Thursday, October 7, 2021 - 13:00 to 14:00

Zoom, Meeting ID: 928 0506 1304

### Abstract or Additional Information

Let G be a reductive group and Gr_G be its affine Grassmannian.

Following a paper of Mirkovic and Vilonen, I will explain that the

category of G_O-equivariant perverse sheaves on Gr_G is equivalent to

the category of representations of the Langlands dual group of G.

Somewhat surprisingly, this can be taken as the definition of the

Langlands dual group. I will not assume that the listeners are

familiar with perverse sheaves but I will assume some knowledge of

affine Grassmannians.