Non-minimal coupling, negative null energy, and effective field theory
Appears in collection : 2024 - PC1 - WS - Curved spacetimes, field theory and beyond
Even classical scalar fields, non-minimally coupled with the curvature, can violate energy conditions such as the null energy condition. In the context of quantum field theory, non-minimally coupled scalars can obey lower bounds, known as quantum energy inequalities, but these are always state dependent. In this talk I will discuss classical and quantum bounds on the null energy and consider possible violations. Further, I will examine the conformal transformation between Jordan and Einstein frames both classically and semiclassically. Finally, I will comment on extensions of this work and connections with self-interacting fields.
