Edward Poon

activity

20122025

most citedPhysical transformations between quantum states

20 citations · 40 across the 10 of their papers we have counts for

collaborators

Showing math.FAShow all

4 papers · 1 filter

math.FA2025

(Real)linear preservers of multiples of unitaries and matrix pairs with some extremal norm properties

Bojan Kuzma, Chi-Kwong Li, Edward Poon

We determine the structure of linear maps on complex (real) square matrices sending unitary (orthogonal) matrices to multiples of unitary (orthogonal) matrices. The result is used…

math.FA2024

Linear preservers of parallel matrix pairs with respect to the $k$ -numerical radius

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

Let $1 \leq k < n$ be integers. Two $n \times n$ matrices $A$ and $B$ form a parallel pair with respect to the $k$ -numerical radius $w_{k}$ if $w_{k} (A + μ B) = w_{k} (A) + w_{k} (B)$ for som…

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.FA2021★ 4 cited

Isospectrality and matrices with concentric circular higher rank numerical ranges

Edward Poon, Hugo J. Woerdeman

We characterize under what conditions $n \times n$ Hermitian matrices $A_{1}$ and $A_{2}$ have the property that the spectrum of $cos t A_{1} + sin t A_{2}$ is independent of $t$ (thus, t…

(Real)linear preservers of multiples of unitaries and matrix pairs with some extremal norm properties

Linear preservers of parallel matrix pairs with respect to the k-numerical radius

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

Isospectrality and matrices with concentric circular higher rank numerical ranges

Linear preservers of parallel matrix pairs with respect to the $k$ -numerical radius

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