Irreducible A1(1)-modules from modules over two-dimensional non-abelian Lie algebra

For any module V over the two-dimensional non-abelian Lie algebra b and scalar α ∈ C, we define a class of weight modules Fα(V) with zero central charge over the affine Lie algebra A1(1). These weight modules have infinitedimensional weight spaces if and only if V is infinite dimensional. In this paper, we will determine necessary and sufficient conditions for these modules Fα(V) to be irreducible. In this way, we obtain a lot of irreducible weight A1(1)-modules with infinite-dimensional weight spaces.