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arXiv · 0910.5019

Geometricity and Polygonality in Free Groups

Sang-hyun Kim
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Abstract

Gordon and Wilton recently proved that the double D of a free group F amalgamated along a cyclic subgroup C of F contains a surface group if a generator w of C satisfies a certain 3-manifold theoretic condition, called virtually geometricity. Wilton and the author defined the polygonality of w which also guarantees the existence of a surface group in D. In this paper, virtual geometricity is shown to imply polygonality up to descending to a finite-index subgroup F' and applying an automorphism on F'. That the converse does not hold will follow from an example formerly considered by Manning.

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Sang-hyun Kim. 2010-01-12. Geometricity and Polygonality in Free Groups. https://arxiv.org/abs/0910.5019

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