A characterisation of nilpotent blocks
A characterisation of nilpotent blocks
Let $B$ be a $p$-block of a finite group, and set $m=$ $\sum \chi (1)^2$, the sum taken over all height zero characters of $B$. Motivated by a result of M. Isaacs characterising $p$-nilpotent finite groups in terms of character degrees, we show that $B$ is nilpotent if and only …