Universal deformation rings, endo-trivial modules, and semidihedral and generalized quaternion 2-groups

Frauke M. Bleher, Ted Chinburg, Roberto C. Soto

Let $k$ be a field of characteristic $p>0$, and let $W$ be a complete discrete valuation ring of characteristic $0$ that has $k$ as its residue field. Suppose $G$ is a finite group…