79 citations · 100 across the 15 of their papers we have counts for
22 papers
A Grassmann formula for the spectral order of matrices
Mohamed Amine Aouichaoui, Eun-Young Lee
For Hermitian matrices and , we prove that $(A\join B)\oplus(A\meet B)$ is unitarily equivalent to , where the join and meet are taken in Olson's spectral order.…
Solutions to some open problems in matrix analysis
Mohamed Amine Aouichaoui, Eun-Young Lee
We solve a problem posed by Audenaert and Kittaneh in 2012 by proving that the Aujla--Bourin subadditivity inequality can be strengthened to an optimal form. We also answer questio…
Some hybrid matrix triangle inequalities
Jean-Christophe Bourin, Eun-Young Lee
A recent result due to Teng Zhang compares the sum of matrices and the sum of their quadratic symmetric moduli: $$ \left\| \sum_{k=1}^m A_k\right\| \le \sqrt{2} \left\| \sum_{k…
Averages over matrix unitary orbits and spectral order
Jean-Christophe Bourin, Eun-Young Lee
We establish matrix versions of the comparisons between the -norms or quasi-norms for sequences of complex numbers. For instance, given , and a family of norm…
Triangle inequalities for the operator symmetric modulus
Jean-Christophe Bourin, Eun-Young Lee
We study the operator symmetric modulus (|Z|+|Z^*|)/2 for matrices Z. Several triangle type inequalities are given.
Involutions and angles between subspaces
Jean-Christophe Bourin, Eun-Young Lee
We provide a complete structure theorem for involutory matrices. This yields a new approach to principal angles between subspaces and provide a series of nice formulae for these an…