Uniqueness of the Momentum map
  We give a detailed discussion about existence and uniqueness of Lu's momentum map. More precisely, we introduce the infinitesimal momentum map, and we study its properties. This allows us to describe the theory of reconstruction of the momentum map from the infinitesimal one. We provide the conditions for the uniqueness of the momentum map. 
Chiara Esposito and Ryszard Nest
math-ph math.DG math.MP