A+ CATEGORY SCIENTIFIC UNIT

An $M_q({\Bbb T})$-functional calculus for power-bounded operators on certain UMD spaces

Volume 167 / 2005

Earl Berkson, T. A. Gillespie Studia Mathematica 167 (2005), 245-257 MSC: Primary 42A45, 46B70, 46E40, 47B40. DOI: 10.4064/sm167-3-6

Abstract

For $1\leq q< \infty $, let ${{\mathfrak M}}_{q}( {\mathbb T}) $ denote the Banach algebra consisting of the bounded complex-valued functions on the unit circle having uniformly bounded $q$-variation on the dyadic arcs. We describe a broad class ${\mathcal I}$ of UMD spaces such that whenever $X\in {\mathcal I}$, the sequence space $\ell ^{2}( {\mathbb Z},X) $ admits the classes ${{\mathfrak M}}_{q}( {\mathbb T}) $ as Fourier multipliers, for an appropriate range of values of $q>1$ (the range of $q$ depending on $X$). This multiplier result expands the vector-valued Marcinkiewicz Multiplier Theorem in the direction ${q>1}$. Moreover, when taken in conjunction with vector-valued transference, this ${{\mathfrak M}}_{q}( {\mathbb T}) $-multiplier result shows that if $X\in {\mathcal I}$, and $U$ is an invertible power-bounded operator on $X$, then $U$ has an ${{\mathfrak M}}_{q}( {\mathbb T}) $-functional calculus for an appropriate range of values of $q>1$. The class ${\mathcal I}$ includes, in particular, all closed subspaces of the von Neumann–Schatten $p$-classes ${\mathcal C}_{p}$ ($1< p< \infty $), as well as all closed subspaces of any UMD lattice of functions on a $\sigma $-finite measure space. The ${{\mathfrak M}}_{q}( {\mathbb T}) $-functional calculus result for ${\mathcal I}$, when specialized to the setting of closed subspaces of $L^{p}( \mu ) $ ($\mu $ an arbitrary measure, $1< p< \infty $), recovers a previous result of the authors.

Authors

  • Earl BerksonDepartment of Mathematics
    University of Illinois
    1409 W. Green St.
    Urbana, IL 61801, U.S.A.
    e-mail
  • T. A. GillespieSchool of Mathematics
    University of Edinburgh
    James Clerk Maxwell Building
    Edinburgh EH9 3JZ, Scotland, U.K.
    e-mail

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