Conformally invariant trilinear forms on the sphere

Jean-Louis Clerc, Bent Orsted

To each complex number $\lambda$ is associated a representation ${\pi }_{\lambda }$ of the conformal group $S{O}_0(1,n)$ on ${\mathcal{C}}^{\infty }(S^{n-1})$ (spherical principal series). For three values $λ…