Curtis Callan
He was awarded the Sakurai Prize in 2000 ("For his classic formulation of the renormalization group, his contributions to instanton physics and to the theory of monopoles and strings"[1]) and the Dirac Medal in 2004.He then pursued graduate studies in physics at Princeton University, where he was a student under Sam Treiman.He received his Ph.D. in physics in 1964 after completing a doctoral dissertation titled "Spherically symmetric cosmological models."[2] His Ph.D. students include Vijay Balasubramanian, William E. Caswell, Peter Woit, Igor Klebanov and Juan Maldacena.[citation needed] Callan is best known for his work on broken scale invariance (Callan–Symanzik equation) and has also made leading contributions to quantum field theory and string theory in the areas of dyon-fermion dynamics, string solitons and black holes.