I've recently read the following line in an interesting paper:

It is well-known that the cohomology ring of a flag variety $G/B$ is isomorphic to the quotient ring of the ring of polynomial functions on the Cartan sub algebra $\frak{h}$ by the ideal generated by the fundamental invariants $f_1 , . . . , f_r, r = $rank$({\frak h})$, of the Weyl group W, i.e. $$ H^∗(G/B,{Q}) \simeq {\text Sym}_Q{\frak h}^∗/(f_1, . . . , f_r). $$

I would like to ask:

(1) Does this result extend to other fields, i.e. the complex and real case?

(2) What is a good understandable reference for learning about this result?

`$A$`

, where the Weyl group is a symmetric group, while Borel (and Hiller) give a more comprehensive treatment in the language of Lie groups or algebraic groups and Weyl groups. – Jim Humphreys Nov 7 '12 at 18:11