Two aspects of graph 3-manifold groups

Hongbin Sun

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arXiv · 2607.04326

Two aspects of graph 3-manifold groups

Hongbin Sun

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Abstract

We prove that fundamental groups of graph 3-manifolds are virtually poly-free and lie in the family Lex. As a consequence, we prove that all finitely generated 3-manifold groups also have these two properties. The first property is a purely group-theoretical concept, and the second is related to the left-exactness property of bounded cohomology of groups. Both properties are proved by constructing sequences of covers of graph 3-manifolds.

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Hongbin Sun. 2026-07-05. Two aspects of graph 3-manifold groups. https://arxiv.org/abs/2607.04326

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