On left and right west-stampfli decomposition

Abstract

In this paper we define and investigate the decomposition of a Hilbert space operator T in the form T = K+Q where K is a compact and the approximate points spectrum (or the surjectivity spectrum) of Q is identical to the set of all accumulation point of the approximate point spectrum ( or the surjectivity spectrum) of T. Also, we provide the relation between operators having these decomposition and left (or right) Stampfli operators.