Lifts of $L_\infty$-morphims to $G_\infty$-morphisms
Résumé
Let $\g_2$ be theHochschild complex of cochains on $C^\infty(\RM^n)$ and $\g_1$ be the space of multivector fields on $\RM^n$.In this paper we prove that given any $G_\infty$-structure ({\rm i.e.}Gerstenhaber algebra up to homotopy structure) on $\g_2$,and any morphism $\varphi$ of Lie algebra up to homotopy between$\g_1$ and $\g_2$, there exists a $G_\infty$-morphism $\Phi$between$\g_1$ and $\g_2$ that restricts to $\varphi$. In particular, themorphism constructed by Kontsevich can be obtained using Tamarkin'smethod for any $G_\infty$-structure on $\g_2$. We also show thatany two of such $G_\infty$-morphisms are homotopic in a certain sense.