I'll be applying for graduate programs in physics and chemical physics in about 2 years, and I want to do research in statistical mechanics, particularly thermodynamics of fluids, non-equilibrium thermodynamics, fluid dynamics, nonlinear dynamics, and other fields related to this. I have time to squeeze in a few more math classes, but not all of them. So far I have taken up to calc 3, ODE, linear algebra, statistics, and a course on Mathematica programming. I have enough room to choose from 4 of the courses below. I will learn on my own whatever I miss. Abstract vector spaces (a linear/abstract algebra course) PDE I PDE II Real analysis I Real analysis II Numerical analysis Complex analysis Variational calculus Nonlinear dynamics and chaos I Nonlinear dynamics and chaos II Probability theory Abstract algebra Mathematical methods in physics I Mathematical methods in physics II Out of all of these, which ones will be most useful for a career in physics research? I can only choose four.