Reply to "Can gravitational dynamics be obtained by diffeomorphism invariance of action?"

TL;DR

This paper defends a method that derives gravitational field equations from boundary terms using diffeomorphism invariance, responding to critiques of its validity.

Contribution

It clarifies and reaffirms the approach of obtaining gravitational dynamics from boundary terms, addressing recent criticisms.

Findings

The boundary term approach is valid for deriving gravitational equations.

Diffeomorphism invariance can be used to obtain gravitational dynamics.

The critique of previous work is addressed and countered.

Abstract

In a previous work we showed that, in a suitable setting, one can use diffeomorphism invariance in order to derive gravitational field equations from boundary terms of the gravitational action. Standing by our results we reply here to a recent comment questioning their validity.