Ya-Shu Wang

activity

20122020

most citedJoint numerical ranges and communtativity of matrices

1 citations · 1 across the 3 of their papers we have counts for

collaborators

3 papers

math.FA2020★ 1 cited

Joint numerical ranges and communtativity of matrices

Chi-Kwong Li, Yiu-Tung Poon, Ya-Shu Wang

The connection between the commutativity of a family of $n \times n$ matrices and the generalized joint numerical ranges is studied. For instance, it is shown that $F$ is a f…

math.RA2019

Nonsurjective maps between rectangular matrix spaces preserving disjointness, triple products, or norms

Chi-Kwong Li, Ming-Cheng Tsai, Ya-Shu Wang +1

Let $M_{m, n}$ be the space of $m \times n$ real or complex rectangular matrices. Two matrices $A, B \in M_{m, n}$ are disjoint if $A^{*} B = 0_{n}$ and $A B^{*} = 0_{m}$ . In this paper, a char…

math.FA2012

Compact and weakly compact disjointness preserving operators on spaces of differentiable functions

Denny H. Leung, Ya-Shu Wang

A pair of functions defined on a set X with values in a vector space E is said to be disjoint if at least one of the functions takes the value 0 at every point in X. An operator ac…