OBSTRUCTED BUNDLES OF RANK TWO ON A QUINTIC SURFACE
Abstract
In this note we consider the moduli space of stable bundles of rank two on a very general quintic surface. We study the potentially obstructed points of the moduli space via the spectral covering of a twisted endomorphism. This analysis leads to generically non-reduced components of the moduli space, and components which are generically smooth of more than the expected dimension. We obtain a sharp bound asked for by O'Grady on when the moduli space is good.
To the memory of Masaki Maruyama