%0 Journal Article
%T Geometricity and Polygonality in Free Groups
%A Sang-hyun Kim
%J Mathematics
%D 2009
%I arXiv
%X 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.
%U http://arxiv.org/abs/0910.5019v2