André's flatness lemma and applications
1 : University of Michigan
A key innovation in André's solution of the direct summand conjecture was a certain flatness lemma for perfectoid rings. In this talk, I will recall this lemma and its relevance for commutative algebra. I will then explain how the lemma surprisingly also provided the essential ingredient in the proof of the odd vanishing theorem in the algebraic K-theory of p-adically complete rings. Joint work with Peter Scholze.