English

The Hanna Neumann conjecture for Demushkin Groups

Group Theory 2019-04-05 v1 Number Theory

Abstract

We confirm the Hanna Neumann conjecture for topologically finitely generated closed subgroups UU and WW of a nonsolvable Demushkin group GG. Namely, we show that \begin{equation*} \sum_{g \in U \backslash G/W} \bar d(U \cap gWg^{-1}) \leq \bar d(U) \bar d(W) \end{equation*} where dˉ(K)=max{d(K)1,0}\bar d(K) = \max\{d(K) - 1, 0\} and d(K)d(K) is the least cardinality of a topological generating set for the group KK.

Keywords

Cite

@article{arxiv.1904.02258,
  title  = {The Hanna Neumann conjecture for Demushkin Groups},
  author = {Andrei Jaikin-Zapirain and Mark Shusterman},
  journal= {arXiv preprint arXiv:1904.02258},
  year   = {2019}
}
R2 v1 2026-06-23T08:28:42.517Z