Perturbative unitarity bounds on field-space curvature in de Sitter spacetime: purity vs scattering amplitude
Abstract
A bstract We study perturbative unitarity bounds on the field-space curvature in de Sitter spacetime, using the momentum-space entanglement approach recently proposed by Duaso Pueyo, Goodhew, McCulloch, and Pajer. As an illustration, we perform a perturbative computation of the purity in two-scalar models and compare the resulting unitarity bounds with those obtained via a flat space approximation. In particular, we find that perturbative unitarity imposes an upper bound on the field-space curvature of the Hubble scale order, in addition to a bound analogous to the flat space result. This reflects the thermal nature of de Sitter spacetime. We also discuss generalizations to higher-dimensional field spaces.
Fields of Study & Subjects
Black Holes and Theoretical Physics
Quantum Electrodynamics and Casimir Effect
Noncommutative and Quantum Gravity Theories
Publication details
- Journal / source
- Journal of High Energy Physics
- Publisher
- Springer Science and Business Media LLC
- Volume
- 2026
- Issue
- 3
- Publication date
- 2 March 2026
- Language
- EN