Hilbert’s irreducibility theorem
In this entry, is a field of characteristic zero and is an irreducible algebraic variety over .
Definition 1.
A variety satisfies the Hilbert property over if is not a thin algebraic set.
Definition 2.
A field is said to be Hilbertian if there exists an irreducible variety of which has the Hilbert property.
Theorem (Hilbert’s irreducibility theorem).
A number field is Hilbertian. In particular, for every , the affine space has the Hilbert property over .
However, the field of real numbers and the field of -adic rationals are not Hilbertian.
References
- 1 J.-P. Serre, Topics in Galois Theory
,Research Notes in Mathematics, Jones and Barlett Publishers, London.