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arXiv · 1804.07800

Semi-free subgroups of a profinite surface group

Matan Ginzburg·Mark Shusterman
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Abstract

We show that every closed normal subgroup of infinite index in a profinite surface group $\Gamma$ is contained in a semi-free profinite normal subgroup of $\Gamma$. This answers a question of Bary-Soroker, Stevenson, and Zalesskii.

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Matan Ginzburg, Mark Shusterman. 2018-04-20. Semi-free subgroups of a profinite surface group. https://arxiv.org/abs/1804.07800

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