---
tag: W2FNJ4KBYT
kind: concept
name: Intermittency
msc: [37G35, 37D45]
sources:
  - url: https://en.wikipedia.org/wiki/Intermittency
same_as:
  wikidata: Q1666248
  wikipedia: Intermittency
---

## Summary

Intermittency is a behaviour of dynamical systems in which long phases of nearly regular motion are interrupted at irregular times by short chaotic bursts.
It typically appears just past a bifurcation at which a stable [[periodic orbit|0AA97XA70K]] disappears or loses stability.
Pomeau and Manneville classified the common cases into types I, II and III, after the kind of bifurcation involved.
Intermittency is one of the standard routes from regular motion to chaos, next to period doubling.

## Explanations

### L1 human

Picture a signal that looks almost periodic for a long time, then goes wild for a moment, then calms down again.
The calm phases happen because the system passes through a narrow channel near a periodic orbit that has just vanished, and it moves slowly there.
The bursts happen when it leaves the channel and wanders chaotically before being reinjected.
The closer the parameter is to the bifurcation, the longer the calm phases last.