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Theorems · Theorem · number theory

gaussSum_sq

∀ {R : Type u} [inst : Field R] [inst_1 : Fintype R] {R' : Type v} [inst_2 : CommRing R'] [IsDomain R']
  {χ : MulChar R R'},
  χ ≠ 1 → χ.IsQuadratic → ∀ {ψ : AddChar R R'}, ψ.IsPrimitive → gaussSum χ ψ ^ 2 = χ (-1) * ↑(Fintype.card R)

When χ is a nontrivial quadratic character, then the square of gaussSum χ ψ is χ(-1) times the cardinality of R.

Defined in
Mathlib.NumberTheory.GaussSum
Cited by
1 results in Mathlib
Foundations
Depth 78 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
FieldFintypeCommRingIsDomain

Around this declaration

Dashed lines are statement dependencies; solid lines are citations in proofs.

Cites20

Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.

  • DFunLike.coestatement and proof · cited by 62,936
  • CommRingstatement and proof · cited by 17,173
  • Fintypestatement and proof · cited by 7,736
  • Fieldstatement and proof · cited by 7,404
  • mul_commproof · cited by 2,262
  • IsDomainstatement and proof · cited by 2,196
  • Units.valproof · cited by 1,966
  • Fintype.cardstatement and proof · cited by 1,386
  • AddCharstatement and proof · cited by 286
  • MulCharstatement and proof · cited by 186
  • pow_twoproof · cited by 150
  • gaussSumstatement and proof · cited by 29

Cited by1

Results whose statement or proof uses this declaration.