Between the years 1965 and 1995 he worked at the
Tata Institute of Fundamental Research and after retirement joined the
National Institute of Advanced Studies, Bangalore where he worked till 2011, the year he died. During the course of his lifetime, he published over 200 articles, of which over 170 have been catalogued by
Mathematical Reviews. His work was primarily in the area of
analytic number theory, working on the
Riemann zeta function and allied functions. Apart from analytic number theory, he made substantial contributions to the theory of
transcendental number theory, in which he is known for his proof of the
six exponentials theorem, achieved independently of
Serge Lang. He also contributed to many other areas of number theory. In 1978 he founded the
Hardy–Ramanujan journal, and published it on behalf of the Hardy–Ramanujan society until his death. == Awards and distinctions==