This is an elementary and self-contained introduction to nonlinear functional analysis and its applications, especially in bifurcation theory.The first part of this introduction deals with the geometry of Banach spaces and includes a discussion of local and global inversion theorems for differential mappings. In the second part, the authors are more concerned with bifurcation theory, including the Hopf bifurcation.The first part of this introduction deals with the geometry of Banach spaces and includes a discussion of local and global inversion theorems for differential mappings. In the second part, the authors are more concerned with bifurcation theory, including the Hopf bifurcation.This is an introduction to nonlinear functional analysis, in particular to those methods based on differential calculus in Banach spaces. It is in two parts; the first deals with the geometry of Banach spaces and includes a discussion of local and global inversion theorems for differential mappings. In the second part, the authors are more concerned with bifurcation theory, including the Hopf bifurcation. They include plenty of motivational and illustrative applications, which indeed provide much of the justification of nonlinear analysis. In particular, they discuss bifurcation problems arising from such areas as mechanics and fluid dynamics.Preface; Preliminaries and notation; 1. Differential calculus; 2. Local inversion theorems; 3.?Global inversion theorems; 4. Semilinear Dirichlet problems; 5. Bifurcation results; 6. Bifurcation problems; 7. Bifurcation of periodic solutions; Further reading. ...will doubtless be a much-valued contribution to the vast literature on nonlinear analysis. Jean Mawhin, Mathematical Reviews