Chi-Kwong Li

activity

19962025

most citedCanonical forms, higher rank numerical range, convexity, totally isotropic subspace, matrix equations

84 citations · 657 across the 85 of their papers we have counts for

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Showing math.FAShow all

31 papers · 1 filter

math.FA2023

Linear maps preserving parallel matrix pairs with respect to the Ky-Fan $k$ -norm

Bojan Kuzma, Chi-Kwong Li, Edward Poon +1

Two bounded linear operators $A$ and $B$ are parallel with respect to a norm $∥ \cdot ∥$ if $∥ A + μ B ∥ = ∥ A ∥ + ∥ B ∥$ for some scalar $μ$ with $∣ μ ∣ = 1$ . Characterization is obtai…

math.FA2022

The $C$ -numerical range and Unitary dilations

Chi-Kwong Li

For an $n \times n$ complex matrix $C$ , the $C$ -numerical range of a bounded linear operator $T$ acting on a Hilbert space of dimension at least $n$ is the set of complex numbers ${…

math.FA2021

Unitarily invariant Norms on Operators

Jor-Ting Chan, Chi-Kwong Li

Let $f$ be a symmetric norm on $R^{n}$ and let $B (H)$ be the set of all bounded linear operators on a Hilbert space $H$ of dimension at lea…

math.FA2021

Commuting normal operators and joint numerical range

Jor-Ting Chan, Chi-Kwong Li, Yiu-Tung Poon

Let $H$ be a complex Hilbert space and let $B (H)$ be the algebra of all bounded linear operators on $H$ . For a positive integer $k$ less…

math.FA2021★ 2 cited

The joint $k$ -numerical range of operators

Jor-Ting Chan, Chi-Kwong Li, Yiu-Tung Poon

Let $B (H)$ be the algebra of all bounded linear operators on the Hilbert space $H$ . For a positive integer $k$ less than the dimension of ${\mathca…

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…

Linear maps preserving parallel matrix pairs with respect to the Ky-Fan k-norm

The C-numerical range and Unitary dilations