouncing and cyclic cosmologies have a long history, but in recent years some shortcomings of the inflationary paradigm have spurred renewed efforts to explore them. However, it is notoriously difficult to construct a stable bounce that avoids all possible instabilities. I will focus on non-singular bouncing models driven by modified gravity theories: since it has been argued that models based on the scalar-tensor class of Horndeski theories suffer from strong coupling problems, we have explored whether a bounce driven by the vector-tensor class of Generalized Proca theories can solve these issues without encountering other pathologies. The preliminary answer seems to intriguingly depend on the requirement that gravity is modified only during the bounce and is still described by General Relativity in the asymptotic past and future.