E2 formality via obstruction theory

Geoffroy Horel

Published 2024-07-23Version 1

We attack the question of E_2-formality of differential graded algebras over prime fields via obstruction theory. We are able to prove that E_2-algebras whose cohomology ring is a polynomial algebra on even degree classes are intrinsically formal. As a consequence we prove E_2-formality of the classifying space of some compact Lie group or of Davis-Januszkiewicz spaces.