Frenkel–Kontorova model

In condensed matter physics, the Frenkel–Kontorova model in its simplest form describes the motion of a chain of interacting particles (“atoms”) subjected to an external on-site periodic potential. The FK model is one of the simplest and richest models of classical mechanics. The nonlinearity of this model leads either to the exactly integrable sine-Gordon equation which admits topological and dynamical solitons, or to the important equation of stochastic theory, the Taylor–Chirikov map.