In this paper we present sufficient conditions for reflexivity of any powers of the multiplication operator acting on Banach spaces of formal Laurent series.
By an elementary proof, we use a result of Conway and Dudziak to show that if A is a hyponormal operator with spectral radius r(A) such that its spectrum is the closed disc {z:|z| ≤ r(A)} then A is reflexive. ...By an elementary proof, we use a result of Conway and Dudziak to show that if A is a hyponormal operator with spectral radius r(A) such that its spectrum is the closed disc {z:|z| ≤ r(A)} then A is reflexive. Using this result, we give a simple proof of a result of Bercovici, Foias, and Pearcy on reflexivity of shift operators. Also, it is shown that every power of an invertible bilateral weighted shift is reflexive.展开更多
Let {β(n)}n be a sequence of positive numbers such that β(0) = 1 and let 1 ≤ p 〈 ≤. We will investigate the reflexivity of all integer powers of the multiplication operator on the Banach spaces of formal Laur...Let {β(n)}n be a sequence of positive numbers such that β(0) = 1 and let 1 ≤ p 〈 ≤. We will investigate the reflexivity of all integer powers of the multiplication operator on the Banach spaces of formal Laurent series, L^P(β).展开更多
文摘In this paper we present sufficient conditions for reflexivity of any powers of the multiplication operator acting on Banach spaces of formal Laurent series.
基金supported by a grant (No.86-GR-SC-27) from Shiraz University Research Council
文摘By an elementary proof, we use a result of Conway and Dudziak to show that if A is a hyponormal operator with spectral radius r(A) such that its spectrum is the closed disc {z:|z| ≤ r(A)} then A is reflexive. Using this result, we give a simple proof of a result of Bercovici, Foias, and Pearcy on reflexivity of shift operators. Also, it is shown that every power of an invertible bilateral weighted shift is reflexive.
文摘Let {β(n)}n be a sequence of positive numbers such that β(0) = 1 and let 1 ≤ p 〈 ≤. We will investigate the reflexivity of all integer powers of the multiplication operator on the Banach spaces of formal Laurent series, L^P(β).