Spectra for Toeplitz Operators Associated with a Constrained Subalgebra

Christopher Felder, Douglas T. Pfeffer, Benjamin P. Russo

Published 2021-10-12, updated 2022-10-11Version 3

A two-point algebra is a set of bounded analytic functions on the unit disk that agree at two distinct points $a,b \in \mathbb{D}$. This algebra serves as a multiplier algebra for the family of Hardy Hilbert spaces $H^2_t := \{ f\in H^2 : f(a)=tf(b)\}$, where $t\in \mathbb{C}\cup\{\infty\}$. We show that various spectra of certain Toeplitz operators acting on these spaces are connected.