Stephen Craig Jackson is an American set theorist at the University of North Texas.
[1] Much of his most notable work has involved the descriptive set-theoretic consequences of the axiom of determinacy.
[2] In particular he is known for having calculated the values of all the projective ordinals (the suprema of the lengths of all prewellorderings of the real numbers at a particular level in the projective hierarchy) under the assumption that the axiom of determinacy holds.
In recent years he has also made contributions to the theory of Borel equivalence relations.
[3][4] Jackson earned his PhD in 1983 at UCLA under the direction of Donald A. Martin, with a dissertation on A Calculation of δ15.