On two Notions of Semistability
arXiv:math/0703859
Abstract
We show that certain semistable sheaves on the projective plane with linear Hilbert polynomial are cokernels of semistable morphisms of decomposable sheaves.We exhibit certain locally closed subvarieties of moduli spaces of semistable sheaves as quotients modulo nonreductive groups.
Version 2 has three sections added. To appear in the Pacific Journal of Mathematics