Quantum principal bundles or principal comodule algebras are re-interpreted
as principal bundles within a framework of Synthetic Noncommutative
Differential Geometry. More specifically, the notion of a noncommutative
principal bundle within a braided monoidal category is introduced and it is
shown that a noncommutative principal bundle in the category opposite to the
category of vector spaces is the same as a faithfully flat Hopf-Galois
extension.Comment: 18 page