OAI/Geometry/EinsteinFour/JacobiDirichletPositivity.lean
1 declarations, 0 contain sorry, 0 declared as axioms
Positive Jacobi pivot ratios give the actual finite curvature matrix.
- theorem
OAI.PositiveEinsteinFour.Jacobi.curvatureDirichlet_posDef_of_ratiosline 16Source documentation
The positive ratios are the ordered Schur pivots of the concrete curvature Dirichlet matrix. No commutation between time samples is used.
theorem curvatureDirichlet_posDef_of_ratios {N : ℕ} {t : ℝ} (ht : t ≠ 0) (R : ℕ → NormalMatrix) (hunit : ∀ i, 1 ≤ i → i ≤ N + 1 → IsUnit (normalizedDiscrete R (t / (N + 1)) i).det) (hpos : ∀ i, 1 ≤ i → i ≤ N → (normalizedDiscrete R (t / (N + 1)) (i + 1) * (normalizedDiscrete R (t / (N + 1)) i)⁻¹).PosDef) : (curvatureDirichlet t (fun i : Fin N => R (i.val + 1) - 1)).PosDef := by …Mentions: OAI.PositiveEinsteinFour.Jacobi.NormalMatrix, OAI.PositiveEinsteinFour.Jacobi.normalizedDiscrete, OAI.PositiveEinsteinFour.Jacobi.curvatureDirichlet