“…Aspects of the relation between integrating out degrees of freedom and homotopy transfer appear to have been known to experts, with instances of this relation being explored for particular models in e.g. [
6–8], and in the
framework relevant for open string theory in [
9, 10], but to the best of our knowledge it was only in [
1, 4, 5] that the role of homotopy transfer for general field theories requiring
‐algebras has been discussed explicitly. Apart from being of conceptual interest, this relation is of importance for applications starting from (classical) closed string field theory, which in Zwiebach's covariant formulation is governed by an
‐algebra [11].…”