Michiya Mori

activity

20172026

most citedTingley's problem through the facial structure of operator algebras

47 citations · 92 across the 19 of their papers we have counts for

collaborators

Showing 2023Show all

4 papers · 1 filter

math.OA2023

On the shape of correlation matrices for unitaries

Michiya Mori

For a positive integer $n$ , we study the collection $F_{fin} (n)$ formed of all $n \times n$ matrices whose entries $a_{ij}$ , $1 \leq i, j \leq n$ , can be written as…

math.FA2023

On the Scottish Book Problem 155 by Mazur and Sternbach

Michiya Mori

Problem 155 of the Scottish Book asks whether every bijection $U : X \to Y$ between two Banach spaces $X, Y$ with the property that, each point of $X$ has a neighborhood on whic…

math.FA2023

On the distance from a matrix to nilpotents

Michiya Mori

We prove that the distance from an $n \times n$ complex matrix $M$ to the set of nilpotents is at least $\frac{1}{2} sec \frac{π}{n + 2}$ if there is a nonzero projection $P$ such that $…

math-ph2023

Nonexpansive and noncontractive mappings on the set of quantum pure states

Michiya Mori, Peter Šemrl

Wigner's theorem characterizes isometries of the set of all rank one projections on a Hilbert space. In metric geometry nonexpansive maps and noncontractive maps are well studied g…