Completely Sidon sets in C*-algebras Academic Article uri icon


  • 2018, Springer-Verlag GmbH Austria, part of Springer Nature. A sequence in a C-algebra A is called completely Sidon if its span in A is completely isomorphic to the operator space version of the space 1 (i.e. 1 equipped with its maximal operator space structure). The latter can also be described as the span of the free unitary generators in the (full) C-algebra of the free group F with countably infinitely many generators. Our main result is a generalization to this context of Drurys classical theorem stating that Sidon sets are stable under finite unions. In the particular case when A= C(G) the (maximal) C-algebra of a discrete group G, we recover the non-commutative (operator space) version of Drurys theorem that we recently proved. We also give several non-commutative generalizations of our recent work on uniformly bounded orthonormal systems to the case of von Neumann algebras equipped with normal faithful tracial states.

published proceedings


author list (cited authors)

  • Pisier, G.

citation count

  • 1

complete list of authors

  • Pisier, Gilles

publication date

  • October 2018