The bilinear generating function for products of two Laguerre 2D polynomials
Lm;n(z; z0) with different arguments is calculated. It corresponds to the
formula of Mehler for the generating function of products of two Hermite
polynomials. Furthermore, the generating function for mixed products of
Laguerre 2D and Hermite 2D polynomials and for products of two Hermite 2D
polynomials is calculated. A set of infinite sums over products of two Laguerre
2D polynomials as intermediate step to the generating function for products of
Laguerre 2D polynomials is evaluated but these sums possess also proper
importance for calculations with Laguerre polynomials. With the technique of
SU(1; 1) operator disentanglement some operator identities are derived in an
appendix. They allow to calculate convolutions of Gaussian functions combined
with polynomials in one- and two-dimensional case and are applied to evaluate
the discussed generating functions. Keywords: Laguerre and Hermite polynomials,
Laguerre 2D polynomials, Jacobi polynomials, Mehler formula, SU(1; 1) operator
disentanglement, Gaussian convolutions.Comment: 28 page