The Frenkel–Kontorova model for dislocation dynamics from 1938 is given by a chain of atoms, where neighbouring atoms interact through a linear spring and are exposed to a smooth periodic on-site potential. A dislocation moving with constant speed corresponds to a heteroclinic travelling wave, making a transition from one well of the on-site potential to another. The ensuing system is nonlocal, nonlinear and nonconvex. We present an existence result for a class of smooth nonconvex on-site potentials. Previous results in mathematics and mechanics have been limited to on-site potentials with harmonic wells. To overcome this restriction, we propose a novel approach: we first develop a global centre manifold theory for anharmonic wave trains, then parametrise the centre manifold to obtain asymptotically correct approximations to the solution sought, and finally obtain the heteroclinic wave via a fixed point argument.
- Anharmonic wells
- Frenkel–Kontorova model
- Heteroclinic travelling waves
- Schauder fixed point theorem
ASJC Scopus subject areas
- Applied Mathematics
Buffoni, B., Schwetlick, H., & Zimmer, J. (2019). Travelling heteroclinic waves in a Frenkel-Kontorova chain with anharmonic on-site potential. Journal de Mathématiques Pures et Appliquées, 123, 1-40. https://doi.org/10.1016/j.matpur.2019.01.002