Lorentz violating inflation and the swampland

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 we 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 spontaneous symmetry breaking inflation and show that the bounds imposed by the swampland on the Lorentz violating parameter can be easily satisfied in these models.

Automated summary

Research has shown that single-field inflation models in a cosmology based on general relativity are in conflict with the swampland conjectures from string theory. However, it has been discovered that these models can still be consistent in certain non-trivial inflationary regimes. By considering a specific type of Lorentz violating inflationary scenario, the researchers demonstrate that the tensions between the swampland conjectures and inflation can be resolved in a general relativity-based cosmology.