We obtain a family of functional identities satisfied by vector-valued
functions of two variables and their geometric inversions. For this we
introduce particular differential operators of arbitrary order attached to
Gegenbauer polynomials. These differential operators are symmetry breaking for
the pair of Lie groups (SL(2,C),SL(2,R)) that arise from
conformal geometry.Comment: To appear in Springer Proceedings in Mathematics and Statistic