Contractibility of the automorphism group of a von Neumann algebra
arXiv:2412.17564
Abstract
We prove that the approximately inner automorphism group of a separable strongly stable von Neumann algebra is contractible in the u-topology. Thus the automorphism group of the hyperfinite type III_1 factor is contractible.
10 pages; typos corrected and a remark added (v2); proofs of lemmas 2 and 4 overhauled (v3)