Toward Singularity Theorems with Torsion

TL;DR

This paper develops a singularity theorem incorporating torsion in timelike curves, deriving a deviation equation, analyzing conjugate points, and identifying conditions under which torsion affects congruence behavior.

Contribution

It introduces a new singularity theorem framework for timelike curves with torsion, including a deviation equation and analysis of torsion effects on congruences.

Findings

Totally antisymmetric torsion does not affect timelike congruence behavior.

A deviation equation alternative to Raychaudhuri with torsion is derived.

Non-autoparallel curves are essential for the singularity theorem.

Abstract

This study examines the formulation of a singularity theorem for timelike curves including torsion, and establishes the foundational framework necessary for its derivation. We begin by deriving the relative acceleration for an arbitrary congruence of timelike curves. The resulting ``deviation equation'' offers an alternative pathway to the well-known Raychaudhuri equation with torsion. Conjugate points are then introduced and analyzed in relation to the behavior of the scalar expansion. Together with the sensible requirement of hypersurface orthogonality, the Raychaudhuri equation is examined for several specific cases of torsion that are prominent in the literature. Our findings indicate that a totally antisymmetric torsion tensor does not influence the behavior of the congruence of timelike curves. Finally, we formulate a singularity theorem for timelike curves and highlight the critical requirement of non-autoparallel curves.