Non-minimal coupling, negative null energy, and effective field theory
Jackson R. Fliss, Ben Freivogel, Eleni-Alexandra Kontou, Diego Pardo Santos
SciPost Phys. 16, 119 (2024) · published 2 May 2024
- doi: 10.21468/SciPostPhys.16.5.119
- Submissions/Reports
Abstract
The non-minimal coupling of scalar fields to gravity has been claimed to violate energy conditions, leading to exotic phenomena such as traversable wormholes, even in classical theories. In this work we adopt the view that the non-minimal coupling can be viewed as part of an effective field theory (EFT) in which the field value is controlled by the theory's cutoff. Under this assumption, the average null energy condition, whose violation is necessary to allow traversable wormholes, is obeyed both classically and in the context of quantum field theory. In addition, we establish a type of "smeared" null energy condition in the non-minimally coupled theory, showing that the null energy averaged over a region of spacetime obeys a state dependent bound, in that it depends on the allowed field range. We finally motivate our EFT assumption by considering when the gravity plus matter path integral remains semi-classically controlled.
Cited by 4
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 2 Jackson R. Fliss,
- 2 3 Ben Freivogel,
- 2 3 4 Eleni-Alexandra Kontou,
- 4 Diego Pardo Santos
- 1 University of Cambridge
- 2 Universiteit van Amsterdam / University of Amsterdam [UvA]
- 3 Gravitational and Astroparticle Physics Amsterdam [GRAPPA]
- 4 King's College London [KCL]