4-rank distribution of Picard groups of hyperelliptic curves via $C$-symmetric matrices

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Gorokhovsky, Elia, Liu, Mengzhen
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866911472993435648
author Gorokhovsky, Elia
Liu, Mengzhen
author_facet Gorokhovsky, Elia
Liu, Mengzhen
contents We determine the large-genus limiting distribution of the 4-rank of the Picard group of hyperelliptic curves over a fixed finite field $\mathbb F_q$ of odd characteristic. This is a function field analogue of a result of Fouvry and Klüners. Our computation agrees with (the Picard group analogue of) the Cohen--Lenstra--Gerth heuristics in the case $q \equiv 3\pmod{4}$, i.e., in the absence of roots of unity in the base field. When roots of unity are present, the result is of the same form as conjectured distribution for class groups of quadratic extensions of number fields containing roots of unity. The limiting distribution does not change when imposing finitely many conditions on the ramification behavior of the curves. In the process, we determine the rank distribution of a certain class of random matrix ensembles over finite fields determined by symmetry conditions.
format Preprint
id arxiv_https___arxiv_org_abs_2602_23707
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle 4-rank distribution of Picard groups of hyperelliptic curves via $C$-symmetric matrices
Gorokhovsky, Elia
Liu, Mengzhen
Number Theory
We determine the large-genus limiting distribution of the 4-rank of the Picard group of hyperelliptic curves over a fixed finite field $\mathbb F_q$ of odd characteristic. This is a function field analogue of a result of Fouvry and Klüners. Our computation agrees with (the Picard group analogue of) the Cohen--Lenstra--Gerth heuristics in the case $q \equiv 3\pmod{4}$, i.e., in the absence of roots of unity in the base field. When roots of unity are present, the result is of the same form as conjectured distribution for class groups of quadratic extensions of number fields containing roots of unity. The limiting distribution does not change when imposing finitely many conditions on the ramification behavior of the curves. In the process, we determine the rank distribution of a certain class of random matrix ensembles over finite fields determined by symmetry conditions.
title 4-rank distribution of Picard groups of hyperelliptic curves via $C$-symmetric matrices
topic Number Theory
url https://arxiv.org/abs/2602.23707