On families of rank-2 uniform bundles on Hirzebruch surfaces and Hilbert schemes of their scrolls

Abstract

Several families of rank-two vector bundles on Hirzebruch surfaces are shown to consist of all very ample, uniform bundles. Under suitable numerical assumptions, the projectivization of these bundles, embedded by their tautological line bundles as linear scrolls, are shown to correspond to smooth points of components of their Hilbert scheme, the latter having the expected dimension. If e = 0, 1 the scrolls fill up the entire component of the Hilbert scheme, while for e = 2 the scrolls exhaust a subvariety of codimension 1.