BPS States, Crystals, and Matrices

Figure 18

Refined plane partitions which count D6-D0 bound states in ℂ³. In each slice balls, which intersect a dashed or solid line, have, respectively, weight 𝑡₁ or 𝑡₂. The resulting generating function is the refined MacMahon function 𝑀_ref(𝑡₁,𝑡₂).