Published online by Cambridge University Press: 11 April 2019
Let ${\mathcal{D}}$ be a Schauder decomposition on some Banach space
$X$. We prove that if
${\mathcal{D}}$ is not
$R$-Schauder, then there exists a Ritt operator
$T\in B(X)$ which is a multiplier with respect to
${\mathcal{D}}$ such that the set
$\{T^{n}:n\geq 0\}$ is not
$R$-bounded. Likewise, we prove that there exists a bounded sectorial operator
$A$ of type
$0$ on
$X$ which is a multiplier with respect to
${\mathcal{D}}$ such that the set
$\{e^{-tA}:t\geq 0\}$ is not
$R$-bounded.
The authors were supported by the French ‘Investissements d’Avenir’ program, project ISITE-BFC (contract ANR-15-IDEX-03).