Geometrical optics in general relativity

TL;DR

This paper explores how geometrical optics within general relativity impacts the understanding of discontinuity surfaces in gravitational fields, highlighting foundational implications first noted by Levi-Civita.

Contribution

It clarifies the physical significance of discontinuity surfaces in gravitational fields through the lens of geometrical optics in general relativity.

Findings

Discontinuity surfaces are crucial for understanding gravitational wave propagation.

Geometrical optics provides insights into the physical meaning of these surfaces.

The work emphasizes Levi-Civita's early observations on this topic.

Abstract

General relativity includes geometrical optics. This basic fact has relevant consequences that concern the physical meaning of the discontinuity surfaces propagated in the gravitational field - as it was first emphasized by Levi-Civita.