Annamalai Ramanathan, Indian mathematician (Madras 29 August 1946 – Chicago 12 March 1993)

Gave a notion of stability for principal G-bundle on a Riemann surface

Constructed a moduli space for semistable principal bundles with a real reductive structure group

With S. Ramanan proved that the tensor product of a semistable vector bundles is semistable (1984)

With V.B. Mehta introduced the notion of a Frobenius split variety and compatibly split subvarieties (1985)

Proved that a principal G-bundle admits an Einstein-Hermitian connection if and only if it is polystable (1988)

EPONYMY

Ramanan-Ramanathan theorem

Rumford-Mehta-Ramanathan restriction theorem

Raghunathan-Ramanathan theorem

Kumar-Narasimhan-Ramanathan lemma

Ramanathan lemma

Ramanathan stability

Mehta-Ramanathan theorem for linear systems

Mehta-Ramanathan theorem for slope K-semistability

Mehta-Ramanathan theorem rank of a real form