I emailed a prof about sitting in on his graduate-level gravitational theory class next semester. He said he would like his students to have understanding of electromagnetism, special relativity and quantum mechanics at the advanced undergraduate level. This is the course description: Presents Einstein's relativistic theory of gravitation from geometric viewpoint; gives applications to astrophysical problems (gravitational waves, stellar collapse, etc.). My question is does GR involves the two subjects? I have the QM down, but I'm not sure if my electromagnetism is at the "advanced undergraduate level" and am not sure if I'll have enough time to bring it up to par if GR needs my understanding to be there. Thanks for your help!