  Using the Okounkov-Maulik stable map, we identify the equivariant cohomology
of instanton moduli spaces with the space of polynomials on an infinite number
of variables. We define the generalized Jack polynomials as the polynomials
representing the classes of fixed points under this identification. Using the
abelianization theorem of Shenfeld we derive the combinatorial formula for the
expansion of generalized Jack polynomials in the basis of Schur polynomials.
