Absolute Objects and General Relativity: Dynamical Considerations

Abstract

The Anderson–Friedman program is one of the most venerable attempts to capture the novelty introduced by General Relativity. It uses the notion of absolute object, establishes a difference between covariance and invariance and is standardly understood as characterising a background independent theory as one that lacks absolute objects. In this paper I discuss the adequacy of such a characterisation, together with the most recent challenge to the program: the scalar density counterexample. According to it, GR has an absolute object and, therefore, it would not be background independent. I propose a modification to the definition of invariance that helps to tackle the counterexample and connects better with the intuition of dynamically relevant absolute objects being those that act and are not acted on.