Lorentz Violating Inflation

TL;DR

This paper investigates how Lorentz violation influences inflation, revealing new inflationary phases and solutions, including Lorentz-violation-driven inflation without a potential, with potential observational consequences.

Contribution

It introduces exact Lorentz-violating inflationary solutions, including a novel potential-free inflation driven solely by Lorentz violation, expanding the understanding of inflationary dynamics.

Findings

Lorentz violation divides inflation into two stages.

Exact de Sitter expansion occurs during Lorentz violating stage.

Inflation can occur without a potential, driven by Lorentz violation.

Abstract

We explore the impact of Lorentz violation on the inflationary scenario. More precisely, we study the inflationary scenario in the scalar-vector-tensor theory where the vector is constrained to be unit and time like. It turns out that the Lorentz violating vector affects the dynamics of the chaotic inflationary model and divides the inflationary stage into two parts; the Lorentz violating stage and the standard slow roll stage. We show that the universe is expanding as an exact de Sitter spacetime in the Lorentz violating stage although the inflaton field is rolling down the potential. Much more interestingly, we find exact Lorentz violating inflationary solutions in the absence of the inflaton potential. In this case, the inflation is completely associated with the Lorentz violation. We also mention some consequences of Lorentz violating inflation which can be tested by observations.