| 9/16/00-present | Professor | |
| 9/16/93-9/15/00 | Associate Professor | |
| 1/1/88-9/15/93 | Assistant Professor |
| 2/10-4/10 | Visitor |
| 9/09-10/09 | Visiting Professor |
| 9/02-12/02 | Robert N. Noyce '49 Visiting Professor in the Physical Sciences, Math, and Computer Science |
| 9/01-6/02 | Hutchcroft Visiting Professor of Mathematics |
| 2/16/95-8/20/95 | Visiting Professor |
| 8/1/94-2/6/95 | Visiting Research Fellow |
| 1/91-6/91 | Research Professor |
| 10/87-12/87 | Tata Institute of Fundamental Research, Bombay, India | |
| 11/87 | University of Poona, Pune, India | |
| 7/87-9/87 | Institute of Mathematical Sciences, Madras, India | |
| 8/87 | Raman Research Institute, Bangalore, India |
| 9/86-7/87 | SERC Postdoctoral Research Fellow |
| 10/84-5/86 | Member |
Last Update: 12/20/13