OAI/NumberTheory/DukePrimeDegree/Geometry/NormalizedLattice.lean

GitHub source file

11 declarations, 0 contain sorry, 0 declared as axioms

Normalized embedded lattices

Changing the sign of the first basis vector makes an invertible real basis matrix positively oriented without changing its integer lattice. Its transpose, scaled by the inverse positive root of its determinant, then gives a point of the column-lattice homogeneous space.

  1. def OAI.DukePrimeDegree.orientBasis line 23

    Source documentation

    Reorient a row basis by changing one sign when necessary.

    noncomputable def orientBasis (B : Matrix (Fin n) (Fin n) ℝ) :
        Matrix (Fin n) (Fin n) ℝ :=
    …
  2. lemma OAI.DukePrimeDegree.det_orientBasis line 27
  3. lemma OAI.DukePrimeDegree.span_orientBasis line 37

    Source documentation

    Reorientation preserves the integer span of the rows.

    lemma span_orientBasis (B : Matrix (Fin n) (Fin n) ℝ) :
        Submodule.span ℤ (Set.range (orientBasis B)) = Submodule.span ℤ (Set.range B) := by
    …

    Mentions: OAI.DukePrimeDegree.orientBasis

  4. def OAI.DukePrimeDegree.normalizationFactor line 63

    Source documentation

    The positive covolume-normalizing scalar.

    noncomputable def normalizationFactor (B : Matrix (Fin n) (Fin n) ℝ) : ℝ :=
    …
  5. lemma OAI.DukePrimeDegree.normalizationFactor_pos line 67
  6. lemma OAI.DukePrimeDegree.det_normalizedBasis line 72
  7. def OAI.DukePrimeDegree.normalizedBasis line 80

    Source documentation

    The special-linear matrix of the normalized column lattice.

    noncomputable def normalizedBasis (B : Matrix (Fin n) (Fin n) ℝ) (hB : B.det ≠ 0) :
        RealSL n := ⟨normalizationFactor B • (orientBasis B)ᵀ, det_normalizedBasis B hB⟩

    Mentions: OAI.DukePrimeDegree.RealSL, OAI.DukePrimeDegree.normalizationFactor, OAI.DukePrimeDegree.orientBasis, OAI.DukePrimeDegree.det_normalizedBasis

  8. def OAI.DukePrimeDegree.latticePoint line 84

    Source documentation

    An invertible row basis determines a covolume-one lattice.

    noncomputable def latticePoint (B : Matrix (Fin n) (Fin n) ℝ) (hB : B.det ≠ 0) :
        LatticeSpace n := QuotientGroup.mk (normalizedBasis B hB)
    …

    Mentions: OAI.DukePrimeDegree.LatticeSpace, OAI.DukePrimeDegree.normalizedBasis

  9. def OAI.DukePrimeDegree.realEmbeddingLinear line 90

    Source documentation

    The ordered real embedding, regarded as an integer-linear map.

    noncomputable def realEmbeddingLinear (σ : EmbeddingOrder K n) :
        K →ₗ[ℤ] (Fin n → ℝ) :=
    …

    Mentions: OAI.DukePrimeDegree.EmbeddingOrder

  10. lemma OAI.DukePrimeDegree.FullLattice.span_embeddingMatrix line 94
  11. def OAI.DukePrimeDegree.FullLattice.point line 118

    Source documentation

    The normalized embedded lattice attached to a full lattice and an ordering of the real embeddings.

    noncomputable def FullLattice.point (M : FullLattice K)
        (σ : EmbeddingOrder K (Module.finrank ℚ K)) :
        LatticeSpace (Module.finrank ℚ K) := by
    …

    Mentions: OAI.DukePrimeDegree.FullLattice, OAI.DukePrimeDegree.EmbeddingOrder, OAI.DukePrimeDegree.LatticeSpace