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arXiv · 1404.4626

A short proof of Handel and Mosher's alternative for subgroups of $\text{Out}(F_N)$

Camille Horbez
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Abstract

We give a short proof of a theorem of Handel and Mosher stating that any finitely generated subgroup of $\text{Out}(F_N)$ either contains a fully irreducible automorphism, or virtually fixes the conjugacy class of a proper free factor of $F_N$, and we extend their result to non finitely generated subgroups of $\text{Out}(F_N)$.

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Camille Horbez. 2014-04-17. A short proof of Handel and Mosher's alternative for subgroups of $\text{Out}(F_N)$. https://arxiv.org/abs/1404.4626

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