English

Remarks on complemented subspaces of von-Neumann algebras

Operator Algebras 2009-09-25 v1 Functional Analysis

Abstract

In this note we include two remarks about bounded (not\underline{not} necessarily contractive) linear projections on a von Neumann-algebra. We show that if MM is a von Neumann-subalgebra of B(H)B(H) which is complemented in B(H) and isomorphic to MMM \otimes M then MM is injective (or equivalently MM is contractively complemented). We do not know how to get rid of the second assumption on MM. In the second part,we show that any complemented reflexive subspace of a CC^*- algebra is necessarily linearly isomorphic to a Hilbert space.

Keywords

Cite

@article{arxiv.math/9201227,
  title  = {Remarks on complemented subspaces of von-Neumann algebras},
  author = {Gilles Pisier},
  journal= {arXiv preprint arXiv:math/9201227},
  year   = {2009}
}