Question: What Columbia University professor proved the Earle-Hamilton fixed-point theorem with Clifford Earle in 1968?
Context: In mathematics, the Earle–Hamilton fixed point theorem is a result in geometric function theory giving sufficient conditions for a holomorphic mapping of an open domain in a complex Banach space into itself to have a fixed point.  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. Wayne A. Hendrickson (born April 25, 1941, New York City) is an American biophysicist and University professor at Columbia.  Dr. Hendrickson is a University Professor at Columbia University in the Department of Biochemistry and Molecular Biophysics and Violin Family Professor of Physiology and Cellular Biophysics.  He is also Chief Life Scientist in the Photon Sciences Directorate at Brookhaven National Laboratory and Scientific Director of the New York Structural Biology Center.  Hendrickson has a B.A. from the University of Wisconsin at River Falls, a Ph.D. in biophysics at Johns Hopkins University with Warner Love, and postdoctoral research experience with Jerome Karle at the Naval Research Laboratory (NRL).  He and his colleagues use biochemistry and x-ray crystallography to study molecular properties in atomic detail with current emphasis on membrane receptors and cellular signaling, on viral proteins and HIV infection, on molecular chaperones and protein folding, and on structural genomics of membrane proteins.  Hendrickson's advances in diffraction methodology have contributed significantly to the emergence of structural biology as a major force in modern biology and molecular medicine. Caroline Walker Bynum, FBA (born in Atlanta, Georgia, in 1941) is an American Medieval scholar.  She is a University Professor emerita at Columbia University and Professor emerita of Western Medieval History at the Institute for Advanced Study in Princeton, New Jersey.  She was the first woman to be appointed University Professor at Columbia.  She is a former Dean of Columbia's School of General Studies, and served as President of the American Historical Association in 1996. Richard Streit Hamilton (born 1943) is Davies Professor of Mathematics at Columbia University. In mathematics, the Caristi fixed-point theorem (also known as the Caristi–Kirk fixed-point theorem) generalizes the Banach fixed point theorem for maps of a complete metric space into itself.  Caristi's fixed-point theorem is a variation of the "ε"-variational principle of Ekeland (1974, 1979).  Moreover, the conclusion of Caristi's theorem is equivalent to metric completeness, as proved by Weston (1977).  The original result is due to the mathematicians James Caristi and William Arthur Kirk. Clifford Seth Stein (born December 14, 1965), a computer scientist, is a professor of industrial engineering and operations research at Columbia University in New York, NY, where he also holds an appointment in the Department of Computer Science.  Stein is chair of the Industrial Engineering and Operations Research Department at Columbia University.  Prior to joining Columbia, Stein was a professor at Dartmouth College in New Hampshire. In mathematics, the Borel fixed-point theorem is a fixed-point theorem in algebraic geometry generalizing the Lie–Kolchin theorem.  The result was proved by . Gordana Vunjak-Novakovic is a Serbian American biomedical engineer.  She is University Professor and The Mikati Foundation Professor of Biomedical Engineering and Medical Sciences at Columbia University, where she directs the Laboratory for Stem Cells and Tissue Engineering.  She is also a faculty in the Irving Comprehensive Cancer Center and in the Center for Human Development at Columbia University, an honorary professor at the Faculty of Technology and Metallurgy at the University of Belgrade, honorary professor at the University of Novi Sad, and an adjunct professor at the Department of Biomedical Engineering at Tufts University. Mortimer Lamson Earle, Ph. D. (1864 – 1905) was an American classical scholar.  He was born in New York City on October 14, 1864, the only child of Mortimer Lent Earle and Mercy Josephine Allen.  He received his early education from Ashland Public School in East Orange, New Jersey and through private tutors, and was educated at Columbia College of Columbia University, receiving his doctorate from Columbia University in 1889.  He studied at the University of Bonn and the American School of Classical Studies at Athens in the period from 1887 to 1889.  At the latter in 1887 he was placed in charge of the excavations of the site of ancient Sikyon by Professor Augustus C. Merriam of Columbia.  In 1892 he married Ethel Deodata Woodward (1864 – 1940).  They had no children. Claudio Lomnitz is the Campbell Family Professor of Anthropology at Columbia University.  Prior to teaching at Columbia, Lomnitz was a Distinguished University Professor of Anthropology and Chair of the Committee on Historical Studies at the New School University.  He served at different points in time as co-director of the University of Chicago's Mexican Studies Program (with Friedrich Katz), Director of the University of Chicago's Latin American Studies Program, and Director of Columbia University's Center for the Study of Ethnicity and Race.  He has also taught at University of Chicago, where he was Professor of History, New York University, El Colegio de México, and Universidad Autónoma Metropolitana Iztapalapa, in Mexico City.  At the New School University, Lomnitz was appointed editor of the academic journal Public Culture, which moved with him to Columbia University in 2006.  He continued to serve as editor until 2011.
Answer: Richard S. Hamilton