Deformations on coadjoint orbits (Q1821402)

A deformation of the polynomial algebra \(S({\mathcal G})\) on \({\mathcal G}^*\) when \(S({\mathcal G})\) is a free \(I({\mathcal G})\) module is considered (\(I({\mathcal G}) =\) algebra of invariant polynomials). This deformation restricts nicely to a large class of orbits. We also give an example to show that deformations of \(S({\mathcal G})\) restricting to orbits may not always be defined by bidifferential operators.