Revisiting the Israel junction conditions in Einstein-Cartan gravity

TL;DR

This paper revisits the Israel junction conditions within Einstein-Cartan gravity, showing modifications to the surface energy-momentum tensor and junction conditions based on torsion discontinuity assumptions.

Contribution

It introduces a new approach to torsion discontinuity, leading to modified junction conditions and clarifies differences from previous studies.

Findings

Surface energy-momentum tensor is tangent to the hypersurface.

Generalized Israel junction conditions are modified.

Clarifies differences with earlier works.

Abstract

The Israel junction conditions of a thin shell in the context of Einstein-Cartan gravity are revisited. It is shown that with a choice of the torsion discontinuity taken to be orthogonal to the hypersurface and consistent with the antisymmetric properties of torsion tensor and contorsion tensor, the generalized asymmetric surface energy-momentum tensor turns out to be tangent to the hypersurface while the resulting generalized Israel junction conditions are modified. The main differences to previous works are mentioned.