Cosmological models in certain scalar-tensor theories

Exact solutions of Einstein field equations are obtained in the scalar-tensor theories developed by Saez and Ballester (1985) and Lau and Prokhovnik (1986) when the line-element has the form ds(2) = exp(sh)dt(2) - exp(2A)(dx(2) + dy(2)) - exp(sB)dz(2) where h, A and B are functions of t only. The solutions are spatially homogeneous, locally rotationally symmetric and admit a Bianchi I group of motions on hypersurfaces t = constant. The dynamical behaviours of these models have also been discussed.