On Picent for blocks with normal defect group
We prove that if $b$ is a block of a finite group with normal abelian defect group and inertial quotient a direct product of elementary abelian groups, then $\operatorname{Picent}(b)$ is trivial. We also provide examples of blocks $b$ of finite groups with non-trivial $\operatorname{Picent}(b)$. We even have examples with normal abelian defect group and abelian inertial quotient.
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Representation Theory