The new student in differential and low-dimensional topology is faced
with a bewildering array of tools and loosely connected theories. This
short book presents the essential parts of each, enabling the reader to
become 'literate' in the field and begin research as quickly as
possible. The only prerequisite assumed is an undergraduate algebraic
topology course. The first half of the text reviews basic notions of
differential topology and culminates with the classification of exotic
seven-spheres. It then dives into dimension three and knot theory. There
then follows an introduction to Heegaard Floer homology, a powerful
collection of modern invariants of three- and four-manifolds, and of
knots, that has not before appeared in an introductory textbook. The
book concludes with a glimpse of four-manifold theory. Students will
find it an exhilarating and authoritative guide to a broad swathe of the
most important topics in modern topology.