@article{Rashid_2020, title={Property $(w)$ of upper triangular operator Matrices}, volume={51}, url={https://journals.math.tku.edu.tw/index.php/TKJM/article/view/2256}, DOI={10.5556/j.tkjm.51.2020.2256}, abstractNote={<p>Let $M_C=\begin{pmatrix}<br /> A & C \\<br /> 0 & B \\<br /> \end{pmatrix}\in\LB(\x,\y)<br />$ be be an upper triangulate Banach space<br />operator. The relationship between the spectra of $M_C$ and $M_0,$ and their<br />various distinguished parts, has been studied by a large number of authors in<br />the recent past. This paper brings forth the important role played by SVEP,<br />the {\it single-valued extension property,} in the study of some of these relations. In this work, we prove necessary and sufficient conditions of implication of the type $M_0$ satisfies property $(w)$ $\Leftrightarrow$ $M_C$ satisfies property $(w)$ to hold. Moreover, we explore certain conditions on $T\in\LB(\hh)$ and $S\in\LB(\K)$ so that the direct sum $T\oplus S$ obeys property $(w)$, where $\hh$ and $\K$ are Hilbert spaces.</p>}, number={2}, journal={Tamkang Journal of Mathematics}, author={Rashid, Mohammad M.H}, year={2020}, month={Jun.}, pages={81-99} }