Prelegent: JULIEN BICHON

Faithful flatness is an algebraic concept arising from algebraic geometry and closely related to the question of forming ''good'' quotients. Also, it plays a key role in the noncommutative world, especially in Hopf-algebra theory. After a review of its use and of what is known about the question of faithful flatness over Hopf subalgebras or coideal subalgebras, I will present and explain a new result concerning the faithful flatness of a Hopf algebra over a coideal subalgebra having a conditional expectation.