theorem
Finset.val.map_coe
{α : Type u_1}
{β : Type u_2}
{γ : Type u_2}
(f : α → β)
(s : Finset α)
[CoeTC β γ]
:
Multiset.map CoeTC.coe (Multiset.map f s.val) = Multiset.map CoeTC.coe (Multiset.map f s.val)
theorem
Finset.val.map_coe'
{α : Type u_1}
{β : Type u_2}
{γ : Type u_2}
(f : α → β)
(s : Finset α)
[Coe β γ]
:
Multiset.map (fun (a : β) => Coe.coe a) (Multiset.map f s.val) = Multiset.map (fun (a : β) => Coe.coe a) (Multiset.map f s.val)
noncomputable def
Matrix.IsAlmostHermitian.matrix
{𝕜 : Type u_1}
[RCLike 𝕜]
{n : Type u_2}
{x : Matrix n n 𝕜}
(hx : x.IsAlmostHermitian)
:
Matrix n n 𝕜
Equations
- hx.matrix = (fun (y : Matrix n n 𝕜) (x : Classical.choose hx • y = x ∧ y.IsHermitian) => y) (Classical.choose ⋯) ⋯
Instances For
noncomputable def
Matrix.IsAlmostHermitian.eigenvalues
{n : Type u_1}
{𝕜 : Type u_2}
[RCLike 𝕜]
[Fintype n]
[DecidableEq n]
{x : Matrix n n 𝕜}
(hx : x.IsAlmostHermitian)
:
n → 𝕜
Instances For
noncomputable def
Matrix.IsAlmostHermitian.spectra
{n : Type u_1}
{𝕜 : Type u_2}
[RCLike 𝕜]
[Fintype n]
[DecidableEq n]
{A : Matrix n n 𝕜}
(hA : A.IsAlmostHermitian)
:
Multiset 𝕜
Equations
- hA.spectra = Multiset.map (fun (i : n) => hA.eigenvalues i) Finset.univ.val
Instances For
noncomputable def
Matrix.IsHermitian.spectra
{n : Type u_1}
{𝕜 : Type u_2}
[RCLike 𝕜]
[Fintype n]
[DecidableEq n]
{A : Matrix n n 𝕜}
(hA : A.IsHermitian)
:
Equations
- hA.spectra = Multiset.map (fun (i : n) => hA.eigenvalues i) Finset.univ.val
Instances For
theorem
Matrix.IsHermitian.spectra_coe
{n : Type u_1}
{𝕜 : Type}
[RCLike 𝕜]
[Fintype n]
[DecidableEq n]
{A : Matrix n n 𝕜}
(hA : A.IsHermitian)
:
Multiset.map RCLike.ofReal hA.spectra = Multiset.map RCLike.ofReal (Multiset.map (fun (i : n) => hA.eigenvalues i) Finset.univ.val)
theorem
Matrix.IsHermitian.mem_coe_spectra_diagonal
{n : Type u_1}
{𝕜 : Type}
[RCLike 𝕜]
[Fintype n]
[DecidableEq n]
{A : n → 𝕜}
(hA : (Matrix.diagonal A).IsHermitian)
(x : 𝕜)
:
x ∈ Multiset.map RCLike.ofReal hA.spectra ↔ ∃ (i : n), A i = x
theorem
Matrix.IsHermitian.spectra_set_eq_spectrum
{n : Type u_1}
{𝕜 : Type}
[RCLike 𝕜]
[Fintype n]
[DecidableEq n]
{A : Matrix n n 𝕜}
(hA : A.IsHermitian)
:
{x : 𝕜 | x ∈ Multiset.map RCLike.ofReal hA.spectra} = spectrum 𝕜 (Matrix.toLin' A)
theorem
Matrix.IsHermitian.of_innerAut
{n : Type u_1}
{𝕜 : Type u_2}
[RCLike 𝕜]
[Fintype n]
[DecidableEq n]
{A : Matrix n n 𝕜}
(hA : A.IsHermitian)
(U : ↥(Matrix.unitaryGroup n 𝕜))
:
((Matrix.innerAut U) A).IsHermitian
theorem
Matrix.IsAlmostHermitian.of_innerAut
{n : Type u_1}
{𝕜 : Type u_2}
[RCLike 𝕜]
[Fintype n]
[DecidableEq n]
{A : Matrix n n 𝕜}
(hA : A.IsAlmostHermitian)
(U : ↥(Matrix.unitaryGroup n 𝕜))
:
((Matrix.innerAut U) A).IsAlmostHermitian
theorem
Matrix.isAlmostHermitian_iff_of_innerAut
{n : Type u_1}
{𝕜 : Type u_2}
[RCLike 𝕜]
[Fintype n]
[DecidableEq n]
{A : Matrix n n 𝕜}
(U : ↥(Matrix.unitaryGroup n 𝕜))
:
A.IsAlmostHermitian ↔ ((Matrix.innerAut U) A).IsAlmostHermitian
def
Matrix.IsAlmostHermitian.HasAlmostEqualSpectraTo
{n : Type u_1}
{𝕜 : Type u_2}
[RCLike 𝕜]
[Fintype n]
[DecidableEq n]
{x : Matrix n n 𝕜}
{y : Matrix n n 𝕜}
(hx : x.IsAlmostHermitian)
(hy : y.IsAlmostHermitian)
:
we say a matrix $x$ has almost equal spectra to another matrix $y$ if there exists some scalar $0\neq\beta \in \mathbb{C}$ such that $x$ and $\beta y$ have equal spectra