James A. Yorke

James A. Yorke (born August 3, 1941) is a Professor of Mathematics and Physics at the University of Maryland, College Park, and a recipient of the 2003 Japan Prize for his work in chaotic systems.

Born in Plainfield, New Jersey, Yorke coined the term chaos in a paper he coauthored with T.Y. Li in a 1975 entitled "Period Three Implies Chaos", in which it was proved that any continuous 1-dimensional map

R → R

that contains a period-3 orbit must contain orbits of every periodicity, as a result of Sharkovsky's theorem and the intermediate value theorem.

Reference

T.Y. Li, and J.A. Yorke, Period Three Implies Chaos, Amer. Math. Monthly 82, 985 (1975).