Charles Royal Johnson

Charles Royal Johnson (born January 28, 1948) is an American mathematician specializing in linear algebra. He is a Class of 1961 professor of mathematics at College of William and Mary. The books "Matrix Analysis" and "Topics in Matrix Analysis", co-written by him with Roger Horn, are standard texts in advanced linear algebra.
Career.
Charles R. Johnson received a B.A. with distinction in Mathematics and Economics from Northwestern University in 1969. In 1972, he received a Ph.D. in Mathematics and Economics from the California Institute of Technology, where he was advised by Olga Taussky Todd; his dissertation was entitled "Matrices whose Hermitian Part is Positive Definite". Johnson held various professorships over ten years at the University of Maryland, College Park starting in 1974. He was a professor at Clemson University from 1984–1987. In 1987, he became a professor of mathematics at the College of William and Mary, where he remains today.