Non-symplectic involutions on manifolds of $K{3}^{[n]}$-type

Abstract

We study irreducible holomorphic symplectic manifolds deformation equivalent to Hilbert schemes of points on a $K3$ surface and admitting a non-symplectic involution. We classify the possible discriminant forms of the invariant and anti-invariant lattice for the action of the involution on cohomology, and explicitly describe the lattices in the cases where the invariant has small rank. We also give a modular description of all $d$-dimensional families of manifolds of $K{3}^{[n]}$-type with a non-symplectic involution for $d\ge 19$ and $n\le 5$, and provide examples arising as moduli spaces of twisted sheaves on a $K3$ surface.

21 pages