The E-normal structure of Petrov's odd unitary groups over commutative rings

Abstract

For an odd quadratic space $V$ of Witt index $\ge 3$ over a commutative ring with pseudoinvolution, we classify the subgroups of the odd unitary group $U(V)$ that are normalized by the elementary subgroup $E{U}_{(e_1,e_{-1})}(V)$ defined by a hyperbolic pair $(e_1,e_{-1})$ in $V$. Further we correct some minor mistakes that exist in the literature on odd unitary groups.