# Bertrand's theorem

> theorem that, among central-force potentials with bound orbits, there are only 2 types of central-force scalar potentials such that all bound orbits are closed: inverse square and radial harmonic

**Wikidata**: [Q2493651](https://www.wikidata.org/wiki/Q2493651)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Bertrand's_theorem)  
**Source**: https://4ort.xyz/entity/bertrand-s-theorem


## References

1. Freebase Data Dumps. 2013