MOORE-PENROSE SPECTRUMS OF 2×2 UPPER TRIANGULAR OPERATOR MATRICES
Guojun Hai · Xitong kexue yu shuxue · 2009
Let H_1 and H_2 be infinite dimensional separable Hilbert spaces.Denote by M_C the 2×2 upper triangular operator matrix acting on H_1H_2 of the form(AOCB).For given operators A∈B(H_1)and B∈B(H_2),the sets■σ_M(M_C)and■σ_M(M_C) are characterized,whereσ_M(·)denotes the Moore-Penrose spectrum.