On the Odd Unitary Analogue of Gram-Schmidt Process
Ambily A. A., Aparna Pradeep V. K
TL;DR
The paper addresses whether a Gram-Schmidt-type construction in Petrov's odd unitary framework can generate all elementary matrices. It develops Vaserstein-type matrices via $\theta(v)$ and $\eta(v)$, built from a fixed form $\Psi=\widetilde{\psi}_{m} \perp \varphi$, and proves these matrices generate the full elementary group ${\rm E}_{n+2m-1}(R)$ for arbitrary $\varphi$. The main contribution is a general, direct proof that the subgroup generated by $\theta(v)$ and $\eta(v)$ coincides with ${\rm E}_{n+2m-1}(R)$, extending previous Pfaffian-1 restricted results. This work broadens the Gram-Schmidt-type generation to the broader setting of Petrov's odd unitary groups, facilitating uniform proofs of classical results and potential applications to stability and $K_1$-type questions in this context.
Abstract
In 1976, L.N. Vaserstein used a construction analogous to the Gram-Schmidt orthogonalisation, for obtaining a set of symplectic matrices from a set of elementary matrices. We have a similar construction for Petrov's odd unitary group. Here, we prove that the elementary matrices in the odd unitary analogue of the Gram-Schmidt process form a set of generators for the elementary linear group.
