PreprintCC BY 4.0arXiv
Codimension of Brill-Noether Loci on Abelian Surfaces and the First Segre Invariant
Abstract
Let X be an abelian surface of Picard rank 1 with ample generator H. We show that, for a Mukai vector v=(r,mH,χ) with r,m≥ 1 and χ≤ 0, the first Brill-Noether loci {E | H0(E)≠ 0} in MX(v) is nonempty of the expected codimension 1−χ. As an application, we study the rank 1 Segre invariant on these abelian surfaces. Specifically, for v a Mukai vector of a μ-stable sheaf of rank≥ 2, we compute the Segre invariant of the general sheaf in MX(v), and we determine the numbers which arise as the Segre invariant of a sheaf in MX(v).
Related
BibTeX
@misc{chien2026codimension,
title = {{Codimension of Brill-Noether Loci on Abelian Surfaces and the First Segre Invariant}},
author = {Jesse Chien},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.24251},
eprint = {2610.24251},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.24251},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Codimension of Brill-Noether Loci on Abelian Surfaces and the First Segre Invariant
AU - Jesse Chien
PY - 2026
DA - 2026/10/16
PB - arXiv
DO - 10.48550/arxiv.2610.24251
UR - https://arxiv.org/abs/2610.24251
AB - Let X be an abelian surface of Picard rank 1 with ample generator H. We show that, for a Mukai vector v=(r,mH,χ) with r,m≥ 1 and χ≤ 0, the first Brill-Noether loci {E | H^0(E)≠ 0} in M_X(v) is nonempty of the expected codimension 1−χ. As an application, we study the rank 1 Segre invariant on these abelian surfaces. Specifically, for v a Mukai vector of a μ-stable sheaf of rank≥ 2, we compute the Segre invariant of the general sheaf in M_X(v), and we determine the numbers which arise as the Segre invariant of a sheaf in M_X(v).
ER -