Definition and stability of Lorentzian manifolds with distributional curvature

TL;DR

This paper develops a coordinate-free geometric framework for Lorentzian manifolds with distributional curvature, enabling rigorous analysis of spacetimes with singularities like shock waves and gravitational waves.

Contribution

It establishes minimal assumptions on the metric for distributional curvature and derives jump relations and geometric properties for hypersurfaces with singularities.

Findings

Derived minimal metric assumptions for distributional curvature

Established jump relations for connection and curvature tensors

Defined distributional curvature and second fundamental form for hypersurfaces

Abstract

Following Geroch, Traschen, Mars and Senovilla, we consider Lorentzian manifolds with distributional curvature tensor. Such manifolds represent spacetimes of general relativity that possibly contain gravitational waves, shock waves, and other singular patterns. We aim here at providing a comprehensive and geometric (i.e., coordinate-free) framework. First, we determine the minimal assumptions required on the metric tensor in order to give a rigorous meaning to the spacetime curvature within the framework of distribution theory. This leads us to a direct derivation of the jump relations associated with singular parts of connection and curvature operators. Second, we investigate the induced geometry on a hypersurface with general signature, and we determine the minimal assumptions required to define, in the sense of distributions, the curvature tensors and the second fundamental form of the hypersurface and to establish the Gauss-Codazzi equations.