Characteristic Subgroup Growth

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Hanany, Liam, Lubotzky, Alexander
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866911192290689024
author Hanany, Liam
Lubotzky, Alexander
author_facet Hanany, Liam
Lubotzky, Alexander
contents Let $s_n^\mathrm{ch}(Γ)$ denote the number of characteristic subgroups of index at most $n$ in a finitely generated group $Γ$. In response to a question of I. Rivin we show that if $Γ= F_r$ is the free group on $r \geq 2$ generators then the growth type of $s_n^{\mathrm{ch}}(F_r)$ is $n^{\mathrm{log}(n)}$. This is in contrast with the expectation of W. Thurston who predicted that there should be a difference between $r = 2$ and $r > 2$. Along the way we answer a question of arXiv:1703.07866 on the normal subgroup growth of large groups.
format Preprint
id arxiv_https___arxiv_org_abs_2510_04150
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Characteristic Subgroup Growth
Hanany, Liam
Lubotzky, Alexander
Group Theory
math.GR
Let $s_n^\mathrm{ch}(Γ)$ denote the number of characteristic subgroups of index at most $n$ in a finitely generated group $Γ$. In response to a question of I. Rivin we show that if $Γ= F_r$ is the free group on $r \geq 2$ generators then the growth type of $s_n^{\mathrm{ch}}(F_r)$ is $n^{\mathrm{log}(n)}$. This is in contrast with the expectation of W. Thurston who predicted that there should be a difference between $r = 2$ and $r > 2$. Along the way we answer a question of arXiv:1703.07866 on the normal subgroup growth of large groups.
title Characteristic Subgroup Growth
topic Group Theory
math.GR
url https://arxiv.org/abs/2510.04150