The book presents a systematic treatment of generalized Orlicz spaces (also known as Musielak–Orlicz spaces) with minimal assumptions on the generating Φ-function. We introduce and develop a technique centered on the use of equivalent Φ-functions. Classical functional analysis-results are presented in detail. Further, new results regarding harmonic analysis are also included. Extrapolation is used to prove e.g. the boundedness of Calderón–Zygmund operators. Finally, we provide central results for Sobolev spaces, including Poincaré and Sobolev–Poincaré inequalities in norm and modular forms.The primary audiences for the book are researchers and PhD students interested in Orlicz spaces or generalized Orlicz spaces. The book can be used as a basis for advanced graduate courses in analysis.weiterlesen