# de Sitter swampland bound in the Dirac-Born-Infeld inflation model

Seo, Min-Seok (Department of Physics, Chung-Ang University, Seoul 06974, Korea)

07 May 2019

Abstract: We study the de Sitter (dS) swampland conjecture in the Dirac-Born-Infeld (DBI) inflation model. We obtain the dS swampland bound for the relativistic regime using Bousso’s entropy bound argument and proper distance. It restricts ${m}_{\mathrm{Pl}}\nabla V/V$ by some positive constant depending on warping and the field range. In the specific case of the DBI model driven by the quadratic potential, the model-dependent backreaction argument is interpreted as a natural bound for the slow-roll parameter. This shows that quasi-dS spacetime in the DBI model is a result of tuning.

Published in: Physical Review D 99 (2019)