Schwarzian Derivative

The Schwarzian derivative is defined by

$$D_{\rm Schwarzian} \equiv {f'''(x)\over f'(x)} -{3\over 2}\left[{f''(x)\over f'(x)}\right]^2.$$

The Feigenbaum Constant is universal for 1-D Maps if its Schwarzian derivative is Negative in the bounded interval (Tabor 1989, p. 220).

See also Feigenbaum Constant

References

Tabor, M. Chaos and Integrability in Nonlinear Dynamics: An Introduction. New York: Wiley, 1989.