Essential norm of Cesàro operators on L and Cesàro spaces

Autor: Georges Habib, Ihab Al Alam, Fares Maalouf, Loïc Gaillard, Pascal Lefèvre
Rok vydání: 2018
Předmět:
Zdroj: Journal of Mathematical Analysis and Applications. 467:1038-1065
ISSN: 0022-247X
DOI: 10.1016/j.jmaa.2018.07.038
Popis: In this paper, we consider the Cesaro-mean operator Γ 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 ∈ ( 1 , + ∞ ] 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 Γ 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.
Databáze: OpenAIRE