Hiroshi Ando

collaborators

4 papers

math.OA2026

Ultrapowers of spectral subspaces

Hiroshi Ando, Isaac Goldbring

We prove, for any W $^{*}$ -probability space $(M, φ)$ where $M$ is a type $III_{1}$ factor, any nontrivial, proper closed $F \subseteq R$ , and any nonprincipal ultrafilt…

math.OA2026

Model theory and Connes' bicentralizer problem

Hiroshi Ando, Isaac Goldbring

We make a series of model-theoretic contributions to Connes' bicentralizer problem, one of the most prominent open problems in the theory of von Neumann algebras. Our work builds o…

math.FA2024

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 $T_{1} \geq T_{2} \geq \dots$ of positive contractions on a separable infinite-…

math.SP2024

Notes on a conjecture by Paszkiewicz on an ordered product of positive contractions

Hiroshi Ando

Paszkiewicz's conjecture asserts that given a decreasing sequence $T_{1} \geq T_{2} \geq \dots$ of positive contractions on a separable infinite-dimensional Hilbert space $H$ , the product…