On perturbation of matrix-valued Riesz bases over LCA groups

Given a $\sigma$-compact and metrizable locally compact abelian (LCA) group $G$, we give new perturbation results for Riesz bases for the matrix-valued function space $L^2(G,{ℂ}^{s\times r})$, $s$ and $r\in \mathbb{N}$.