This talk is part of a subprogram of the Mathematical Science Literature Lecture series, a Memorial Conference for the founders of index theory: Atiyah, Bott, Hirzebruch and Singer. Registration：https://harvard.zoom.us/webinar/register/3516062319845/WN_9Qb6IBIfQ0ujujfLvue2eA

Dame Frances Clare Kirwan, DBE FRS is a British mathematician, currently Savilian Professor of Geometry at the University of Oxford. Her fields of specialisation are algebraic and symplectic geometry.