On Sylvester equations in Banach subalgebras

Qiquan Fang, Chang Eon Shin, Qiyu Sun

Let $\mathcal{B}$ be a Banach algebra and $\mathcal{A}$ be a Banach subalgebra that admits norm-controlled inversion in $\mathcal{B}$. In this work, we take $A,B$ in the Banach…