About the journal

Cobiss

Filomat 2020 Volume 34, Issue 14, Pages: 4649-4657
https://doi.org/10.2298/FIL2014649H
Full text ( 184 KB)
Cited by


Some inequalities involving Hilbert-Schmidt numerical radius on 2 x 2 operator matrices

Hajmohamadi Monire (Department of Mathematics, University of Sistan and Baluchestan, Zahedan, I.R. Iran), monire.hajmohamadi@yahoo.com
Lashkaripour Rahmatollah (Department of Mathematics, University of Sistan and Baluchestan, Zahedan, I.R. Iran), lashkari@hamoon.usb.ac.ir

We present some inequalities related to the Hilbert-Schmidt numerical radius of 2 x 2 operator matrices. More precisely, we present a formula for the Hilbert-Schmidt numerical radius of an operator as follows: w2(T) = sup α2+β2=1 ||αA + βB||2, where T = A + iB is the Cartesian decomposition of T ∈ HS(H).

Keywords: Cartesian decomposition, Hilbert-Schmidt Numerical radius, Off-diagonal part, Operator matrix