Professor and former Dean, School of Technology and Computer Science, Tata Institute of Fundamental Research, Mumbai, India. Researcher in Theoretical Computer Science, focusing on Complexity Theory, Randomness in Computation, Quantum Complexity, and Combinatorics. He has served on the editorial boards of the journals ACM Transactions on Computation Theory, Discrete Mathematics and Theoretical Computer Science, SIAM Journal on Discrete Mathematics, and Theory of Computing. He received the Machtey Award in 1991 and the SS Bhatnagar Prize for Mathematical Sciences in 2008. Since 2007 he has been a Fellow of the Indian Academy of Sciences.