# gravitational instanton

> four-dimensional complete Riemannian manifold satisfying the vacuum Einstein equations

**Wikidata**: [Q5597999](https://www.wikidata.org/wiki/Q5597999)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Gravitational_instanton)  
**Source**: https://4ort.xyz/entity/gravitational-instanton