A new proof (due to X Cabre) of the classical isoperimetric theorem, based on Alexandrov’s idea of moving planes, will be presented. Compared to the usual proofs, which use geometric measure theory, this proof will be based on elementary ideas from calculus and partial differential equations (Laplace equation).
KeywordsIsoperimetric inequality moving planes Neumann problem lower contact set elliptic equations
Unable to display preview. Download preview PDF.