Princeton University High Energy Theory Seminar

Abstract: Scherk–Schwarz compactifications have been widely studied for model building and as a testing ground for non-supersymmetric de Sitter and AdS vacua. I will use a simple correspondence between the radion potential and the thermal free energy of a higher-dimensional theory to derive bottom-up constraints in this corner of the quantum gravity landscape from unitarity and thermodynamic positivity. The resulting inequalities exhibit remarkable agreement with Swampland conjectures proposed to hold more broadly. These constraints extend into the interior of moduli space and, within their regime of validity, imply perturbative instability of Scherk–Schwarz de Sitter vacua and obstruct conventional slow-roll inflation. I will present nontrivial tests of these constraints in string theory and discuss the distinct roles of tachyonic modes, how they generate complex potentials, and the bounds that can be established on those potentials. Finally, if time permits, I will discuss generalizations to other twisted compactifications.