Abstract:
Given a suitable weight on ℝ d , there exist many (recursive) three-term recurrence relations for the corresponding multivariate orthogonal polynomials. In principle, these can be obtained by calculating pseudoinverses of a sequence of matrices. Here we give an explicit recursive three-term recurrence for the multivariate Jacobi polynomials on a simplex. This formula was obtained by seeking the best possible three-term recurrence. It defines corresponding linear maps, which have the same symmetries as the spaces of Jacobi polynomials on which they are defined. The key idea behind this formula is that some Jacobi polynomials on a simplex can be viewed as univariate Jacobi polynomials, and for these the recurrence reduces to the univariate three-term recurrence.