He is a member of the Physics Department's High Energy Physics group and also heads the Early Universe Cosmology and String Theory division of Baylor's Center for Astrophysics, Space Physics, and Engineering Research. Gerald earned his Ph.D. at Caltech in 1993, where he studied under John H. Schwarz, one of the founders of string theory. Cleaver has written over 60 peer-reviewed journal papers and conference proceedings, which have received over 1200 total citations. He is the author of one book chapter and a co-author of two books currently in draft form.