# Christopher Cox: New Models of Mathematical Billiards

Mathematical billiards, in which a particle travels freely in a domain until colliding at a boundary and reflecting according to the "angle in equals angle out" model, have been studied for over a century. They have proven extremely valuable in modeling physical systems, for example the Lorenz model for gases, and for examples to better understand dynamical systems. We look at new work investigating alternative models, including recent work by undergraduates.