Author = Sheikhhosseini, Alemeh

Cartesian decomposition of matrices and some norm inequalities

Volume 3, Issue 2, 2016, Pages 33-42

https://doi.org/10.22072/wala.2016.23238

Alemeh Sheikhhosseini, Golamreza Aghamollaei

Abstract Let ‎X be an ‎‎n-‎‎‎‎‎‎square complex matrix with the ‎Cartesian decomposition ‎‎X = A + i ‎B‎‎‎‎‎, ‎where ‎‎A ‎and ‎‎B ‎are ‎‎‎n ‎‎times n‎ ‎Hermitian ‎matrices. ‎It ‎is ‎known ‎that ‎‎$Vert X Vert_p^2 ‎leq 2(Vert A Vert_p^2 + Vert B Vert_p^2)‎‎‎$, ‎where ‎‎$‎p ‎‎geq 2‎$‎ ‎and ‎‎$‎‎Vert . Vert_p$ ‎is ‎the ‎Schatten ‎‎‎‎p-norm.‎ ‎‎ ‎‎In this paper‎, this inequality and some of its improvements are studied and investigated ‎for the joint C-numerical radius, joint spectral radius, and for the ‎C-spectral norm of matrices.