Essential norm of Cesaro operators on Lp and Cesaro spaces

被引:4
|
作者
Al Alam, Ihab [1 ]
Gaillard, Loic [2 ]
Habib, Georges [1 ]
Lefevre, Pascal [2 ]
Maalouf, Fares [3 ]
机构
[1] Lebanese Univ, Fac Sci 2, Dept Math, POB 90656, Fanar Matn, Lebanon
[2] Univ Artois, LML, EA 2462, Federat CNRS Nord Pas de Calais FR 2956, Rue Jean Souvraz SP 18, F-62307 Lens, France
[3] Univ St Joseph, Campus Sci & Technol ESIB,POB 1514, Beirut 11072050, Lebanon
关键词
Cesaro spaces; Cesaro operator; Muntz spaces; Compact operator; Essential norm; Multiplication operator;
D O I
10.1016/j.jmaa.2018.07.038
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
In this paper, we consider the Cesaro-mean operator Gamma acting on some Banach spaces of measurable functions on (0, 1), as well as its discrete version on some sequences spaces. We compute the essential norm of this operator on L-P([0, 1]), for p is an element of(1, +infinity] and show that its value is the same as its norm: p/(p-1). The result also holds in the discrete case. On Cesaro spaces the essential norm of Gamma turns out to be 1. At last, we introduce the Muntz-Cesaro spaces and study some of their geometrical properties. In this framework, we also compute the value of the essential norm of the Cesaro operator and the multiplication operator restricted to those Muntz-Cesaro spaces. (C) 2018 Elsevier Inc. All rights reserved.
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页码:1038 / 1065
页数:28
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