The Strong Homotopy Structure of BRST Reduction

In this paper we propose a reduction scheme for polydifferential operators phrased in terms of $L_\infty$-morphisms. The desired reduction $L_\infty$-morphism has been obtained by applying an explicit version of the homotopy transfer theorem. Finally, we prove that the reduced star product induced by this reduction $L_\infty$-morphism and the reduced star product obtained via the formal Koszul complex are equivalent.