Hole argument

About: Hole argument is a research topic. Over the lifetime, 130 publications have been published within this topic receiving 13826 citations.

What Is Observable in Classical and Quantum Gravity

Abstract: The problem of the identification of the observable quantities in quantum gravity (or in any diffeomorphism invariant quantum theory) is considered. The author recalls Einstein's 'hole argument' on the impossibility of a priori identifying spacetime points. He argues that only by explicitly taking into account the physical nature of the bodies that form the reference system and their gravitational interactions one can get well defined gauge-invariant (and 'local') observables and a definition of physical spacetime points. A model is considered in which general relativity is coupled to matter: the matter represents the physical reference system. The gauge-invariant physical observables of this theory are displayed.

General covariance and the foundations of general relativity: eight decades of dispute

Abstract: Einstein offered the principle of general covariance as the fundamental physical principle of his general theory of relativity and as responsible for extending the principle of relativity to accelerated motion. This view was disputed almost immediately with the counter-claim that the principle was no relativity principle and was physically vacuous. The disagreement persists today. This article reviews the development of Einstein's thought on general covariance, its relation to the foundations of general relativity and the evolution of the continuing debate over his viewpoint.