Witt vectors and Tambara functors

Abstract

We give, for every finite group G, a combinatorial description of the ring of G-Witt vectors on a polynomial algebra over the integers. Using this description we show that the functor, which takes a ring with trivial action of G to its ring of Witt vectors, coincides with the left adjoint of the algebraic functor from the category of G-Tambara functors to the category of rings with an action of G.

22 pages, minor correctins

Cited by in corpus (1)

• Generalized Burnside-Grothendieck ring functor and aperiodic ring functor associated with profinite groups