This book is a unified presentation of both classical and contemporary results in the calculus of variations. It offers a comprehensive analysis of necessary and sufficient conditions for sequential lower semicontinuity of functionals on Lp spaces, followed by relaxation techniques. In recent years there has been a remarkable and renewed interest in this area, motivated in part by applications of allied disciplines. Based on a series of lectures by Irene Fonseca at Carnegie Mellon University, this book was written in response to the need to bring together in one volume contemporary developments in the calculus of variations. Because it is largely self-contained, the book will appeal to non-specialists and new students in this discipline. It is intended for use as a graduate text and as a reference for more experienced researchers working in the area.
