Hello everyone, I'm a undergraduate at UC Berkeley. I'm doing theoretical physics but technically I'm a math major. I really want to study quantum gravity in the future. Now I have a problem of choosing courses. For next semester, I have only one spot available for either representation theory or algebraic topology. Both are graduate courses and I have substantial previous experiences on both subjects. I'm wondering which class is more essential to my academic goal. It's very sad that I cannot choose both at the same time due to scheduling problem. Any help will be appreciated. Thanks!