The crepant resolution conjecture for Donaldson-Thomas invariants

Donaldson-Thomas (DT) invariants are integers that enumerate curves in a given Calabi-Yau 3-fold. Let X be a 3-dimensional Calabi-Yau orbifold, and let Y be a crepant resolution of its coarse moduli space. When X satisfies the Hard Lefschetz condition, i.e., the fibres of the resolution are at most 1-dimensional, the Crepant Resolution Conjecture (CRC) of Bryan-Cadman-Young gives a precise relation between the generating functions of DT invariants of X and Y.