No CrossRef data available.
Published online by Cambridge University Press: 23 August 2019
In this manuscript, we generalize Lewis’s result about a central series associated with the vanishing off subgroup. We write $V_{1}=V(G)$ for the vanishing off subgroup of
$G$, and
$V_{i}=[V_{i-1},G]$ for the terms in this central series. Lewis proved that there exists a positive integer
$n$ such that if
$V_{3}<G_{3}$, then
$|G\,:\,V_{1}|=|G^{\prime }\,:\,V_{2}|^{2}=p^{2n}$. Let
$D_{3}/V_{3}=C_{G/V_{3}}(G^{\prime }/V_{3})$. He also showed that if
$V_{3}<G_{3}$, then either
$|G\,:\,D_{3}|=p^{n}$ or
$D_{3}=V_{1}$. We show that if
$V_{i}<G_{i}$ for
$i\geqslant 4$, where
$G_{i}$ is the
$i$-th term in the lower central series of
$G$, then
$|G_{i-1}\,:\,V_{i-1}|=|G\,:\,D_{3}|$.