Generalized grand unified big-bang models which include initial fermion degeneracies are considered, and limits are obtained on specific entropy and lepton number valid for any theory which contains SU(5). Lepton degeneracies may occur which significantly affect element production. These results affect inferences about the early universe based on the standard model.

• Received 12 July 1982

DOI:https://doi.org/10.1103/PhysRevLett.49.1873