Taught at: 2024 -- Graduate course, Universidade Federal de Santa Catarina (UFSC)
Ordinary Differential Equations (ODEs) are used to describe various types of phenomena in nature. On one hand, they allow us to look at systems in a comprehensive and abstract way. However, finding general solutions even for linear problems can be challenging. Adding nonlinearities makes the situation even more complex, as, among other things, the principle of superposition no longer holds. In this short course, we will introduce simple yet powerful principles that can be used to get an overview of the entire family of solutions of nonlinear ODEs. Through examples (Lasers, Josephson Junctions, Ising Model, Electrical Circuits, Oscillators, Chemical Reactions, etc.), concepts such as phase space, fixed point, limit cycle, attracting, repelling, and chaotic orbits, and bifurcations (when a solution transforms into another through parameter changes) will be discussed. Read more