Topology IV.a - Cohomology rings

Week 4: The course notes have been slightly updated (some typos have been fixed, thank you Elsa). This Monday I will first finish the proof of the Hopf formula, since we needed to identify the conjugation action with that of the deck transformations. Section 10 about more general coefficients I will only mention, please read this section and prepare your questions if you have any. I will then start with cohomology with arbitrary coefficients (another reason to skip Section 10).