New derived autoequivalences of Hilbert schemes and generalised Kummer varieties
arXiv:1301.4970
Abstract
We show that for every smooth projective surface X and every the push-forward along the diagonal embedding gives a -functor into the -equivariant derived category of X^n. Using the Bridgeland--King--Reid--Haiman equivalence this yields a new autoequivalence of the derived category of the Hilbert scheme of n points on X. In the case that the canonical bundle of X is trivial and n=2 this autoequivalence coincides with the known EZ-spherical twist induced by the boundary of the Hilbert scheme. We also generalise the 16 spherical objects on the Kummer surface given by the exceptional curves to n^4 orthogonal -Objects on the generalised Kummer variety.
Mistakes in Lemma 3.3, Prop. 4.4, and Remark 4.7 corrected. The changes do not affect the main results