拟-*-A类算子的Riesz幂等元

On The Riesz Idempotent of Quasi-*-Class A Operators

证明了若T是拟-＊-A类算子且λ_0是σ（T）的孤立点谱,则E是自共轭算子且满足EH=Ker（T-λ_0）=Ker（T-λ_0）~＊,其中E是算子T关于λ_0的Riesz幂等元.

In this paper, we show that if T is a quasi-＊-class A operator satisfying Property（E） and ＋λ0 is a non-zero isolated eigenvalue of σ（T）, then EH = ker（T - ＋λ0） ：- ker（T - λ0）＊, where E is the Riesz idempotent of T for λ0. In this case, E is self-adjoint.