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arXiv · 0901.3774

Graphs of subgroups of free groups

Larsen Louder·D. B. McReynolds
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Abstract

We construct an efficient model for graphs of finitely generated subgroups of free groups. Using this we give a very short proof of Dicks's reformulation of the strengthened Hanna Neumann Conjecture as the Amalgamated Graph Conjecture. In addition, we answer a question of Culler and Shalen on ranks of intersections in free groups. The latter has also been done independently by R. P. Kent IV.

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Larsen Louder, D. B. McReynolds. 2009-01-25. Graphs of subgroups of free groups. https://arxiv.org/abs/0901.3774

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