Clarify the significance of the conformal c-anomaly cancellation in N ≥ 5 supergravities

Clarify the physical meaning and implications of the cancellation of the four-dimensional conformal c-anomaly in N ≥ 5 supergravity theories, and determine whether it signals an underlying hidden superconformal structure.

Background

In N ≥ 5 supergravities, certain anomalies exhibit non-trivial cancellations, including the vanishing of the conformal c-anomaly. While these theories are not classically conformal, the cancellations might hint at deeper structures.

Understanding whether and how such cancellations reflect hidden symmetries, such as superconformal invariance, is important for the ultraviolet behavior and possible finiteness properties of extended supergravity theories.