Ruijsenaars–Schneider model
Ruijsenaars–Schneider models (short RS models) are relativistic generalizations of Calogero–Moser–Sutherland models (short CMS models), which are closely connected with relativistic field theories like the Sine-Gordon model. RS models are named after Simon N. M. Ruijsenaars and Harald Schneider. Both of them introduced the classical models in 1986 and Ruijsenaars introduced the quantum models in 1987.