Question: What Columbia University professor proved the Earle-Hamilton fixed-point theorem with Clifford Earle in 1968?
Sentence (from "Earle–Hamilton fixed-point theorem"): The result was proved in 1968 by Clifford Earle and Richard S. Hamilton by showing that, with respect to the Carathéodory metric on the domain, the holomorphic mapping becomes a contraction mapping to which the Banach fixed-point theorem can be applied.
Relevant evidence: Yes