J. Korean Math. Soc. 2018; 55(4): 877-895
Online first article March 14, 2018 Printed July 1, 2018
https://doi.org/10.4134/JKMS.j170497
Copyright © The Korean Mathematical Society.
Aref Jeribi, Bilel Krichen, Makrem Salhi
University of Sfax, University of Sfax, University of Sfax
In this paper, we show that an unbounded $S_{0}$-demicompact linear operator $T$ with respect to a bounded linear operator $S_{0}$, acting on a Banach space, can be characterized by the Kuratowskii measure of noncompactness. Moreover, some other quantities related to this measure provide sufficient conditions to the operator $T$ to be $S_{0}$-demicompact. The obtained results are used to discuss the connection with Fredholm and upper Semi-Fredholm operators.
Keywords: demicompact operator, Fredholm and semi-Fredholm operators, Kuratowskii measure of noncompactness
MSC numbers: 47A55, 47A53, 47H08
© 2022. The Korean Mathematical Society. Powered by INFOrang Co., Ltd