Gravity: local or nonlocal

Abstract

Abstract While gravity is often imagined to have the characteristics of a local gauge theory, no such gauge theory has so far been constructed, with all attempts at quantum gravity leading to nonrenormalizable infinities. All known gauge theories, however, have both local and nonlocal aspects, and it is worth exploring how far we can describe gravity using a nonlocal starting point. It is suggested that this leads to a local theory which privileges inertia rather than gravity. Such a theory based on a repulsive force, would be renormalizable, and it would also have consequences that can be linked to cosmological redshift, dark energy and possibly also dark matter. It further suggests generic connections between gravity and inertia and between general relativity and Newtonian gravity.