On joins and intersections of subgroups in free groups

2016/07/17 by Ivanov, Sergei V.
#20E07 #20F65 #57M07 #FOS: Mathematics #Geometric Topology (math.GT) #Group Theory (math.GR) #Primary 20E05

paper · doi:10.48550/arxiv.1607.04890

Abstract

We study graphs of (generalized) joins and intersections of finitely generated subgroups of a free group. We show how to disprove a lemma of Imrich and Müller on these graphs and how to repair this lemma.

Related

• The Hanna Neumann Conjecture and the rank of the join
• On rank of the join of two subgroups in a free group
• On a conjecture of Imrich and Müller
• On the intersections of finitely generated subgroups of free groups: reduced rank to full rank
• On the rank of the intersection of free subgroups in virtually free groups