Uhlenbeck spaces for $A^2$ and affine Lie algebra ${\widehat{sl}}_n$

Michael Finkelberg, Dennis Gaitsgory, Alexander Kuznetsov

We introduce an Uhlenbeck closure of the space of based maps from projective line to the Kashiwara flag scheme of an untwisted affine Lie algebra. For the algebra ${\widehat{sl}}_n$ this…