A stacky approach to identifying the semistable locus of bundles
- Resource Type
- Working Paper
- Authors
- Weissmann, Dario; Zhang, Xucheng
- Source
- Subject
- Mathematics - Algebraic Geometry
- Language
We show that the semistable locus is the unique maximal open substack of the moduli stack of principal bundles over a curve that admits a schematic moduli space. For rank $2$ vector bundles it coincides with the unique maximal open substack that admits a separated moduli space, but for higher rank there exist other open substacks that admit separated moduli spaces.
Comment: Theorem A now includes the case of semistable principal bundles and the characteristic can be arbitrary in Theorem B and C. To appear in Algebraic Geometry (AG)