On strong variations of weyl type theorems

Abstract:

An operator T acting on a Banach space X satisfies the property (UWE) if (Formula Presented), where σa(T) is the aproximate point spectrum of (Formula Presented) is the upper semi-Weyl spectrum of T and E(T) is the set of all eigen values of T that are isolated in the spectrum σ(T) of T. In this paper, we introduce and study two new spectral properties, namely (VE) and (VEa), in connection with Weyl type theorems. Among other results, we have that T satisfies property (VE) if and only if T satisfies property (UWE) and σ(T) = σa(T).

Año de publicación:

2017

Keywords:

• Weyl's theorem
• Property (VE)
• Property (UWE)
• Property (WE)
• Semi-Fredholm operator

Fuente:

scopus