Non-commutative formality implies commutative and Lie formality
arXiv:1609.02540 · doi:10.2140/agt.2017.17.2523
Abstract
Over a field of characteristic zero we prove two formality conditions. We prove that a dg Lie algebra is formal if and only if its universal enveloping algebra is formal. We also prove that a commutative dg algebra is formal as a dg associative algebra if and only if it is formal as a commutative dg algebra. We present some consequences of these theorems in rational homotopy theory.
Final version. To appear in Algebraic & Geometric Topology