|Speaker:||Dmitry Kaledin (Steklov)|
|Title:||Witt vectors as a polynomial functor|
|Date (JST):||Mon, Jan 31, 2011, 14:00 - 17:00|
|Place:||Seminar Room A|
I want to revisit the classical construction of Witt vectors from a modern point of view. In particular, I will introduce a certain
two-parameter generalization of the Witt vectors functor, and I will use it to construct a version of the de Rham-Witt complex of Deligne and Illusie valid for any non-commutative algebra. In the process of doing so, I will also introduce a new computation-free construction of the product of Witt vectors; surprisingly, it uses Tate residue and the well-known central extension of Date-Jimbo-Kashiwara-Miwa. Since Witt vectors are somewhat esoteric for people not working in positive characteristic, I will not assume any familiarity with the subject at all and give all the necessary background.
|Remarks:||break at 15:00-15:30|