English

Strong uncountable cofinality for unitary groups of von Neumann algebras

Group Theory 2019-12-18 v2 Functional Analysis Operator Algebras

Abstract

We show that unitary groups of II1_1 factors and of properly infinite von Neumann algebras have strong uncountable cofinality. In particular, we obtain a short alternative proof for the strong uncountable cofinality of U(2(N))U(\ell^2(\mathbb{N})), which was first proven by Ricard and Rosendal.

Keywords

Cite

@article{arxiv.1804.09515,
  title  = {Strong uncountable cofinality for unitary groups of von Neumann algebras},
  author = {Philip A. Dowerk},
  journal= {arXiv preprint arXiv:1804.09515},
  year   = {2019}
}

Comments

Title changed for historical correctness, minor mistakes corrected, additional preliminaries provided. 13 pages