Morse Theory of Gradient Flows, Concavity and Complexity on Manifolds with Boundary - Tapa dura

This monograph is an account of the author's investigations of gradient vector flows on compact manifolds with boundary. Many mathematical structures and constructions in the book fit comfortably in the framework of Morse Theory and, more generally, of the Singularity Theory of smooth maps.The geometric and combinatorial structures, arising from the interactions of vector flows with the boundary of the manifold, are surprisingly rich. This geometric setting leads organically to many encounters with Singularity Theory, Combinatorics, Differential Topology, Differential Geometry, Dynamical Systems, and especially with the boundary value problems for ordinary differential equations. This diversity of connections animates the book and is the main motivation behind it.The book is divided into two parts. The first part describes the flows in three dimensions. It is more pictorial in nature. The second part deals with the multi-dimensional flows, and thus is more analytical. Each of the nine chapters starts with a description of its purpose and main results. This organization provides the reader with independent entrances into different chapters.

Putting constraints on the nature of the interaction between nonsingular gradient-like fields and the boundary of a smooth compact manifold have profound implications for the topology of the manifold, and this book describes these implications. Along the way, this study extends into the spaces of flow trajectories, their complexity and intricate combinatorics. New invariants of gradient flows, as well as invariants of the underlying manifold are produced, based on the understanding of these structures (on the space of trajectories and on the flow-generated spines).

The process leading to a discovery is equally if not more important than the discover itself and in this book, classical singularity theory guides our investigations, and algebraic topology provides the tools.