Title: Old and new on the de Rham-Witt complex III. Liftings mod $p^2$ and the Nygaard filtration I Speaker: Prof. Luc Illusie (Université Paris-Sud) Time: 2019-9-18, 11:00—12:00 Place: N202 Abstract: I will discuss some open problems arising from this new approach. In the second part, I will revisit liftings mod $p^2$ and decompositions of de Rham complexes ("Deligne-Illusie") in relation with a certain filtration on the de Rham-Witt complex. Attachment: