Gregory Gabadadze, A New Gravitational Action for the Trace Anomaly 

ITMP seminar, May 3, 2023
Speaker: Prof. Gregory Gabadadze, New York University
Title: A New Gravitational Action for the Trace Anomaly
Abstract: General Relativity (GR) combined with the existing action for the trace anomaly is an inconsistent low energy effective field theory. This issue is addressed by extending GR into a certain scalar-tensor theory, which preserves the GR trace anomaly equation, up to higher order corrections. The extension introduces a new mass scale - assumed to be below the Planck scale - that governs four high dimensional terms in a local diff-invariant trace anomaly action. Such terms can be kept, while an infinite number of Planck-suppressed invariants are neglected. The resulting theory maintains two derivative equations of motion. In a certain approximation it reduces to the conformal Galileon, which could have physical consequences.