> The new approaches disguise that nonlinearity as a more digestible set of linear approximations, though their exact methods vary considerably. The idea of re

> The new approaches disguise that nonlinearity as a more digestible set of linear approximations, though their exact methods vary considerably. The idea of reducing a nonlinear problem to a sequence of linear problems is the bread and butter of nonlinear PDE, both theoretical and numerical. The trick is always in the reduction and I guess here you want the reduction to have a nice "quantum" solution. I'm not qualified to say what either of these papers have to do with "chaos". You'll notice that this word only appears in one of the papers and then only once in the intro.