Uniformly continuous cosine families properties around weak demicompactness concept

Year 2022, Volume: 51 Issue: 6, 1674 - 1679, 01.12.2022

Dr Hedi Benkhaled , Dr Srar Elleuch Professor Dr.

https://doi.org/10.15672/hujms.1035373

Abstract

In this paper, we use the concept of weak demicompactness in order to give some properties for the uniformly continuous cosine families. Our theoretical results will be illustrated by investigating the spectral inclusion for a uniformly continuous cosine family for an upper semi-Fredholm spectrum.

Keywords

cosine family, weakly demicompact operator, upper semi-Fredholm spectrum, spectral inclusion

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