  We give an introductory survey of the results in arXiv: 1708.01418. We
discuss a sheafified elliptic quantum group associated to any symmetric
Kac-Moody Lie algebra. The sheafification is obtained by applying the
equivariant elliptic cohomological theory to the moduli space of
representations of a preprojective algebra. By construction, the elliptic
quantum group naturally acts on the equivariant elliptic cohomology of Nakajima
quiver varieties. As an application, we obtain a relation between the
sheafified elliptic quantum group and the global affine Grassmannian over an
elliptic curve.
