Alex Weekes, University of British Columbia
"Nilpotent orbits and affine Grassmannians"
Nilpotent orbits are important algebraic varieties arising in a number of different areas of mathematics. In spite of their simple definition, it is an open problem to give the defining equations of nilpotent orbit closures over a field of positive characteristic. For certain nilpotent orbits, Pappas and Rapoport conjectured a simple and explicit characteristic-free answer to this problem, with applications to their work in number theory. In this talk I will discuss a proof of their conjecture, which fits into a larger program describing the defining equations of an infinite-dimensional variety called the affine Grassmannian. I will also give an overview of the basics of nilpotent orbits, a subject which doesn't require much more than a background in basic linear algebra. This is based on joint work with Dinakar Muthiah and Oded Yacobi.
A post-colloquium meet and greet will be held at 2:00 pm using the same Zoom meeting link.
Zoom meeting: https://zoom.us/j/92428468231?pwd=OCt4SDcwTW9rbkZwZi8rRFh0Unc1dz09