nLab
rational variety

A nn-dimensional algebraic kk-variety MM is rational if there is a birational map MP k nM\to P^n_k to the projective space. A variety is irrational if it is not rational. It is often a difficult question wheather some concrete example of a variety is rational.

Revised on May 19, 2010 18:27:58 by Zoran Škoda (161.53.130.104)