$H^\infty$ Functional Calculus for a Commuting tuple of $\text{Ritt}_{\text{E}}$ Operators
Suman Mondal, Subhajit Palai, Samya Kumar Ray
TL;DR
This work develops a comprehensive joint $H^\infty$-functional calculus for commuting tuples of $\text{Ritt}_{\text{E}}$ operators on Banach spaces. It introduces a transfer principle linking multivariate calculus for $\text{Ritt}_{\text{E}}$ tuples to sectorial tuples, and proves a joint dilation theorem on broad Banach spaces, connecting calculus, dilation, and boundedness notions. As a key application, the authors derive equivalent $L^p$-space criteria ($1<p<\infty$) for when a commuting tuple admits a joint bounded calculus, and show the equivalence with $p$-polynomial boundedness and loose dilation. By unifying discrete $Ritt_{\text{E}}$ operator theory with sectorial techniques, the results have implications for time-discretized evolution equations and maximal regularity in Banach spaces.
Abstract
In this article, we develop a framework for the joint functional calculus of commuting tuples of $\text{Ritt}_{\text{E}}$ operators on Banach spaces. We establish a transfer principle that relates the bounded holomorphic functional calculus for tuples of $\text{Ritt}_{\text{E}}$ operators to that of their associated sectorial counterparts. In addition, we prove a joint dilation theorem for commuting tuples of $\text{Ritt}_{\text{E}}$ operators on a broad class of Banach spaces. As a key application, we obtain an equivalent set of criteria on $L^p$-spaces for $1<p< \infty$ that determine when a commuting tuple of $\text{Ritt}_{\text{E}}$ operators admits a joint bounded functional calculus.
