Gk. Zhang, SOME RECURRENCE FORMULAS FOR SPHERICAL POLYNOMIALS ON TUBE DOMAINS, Transactions of the American Mathematical Society, 347(5), 1995, pp. 1725-1734
For a tube domain G/K we study the tenser products of two spherical re
presentations of the maximal compact group K and the product of the co
rresponding spherical polynomials. When one of these is a fundamental
representation, we prove that the spherical representations appear wit
h multiplicity at most one and we then find all the coefficients in th
e recurrence formula for the product of the spherical polynomials. Thi
s generalizes the previous result of L. Vretare and proves for certain
cases a conjecture of R. Stanley on Jack symmetric polynomials.