Squishing Dimers on the Hexagon Lattice

Abstract

We describe an operation on dimer configurations on the hexagon lattice, called "squishing", and use this operation to explain some of the properties of the Donaldson-Thomas partition function for the orbifold ${\Bbb C}^3 / {\Bbb Z}_2 \times {\Bbb Z}_2$ (a certain four-variable generating function for plane partitions which comes from algebraic geometry).