>[!abstract]
>The Feigenbaum constant ($\delta \approx 4.6692$) is a mathematical constant that describes the limit of the ratio of the distances between successive bifurcation points in a period-doubling cascade that leads to chaos. It is a fundamental constant in chaos theory, indicative of a universal behavior found in various dynamical systems, such as the [[logistic map]]. Other maps also reproduce this ratio; in this sense, the Feigenbaum constant $\delta$ in bifurcation theory is analogous to $π$ in geometry and $e$ in calculus.
>[!related]
>- **North** (upstream): [[Bifurcation theory]]
>- **West** (similar): [[Logistic map]]
>- **East** (different): —
>- **South** (downstream): —