On the Local Structure of Morita and Rickard Equivalences...
Puig, Lluis Brauer had already introduced the defect of a block and opened the way towards a classification by solving all the problems in defects zero and one, and by providing some evidence for the finiteness of the set of blocks with a given defect. In 1959 he discovered the defect group, and in 1964 Dade determined the blocks with cyclic defect groups.In 1978 Alperin and Broué discovered the Brauer category, and Broué and the author determined the blo...