Quantum equations for massless particles of any spin in curved spacetime

Quantum equations for massless particles of any spin in curved spacetime are presented. These equations can be extended to a global spacetime from the ones derived in a flat spacetime. Here we demonstrate that these equations can be derived also from a scalar Lagrangian, and they form a basis for quantum theory of spins 1 and 2 in in the vicinity of massive objects. The conserved current is calculated by applying Noether theorem and a complete set of commutative observables is determined. The solutions of these equations are considered in a flat Minkowski spacetime and in axially symmetric spacetimes.