2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/35110In a recent paper [1] we have constructed the spin and tensor representations of SO(4) from which the invariant weight can be derived for the Barrett-Crane model in quantum gravity. By analogy with the SO(4) group, we present the complexified Clebsch-Gordan coefficients in order to construct the Biedenharn-Dolginov function for the SO(3,1) group and the spherical function as the Lorentz invariant weight of the model.LaTex, 6 pages. Communication presented to the XXV international Colloquium on Group Theoretical Methods in Physics, Cocoyoc, Mexico August 2004. To be published by IOP PublishersGeneral Relativity and Quantum Cosmologytext