Czechoslovak Mathematical Journal, Vol. 71, No. 4, pp. 1199-1209, 2021
An example of a reflexive Lorentz Gamma space with trivial Boyd and Zippin indices
Alexei Karlovich, Eugene Shargorodsky
Received August 14, 2020. Published online June 25, 2021.
Abstract: We show that for every $p\in(1,\infty)$ there exists a weight $w$ such that the Lorentz Gamma space $\Gamma_{p,w}$ is reflexive, its lower Boyd and Zippin indices are equal to zero and its upper Boyd and Zippin indices are equal to one. As a consequence, the Hardy-Littlewood maximal operator is unbounded on the constructed reflexive space $\Gamma_{p,w}$ and on its associate space $\Gamma_{p,w}'$.
Keywords: Lorentz Gamma space; reflexivity; Boyd indices; Zippin indices
Affiliations: Alexei Karlovich (corresponding author), Centro de Matemática e Aplicações, Departamento de Matemática, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal, e-mail: oyk@fct.unl.pt; Eugene Shargorodsky, Department of Mathematics, King's College London, Strand, London WC2R 2LS, United Kingdom; Technische Universität Dresden, Fakultät Mathematik, 01062 Dresden, Germany, e-mail: eugene.shargorodsky@kcl.ac.uk