Macdonald polynomials, Laumon spaces and perverse coherent sheaves

Let $G$ be an almost simple simply connected complex Lie group, and let $G/U_-$ be its base affine space. In this paper we formulate a conjecture, which provides a new geometric interpretation of the Macdonald polynomials associated to $G$ via perverse coherent sheaves on the scheme of formal arcs in the affinization of $G/U_-$. We prove our conjecture for $G=SL(N)$ using the so called Laumon resolution of the space of quasi-maps (using this resolution one can reformulate the statement so that only "usual" (not perverse) coherent sheaves are used). In the course of the proof we also give a $K$-theoretic version of the main result of arXiv/0811.4454.