# spectrum

> in algebraic topology, a sequence of spaces Xᵢ with structure maps ΣXᵢ → Xᵢ₊₁ from (reduced) suspensions, such that its stable homotopy groups can be defined

**Wikidata**: [Q7575269](https://www.wikidata.org/wiki/Q7575269)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Spectrum_(topology))  
**Source**: https://4ort.xyz/entity/spectrum-q7575269