\(\pi\)-blocks of characters in a finite group (Q5925855)

The paper under review contributes to the theory of \(\pi\)-blocks of finite groups, for a set \(\pi\) of primes. In particular, the author deals with elementary divisors of Cartan matrices, kernels of \(\pi\)-blocks and Clifford theory. However, the proof of Theorem 4.2 in the paper is incomplete; an erratum will be published in the same journal. Thus the author's assertion concerning the number of irreducible characters in a \(\pi\)-block must be regarded as unproved.