Lie algebras for multiple Eisenstein series and multiple q-zeta values

Abstract

Racinet's double shuffle Lie algebra $\mathfrak{dm}_0$ encodes the double shuffle relations of multiple zeta values. We study two analogues of $\mathfrak{dm}_0$ for multiple Eisenstein series and $q$-analogues of multiple zeta values, namely the space $\operatorname{BARI}_{\operatorname{swap},\mathrm{il}}$ of swap-invariant alternil bimoulds with the uri bracket of Kühn and Schneps, and Burmester's balanced double shuffle space $\mathfrak{bm}_0$. Both were conjectured to be Lie algebras. We prove both conjectures and show that $\mathfrak{bm}_0$ is isomorphic to the Lie algebra of finite-depth polynomial elements of $\operatorname{BARI}_{\operatorname{swap},\mathrm{il}}$.