Q-Kostka polynomials and spin Green polynomials

We study the Q-Kostka polynomials L-lambda mu(t) by the vertex operator realization of the QHall-Littlewood functions G(lambda)( x; t) and derive new formulae for L-lambda mu(t). In particular, we have established stability property for the Q-Kostka polynomials. We also introduce spin Green polynomials Y-mu(lambda)(t) as both an analogue of the Green polynomials and deformation of the spin irreducible characters of delta(n). Iterative formulas of the spin Green polynomials are given and some favorable properties parallel to the Green polynomials are obtained. Tables of Y-mu(lambda)(t) are included for n <= 7.