Nonlocal symmetries of integrable two-field divergent evolutionary systems
arXiv:0803.1425 · doi:10.1007/s11232-008-0105-9
Abstract
Nonlocal symmetries for exactly integrable two-field evolutionary systems of the third order have been computed. Differentiation of the nonlocal symmetries with respect to spatial variable gives a few nonevolutionary systems for each evolutionary system. Zero curvature representations for some new nonevolution systems are presented.