Parametric solution method for self-consistency equations and order parameter equations derived from nonlinear Fokker–Planck equations

We propose a parametric approach to solve self-consistency equations that naturally arise in many-body systems described by nonlinear Fokker–Planck equations in general and nonlinear Vlasov–Fokker–Planck equations of Haissinski type in particular. We demonstrate for the Hess–Doi–Edwards model and the McMillan model of nematic and smectic liquid crystals that the parametric approach can be used to compute bifurcation diagrams and critical order parameters for systems exhibiting one or more than one order parameters. In addition, we show that in the context of the parametric approach solutions of the Haissinski model can be studied from the perspective of a pseudo order parameter.