Uniformly continuous cosine families properties around weak demicompactness concept

Authors : Dr Hedi BENKHALED, Dr Srar ELLEUCH, Professor DR.

Pages : 1674-1679

Doi:10.15672/hujms.1035373

View : 16 | Download : 7

Publication Date : 2022-12-01

Article Type : Research Paper

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