# Vertex models of statistical mechanics

• Norm of a bound state is proportional to the Jacobian.
• In one dimensional fermi Hubbard model the square of the norm of Bethe wave function is also proportional to the determinant of second derivatives of Yang's action .
• The R-matrix for Zhiber-Shabat-Mikhailov model was discovered in 1981. Domain wall boundary conditions for 19 vertex model was introduced and determinant representation obtained
• IK loop model is used as a floor decoration of Vienna airport. Look at an illustration