On the stress–energy tensor of a null shell in Einstein–Cartan gravity

Abstract

The stress-energy tensor of a matter shell whose history coincides with a null hypersurface in the Einstein-Cartan gravity is revisited. It is demonstrated that with a proper choice for the torsion discontinuity taken to be orthogonal to the null hypersurface and consistent with the antisymmetric property of torsion tensor, the modified expression for the asymmetric stress-energy tensor is automatically tangent to the hypersurface. The main differences with respect to a previous work are addressed.

Revisiting the Israel junction conditions in Einstein-Cartan gravity

“…This paper aims to apply a proper choice for the torsion discontinuity taken to be orthogonal to a timelike or spacelike hypersurface to find the generalized form of the Israel junction conditions in the presence of torsion. Very recently this approach was applied for a null shell in the context of Einstein-Cartan theory of gravity [10]. Conventions.…”