We attack the question of E 2 -formality of differential graded algebras over 𝔽 p via obstruction theory. We are able to prove that E 2 -algebras whose cohomology ring is a polynomial algebra on even degree classes are formal. As a consequence we prove E 2 -formality of the classifying space of some compact Lie groups or of Davis–Januszkiewicz spaces.
Geoffroy Horel (Fri,) studied this question.