In mathematics, the fundamental group scheme is a group scheme canonically attached to a scheme over a Dedekind scheme (e.g. the spectrum of a field or the spectrum of a discrete valuation ring). It is a generalisation of the étale fundamental group. Although its existence was conjectured by Alexander Grothendieck, the first construction is due to Madhav Nori, who only worked on schemes over fields. A generalisation to schemes over Dedekind schemes is due to Marco Antei, Michel Emsalem and Carlo Gasbarri.