Skip to main content
2 of 3
edited tags
David E Speyer
  • 156.2k
  • 14
  • 419
  • 763

When does Tannakian theory work over affine schemes besides fields?

By 'work' I would like the correspondence between fiber functors (to finitely generated projective modules) and algebraic groups to be the same as in the field case.

Specifically, if A is an affine ring, and if Proj(A) is the category of finitely generated projective A-modules, when can we say that a fiber functor w:T->Proj(A) corresponds to an algebraic group over A, where T is an A-linear tensor category.

Benjamin Antieau
  • 5.1k
  • 2
  • 27
  • 37