Title: Quiver Yangians and Donaldson-Thomas Invariants

Abstract: Over decades string theory has stimulated mathematical studies of enumerative invariants of Calabi-Yau manifolds. In this talk, we discuss Donaldson-Thomas-type invariants associated with toric Calabi-Yau three-folds. We find that the invariants are counted by a combinatorial model of crystal melting, which can be regarded as a weight space of a representation of an infinite-dimensional algebra known as the quiver Yangian. Here the quiver Yangian generalizes the affine Yangian associated with a Lie algebra, and contain the cohomological hall algebra (CoHA) as the upper-triangular part.