Joel R. Primack (born July 14, 1945) is a professor of physics and astrophysics at the University of California, Santa Cruz and is a member of the Santa Cruz Institute for Particle Physics. Primack received his A.B. from Princeton University in 1966 and his Ph.D. from Stanford University in 1970. His fields of study are relativistic quantum field theory, cosmology, and particle astrophysics. He is also involved in supercomputer simulations of dark matter models. He directs the University of California High-Performance AstroComputing Center (UC-HiPACC). Primack is best known for his co-authorship with George Blumenthal, Sandra Moore Faber, and Martin Rees of the theory of cold dark matter (CDM) in 1984. He co-authored two books with Nancy Abrams, The View from the Center of the Universe (20