简介:Inthispaper,westudytheperturbationofspectrafor2×2operatormatricessuchasMX=(AX0B)andMZ=(ACZB)ontheHilbertspaceH⊕Kandthesets∩X∈B(K,H)Pσ(MX),∩X∈B(K,H)Rσ(MX)and∩Z∈B(H,K)σ(MZ),∩Z∈B(H,K)Pσ(MZ),∩Z∈B(H,K)Rσ(MZ),∩Z∈B(H,K)Cσ(MZ),whereR(C)isaclosedsubspace,arecharacterized