Coxeter Group Actions on Interacting Particle Systems

We provide a conceptual proof of the color-position symmetry of colored ASEP by relating it to the actions of Coxeter groups. The group action (and hence the color-position symmetry) also applies to more general interacting particle systems, such as the colored ASEP(q,j) or systems with open boundary conditions. As an application, we find the asymptotics of the expected positions of second-class particles in the ASEP(q,j).