Relative local control and the block source algebras

The local control of pointed groups is generalized to the concept of relative local control, and it is proved that there exists a lifting for a covering of a block source algebra if the relative local control holds. As an application, a result is proved on the source algebras of blocks, whose defect groups are direct products of a normal subgroup and a subgroup that gives a relative local control. Project supported by the National Natural Science Foundation of China.