Schwarzian derivative

This map has a single quadratic extremum, similar to tliat of tire WR model described in detail earlier. Such maps (togetlier witli tire technical constraint of negative Schwarzian derivative) [23] possess universal properties. In particular, tire universal (U) sequence in which tire periodic orbits appear [24] was observed in tire BZ reaction in accord witli tliis picture of tire chemical dynamics. 

Note that the first Lyapunov value is always negative for a flip-bifurcation of any periodic orbit in the logistic map. Indeed, the Schwarzian derivative ... 

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