Abstracto
- It is shown that the spin‐weighted cylindrical harmonics s Jαm(ρ,φ), which are functions defined on the plane, are related to representation matrices of the group of rigid motions on the plane. It is also shown that the raising and lowering operators of the spin weight and of the z component of the angular momentum are related to two copies of the Lie algebra of the Euclidean group of the plane.