ALL UNIVERSAL COVERINGS OF 2-DIMENSIONAL GRAVITY WITH TORSION

Global solutions of two-dimensional gravity with torsion are found and elucidated. The model admits complete analysis of possible maximally continued space-times by means of Penrose's diagrams. There are 13 types of orientable universal coverings. For zero cosmological constant there is flat two-dimensional Minkowskian space-time. For nonzero cosmological constant the universal covering of zero torsion covers one-sheet hyperboloid with Lorenzian metric of constant curvature. All other universal coverings are the surfaces of nonzero torsion and nonconstant curvature. The global solutions include surfaces of a black hole configuration.