Sobolev spaces are a fundamental tool in the modern study of partial differential equations. In this book, Leoni takes a novel approach to the theory by looking at Sobolev spaces as the natural development of monotone, absolutely continuous, and BV functions of one variable. In this way, the majority of the text can be read without the prerequisite of a course in functional analysis.
The first part of this text is devoted to studying functions of one variable. Several of the topics treated occur in courses on real analysis or measure theory. Here, the perspective emphasizes their applications to Sobolev functions, giving a very different flavor to the treatment. This elementary start to the book makes it suitable for advanced undergraduates or beginning graduate students. Moreover, the one-variable part of the book helps to develop a solid background that facilitates the reading and understanding of Sobolev functions of several variables.
The second part of the book is more classical, although it also contains some recent results. Besides the standard results on Sobolev functions, this part of the book includes chapters on BV functions, symmetric rearrangement, and Besov spaces.
The book contains over 200 exercises.
Giovanni Leoni: Carnegie Mellon University, Pittsburgh, PA
Part 1. Functions of one variable Chapter 1. Monotone functions Chapter 2. Functions of bounded pointwise variation Chapter 3. Absolutely continuous functions Chapter 4. Curves Chapter 5. Lebesgue–Stieltjes measures Chapter 6. Decreasing rearrangement Chapter 7. Functions of bounded variation and Sobolev functions
Part 2. Functions of several variables Chapter 8. Absolutely continuous functions and change of variables Chapter 9. Distributions Chapter 10. Sobolev spaces Chapter 11. Sobolev spaces: Embeddings Chapter 12. Sobolev spaces: Further properties Chapter 13. Functions of bounded variation Chapter 14. Besov spaces Chapter 15. Sobolev spaces: Traces Chapter 16. Sobolev spaces: Symmetrization
Appendix A. Functional analysis Appendix B. Measures Appendix C. The Lebesgue and Hausdorff measures Appendix D. Notes Appendix E. Notation and list of symbols