Herz–Schur multipliers of dynamical systems
Artikel i vetenskaplig tidskrift, 2018

We extend the notion of a Herz–Schur multiplier to the setting of non-commutative dynamical systems: given a C*-algebra A, a locally compact group G, and an action α of G on A, we define transformations on the reduced crossed product of A by α which, in the case A=C, reduce to the classical Herz–Schur multipliers. We introduce Schur A-multipliers, establish a characterisation that generalises the classical descriptions of Schur multipliers, and present a transference theorem in the new setting, identifying isometrically the Herz–Schur multipliers of the dynamical system (A,G,α) with the invariant part of the Schur A-multipliers. We discuss special classes of Herz–Schur multipliers, in particular, those associated to a locally compact abelian group G and its canonical action on the C*-algebra C ⁎ (Γ) of the dual group Γ.

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Herz–Schur multiplier


A. McKee

Queen's University Belfast

I. G. Todorov

Queen's University Belfast

Nankai University

Lyudmyla Turowska

Chalmers, Matematiska vetenskaper, Analys och sannolikhetsteori

Advances in Mathematics

0001-8708 (ISSN) 1090-2082 (eISSN)

Vol. 331 387-438


Algebra och logik


Matematisk analys