IMHO, pick a theoretical field you like and you focus on it. Theoretical physics doesn't mean particle physics or relativity. Every field in physics can be both

IMHO, pick a theoretical field you like and you focus on it. Theoretical physics doesn't mean particle physics or relativity. Every field in physics can be both theoretical and experimental. I got a graduate degree in theoretical physics, focusing on condensed matter physics. To be exact, I model the phenomenon called quantum solid, using Ginzburg-Landau theory.