· Professor Emeritus, California Institute of Technology2025–
· Professor of Mathematics, California Institute of Technology1981–2025
· Associate Professor, California Institute of Technology1976–1981
· Assistant Professor, California Institute of Technology1974–1976
· C.L.E. Moore Instructor, Massachusetts Institute of Technology1972–1974
· Ph.D. in Mathematics, University of California, Los Angeles1972–
· M.S. in Electrical and Mechanical Engineering, National Technical University of Athens1969–