| C.S. Seshadri | |
| Birth Name: | Conjeevaram Srirangachari Seshadri |
| Birth Date: | 29 February 1932 |
| Death Place: | Chennai, India |
| Field: | Mathematics |
| Work Institution: | Chennai Mathematical Institute |
| Doctoral Advisor: | K. S. Chandrasekharan |
| Doctoral Students: | Vikraman Balaji, V. Lakshmibai |
| Known For: | Seshadri constant Narasimhan–Seshadri theorem Standard monomial theory |
| Prizes: | Shanti Swarup Bhatnagar Award, Padma Bhushan, Fellow of the Royal Society |
Conjeevaram Srirangachari Seshadri [1] (29 February 1932 – 17 July 2020) was an Indian mathematician.[2] He was the founder and director-emeritus of the Chennai Mathematical Institute, and is known for his work in algebraic geometry.[3] The Seshadri constant is named after him. He was also known for his collaboration with mathematician M. S. Narasimhan, for their proof of the Narasimhan–Seshadri theorem which proved the necessary conditions for stable vector bundles on a Riemann surface.
He was a recipient of the Padma Bhushan in 2009, the third highest civilian honor in the country.[4]
Seshadri was born into a Hindu Brahmin family in Kanchipuram, Tamil Nadu.[5] He received his B.A. (Hons) degree in mathematics from Madras University in 1953 and was mentored by the Jesuit priest Fr. Charles Racine and S. Naryanan there.[6] [7] He completed his PhD from Bombay University in 1958 under the supervision of K. S. Chandrasekharan. He was elected Fellow of the Indian Academy of Sciences in 1971.[8]
Seshadri worked in the School of Mathematics at the Tata Institute of Fundamental Research in Bombay from 1953 to 1984 starting as a Research Scholar and rising to a senior professor. From 1984 to 1989, he worked at the Institute of Mathematical Sciences, Chennai. From 1989 to 2010, he worked as the founding director of the Chennai Mathematical Institute. After stepping down he continued to be the institute's Director-Emeritus till his death in 2020. He also served on the Mathematical Sciences jury for the Infosys Prize in 2010 and 2011.
He has given talks at the ICM.
Seshadri's main work was in algebraic geometry. His work with M S Narasimhan on unitary vector bundles and the Narasimhan–Seshadri theorem has influenced the field. His work on Geometric Invariant Theory and on Schubert varieties, in particular his introduction of standard monomial theory, is widely recognized.