학술논문

Parity sheaves on the affine Grassmannian and the Mirković-Vilonen conjecture.
Document Type
Article
Source
Acta Mathematica (Springer Nature). Dec2015, Vol. 215 Issue 2, p183-216. 34p.
Subject
*GRASSMANN manifolds
*DIFFERENTIAL topology
*MANIFOLDS (Mathematics)
*LOGICAL prediction
*SCHUBERT varieties
*FERMAT'S little theorem
*TWIN prime conjecture
Language
ISSN
0001-5962
Abstract
We prove the Mirković-Vilonen conjecture: the integral local intersection cohomology groups of spherical Schubert varieties on the affine Grassmannian have no p-torsion, as long as p is outside a certain small and explicitly given set of prime numbers. (Juteau has exhibited counterexamples when p is a bad prime.) The main idea is to convert this topological question into an algebraic question about perverse-coherent sheaves on the dual nilpotent cone using the Juteau-Mautner-Williamson theory of parity sheaves. [ABSTRACT FROM AUTHOR]