OAI/NumberTheory/DukePrimeDegree/Arithmetic/FieldDegree.lean
1 declarations, 0 contain sorry, 0 declared as axioms
Prime degree excludes quadratic subfields
The tower-degree formula excludes the quadratic subfields in Stark's exceptional-zero alternative, giving the field-degree hypothesis for the uniform residue estimate.
- theorem
OAI.DukePrimeDegree.no_quadratic_intermediateFieldline 18Source documentation
A number field of prime degree at least three has no quadratic intermediate field over the rationals.
theorem no_quadratic_intermediateField {K : Type*} [Field K] [NumberField K] (hprime : (Module.finrank ℚ K).Prime) (hdegree : 3 ≤ Module.finrank ℚ K) (F : IntermediateField ℚ K) : Module.finrank ℚ F ≠ 2 := by …