English

Moduli Spaces of Unstable Objects: Sheaves of Harder-Narasimhan Length 2

Algebraic Geometry 2021-11-16 v1

Abstract

Given a moduli problem posed using Geometric Invariant Theory, one can use Non-Reductive Geometric Invariant Theory to quotient unstable HKKN strata and construct 'moduli spaces of unstable objects', extending the usual moduli classifications. After giving a self-contained account of how to do this, we apply this method to construct moduli spaces for certain unstable coherent sheaves of HN length 2 on a projective scheme, which we call τ\tau-stable sheaves. This extends a previous result of Brambila-Paz and Mata-Guti\'{e}rrez for rank two vector bundles on a curve.

Keywords

Cite

@article{arxiv.2111.07428,
  title  = {Moduli Spaces of Unstable Objects: Sheaves of Harder-Narasimhan Length 2},
  author = {Joshua Jackson},
  journal= {arXiv preprint arXiv:2111.07428},
  year   = {2021}
}