OPERATORS AND MATRICES, vol.15, no.4, pp.1445-1460, 2021 (Journal Indexed in SCI)
We consider operator A on the reproducing Kernel Hilbert space H = H (Omega) over some set Omega with the reproducing kernel K-lambda (z) = K (z, lambda) and define Davis-Wielandt-Berezin radius eta(A) by the formula