Threedimensional spacetimes.
Abstract
A real version of the NewmanPenrose formalism is developed for (2+1)dimensional spacetimes. The complete algebraic classification of the (Ricci) curvature is given. The field equations of Deser, Jackiw, and Templeton, expressing balance between the Einstein and Bach tensors, are reformulated in triad terms. Two exact solutions are obtained, one characterized by a null geodesic eigencongruence of the Ricci tensor, and a second for which all the polynomial curvature invariants are constant.
 Publication:

General Relativity and Gravitation
 Pub Date:
 November 1987
 DOI:
 10.1007/BF00759150
 Bibcode:
 1987GReGr..19.1137H
 Keywords:

 General Relativity:SpaceTime