Module

CyclotomicExtension.lean

Nyll.Yamaguchi26AbfaithfulGalois.FormalHilbert90.CyclotomicExtension
2 declarations indexed from sourceView source ↗

Cyclotomic extensions and infinite orientations

Adjoining every primary root of unity gives the primary cyclotomic extension. Infinite degree of that extension forces the absolute cyclotomic orientation to have infinite image.

Declarations

Yamaguchi26AbfaithfulGalois.primaryCyclotomicExtension

The actual field obtained by adjoining every p-power root of unity.

Source context 2 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace Yamaguchi26AbfaithfulGalois
universe u
def primaryCyclotomicExtension (K : Type u) [Field K] (p : ℕ) :
    IntermediateField K (SeparableClosure K)
Yamaguchi26AbfaithfulGalois.infinite_range_absoluteCyclotomicOrientation_of_infinite_extension

Infinite degree of the cyclotomic extension forces the absolute cyclotomic orientation to have infinite image.

Source context 2 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace Yamaguchi26AbfaithfulGalois
universe u
theorem infinite_range_absoluteCyclotomicOrientation_of_infinite_extension
    (p : ℕ) [Fact p.Prime] (K : Type u) [Field K] [NeZero (p : K)]
    (hdegree : ¬ FiniteDimensional K (primaryCyclotomicExtension K p)) :
    Set.Infinite (Set.range (absoluteCyclotomicOrientation p K))