Inflationary implications of the Covariant Entropy Bound and the Swampland de Sitter Conjectures

TL;DR

This paper links the de Sitter Conjecture to the Covariant Entropy Bound in inflationary models, showing that the conjecture's inequalities naturally follow from entropy considerations, with implications for multi-field inflation and extra dimensions.

Contribution

It establishes a connection between the de Sitter Conjecture and the Covariant Entropy Bound, incorporating extra-dimensional entropy contributions to derive the conjecture's inequalities.

Findings

dSC inequalities follow from the CEB in inflationary scenarios

Constants c and c' relate to entropy change, Hubble constant, and scalar field dynamics

Example provided with flux string scenario affecting four-dimensional entropy

Abstract

We present a proposal to relate the de Sitter Conjecture (dSC) to the Covariant Entropy Bound (CEB). By assuming an early phase of accelerated expansion where the CEB is satisfied, we take into account a contribution from extra-dimensions to the four-dimensional entropy which restricts the values of the usual slow-roll parameters. We show in this context that the dSC inequalities follow from the CEB -- including their mutual exclusion -- in both single and multi-field inflationary scenarios. We also observe that the order one constants, c and c' in the conjecture are given in terms of physical quantities such as the change in entropy over time, the Hubble constant and the dynamics of the effective scalar fields. Finally, we give a simple example to illustrate a possible contribution to the four-dimensional entropy from a flux string scenario.