OAI/Geometry/EinsteinFour/JacobiNormalized.lean

GitHub source file

6 declarations, 0 contain sorry, 0 declared as axioms

Removing the zero of the Jacobi matrix at its initial endpoint.

  1. def OAI.PositiveEinsteinFour.Jacobi.normalizedJacobi line 14
  2. theorem OAI.PositiveEinsteinFour.Jacobi.normalizedJacobi_zero line 16
  3. theorem OAI.PositiveEinsteinFour.Jacobi.normalizedJacobi_pos line 20
  4. theorem OAI.PositiveEinsteinFour.Jacobi.normalizedJacobi_continuousOn line 24
  5. theorem OAI.PositiveEinsteinFour.Jacobi.normalizedJacobi_isUnit line 35

    Source documentation

    Preconjugacy gives invertibility of the normalized curve on the closed interval, including its value one at the initial endpoint.

    theorem normalizedJacobi_isUnit {J : ℝ → R} {t : ℝ}
        (hJ0 : J 0 = 0) (hJ : HasDerivAt J 1 0)
        (hpre : ∀ s, 0 < s → s ≤ t → IsUnit (J s)) :
        ∀ s ∈ Set.Icc 0 t, IsUnit (normalizedJacobi J s) := by
    …

    Mentions: OAI.PositiveEinsteinFour.Jacobi.normalizedJacobi

  6. theorem OAI.PositiveEinsteinFour.Jacobi.normalizedJacobi_inverse_neighborhood line 53

    Source documentation

    Uniform inverse control applies through zero without a lower time cutoff. The actual Jacobi matrix itself vanishes at zero.

    theorem normalizedJacobi_inverse_neighborhood {J : ℝ → R} {t : ℝ}
        (hc : ContinuousOn J (Set.Icc 0 t)) (hJ0 : J 0 = 0) (hJ : HasDerivAt J 1 0)
        (hpre : ∀ s, 0 < s → s ≤ t → IsUnit (J s)) :
        ∃ K : ℝ, 0 < K ∧ ∀ s ∈ Set.Icc 0 t, ∀ A : R,
          ‖A - normalizedJacobi J s‖ ≤ 1 / (2 * K) →
          IsUnit A ∧ ‖Ring.inverse A‖ ≤ 2 * K ∧
            ‖Ring.inverse A - Ring.inverse (normalizedJacobi J s)‖ ≤
              2 * K ^ 2 * ‖A - normalizedJacobi J s‖ :=
    …

    Mentions: OAI.PositiveEinsteinFour.Jacobi.normalizedJacobi