Geodesic motion and confinement in Gödel's universe

Abstract

We present a complete study of geodesic motion in G\"odel's universe, using the method of the effective potential. A clear physical picture of free motion and its stability in this universe emerges. A large class of geodesics have finite intervals in which the particle moves back in time ($\frac{\mathrm{dt}}{\mathrm{ds}}<0$) without violation of causality. G\"odel's geometry produces the important property of confinement for a large class of geodesics. We use this property to discuss the construction of a gravitational container. This structure is highly stable, since there is no singularity in its interior, and is independent of the energy of the particles contained in it.