# Denjoy's theorem on rotation number

> When a diffeomorphism of the circle is topologically conjugate to an irrational rotation

**Wikidata**: [Q4454940](https://www.wikidata.org/wiki/Q4454940)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Denjoy's_theorem_on_rotation_number)  
**Source**: https://4ort.xyz/entity/denjoy-s-theorem-on-rotation-number