Torsion in two dimensions: autoparallels, symmetries, and applications to black holes

We explore spacetime torsion in a two-dimensional setting, wherein it corresponds to a vector field. Without invoking field equations of a particular gravitational theory, we develop visualization techniques for such torsion fields, consider a generalization of Killing vectors to the presence of torsion, and find explicit representations of such Killing vectors (and their generalized algebra) in the presence of constant torsion. We then utilize these structures to derive general properties of surface gravities of static black holes whose near-horizon region features approximately constant torsion fields. Under certain assumptions, the two-dimensional results can be lifted to four dimensions.