incompressible-fluid-equations
《incompressible-fluid-equations》 · 第 25–26 页 · Example 2.11「The Segre Maps」
The Segre maps $\sigma:\mathbb P^n\times\mathbb P^m\to\mathbb P^{(n+1)(m+1)-1}$ are defined by sending a pair $([X],[Y])$ to the point whose coordinates are the pairwise products of the coordinates $X_i$ and $Y_j$. The image of the Segre map is an algebraic variety, called a Segre variety.