PreprintCC BY 4.0arXiv
Genus 4 Supermoduli Space Is Not Projected
Abstract
The supermoduli stack Mg, parametrizing smooth unpunctured super Riemann surfaces of genus g, is known to be non-projected for g ≥ 5. We extend this result to the even-spin component of M4. This is done by exhibiting an appropriate compact curve in the spin moduli space 𝒮ℳ4+, and computing the restriction to it of the class obstructing the projectedness of M4+. This restriction turns out to be non-zero, proving that M4+ is non-projected.
Related
- Supermoduli spaces are non-projected in every genus g≥ 3
- A complete curve of genus 5 in the moduli space of curves of genus 3 and related questions
- The moduli space of curves of genus 16 is uniruled
- The Weil-Petersson diameter of moduli space for large genus
- The unbearable projectivity of being a good moduli space of Gorenstein curves of genus one with non-colliding markings
BibTeX
@misc{donagi2026genus,
title = {{Genus 4 Supermoduli Space Is Not Projected}},
author = {Ron Donagi and Simone Noja},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2608.24996},
eprint = {2608.24996},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.24996},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Genus 4 Supermoduli Space Is Not Projected
AU - Ron Donagi
AU - Simone Noja
PY - 2026
DA - 2026/09/14
PB - arXiv
DO - 10.48550/arxiv.2608.24996
UR - https://arxiv.org/abs/2608.24996
AB - The supermoduli stack M_g, parametrizing smooth unpunctured super Riemann surfaces of genus g, is known to be non-projected for g ≥ 5. We extend this result to the even-spin component of M_4. This is done by exhibiting an appropriate compact curve in the spin moduli space 𝒮ℳ_4^+, and computing the restriction to it of the class obstructing the projectedness of M_4^+. This restriction turns out to be non-zero, proving that M_4^+ is non-projected.
ER -