CS Seshadri: Math world loses a tall luminary

Professor Conjeevaram Srirangachari Seshadri, one of India’s most eminent mathematicians, passed away on July 17, at the age of 89.

Seshadri’s work and publications have had a great impact in shaping India as a major centre for mathematics research. He established the Chennai Mathematical Institute (CMI), which is now a leading centre for advanced research in mathematics globally.

Born on February 29, 1932 in Kanchipuram, Seshadri did his schooling at St Joseph’s School, followed by an Honours degree in mathematics at Madras University. He completed his Doctoral research from Bombay University in 1958 under the supervision of K S Chandrasekharan.

Seshadri worked in the School of Mathematics at TIFR in Bombay from 1953 to 1984, starting as a research scholar, and rose to become a senior professor. He was elected Fellow of the Indian Academy of Sciences in 1971.

My condolences on passing away of Prof. C.S.Seshadri – a towering Mathematician, who carved his niché in Algebraic Geometry. His contribution to diverse stream of mathematics & role in institution building to encourage basic research & inquisitiveness will forever be remembered.

— Pranab Mukherjee (@CitiznMukherjee) July 18, 2020

From 1984 to 1989, he worked in IMSc, Chennai. From 1989 to 2010, he worked as the founding director of the Chennai Mathematical Institute. He stepped down from his Directorship of the Chennai Mathematical Institute in December 2010, and continued to be a part of CMI as ‘Emeritus-Director’ till his demise in 2020.

A Carnatic music connoisseur, Seshadri was also formally trained in it. He was a recipient of the Padma Bhushan in 2009, the third highest civilian honour in the country.

CSS, as he was also known, was a Fellow of the Royal Society and was the second Indian mathematician to achieve this honour after Srinivasa Ramanujan.

Along with his colleague and classmate M S Narasimhan, he published their theorem ‘Narasimhan–Seshadri theorem’ in 1965 in their paper, ‘Stable and Unitary Vector Bundles on a Compact Riemann Surface’, which proved that a holomorphic vector bundle over a Riemann surface is stable iff (if and only if is written as ‘iff’) it comes from an irreducible projective unitary representation of the fundamental group. The Seshadri constant in algebraic geometry is named after him.

In the passing away of Professor C. S. Seshadri, we have lost an intellectual stalwart who did outstanding work in mathematics. His efforts, especially in algebraic geometry, will be remembered for generations. Condolences to his family and admirers. Om Shanti.

— Narendra Modi (@narendramodi) July 18, 2020

This path-breaking theorem, with all generalisations and analogues, has been at the centre of various aspects of algebraic geometry and number theory, for over half a century. The application of their mathematics has had deep ramifications in our understanding of the Quantum field theory.

Vikraman Balaji, a professor of mathematics at Chennai Mathematical Institute, who did his doctorate in Mathematics under the supervision of Seshadri. speaks about ‘the Man and his Mathematics’.

Balaji was awarded the 2006 Shanti Swarup Bhatnagar Award in Mathematical Sciences for his outstanding contributions. He was also elected Fellow of the Indian Academy of Sciences in 2007 and Fellow of the Indian National Science Academy in 2015.