136 citations · 743 across the 56 of their papers we have counts for
56 papers
The hyperfinite II_1 factor is not quasidiagonal
Narutaka Ozawa
We construct an MF C*-algebra A such that the spatial tensor product of A and the hyperfinite II_1 factor R contains a proper isometry. Consequently, stable finiteness of C*-algebr…
Uniform amenability at infinity
Narutaka Ozawa
We introduce the notion of uniform exactness, or uniform amenability at infinity, for discrete groups and prove it for a wide class of groups containing free groups and their limit…
Proximality and selflessness for group C*-algebras
Narutaka Ozawa
We prove that the reduced group C*-algebras of infinite countable discrete groups having topologically-free extreme boundaries, or more generally groups that satisfy certain combin…
Total sequences and the lower frame inequality
Narutaka Ozawa
We prove that every total sequence in a Hilbert space satisfies the lower frame inequality after scaling. This solves A. Kulikov's "exercise" at mathoverflow.
Contractibility of the automorphism group of a von Neumann algebra
Narutaka Ozawa
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 hy…
Proof of the Paszkiewicz's conjecture about a product of positive contractions
Hiroshi Ando, Yuki Miyamoto, Narutaka Ozawa
The Paszkiewicz conjecture about a product of positive contractions asserts that given a decreasing sequence of positive contractions on a separable infinite-…