HEP Theory Journal Club

Contracting Cosmologies and the Swampland

Heliudson de Oliveira Bernardo

McGill

We consider the cosmology obtained using scalar fields with a negative exponential potential energy, such as employed to obtain an Ekpyrotic phase of contraction. Applying the covariant entropy bound to the tower of states dictated by the distance conjecture, we find that the relative slope of the potential|V'|/|V|is bounded from below by a constant of the order one in Planck units. The bound is consistent with the requirement to obtain slow Ekpyrotic contraction. Our results motivate us to propose a new swampland criterium, which constrains low energy EFTs with negative potentials.