2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/67320We 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 correctinsCommutative AlgebraAlgebraic Topology13K05; 18C10; 19A22text