Generalized Orlicz spaces and related PDE
: Harjulehto P, Hasto P, Klen R
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
: 2016
: Nonlinear Analysis: Theory, Methods and Applications
: NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS
: NONLINEAR ANAL-THEOR
: 143
: 155
: 173
: 0362-546X
DOI: https://doi.org/10.1016/j.na.2016.05.002
We prove the boundedness of the maximal operator in generalized Orlicz spaces defined on subsets of R-n. The proof is based on an extension result for Phi-functions. We study generalized Sobolev-Orlicz spaces and establish density of smooth functions and the Poincare inequality. As applications we establish the existence of solutions of the phi-Laplace equation with zero and non-zero right-hand side. Further, we systematize assumptions for Phi-functions and prove several basic tools needed for the study of differential equations of generalized Orlicz growth. (C) 2016 Elsevier Ltd. All rights reserved.