On Jordan ideals and matrix rings
Results of \textit{D. L. Costa} and \textit{G. E. Keller} [J. Reine Angew. Math. 427, 51--105 (1992; Zbl 0739.20023)] about subgroups of the symplectic group \(Sp_4A\) normalized by \(Ep_4A\) where \(A\) is a commutative ring with 1, are generalized by replacing the matrix algebra \(M_2A\) by an associative \(A\)-algebra with involution.
scientific article; zbMATH DE number 5603583