English

Bounded Normal Generation and Invariant Automatic Continuity

Operator Algebras 2015-08-13 v2 Functional Analysis Group Theory

Abstract

We study the question how quickly products of a fixed conjugacy class in the projective unitary group of a II1{}_1-factor von Neumann algebra cover the entire group. Our result is that the number of factors that are needed is essentially as small as permitted by the 11-norm - in analogy to a result of Liebeck-Shalev for non-abelian finite simple groups. As an application of the techniques, we prove that every homomorphism from the projective unitary group of a II1{}_1-factor to a polish SIN group is continuous. Moreover, we show that the projective unitary group of a II1{}_1-factor carries a unique polish group topology.

Keywords

Cite

@article{arxiv.1506.08549,
  title  = {Bounded Normal Generation and Invariant Automatic Continuity},
  author = {Philip A. Dowerk and Andreas Thom},
  journal= {arXiv preprint arXiv:1506.08549},
  year   = {2015}
}

Comments

v2 minor changes, 42 pages

R2 v1 2026-06-22T10:01:56.290Z