Lorentz violating inflation and the Swampland

Abstract

The swampland conjectures from String theory have had very interesting implications for cosmology and particularly for Inflation. It has been shown that the single field inflationary models in a GR based cosmology are in unavoidable tensions with these conjectures, while these single field models can still be consistent in certain non-trivial inflationary regimes. So it becomes interesting to see whether there is a way to overcome the issues of the swampland and single field inflation in an essentially GR based cosmology. We show that this can indeed be the case and for this, we consider a certain type of Lorentz violating inflationary scenario. We work out the swampland bounds for Lorentz violating inflationary models after which show that inflationary models which would have had otherwise serious tensions with these conjectures in a usual GR based scenario, can be very tranquil with the criterion in this regime. For this we take examples of Higgs inflation, radion gauge inflation and Spontaenous symmetry breaking inflation and show that the bounds imposed by the swampland on the Lorentz violating parameter can be easily satisfied in these models.

Dynamics of Einstein–Aether scalar field cosmology

“…It has been used as a toy model for the definition of a Lorentz violating DGP model with no ghosts [55]. Lorentz violating inflationary models has been widely studied in the literature, see for instance [56][57][58][59]. In [60], the authors investigated the effects of Lorentz violation in the cosmological history.…”