During the short period of five years that have elapsed since the publication of the first edition a number of interesting mathematical developments have taken place and important results have been obtained that relate to the theme of this book.
First of all, as predicted in the Preface to the first edition, Morse theory, indeed, has gone through a dramatic change, influenced by the work by ...... 更多

Chapter I. The Direct Methods in the Calculus of Variations
1. Lower Semi-Continuity
Degenerate Elliptic Equations, 4 -- Minimal Partitioning Hypersurfaces, 6
-- Minimal Hypersurfaces in Riemannian Manifolds, 7 -- A General Lower
Semi-Continuity Result, 8
2. Constraints 更多