Pseudo-Monotone Operator Theory for Unsteady Problems with Variable Exponents

This book provides a comprehensive analysis of the existence of weak solutions of unsteady problems with variable exponents. The central motivation is the weak solvability of the unsteady p(.,.)-NavierStokes equations describing the motion of an incompressible electro-rheological fluid. Due to the variable dependence of the power-law index p(.,.) in this system, the classical weak existence analysis based on the pseudo-monotone operator theory in the framework of BochnerLebesgue spaces is not applicable. As a substitute for BochnerLebesgue spaces, variable BochnerLebesgue spaces are introduced and analyzed. In the mathematical framework of this substitute, the theory of pseudo-monotone operators is extended to unsteady problems with variable exponents, leading to the weak solvability of the unsteady p(.,.)-NavierStokes equations under general assumptions. Aimed primarily at graduate readers, the book develops the material step-by-step, starting with the basics of PDE theory andnon-linear functional analysis. The concise introductions at the beginning of each chapter, together with illustrative examples, graphics, detailed derivations of all results and a short summary of the functional analytic prerequisites, will ease newcomers into the subject.

Includes the first proof of the existence of weak solutions of the unsteady p(t,x)-Navier-Stokes equations Provides a comprehensive review of the rapidly expanding field of unsteady problems with variable >exponents Requires only a basic knowledge of functional analysis

Auteur

Résumé

"This book is essentially based on the author's doctoral thesis ... . The book also contains an appendix and references. ... The book could be used by graduate students and researchers working on such problems." (Gheorghe Morosanu, zbMATH 1526.35002, 2024)

Contenu

• 1. Introduction. - 2. Preliminaries. - Part I Main Part. -
     3. Variable BochnerLebesgue Spaces. - 4. Solenoidal Variable BochnerLebesgue Spaces. - 5. Existence Theory for Lipschitz Domains. - Part II Extensions . - 6. Pressure Reconstruction. - 7. Existence Theory for Irregular Domains. - 8. Existence Theory for p- < 2. - 9. Appendix.