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arXiv · 2606.28214

Connecting $H^\infty$-functional calculus and isometric dilations for commuting families of Ritt$_E$ operators

Christian Le Merdy·M. N. Reshmi
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Abstract

Let $(T_1,\ldots,T_d)$ be a commuting $d$-tuple of Ritt$_E$ operators on some UMD Banach space $X$. We show that $(T_1,\ldots,T_d)$ admits a bounded $H^\infty$-functional calculus if and only if $T_k$ is an $R$-Ritt$_E$ operator for every $k=1,\ldots,d$, and the $d$-tuple $(T_1,\ldots,T_d)$ admits an isometric dilation $(U_1,\ldots,U_d)$ on some UMD Banach space $Y$ such that $(U_1,\ldots,U_d)$ is polynomially bounded. In the case where $X$ further possesses property $(\alpha)$, we establish other characterizations of the $H^\infty$-functional calculus property for $(T_1,\ldots,T_d)$ in terms of isometric dilations.

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Christian Le Merdy, M. N. Reshmi. 2026-06-26. Connecting $H^\infty$-functional calculus and isometric dilations for commuting families of Ritt$_E$ operators. https://arxiv.org/abs/2606.28214

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