We construct a four-parameter family of affine Yangian algebras by gluing two
copies of the affine Yangian of gl1. Our construction allows for
gluing operators with arbitrary (integer or half integer) conformal dimension
and arbitrary (bosonic or fermionic) statistics, which is related to the
relative framing. The resulting family of algebras is a two-parameter
generalization of the N=2 affine Yangian, which is isomorphic to
the universal enveloping algebra of u(1)⊕W∞N=2[λ]. All algebras that we construct
have natural representations in terms of "twin plane partitions", a pair of
plane partitions appropriately joined along one common leg. We observe that the
geometry of twin plane partitions, which determines the algebra, bears striking
similarities to the geometry of certain toric Calabi-Yau threefolds.Comment: 88 pages, 12 figure