This is the third of three volumes on partial differential equations. It is devoted to nonlinear PDE. There are treatments of a number of equations of classical continuum mechanics, including relativistic versions. There are also treatments of various equations arising in differential geometry, such as in the study of minimal surfaces, isometric imbedding, conformal deformation, harmonic maps, and prescribed Gauss curvature. In addition, some nonlinear diffusion problems are studied. Analytical tools introduced in this volume include the theory of L^p Sobolev spaces, H lder spaces, Hardy spaces, and Morrey spaces, and also a development of Calderon-Zygmund theory and paradifferential operator calculus. The book is addressed to graduate students in mathematics and to professional mathematicians, with an interest in partial differential equations, mathematical physics, differential geometry, harmonic analysis and complex analysis.
