Cyclotomic character fields and sets of primes

Eugenio Giannelli, J. Miquel Martínez, Carolina Vallejo

Let $\ddot{I}€=\{2,q\}$ where $q$ is an odd prime. Let $G$ be a finite group of order divisible by a prime $p\in \ddot{I}€$. We show that the principal $p$-block of $G$ contains a nontrivial…