Riccati-Ermakov systems and explicit solutions for variable coefficient reaction-diffusion equations

Abstract: We present several families of nonlinear reaction diffusion equations with variable coefficients including Fisher-KPP and Burgers type equations. Special exact solutions such as traveling wave, rational, triangular wave and N-wave type solutions are shown. By means of similarity transformations the variable coefficients are conditioned to satisfy Riccati or Ermakov systems of equations. When the Riccati system is used, conditions are established so that finite-time singularities might occur. The solutions presented contain multi-parameters providing a control on the dynamics of the solutions. In the suplementary material, we provide a computer algebra verification of the solutions and exemplify nontrivial dynamics of the solutions.