Blowing down

From Wikipedia, the free encyclopedia

In mathematics, blowing down is a type of geometric modification in algebraic geometry. It is the inverse operation of blowing up.

On an algebraic surface, blowing down a curve lying on the surface is a typical effect of a birational transformation. The curves that blow down, to a non-singular point, are of a special kind: they are rational curves, with self-intersection number −1.

This algebra-related article is a stub. You can help Wikipedia by expanding it.
In other languages