![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Stereoprojzero.svg/640px-Stereoprojzero.svg.png&w=640&q=50)
Birational geometry
Field of algebraic geometry / From Wikipedia, the free encyclopedia
In mathematics, birational geometry is a field of algebraic geometry in which the goal is to determine when two algebraic varieties are isomorphic outside lower-dimensional subsets. This amounts to studying mappings that are given by rational functions rather than polynomials; the map may fail to be defined where the rational functions have poles.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Stereoprojzero.svg/220px-Stereoprojzero.svg.png)