This book is essentially devoted to complex properties (Phase plane structure and bifurcations) of two-dimensional noninvertible maps, i.e. maps having either a non-unique inverse, or no real inverse, according to the plane point. They constitute models of sets of discrete dynamical systems encountered in Engineering (Control, Signal Processing, Electronics), Physics, Economics, Life Sciences. Compared to the studies made in the one-dimensional case, the two-dimensional situation remained a long time in an underdeveloped state. It is only since these last years that the interest for this research has increased. Therefore the book purpose is to give a global presentation of a matter, available till now only in a partial form. Fundamental notions and tools (such as “critical manifolds”), as the most part of results, are accompanied by many examples and figures.

Iteration theory has its roots in the operation of substituting functions into itself. This has led to questions like that of the behaviour of functions by repeating this substitution and when the number of iterations tends to infinity. The terms ''orbit'' and ''chaos'' appropriately describe this behaviour. Dynamical systems and the theory of functional equations play important roles in this field.

The main theme of the ECIT conferences is Iteration Theory, on the borderline between Dynamics and Functional Equations. The aim is to foster symbiosis between mainstream dynamics and iteration theory treated in the style of functional equations theory. The following topics are focused: turbulence and iteration, characterization of chaos, kneading theory, symbolic dynamics, bifurcation, periods of maps, topological dynamics, discrete retarded dynamical systems, cellular automata as dynamical systems, iterative roots of formal power series, iterative roots of polynomials, phantom iterative roots, iterative groups and semigroups, families of commuting functions, algebraic aspects of iteration theory and functional equations.

The main topics of this proceedings stress the interactions between the theory of functional equations and the theory of dynamical systems. A total of 38 invited lectures are included.

This book is essentially devoted to complex properties (Phase plane structure and bifurcations) of two-dimensional noninvertible maps, i.e. maps having either a non-unique inverse, or no real inverse, according to the plane point. They constitute models of sets of discrete dynamical systems encountered in Engineering (Control, Signal Processing, Electronics), Physics, Economics, Life Sciences. Compared to the studies made in the one-dimensional case, the two-dimensional situation remained a long time in an underdeveloped state. It is only since these last years that the interest for this research has increased. Therefore the book purpose is to give a global presentation of a matter, available till now only in a partial form. Fundamental notions and tools (such as “critical manifolds”), as the most part of results, are accompanied by many examples and figures.

Iteration theory has its roots in the operation of substituting functions into itself. This has led to questions like that of the behaviour of functions by repeating this substitution and when the number of iterations tends to infinity. The terms ''orbit'' and ''chaos'' appropriately describe this behaviour. Dynamical systems and the theory of functional equations play important roles in this field.

The main theme of the ECIT conferences is Iteration Theory, on the borderline between Dynamics and Functional Equations. The aim is to foster symbiosis between mainstream dynamics and iteration theory treated in the style of functional equations theory. The following topics are focused: turbulence and iteration, characterization of chaos, kneading theory, symbolic dynamics, bifurcation, periods of maps, topological dynamics, discrete retarded dynamical systems, cellular automata as dynamical systems, iterative roots of formal power series, iterative roots of polynomials, phantom iterative roots, iterative groups and semigroups, families of commuting functions, algebraic aspects of iteration theory and functional equations.

The main topics of this proceedings stress the interactions between the theory of functional equations and the theory of dynamical systems. A total of 38 invited lectures are included.