Skip to content
DraconiticResearch
Search Sources API
197,768 studies31 sourcesUpdated 21 min ago
PreprintCC BY 4.0arXiv

Intrinsic Non-Reductive Geometric Invariant Theory and Moduli Spaces of Principal Bundles with Non-Reductive Structure Groups

Abstract

We prove the existence of moduli spaces for algebraic stacks with a weak action of Θ= [𝔸1/𝔾m] (including stacks of filtered objects and unstable Θ-strata) for which the center admits a good moduli space and the retraction to the center has flat, finitely presented relative inertia, providing a stack-intrinsic generalization of the existence of non-reductive Geometric Invariant Theory quotients. As an application, we construct quasi-projective coarse moduli spaces of principal bundles over a smooth projective curve with non-reductive structure groups, including moduli spaces of Ramanathan unstable principal bundles of fixed Harder--Narasimhan type.

Related

  1. Relative Geometric Invariant Theory: Reductive and Non-reductive
    Eloise Hamilton, Victoria Hoskins, Joshua Jackson
    arXivPreprintCC BY 4.0Full textAlgebra & number theoryarXiv
  2. Helly Numbers for Connected Reductive Groups and Splitting of Toric Principal Bundles
    Boris Tsvelikhovskiy
    arXivPreprintarXiv licenceFull textAlgebra & number theoryarXiv
  3. Zeta functions of quasi-split reductive algebraic groups over local fields
    Marcus du Sautoy
    arXivPreprintarXiv licenceFull textAlgebra & number theoryarXiv
  4. Quantized integral models of reductive monoids
    Jingren Chi, Simon Jacques
    arXivPreprintCC BY-NC-ND 4.0Full textAlgebra & number theoryarXiv
  5. Reductive monoids over general base
    Jingren Chi, Simon Jacques
    arXivPreprintCC BY-NC-ND 4.0Full textAlgebra & number theoryarXiv
BibTeX
@misc{cooper2026intrinsic,
  title = {{Intrinsic Non-Reductive Geometric Invariant Theory and Moduli Spaces of Principal Bundles with Non-Reductive Structure Groups}},
  author = {George Cooper and Ludvig Modin},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.38837},
  eprint = {2610.38837},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.38837},
  note = {CC BY 4.0},
}
RIS
TY  - UNPB
TI  - Intrinsic Non-Reductive Geometric Invariant Theory and Moduli Spaces of Principal Bundles with Non-Reductive Structure Groups
AU  - George Cooper
AU  - Ludvig Modin
PY  - 2026
DA  - 2026/10/28
PB  - arXiv
DO  - 10.48550/arxiv.2610.38837
UR  - https://arxiv.org/abs/2610.38837
AB  - We prove the existence of moduli spaces for algebraic stacks with a weak action of Θ= [𝔸^1/𝔾_m] (including stacks of filtered objects and unstable Θ-strata) for which the center admits a good moduli space and the retraction to the center has flat, finitely presented relative inertia, providing a stack-intrinsic generalization of the existence of non-reductive Geometric Invariant Theory quotients. As an application, we construct quasi-projective coarse moduli spaces of principal bundles over a smooth projective curve with non-reductive structure groups, including moduli spaces of Ramanathan unstable principal bundles of fixed Harder--Narasimhan type.
ER  -