Jet-determination of symmetries of parabolic geometries (Q1659930)

In this comprehensive and well-written paper, the authors establish 2-jet determinacy for the symmetry algebra of the underlying structure of any real or complex parabolic geometry. The authors prove that the symmetry algebra is 1-jet determined at non-flat points. Additionally, 1-jet determinacy at any point for a variety of non-flat parabolic geometries is established. This includes torsion-free, parabolic contact and several other classes of geometries.