85 citations · 173 across the 9 of their papers we have counts for
5 papers · 1 filter
Recognizing flag varieties and reductive groups
I. Grojnowski, N. I. Shepherd-Barron
Fix a flat and projective morphism of schemes. We show, first, that any set of -fibrations on defines a set of simple roots, a set of simple coroo…
"Del Pezzo surfaces as Springer fibres for exceptional groups"
I. Grojnowski, N. I. Shepherd-Barron
We show that simultaneous log resolutions of simply elliptic singularities can be constructed inside suitable stacks of principal bundles over elliptic curves. In particular, we gi…
A d-shifted Darboux theorem
E. Bouaziz, I. Grojnowski
We give a local model for d-shifted symplectic dg-schemes, or Deligne-Mumford dg-stacks [PTVV]. Locally any such is a product of a "twisted shifted cotangent bundle", where the twi…
The strong Macdonald conjecture and Hodge theory on the Loop Grassmannian
Susanna Fishel, Ian Grojnowski, Constantin Teleman
We prove the strong Macdonald conjecture of Hanlon and Feigin for reductive groups G. In a geometric reformulation, we show that the Dolbeault cohomology of the loop G…
Hilbert schemes, Hecke algebras and the Calogero-Sutherland system
K. Costello, I. Grojnowski
We describe the ring structure of the cohomology of the Hilbert scheme of points for a smooth surface X. When the canonical class K_X = 0, this was done by Lehn and Sorger, extendi…