Geometric study of Gardner equation
  In this paper, we apply the method of approximate transformation groups proposed by Baikov, Gaziziv and Ibragimov, to compute the first-order approximate symmetry for the Gardner equations with the small parameters. We compute the optimal system and analyze some invariant solutions of These types of equations. Particularly, general forms of approximately Galilean-invariant solutions have been computed. 
Mehdi Nadjafikhah, Ardavan Mokhtary
math.AP math-ph math.DG math.MP