Synopses & Reviews
This book provides a detailed introduction to nonlinear potential theory based on supersolutions to certain degenerate elliptic equations of the p-Laplacian type. Recent research has shown that classical notions such as blayage, polar sets, Perron's method, and fine topology have their proper analogues in a nonlinear setting, and this book presents a coherent exposition of this natural extension of classical potential theory. Yet fundamental differences to classical potential theory exist, and in many places a new approach is mandatory. Sometimes new or long-forgotten methods emerge that are applicable to problems in classical potential theory. Quasiregular mappings constitute a natural field of applications, and a careful study of the potential theoretical aspects of these mappings is included. The principle aim of the book is to explore the ground where partial differential equations, harmonic analysis, and function theory meet. The quasilinear equations considered in this book involve a degeneracy condition given in terms of a weight function and therefore most results appear here for the first time in print. The reader interested exclusively in the unweighted theory will find new results, new proofs, and a reorganization of the material as compared to the existing literature. The book is intended for researchers and graduate students in potential theory, variational calculus, partial differential equations, and quasiconformal mappings.
Description
Includes bibliographical references (p. 342-355) and index.
Table of Contents
Introduction
1. Weighted Sobolev spaces
2. Capacity
3. Supersolutions and the obstacle problem
4. Refined Sobolev spaces
5. Variational integrals
6. A-harmonic functions
7. A superharmonic functions
8. Balayage
9. Perron's method, barriers, and resolutivity
10. Polar sets
11. A-harmonic measure
12. Fine topology
13. Harmonic morphisms
14. Quasiregular mappings
15. Ap-weights and Jacobians of quasiconformal mappings
16. Axiomatic nonlinear potential theory
17. Appendix I: The existence of solutions
18. Appendix II: The John-Nirenberg lemma
Bibliography
List of symbols
Index