# Soluble products of connected subgroups

### M. Pilar Gállego

Universidad de Zaragoza, Spain### Peter Hauck

Universität Tübingen, Germany### M. Dolores Pérez-Ramos

Universitat de València, Burjassot (Valencia), Spain

## Abstract

The main result in the paper states the following: For a finite group $G=AB$, which is the product of the soluble subgroups $A$ and $B$, if $⟨a,b⟩$ is a metanilpotent group for all $a∈A$ and $b∈B$, then the factor groups $⟨a,b⟩F(G)/F(G)$ are nilpotent, $F(G)$ denoting the Fitting subgroup of $G$. A particular generalization of this result and some consequences are also obtained. For instance, such a group $G$ is proved to be soluble of nilpotent length at most $l+1$, assuming that the factors $A$ and $B$ have nilpotent length at most $l$. Also for any finite soluble group $G$ and $k≥1$, an element $g∈G$ is contained in the preimage of the hypercenter of $G/F_{k−1}(G)$, where $F_{k−1}(G)$ denotes the ($k−1$)th term of the Fitting series of $G$, if and only if the subgroups $⟨g,h⟩$ have nilpotent length at most $k$ for all $h∈G$.

## Cite this article

M. Pilar Gállego, Peter Hauck, M. Dolores Pérez-Ramos, Soluble products of connected subgroups. Rev. Mat. Iberoam. 24 (2008), no. 2, pp. 433–461

DOI 10.4171/RMI/542