PreprintCC BY 4.0arXiv
Nonexistence of maximal curves of genus five over F64
Abstract
We show that there is no maximal curve of genus five over F64. As a consequence, N64(5)=140, and the genus spectrum of maximal curves over F64 is determined. The proof uses the vanishing of the third iterate of the Cartier operator. We prove that a nonhyperelliptic curve of genus five in characteristic two satisfying this condition is nontrigonal. Its canonical theta characteristic defines a separable cover of degree four with one geometric branch value. The two possible ramification types give either a rational subcanonical point or a point bound obtained from the cubic resolvent. Both cases exclude maximality over F64.
Related
- Splitting Brauer classes by genus one curves over number fields
- A maximal function field of genus $17$ over 𝔽112
- Maximal singular curves over finite fields from elliptic and hyperelliptic curves
- A quotient of the Bruhat-Tits building classifying maximal matrix orders over curves
- Nonexistence of degree two rational multisections of conic bundles over the plane
BibTeX
@misc{filho2026nonexistence,
title = {{Nonexistence of maximal curves of genus five over $\F_64$}},
author = {Gilberto B. Almeida Filho and Saeed Tafazolian and Stéfani C. Vieira},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.36456},
eprint = {2609.36456},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.36456},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Nonexistence of maximal curves of genus five over F_64
AU - Gilberto B. Almeida Filho
AU - Saeed Tafazolian
AU - Stéfani C. Vieira
PY - 2026
DA - 2026/09/29
PB - arXiv
DO - 10.48550/arxiv.2609.36456
UR - https://arxiv.org/abs/2609.36456
AB - We show that there is no maximal curve of genus five over F_64. As a consequence, N_64(5)=140, and the genus spectrum of maximal curves over F_64 is determined. The proof uses the vanishing of the third iterate of the Cartier operator. We prove that a nonhyperelliptic curve of genus five in characteristic two satisfying this condition is nontrigonal. Its canonical theta characteristic defines a separable cover of degree four with one geometric branch value. The two possible ramification types give either a rational subcanonical point or a point bound obtained from the cubic resolvent. Both cases exclude maximality over F_64.
ER -