Operators and Matrices, cilt.16, sa.1, ss.337-347, 2022 (SCI-Expanded)
© 2022, Element D.O.O.. All rights reserved.In the present study, we investigate how the gaps between some spectral characteristics (operator norm, upper and lower bounds of spectrum and numerical range) of finite direct sum of Hilbert space operators are related to the same spectral characteristics of the coordinate operators.