Wald's gravitational entropy for ghost-free, infinite derivative theories of Gravity

TL;DR

This paper shows that in ghost-free, infinite derivative gravity theories, the entropy of spherically symmetric black holes follows the area law, indicating Einstein-Hilbert dominance in infrared behavior when only massless gravitons propagate.

Contribution

It demonstrates that Wald's entropy for such black holes depends only on the area, highlighting the Einstein-Hilbert term's role in infrared gravity behavior.

Findings

Wald's entropy aligns with the area law in these theories.

Infrared behavior is governed by Einstein-Hilbert action.

Massless graviton remains the sole propagating degree of freedom.

Abstract

In this paper, we demonstrate that the Wald's entropy for any spherically symmetric blackhole within an infinite derivative theory of gravity is determined solely by the area law. Thus, the infrared behaviour of gravity is captured by the Einstein-Hilbert term, provided that the massless graviton remains the only propagating degree of freedom in the spacetime.