Extremal Projector and Dynamical Twist

We describe a relation between the dynamical twist $J(\lambda)$ and the extremal projector for simple Lie algebras. This correspondence finds two obvious applications: first, the solution of the Arnaudon–Buffenoir–Ragoucy–Roche equation can be obtained from the known multiplicative expression for the extremal projector; second, the structure constants are determined by the matrix coefficients of the dynamical twist.