OSCILLATORY BEHAVIOR IN COSMOLOGICAL MODELS

Oscillatory behavior in cosmological models is investigated, motivated , in part, by the apparent periodic distribution of galaxies in deep n arrow-cone red-shift surveys. In particular, oscillatory behavior in t wo cosmological models is studied; a qualitative analysis is performed and approximate solutions are found for a soft inflationary model and for a Friedmann-Robertson-Walker model containing a perfect fluid and a scalar field source. These two models are 'conformally equivalent' to particular models arising from a large class of scalar-tensor theor ies. It is then argued that such oscillatory behavior is a generic pro perty of scalar-tensor theories of gravity.