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Project-declaredLean 4.32.0 ยท mathlib@81a5d257c8e4

Schur triangulation

Matrix.schur_triangulation

Plain-language statement

Schur triangulation, Schur decomposition for matrices over an algebraically closed field. In particular, a complex matrix can be converted to upper-triangular form by a change of basis. In other words, any complex matrix is unitarily similar to an upper triangular matrix.

Exact Lean statement

lemma schur_triangulation :
    A = A.schurTriangulationUnitary * A.schurTriangulation * star A.schurTriangulationUnitary

Formal artifact

Lean source

Canonical source
Full Lean sourceLean 4
lemma schur_triangulation :    A = A.schurTriangulationUnitary * A.schurTriangulation * star A.schurTriangulationUnitary :=  let U := A.schurTriangulationUnitary  have h : U * A.schurTriangulation.val = A * U :=    let b := A.schurTriangulationBasis.toBasis    let c := (EuclideanSpace.basisFun n ๐•œ).toBasis    calc c.toMatrix b * LinearMap.toMatrix b b (toEuclideanLin A)      _ = LinearMap.toMatrix c c (toEuclideanLin A) * c.toMatrix b := by simp      _ = LinearMap.toMatrix c c (toLin c c A) * U := rfl      _ = A * U := by simp  calc A    _ = A * U * star U := by simp [mul_assoc]    _ = U * A.schurTriangulation * star U := by rw [โ† h]
Project
Physlib
License
Apache-2.0
Commit
dd43e9e65791
Source
Physlib/Mathematics/SchurTriangulation.lean:278-290

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Project-declaredLean 4.32.0

Adiabatic relation log

adiabatic_relation_log

Plain-language statement

Adiabatic relation in logarithmic form: If S(Ua,Va,N) = S(Ub,Vb,N) with N fixed, then c * log (Ua/Ub) + log (Va/Vb) = 0.

physicsquantum field theoryrelativity

Source project: Physlib

Person-level attribution pending.

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Project-declaredLean 4.32.0

Adiabatic relation Ua Ub Va Vb

adiabatic_relation_UaUbVaVb

Plain-language statement

Adiabatic relation in product form: If S(Ua,Va,N) = S(Ub,Vb,N) with N fixed, then (Ua/Ub)^c * (Va/Vb) = 1.

physicsquantum field theoryrelativity

Source project: Physlib

Person-level attribution pending.

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