PUB - Publikationen an der Universität Bielefeld

We present the tau-invariant balanced quasi-shuffle algebra Gf, whose elements formalize (combinatorial) multiple Eisenstein series as well as multiple q-zeta values. In particular, Gf has natural maps into these two algebras, and we expect these maps to be isomorphisms. Racinet studied the algebra Zf of formal multiple zeta values by examining the corresponding afflne scheme DM. Similarly, we present the afflne scheme BM corresponding to the algebra Gf. We show that Racinet's afflne scheme DM embeds into our afflne scheme BM. This leads to a projection from the algebra Gfonto Zf. Via the above natural maps, this projection corresponds to extracting the constant terms of multiple Eisenstein series or the limit q -> 1 of multiple q-zeta values. (c) 2024 The Author. Published by Elsevier Inc. This is an open access article under the CC BY license (http://