GRAVITATION AND COSMOLOGY IN GENERALIZED (1+1)-DIMENSIONAL DILATON GRAVITY

The actions of the 'R = T' and string-inspired theories of gravity in (1 + 1) dimensions are generalized into one single action which is characterized by two functions. We discuss differing interpretations of the matter stress-energy tenser, and show how two such different interpretations can yield two different sets of field equations from this action. The weak-field approximation, post-Newtonian expansion, hydrostatic equilibrium state of a star and two-dimensional cosmology are studied separately by using the two sets of field equations. Some properties in the 'R = T' and string-inspired theories are shown to be generic in the theory induced by the generalized action.