Brown-Zagier Relation for Associators

Francis Brown used a certain evaluation formula for multiple zeta values proved by Zagier to prove the injectivity of the homomorphism from the Motivic Galois group to the automorphism of fundamental group of projective line deleted three points. In this paper, we prove that any associators satisfies this relation. As a consequence, this relation holds for motivic multiple zeta values which is also proved in Brown’s paper. We used certain cohomology theory and Li’s method for the computation.