2 articles
Representation ring
The representation ring R(G) of a group is the Grothendieck ring of its finite-dimensional representations, with addition from direct sums and multiplication from tensor products.
Tannakian category
A Tannakian category is a rigid abelian tensor category admitting a fiber functor, a formalism developed by Grothendieck and Deligne that reconstructs affine group schemes from their categories of representations.