What Columbia University professor proved the Earle-Hamilton fixed-point theorem with Clifford Earle in 1968?
Richard S. Hamilton Richard Streit Hamilton (born 1943) is Davies Professor of Mathematics at Columbia University.
Neil Robertson (mathematician) George Neil Robertson (born November 30, 1938) is a mathematician working mainly in topological graph theory, currently a distinguished professor emeritus at the Ohio State University. He earned his B.Sc. from Brandon College in 1959, and his Ph.D. in 1969 at the University of Waterloo under his doctoral advisor William Tutte.