Dr. Rafael Chacon

The work of R.V.S. Chacon deals with probability and ergodic theory. His papers are characterized by outstanding originality and clever ingenuity. He has solved difficult outstanding problems. Among these achievements is a complete answer to a deep conjecture of E. Hopf of 1954 in the Chacon-Ornstein ergodic theorem. In answer to a question of Halmos he has constructed a 1-1 measure preserving transformation of the unit interval into itself which has a continuous spectrum, no non-singular square root and is not strongly mixing in the ergodic sense. Much of his work contains promise of interesting subsequent development, some of which has already been realized in the rather large number of his joint papers.