H-separable Extensions and Torsion Theories
H-separable Extensions and Torsion Theories
A\otimes_{B}A$ is isomorphic to a direct summand of a finite direct sum of copies of $A$ as $(A$ , $A)$ -bimodules.Let $C$ be the center of $A$ and $V_{A}(B)$ the commutator of $B$ in $A$ .Then it is well-known that $A$ is $H$ -separable over $B$ iff the maping $\eta$ …