Resumen de Minimal models, GT-action and formality of the little disk operad

Dan Petersen

• We give a new proof of formality of the operad of little disks. The proof makes use of an operadic version of a simple formality criterion for commutative differential graded algebras due to Sullivan. We see that formality is a direct consequence of the fact that the Grothendieck–Teichmüller group operates on the chain operad of little disks.