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Bibliographic Details
Main Author: Coppens, Marc
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2312.10804
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author Coppens, Marc
author_facet Coppens, Marc
contents Let $Γ$ be a chain of cycles of genus $g$. Let $d$,$r$ be integers with $1 \leq r \leq g-2$ and $2r\leq d \leq g-3+r$. Then $w^r_d(Γ)=d-2r$ implies $Γ$ is hyperelliptic. For each $g \geq 2r+3$ there exist non-hyperelliptic chains of cycles satisfying $w^r_{g-2+r}(Γ)=g-2-r$. In the case of algebraic curves such equality implies the curve is hyperelliptic. In particular we obtain the existence of chains of cycles $Γ$ such that $w^r_{g-2+r}(Γ) \neq w^1_{g-r}(Γ)$ in case $r \geq 2$. In the case of algebraic curves such numbers are equal because of the Riemann-Roch Theorem.
format Preprint
id arxiv_https___arxiv_org_abs_2312_10804
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A study of H. Martens' Theorem on chains of cycles
Coppens, Marc
Combinatorics
Algebraic Geometry
05C25, 14T15
Let $Γ$ be a chain of cycles of genus $g$. Let $d$,$r$ be integers with $1 \leq r \leq g-2$ and $2r\leq d \leq g-3+r$. Then $w^r_d(Γ)=d-2r$ implies $Γ$ is hyperelliptic. For each $g \geq 2r+3$ there exist non-hyperelliptic chains of cycles satisfying $w^r_{g-2+r}(Γ)=g-2-r$. In the case of algebraic curves such equality implies the curve is hyperelliptic. In particular we obtain the existence of chains of cycles $Γ$ such that $w^r_{g-2+r}(Γ) \neq w^1_{g-r}(Γ)$ in case $r \geq 2$. In the case of algebraic curves such numbers are equal because of the Riemann-Roch Theorem.
title A study of H. Martens' Theorem on chains of cycles
topic Combinatorics
Algebraic Geometry
05C25, 14T15
url https://arxiv.org/abs/2312.10804