On the spectral $ν$-continuity

Salvador Sánchez-Perales, Sergio Palafox, Tomás Pérez-Becerra

Published 2020-09-18Version 1

In this paper we study the $\nu$-continuity of the spectrum and some of its parts. We show that the approximate point spectrum $\sigma_{ap}$ is upper semi-$\nu$-continuous at every Fredholm operator, then we give sufficient conditions to guarantee the $\nu$-continuity of $\sigma_{ap}$. Also we show that the restriction of the Weyl spectrum on the class of essentially $G_1$ operators is $\nu$-continuous. Finally, we investigate the $\nu$-continuity of the spectrum on the class of $p$-hyponormal operators.