Commit 2024-11-05 11:12 c5938ebb

feat(AlgebraicGeometry/Pullback): description of the underlying topological space of a fiber product of schemes (#17767) Let f : X ⟶ S and g : Y ⟶ S be morphisms of schemes. In this PR we describe the underlying topological space of pullback f g, i.e. the fiber product X ×[S] Y. In particular, we show that the points of X ×[S] Y correspond bijectively to pairs (z, p) of triples z = (x, y, s) with f x = s = g y and prime ideals q of κ(x) ⊗[κ(s)] κ(y). From the valuative criterion project.