Tropical R is the birational map that intertwines products of geometric crystals and satisfies the Yang-Baxter equation. We show that the D^{ (1)}_n tropical R introduced by the authors and its reduction to A^{ (2)}_{ 2n-1} and C^{ (1)}_n are equivalent to a system of bilinear difference equations of Hirota type. Associated tropical vertex models admit solutions in terms of tau functions of the BKP and DKP hierarchies.
Categories: math.QA math-ph math.MP nlin.SI