Under the first Bass stable range condition on a commutative ring A = 2A, Costa and Keller have described all normal subgroups of SL2A = E2A. We generalize this description, dropping the commutativity assumption. Our answer involves quasi-ideals of A rather than ideals (for all commutative rings A = 2A, every quasi-ideal is an ideal).
All Science Journal Classification (ASJC) codes
- Algebra and Number Theory