Abstract In this paper, it is characterized when a multiple unilateral weighted shift belongs to the classes An （1 ≤ n ≤ x0）. As a result, we perfect and generalize the previous conclusions given by H. Bercovici, ...Abstract In this paper, it is characterized when a multiple unilateral weighted shift belongs to the classes An （1 ≤ n ≤ x0）. As a result, we perfect and generalize the previous conclusions given by H. Bercovici, C. Foias, and C. Pearcy. Moreover, we remark that Question 21 posed by Shields has been negatively answered.展开更多
文摘Abstract In this paper, it is characterized when a multiple unilateral weighted shift belongs to the classes An （1 ≤ n ≤ x0）. As a result, we perfect and generalize the previous conclusions given by H. Bercovici, C. Foias, and C. Pearcy. Moreover, we remark that Question 21 posed by Shields has been negatively answered.
