##### Department of Mathematics,

University of California San Diego

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### Math 209 - Number Theory

## Kiran Kedlaya

#### UCSD

## Witt vectors in mixed characteristic and p-adic Hodge theory

##### Abstract:

The functor of p-typical Witt vectors is most well known for lifting perfect fields of characteristic p into complete discrete valuation rings. However, it is a well-defined functor on arbitrary rings; we will indicate how applying this functor to local rings of mixed characteristic gives some new perspectives on p-adic Hodge theory. We will also touch briefly upon some mysterious links to algebraic K-theory coming from the work of Hesselholt. Based on joint papers with Chris Davis (Copenhagen).

Host: Claus Sorensen

### April 24, 2014

### 2:00 PM

### AP&M 7321

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