Even root matrix det ne zero
ProvedD1Bound5.even_root_matrix_det_ne_zerodiophantine-tuplesnumber-theory
The even-dimensional integral root matrix is nonsingular over the full integer ring of every quadratic number field. No quotient properness assumption is added: the explicit reduction has a nontrivial target.
Preamble
import Mathlib.Algebra.CharP.Frobenius import Mathlib.Algebra.CharP.Two import Mathlib.Algebra.QuadraticAlgebra.Basic import Mathlib.Algebra.Ring.Basic import Mathlib.Algebra.Ring.Equiv import Mathlib.Analysis.Complex.Norm import Mathlib.Data.Finset.Card import Mathlib.Data.Int.GCD import Mathlib.Data.ZMod.Basic import Mathlib.LinearAlgebra.Dimension.Free import Mathlib.LinearAlgebra.Matrix.SchurComplement import Mathlib.NumberTheory.NumberField.InfinitePlace.TotallyRealComplex import Mathlib.NumberTheory.NumberField.Norm import Mathlib.Tactic.Linarith import Mathlib.Tactic.LinearCombination
Formal statement
section
open scoped NumberField BigOperators
open Matrix Module
namespace D1Bound5
theorem _root_.D1Bound5.even_root_matrix_det_ne_zero {K n : Type*} [Field K] [NumberField K]
[Fintype n] [DecidableEq n] (hK : finrank ℚ K = 2)
(hn : Even (Fintype.card n)) (v : n → 𝓞 K) (M : Matrix n n (𝓞 K))
(hd : ∀ i, M i i = v i)
(hs : ∀ i j, i ≠ j → (M i j)^2 = v i*v j+1) : M.det ≠ 0 := by sorry
end D1Bound5
end
Source
D1Bound5/EvenDeterminant.lean, lines 80-106, SHA-256 8be5563bc593805dbec0a0a77973231e6167cbe9b0c64e31ce73f3d46b08cc4c. Project: https://github.com/tomislav-math/d1-bound5-lean