This is a series of lecture notes on nonlinear dynamics for physicists. The level is that of an advanced undergraduate or beginning graduate student. The main aim of these lectures is to present a balance of qualitative and quantitative material. The book also aims to address three main questions about nonlinear dynamics: what is nonlinear dynamics all about and what makes it differ from linear dynamics which permeate all familiar textbooks?; from the physicist's point of view, why should we study nonlinear systems and leave the comfortable territory of linearity?; and how can one progress in...