BLACK-HOLES OF A GENERAL 2-DIMENSIONAL DILATON GRAVITY THEORY

A general dilaton gravity theory in 1+1 spacetime dimensions, with a c osmological constant lambda and a new dimensionless parameter omega, c ontains as special cases the constant curvature theory of Teitelboim a nd Jackiw, the theory equivalent to vacuum planar general relativity, the first-order string theory, and a two-dimensional purely geometrica l theory. The equations of this general two-dimensional theory admit s everal different black holes with various types of singularities. The singularities can be spacelike, timelike, or null, and there are even cases without singularities. Evaluation of the ADM mass, as a charge d ensity integral, is possible in some situations by carefully subtracti ng the black hole solution from the corresponding linear dilaton at in finity.