Trans-Planckian censorship and other swampland bothers addressed in warm inflation

TL;DR

This paper explores how the Trans-Planckian censorship conjecture affects warm inflation models, showing that multi-stage inflation can relax censorship constraints and allow for larger tensor-to-scalar ratios.

Contribution

It introduces a two-stage inflationary model within warm inflation that alleviates TCC constraints, expanding the viable parameter space for inflationary scenarios.

Findings

Single-stage warm inflation faces similar TCC constraints as cold inflation.

Two-stage inflation with an intermediate radiation era relaxes TCC bounds.

Tensor-to-scalar ratio can be as high as 10^{-5} under weaker TCC assumptions.

Abstract

The implications of the recently proposed Trans-Planckian censorship conjecture (TCC) are analyzed in the context of warm inflation. It is found that for a single-stage accelerated expansion the constraints imposed by the censorship are roughly the same as for cold inflation. Next, we study how a two-stage inflationary expansion with an intermediate radiation-dominated era can alleviate the bounds imposed by the censorship. For a demonstrative toy model we found $r<10^{-23}$, but can be $r<10^{-5}$ for a weaker form of TCC for the later stages of expansion, while still satisfying the other swampland conditions.