东北数学（英文版）
東北數學（英文版）
동북수학（영문판）
NORTHEASTERN MATHEMATICAL JOURNAL
2001年
4期
481-486
,共6页
irreducible operator%unitary equivalence%K0-group
We show that two irreducible operators on H are unitarily equivalent if and only if W*(A(Θ)B)′≌M2(C), and give an answer to the open question posed by J. B. Conway (Subnormal Operators, π Pitman, Advanced Publishing Program,Boston, London, Melbourne, 1981) for irreducible operator. We also show that if T, T1 and T2 are irreducible operators with T((Θ)T1 ≌T(Θ)T2, then T1 ≌T2. Finally, we show that K0(A(D))≌Z, giving a new result on the K0-group of Banach algebras.
