NUCLEOSYNTHESIS BOUNDS ON THE SCHMIDT-GREINER-HEINZ-MULLER THEORY OF GRAVITATION

We present a detailed calculation of light-element production in the S chmidt-Greiner-Heinz-Muller theory of gravitation. The comparison of o ur results with current observations implies very strong bounds on the allowed deviation from general relativity. These bounds lead to cosmo logical models which do not significantly differ from the standard Fri edmann-Robertson-Walker (FRW) predictions. This result, together with those previously obtained in the literature for other scalar-tensor th eories, allows us to conclude that there still does not exist any alte rnative metric theory of gravitation with a scalar field leading to a viable cosmological evolution distinguishable from the standard FRW on e.