“…In the framework of deformation quantization, however, this incorporation can at least be formulated very naturally as it has already been indicated in the pioneering articles [2] by Bayen, Flato, Frønsdal, Lichnerowicz, and Sternheimer. Various notions of invariance of star products with respect to actions of Lie groups and Lie algebras were introduced and discussed by Arnal, Cortet, Molin, and Pinczon in [1]. Previously, the existence of G-invariant symplectic connections has been related to that of certain G-invariant star products by Lichnerowicz in [20].…”