---
tag: 0GXMPDNYX3
kind: concept
name: Laurent series
aliases: [laurent-expansion]
msc: [30B10]
sources:
  - url: https://en.wikipedia.org/wiki/Laurent_series
    locator: lead section
same_as:
  wikidata: Q425432
  wikipedia: Laurent series
---

## Summary

A Laurent series is a series $\sum_{n \in \mathbb{Z}} a_n (z - c)^n$ with powers of $z - c$ of all integer degrees, see the [[definition|0X3XD2ATB0]].
It represents holomorphic functions on annuli, also near isolated singularities where a Taylor series does not exist.