Categorified Quantum sl(2) and Equivariant Cohomology of Iterated Flag Varieties

A 2-category was introduced in that categorifies Lusztig’s integral version of quantum sl(2). Here we construct for each positive integer N a representation of this 2-category using the equivariant cohomology of iterated flag varieties. This representation categorifies the irreducible (N + 1)-dimensional representation of quantum sl(2).