New modes from higher curvature corrections in holography

TL;DR

This paper investigates how higher curvature corrections in gravitational theories affect the holographic duality, revealing new modes that require modified boundary expansions and analyzing their behavior.

Contribution

It identifies infinite families of theories with non-truncatable modes, proposing a modified Fefferman-Graham expansion to accommodate these additional degrees of freedom.

Findings

New modes cannot be truncated in certain higher curvature theories

Modified boundary expansion is necessary for these theories

Analysis of fall-off properties of extra modes

Abstract

In gravitational theories involving higher curvature corrections the metric describes additional degrees of freedom beyond the graviton. Holographic duality maps these to operators in the dual CFT. We identify infinite families of theories for which these new modes cannot be truncated and the usual Fefferman-Graham expansion needs to be modified. New massive gravity in three dimensions and critical gravity in four dimensions are particular representatives of these families. We propose modified expansion, study the near-boundary behaviour of the metric and derive fall-off properties of the additional modes in theories involving higher derivative corrections.