4 citations · 4 across the 7 of their papers we have counts for
8 papers
Generalized matrix nearness problems II
Rongbiao Thomas Wang, Chi-Kwong Li, Lek-Heng Lim
Given a matrix , a matrix nearness problem seeks an that most closely approximates in the sense of minimizing under a variety of constraints on .…
Semigroup automorphisms of total positivity
Projesh Nath Choudhury, Shaun Fallat, Chi-Kwong Li
Totally positive (TP) and totally nonnegative (TN) matrices connect to analysis, mechanics, and to dual canonical bases in reductive groups, by well-known works of Schoenberg, Gant…
(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…
Approximating quantum states by states of low rank
Nathaniel Johnston, Chi-Kwong Li
Given a positive integer k, it is natural to ask for a formula for the distance between a given density matrix (i.e., mixed quantum state) and the set of density matrices of rank a…
Geometry of essential matrix ranges and the Smith-Ward problem for operator systems
Douglas Farenick, Chi-Kwong Li, Sushil Singla
A -tuple of bounded linear selfadjoint operators acting on an infinite-dimensional separable Hilbert space is said to have the Smith-Ward property if the identity map of the ima…
Noncommutative distances on graphs: An explicit approach via Birkhoff-James orthogonality
Pierre Clare, Chi-Kwong Li, Edward Poon +1
We study the problem of calculating noncommutative distances on graphs, using techniques from linear algebra, specifically, Birkhoff-James orthogonality. A complete characterizatio…