AFFINE HALL–LITTLEWOOD FUNCTIONS FOR A(1)1 AND SOME CONSTANT TERM IDENTITIES OF CHEREDNIK–MACDONALD–MEHTA TYPE

We study t-analogs of string functions for integrable highest weight representations of the affine Kac–Moody algebra A⁽¹⁾1. We obtain closed form formulas for certain t-string functions of levels 2 and 4. As corollaries, we obtain explicit identities for the corresponding affine Hall–Littlewood functions, as well as higher level generalizations of Cherednik's Macdonald and Macdonald–Mehta constant term identities.