Let $T$ be an $R$-tree, equipped with a very small action of the
rank $n$ free group $F_n$, and let $H F_n$ be finitely generated. We
consider the case where the action $F_n T$ is
indecomposable--this is a strong mixing property introduced by Guirardel. In
this case, we show that the action of $H$ on its minimal invarinat subtree
$T_H$ has dense orbits if and only if $H$ is finite index in $F_n$. There is an
interesting application to dual algebraic laminations; we show that for $T$
free and indecomposable and for $H F_n$ finitely generated, $H$ carries a
leaf of the dual lamination of $T$ if and only if $H$ is finite index in $F_n$.
This generalizes a result of Bestvina-Feighn-Handel regarding stable trees of
fully irreducible automorphisms.
Description
On indecomposable trees in the boundary of Outer space
%0 Generic
%1 Reynolds2010
%A Reynolds, Patrick
%D 2010
%K boundary indecomposable outer space trees
%T On indecomposable trees in the boundary of Outer space
%U http://arxiv.org/abs/1002.3141
%X Let $T$ be an $R$-tree, equipped with a very small action of the
rank $n$ free group $F_n$, and let $H F_n$ be finitely generated. We
consider the case where the action $F_n T$ is
indecomposable--this is a strong mixing property introduced by Guirardel. In
this case, we show that the action of $H$ on its minimal invarinat subtree
$T_H$ has dense orbits if and only if $H$ is finite index in $F_n$. There is an
interesting application to dual algebraic laminations; we show that for $T$
free and indecomposable and for $H F_n$ finitely generated, $H$ carries a
leaf of the dual lamination of $T$ if and only if $H$ is finite index in $F_n$.
This generalizes a result of Bestvina-Feighn-Handel regarding stable trees of
fully irreducible automorphisms.
@misc{Reynolds2010,
abstract = { Let $T$ be an $\mathbb{R}$-tree, equipped with a very small action of the
rank $n$ free group $F_n$, and let $H \leq F_n$ be finitely generated. We
consider the case where the action $F_n \curvearrowright T$ is
indecomposable--this is a strong mixing property introduced by Guirardel. In
this case, we show that the action of $H$ on its minimal invarinat subtree
$T_H$ has dense orbits if and only if $H$ is finite index in $F_n$. There is an
interesting application to dual algebraic laminations; we show that for $T$
free and indecomposable and for $H \leq F_n$ finitely generated, $H$ carries a
leaf of the dual lamination of $T$ if and only if $H$ is finite index in $F_n$.
This generalizes a result of Bestvina-Feighn-Handel regarding stable trees of
fully irreducible automorphisms.
},
added-at = {2010-11-01T12:43:06.000+0100},
author = {Reynolds, Patrick},
biburl = {https://www.bibsonomy.org/bibtex/28c0fa51fc4d868bd36b6e44e02dcfab5/uludag},
description = {On indecomposable trees in the boundary of Outer space},
interhash = {bf04f4f8fafb29fac645544a4f57a8a1},
intrahash = {8c0fa51fc4d868bd36b6e44e02dcfab5},
keywords = {boundary indecomposable outer space trees},
note = {cite arxiv:1002.3141
Comment: 12 pages. reorganized introduction, corrected typos},
timestamp = {2010-11-01T12:43:06.000+0100},
title = {On indecomposable trees in the boundary of Outer space},
url = {http://arxiv.org/abs/1002.3141},
year = 2010
}