chore: Clean up index notation

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jstoobysmith 2024-10-17 11:52:49 +00:00
parent ac11a510cf
commit 3cd0980f5a
34 changed files with 0 additions and 8197 deletions

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@ -9,7 +9,6 @@ import HepLean.SpaceTime.SL2C.Basic
import HepLean.SpaceTime.LorentzVector.Modules
import HepLean.Meta.Informal
import Mathlib.RepresentationTheory.Rep
import HepLean.Tensors.Basic
import HepLean.SpaceTime.PauliMatrices.SelfAdjoint
/-!

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@ -1,368 +0,0 @@
/-
Copyright (c) 2024 Joseph Tooby-Smith. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Joseph Tooby-Smith
-/
import HepLean.SpaceTime.LorentzVector.LorentzAction
import HepLean.SpaceTime.LorentzVector.Covariant
import HepLean.Tensors.Basic
/-!
# Contractions of Lorentz vectors
We define the contraction between a covariant and contravariant Lorentz vector,
as well as properties thereof.
The structures in this file are used in `HepLean.SpaceTime.LorentzTensor.Real.Basic`
to define the contraction between indices of Lorentz tensors.
-/
noncomputable section
open TensorProduct
namespace LorentzVector
open Matrix
variable {d : } (v : LorentzVector d)
/-- The bi-linear map defining the contraction of a contravariant Lorentz vector
and a covariant Lorentz vector. -/
def contrUpDownBi : LorentzVector d →ₗ[] CovariantLorentzVector d →ₗ[] where
toFun v := {
toFun := fun w => ∑ i, v i * w i,
map_add' := by
intro w1 w2
rw [← Finset.sum_add_distrib]
refine Finset.sum_congr rfl (fun i _ => mul_add _ _ _)
map_smul' := by
intro r w
simp only [RingHom.id_apply, smul_eq_mul]
rw [Finset.mul_sum]
refine Finset.sum_congr rfl (fun i _ => ?_)
simp only [HSMul.hSMul, SMul.smul]
ring}
map_add' v1 v2 := by
apply LinearMap.ext
intro w
simp only [LinearMap.coe_mk, AddHom.coe_mk, LinearMap.add_apply]
rw [← Finset.sum_add_distrib]
refine Finset.sum_congr rfl (fun i _ => add_mul _ _ _)
map_smul' r v := by
apply LinearMap.ext
intro w
simp only [LinearMap.coe_mk, AddHom.coe_mk, LinearMap.smul_apply]
rw [Finset.smul_sum]
refine Finset.sum_congr rfl (fun i _ => ?_)
simp only [HSMul.hSMul, SMul.smul]
exact mul_assoc r (v i) (w i)
/-- The linear map defining the contraction of a contravariant Lorentz vector
and a covariant Lorentz vector. -/
def contrUpDown : LorentzVector d ⊗[] CovariantLorentzVector d →ₗ[] :=
TensorProduct.lift contrUpDownBi
lemma contrUpDown_tmul_eq_dotProduct {x : LorentzVector d} {y : CovariantLorentzVector d} :
contrUpDown (x ⊗ₜ[] y) = x ⬝ᵥ y := by
rfl
@[simp]
lemma contrUpDown_stdBasis_left (x : LorentzVector d) (i : Fin 1 ⊕ Fin d) :
contrUpDown (x ⊗ₜ[] (CovariantLorentzVector.stdBasis i)) = x i := by
simp only [contrUpDown, contrUpDownBi, lift.tmul, LinearMap.coe_mk, AddHom.coe_mk]
rw [Finset.sum_eq_single_of_mem i]
· simp only [CovariantLorentzVector.stdBasis]
erw [Pi.basisFun_apply]
simp only [Pi.single_eq_same, mul_one]
· exact Finset.mem_univ i
· intro b _ hbi
simp only [CovariantLorentzVector.stdBasis, mul_eq_zero]
erw [Pi.basisFun_apply]
simp only [Pi.single_apply, ite_eq_right_iff, one_ne_zero, imp_false]
apply Or.inr hbi
@[simp]
lemma contrUpDown_stdBasis_right (x : CovariantLorentzVector d) (i : Fin 1 ⊕ Fin d) :
contrUpDown (e i ⊗ₜ[] x) = x i := by
simp only [contrUpDown, contrUpDownBi, lift.tmul, LinearMap.coe_mk, AddHom.coe_mk]
rw [Finset.sum_eq_single_of_mem i]
· erw [Pi.basisFun_apply]
simp only [Pi.single_eq_same, one_mul]
· exact Finset.mem_univ i
· intro b _ hbi
simp only [CovariantLorentzVector.stdBasis, mul_eq_zero]
erw [Pi.basisFun_apply]
simp only [Pi.single_apply, ite_eq_right_iff, one_ne_zero, imp_false]
exact Or.intro_left (x b = 0) hbi
/-- The linear map defining the contraction of a covariant Lorentz vector
and a contravariant Lorentz vector. -/
def contrDownUp : CovariantLorentzVector d ⊗[] LorentzVector d →ₗ[] :=
contrUpDown ∘ₗ (TensorProduct.comm _ _).toLinearMap
lemma contrDownUp_tmul_eq_dotProduct {x : CovariantLorentzVector d} {y : LorentzVector d} :
contrDownUp (x ⊗ₜ[] y) = x ⬝ᵥ y := by
rw [dotProduct_comm x y]
rfl
/-!
## The unit of the contraction
-/
/-- The unit of the contraction of contravariant Lorentz vector and a
covariant Lorentz vector. -/
def unitUp : CovariantLorentzVector d ⊗[] LorentzVector d :=
∑ i, CovariantLorentzVector.stdBasis i ⊗ₜ[] LorentzVector.stdBasis i
lemma unitUp_rid (x : LorentzVector d) :
TensorStructure.contrLeftAux contrUpDown (x ⊗ₜ[] unitUp) = x := by
simp only [unitUp, LinearEquiv.refl_toLinearMap]
rw [tmul_sum]
simp only [TensorStructure.contrLeftAux, LinearEquiv.refl_toLinearMap, Fintype.sum_sum_type,
Finset.univ_unique, Fin.default_eq_zero, Fin.isValue, Finset.sum_singleton, map_add,
LinearMap.coe_comp, LinearEquiv.coe_coe, Function.comp_apply, assoc_symm_tmul, map_tmul,
contrUpDown_stdBasis_left, LinearMap.id_coe, id_eq, lid_tmul, map_sum, decomp_stdBasis']
/-- The unit of the contraction of covariant Lorentz vector and a
contravariant Lorentz vector. -/
def unitDown : LorentzVector d ⊗[] CovariantLorentzVector d :=
∑ i, LorentzVector.stdBasis i ⊗ₜ[] CovariantLorentzVector.stdBasis i
lemma unitDown_rid (x : CovariantLorentzVector d) :
TensorStructure.contrLeftAux contrDownUp (x ⊗ₜ[] unitDown) = x := by
simp only [unitDown, LinearEquiv.refl_toLinearMap]
rw [tmul_sum]
simp only [TensorStructure.contrLeftAux, contrDownUp, LinearEquiv.refl_toLinearMap,
Fintype.sum_sum_type, Finset.univ_unique, Fin.default_eq_zero, Fin.isValue,
Finset.sum_singleton, map_add, LinearMap.coe_comp, LinearEquiv.coe_coe, Function.comp_apply,
assoc_symm_tmul, map_tmul, comm_tmul, contrUpDown_stdBasis_right, LinearMap.id_coe, id_eq,
lid_tmul, map_sum, CovariantLorentzVector.decomp_stdBasis']
/-!
# Contractions and the Lorentz actions
-/
open Matrix
@[simp]
lemma contrUpDown_invariant_lorentzAction : @contrUpDown d ((LorentzVector.rep g) x ⊗ₜ[]
(CovariantLorentzVector.rep g) y) = contrUpDown (x ⊗ₜ[] y) := by
rw [contrUpDown_tmul_eq_dotProduct, contrUpDown_tmul_eq_dotProduct]
simp only [rep_apply, CovariantLorentzVector.rep_apply]
rw [Matrix.dotProduct_mulVec, vecMul_transpose, mulVec_mulVec]
simp only [LorentzGroup.subtype_inv_mul, one_mulVec]
@[simp]
lemma contrDownUp_invariant_lorentzAction : @contrDownUp d ((CovariantLorentzVector.rep g) x ⊗ₜ[]
(LorentzVector.rep g) y) = contrDownUp (x ⊗ₜ[] y) := by
rw [contrDownUp_tmul_eq_dotProduct, contrDownUp_tmul_eq_dotProduct]
rw [dotProduct_comm, dotProduct_comm x y]
simp only [rep_apply, CovariantLorentzVector.rep_apply]
rw [Matrix.dotProduct_mulVec, vecMul_transpose, mulVec_mulVec]
simp only [LorentzGroup.subtype_inv_mul, one_mulVec]
end LorentzVector
namespace minkowskiMatrix
open LorentzVector
open TensorStructure
open scoped minkowskiMatrix
variable {d : }
/-- The metric tensor as an element of `LorentzVector d ⊗[] LorentzVector d`. -/
def asTenProd : LorentzVector d ⊗[] LorentzVector d :=
∑ μ, ∑ ν, η μ ν • (LorentzVector.stdBasis μ ⊗ₜ[] LorentzVector.stdBasis ν)
lemma asTenProd_diag :
@asTenProd d = ∑ μ, η μ μ • (LorentzVector.stdBasis μ ⊗ₜ[] LorentzVector.stdBasis μ) := by
simp only [asTenProd]
refine Finset.sum_congr rfl (fun μ _ => ?_)
rw [Finset.sum_eq_single μ]
· intro ν _ hμν
rw [minkowskiMatrix.off_diag_zero hμν.symm]
exact TensorProduct.zero_smul (e μ ⊗ₜ[] e ν)
· intro a
rename_i j
exact False.elim (a j)
/-- The metric tensor as an element of `CovariantLorentzVector d ⊗[] CovariantLorentzVector d`. -/
def asCoTenProd : CovariantLorentzVector d ⊗[] CovariantLorentzVector d :=
∑ μ, ∑ ν, η μ ν • (CovariantLorentzVector.stdBasis μ ⊗ₜ[] CovariantLorentzVector.stdBasis ν)
lemma asCoTenProd_diag :
@asCoTenProd d = ∑ μ, η μ μ • (CovariantLorentzVector.stdBasis μ ⊗ₜ[]
CovariantLorentzVector.stdBasis μ) := by
simp only [asCoTenProd]
refine Finset.sum_congr rfl (fun μ _ => ?_)
rw [Finset.sum_eq_single μ]
· intro ν _ hμν
rw [minkowskiMatrix.off_diag_zero hμν.symm]
simp only [zero_smul]
· intro a
simp_all only
@[simp]
lemma contrLeft_asTenProd (x : CovariantLorentzVector d) :
contrLeftAux contrDownUp (x ⊗ₜ[] asTenProd) =
∑ μ, ((η μ μ * x μ) • LorentzVector.stdBasis μ) := by
simp only [asTenProd_diag]
rw [tmul_sum]
rw [map_sum]
refine Finset.sum_congr rfl (fun μ _ => ?_)
simp only [contrLeftAux, contrDownUp, LinearEquiv.refl_toLinearMap, tmul_smul, map_smul,
LinearMap.coe_comp, LinearEquiv.coe_coe, Function.comp_apply, assoc_symm_tmul, map_tmul,
comm_tmul, contrUpDown_stdBasis_right, LinearMap.id_coe, id_eq, lid_tmul]
exact smul_smul (η μ μ) (x μ) (e μ)
@[simp]
lemma contrLeft_asCoTenProd (x : LorentzVector d) :
contrLeftAux contrUpDown (x ⊗ₜ[] asCoTenProd) =
∑ μ, ((η μ μ * x μ) • CovariantLorentzVector.stdBasis μ) := by
simp only [asCoTenProd_diag]
rw [tmul_sum]
rw [map_sum]
refine Finset.sum_congr rfl (fun μ _ => ?_)
simp only [contrLeftAux, LinearEquiv.refl_toLinearMap, tmul_smul, LinearMapClass.map_smul,
LinearMap.coe_comp, LinearEquiv.coe_coe, Function.comp_apply, assoc_symm_tmul, map_tmul,
contrUpDown_stdBasis_left, LinearMap.id_coe, id_eq, lid_tmul]
exact smul_smul (η μ μ) (x μ) (CovariantLorentzVector.stdBasis μ)
@[simp]
lemma asTenProd_contr_asCoTenProd :
(contrMidAux (contrUpDown) (asTenProd ⊗ₜ[] asCoTenProd))
= TensorProduct.comm _ _ (@unitUp d) := by
simp only [contrMidAux, LinearEquiv.refl_toLinearMap, asTenProd_diag, LinearMap.coe_comp,
LinearEquiv.coe_coe, Function.comp_apply]
rw [sum_tmul, map_sum, map_sum, unitUp]
simp only [Finset.univ_unique, Fin.default_eq_zero, Fin.isValue,
Finset.sum_singleton, map_add, comm_tmul, map_sum]
refine Finset.sum_congr rfl (fun μ _ => ?_)
rw [← tmul_smul, TensorProduct.assoc_tmul]
simp only [map_tmul, LinearMap.id_coe, id_eq, contrLeft_asCoTenProd]
rw [tmul_sum, Finset.sum_eq_single_of_mem μ, tmul_smul]
· change (η μ μ * (η μ μ * e μ μ)) • e μ ⊗ₜ[] CovariantLorentzVector.stdBasis μ = _
rw [LorentzVector.stdBasis]
erw [Pi.basisFun_apply]
simp only [Pi.single_eq_same, mul_one, η_apply_mul_η_apply_diag, one_smul]
· exact Finset.mem_univ μ
· intro ν _ hμν
rw [tmul_smul]
change (η ν ν * (η μ μ * e μ ν)) • (e μ ⊗ₜ[] CovariantLorentzVector.stdBasis ν) = _
rw [LorentzVector.stdBasis]
erw [Pi.basisFun_apply]
simp only [Pi.single_apply, mul_ite, mul_one, mul_zero, ite_smul, zero_smul,
ite_eq_right_iff, smul_eq_zero, mul_eq_zero]
exact fun a => False.elim (hμν a)
@[simp]
lemma asCoTenProd_contr_asTenProd :
(contrMidAux (contrDownUp) (asCoTenProd ⊗ₜ[] asTenProd))
= TensorProduct.comm _ _ (@unitDown d) := by
simp only [contrMidAux, LinearEquiv.refl_toLinearMap, asCoTenProd_diag,
LinearMap.coe_comp, LinearEquiv.coe_coe, Function.comp_apply]
rw [sum_tmul, map_sum, map_sum, unitDown]
simp only [Finset.univ_unique, Fin.default_eq_zero, Fin.isValue,
Finset.sum_singleton, map_add, comm_tmul, map_sum]
refine Finset.sum_congr rfl (fun μ _ => ?_)
rw [smul_tmul, TensorProduct.assoc_tmul]
simp only [tmul_smul, LinearMapClass.map_smul, map_tmul, LinearMap.id_coe, id_eq,
contrLeft_asTenProd]
rw [tmul_sum, Finset.sum_eq_single_of_mem μ, tmul_smul, smul_smul, LorentzVector.stdBasis]
· erw [Pi.basisFun_apply]
simp only [Pi.single_eq_same, mul_one, η_apply_mul_η_apply_diag, one_smul]
· exact Finset.mem_univ μ
· intro ν _ hμν
rw [tmul_smul]
rw [LorentzVector.stdBasis]
erw [Pi.basisFun_apply]
simp only [Pi.single_apply, mul_ite, mul_one, mul_zero, ite_smul, zero_smul,
ite_eq_right_iff, smul_eq_zero, mul_eq_zero]
exact fun a => False.elim (hμν a)
lemma asTenProd_invariant (g : LorentzGroup d) :
TensorProduct.map (LorentzVector.rep g) (LorentzVector.rep g) asTenProd = asTenProd := by
simp only [asTenProd, map_sum, LinearMapClass.map_smul, map_tmul, rep_apply_stdBasis,
Matrix.transpose_apply]
trans ∑ μ : Fin 1 ⊕ Fin d, ∑ ν : Fin 1 ⊕ Fin d, ∑ φ : Fin 1 ⊕ Fin d,
η μ ν • (g.1 φ μ • e φ) ⊗ₜ[] ∑ ρ : Fin 1 ⊕ Fin d, g.1 ρ ν • e ρ
· refine Finset.sum_congr rfl (fun μ _ => Finset.sum_congr rfl (fun ν _ => ?_))
rw [sum_tmul, Finset.smul_sum]
trans ∑ μ : Fin 1 ⊕ Fin d, ∑ ν : Fin 1 ⊕ Fin d, ∑ φ : Fin 1 ⊕ Fin d, ∑ ρ : Fin 1 ⊕ Fin d,
(η μ ν • (g.1 φ μ • e φ) ⊗ₜ[] (g.1 ρ ν • e ρ))
· refine Finset.sum_congr rfl (fun μ _ => Finset.sum_congr rfl (fun ν _ =>
Finset.sum_congr rfl (fun φ _ => ?_)))
rw [tmul_sum, Finset.smul_sum]
rw [Finset.sum_congr rfl (fun μ _ => Finset.sum_comm)]
rw [Finset.sum_congr rfl (fun μ _ => Finset.sum_congr rfl (fun ν _ => Finset.sum_comm))]
rw [Finset.sum_comm]
rw [Finset.sum_congr rfl (fun φ _ => Finset.sum_comm)]
trans ∑ φ : Fin 1 ⊕ Fin d, ∑ ρ : Fin 1 ⊕ Fin d, ∑ μ : Fin 1 ⊕ Fin d, ∑ ν : Fin 1 ⊕ Fin d,
((g.1 φ μ * η μ ν * g.1 ρ ν) • (e φ) ⊗ₜ[] (e ρ))
· refine Finset.sum_congr rfl (fun φ _ => Finset.sum_congr rfl (fun ρ _ =>
Finset.sum_congr rfl (fun μ _ => Finset.sum_congr rfl (fun ν _ => ?_))))
rw [smul_tmul, tmul_smul, tmul_smul, smul_smul, smul_smul]
ring_nf
rw [Finset.sum_congr rfl (fun φ _ => Finset.sum_congr rfl (fun ρ _ =>
Finset.sum_congr rfl (fun μ _ => Finset.sum_smul.symm)))]
rw [Finset.sum_congr rfl (fun φ _ => Finset.sum_congr rfl (fun ρ _ => Finset.sum_smul.symm))]
trans ∑ φ : Fin 1 ⊕ Fin d, ∑ ρ : Fin 1 ⊕ Fin d,
(((g.1 * minkowskiMatrix * g.1.transpose : Matrix _ _ _) φ ρ) • (e φ) ⊗ₜ[] (e ρ))
· refine Finset.sum_congr rfl (fun φ _ => Finset.sum_congr rfl (fun ρ _ => ?_))
apply congrFun
apply congrArg
simp only [Matrix.mul_apply, Matrix.transpose_apply]
rw [Finset.sum_comm]
refine Finset.sum_congr rfl (fun μ _ => ?_)
rw [Finset.sum_mul]
simp
open CovariantLorentzVector in
lemma asCoTenProd_invariant (g : LorentzGroup d) :
TensorProduct.map (CovariantLorentzVector.rep g) (CovariantLorentzVector.rep g)
asCoTenProd = asCoTenProd := by
simp only [asCoTenProd, map_sum, LinearMapClass.map_smul, map_tmul,
CovariantLorentzVector.rep_apply_stdBasis, Matrix.transpose_apply]
trans ∑ μ : Fin 1 ⊕ Fin d, ∑ ν : Fin 1 ⊕ Fin d, ∑ φ : Fin 1 ⊕ Fin d,
η μ ν • (g⁻¹.1 μ φ • CovariantLorentzVector.stdBasis φ) ⊗ₜ[]
ρ : Fin 1 ⊕ Fin d, g⁻¹.1 ν ρ • CovariantLorentzVector.stdBasis ρ
· refine Finset.sum_congr rfl (fun μ _ => Finset.sum_congr rfl (fun ν _ => ?_))
rw [sum_tmul, Finset.smul_sum]
trans ∑ μ : Fin 1 ⊕ Fin d, ∑ ν : Fin 1 ⊕ Fin d, ∑ φ : Fin 1 ⊕ Fin d, ∑ ρ : Fin 1 ⊕ Fin d,
(η μ ν • (g⁻¹.1 μ φ • CovariantLorentzVector.stdBasis φ) ⊗ₜ[]
(g⁻¹.1 ν ρ • CovariantLorentzVector.stdBasis ρ))
· refine Finset.sum_congr rfl (fun μ _ => Finset.sum_congr rfl (fun ν _ =>
Finset.sum_congr rfl (fun φ _ => ?_)))
rw [tmul_sum, Finset.smul_sum]
rw [Finset.sum_congr rfl (fun μ _ => Finset.sum_comm)]
rw [Finset.sum_congr rfl (fun μ _ => Finset.sum_congr rfl (fun ν _ => Finset.sum_comm))]
rw [Finset.sum_comm]
rw [Finset.sum_congr rfl (fun φ _ => Finset.sum_comm)]
trans ∑ φ : Fin 1 ⊕ Fin d, ∑ ρ : Fin 1 ⊕ Fin d, ∑ μ : Fin 1 ⊕ Fin d, ∑ ν : Fin 1 ⊕ Fin d,
((g⁻¹.1 μ φ * η μ ν * g⁻¹.1 ν ρ) • (CovariantLorentzVector.stdBasis φ) ⊗ₜ[]
(CovariantLorentzVector.stdBasis ρ))
· refine Finset.sum_congr rfl (fun φ _ => Finset.sum_congr rfl (fun ρ _ =>
Finset.sum_congr rfl (fun μ _ => Finset.sum_congr rfl (fun ν _ => ?_))))
rw [smul_tmul, tmul_smul, tmul_smul, smul_smul, smul_smul]
ring_nf
rw [Finset.sum_congr rfl (fun φ _ => Finset.sum_congr rfl (fun ρ _ =>
Finset.sum_congr rfl (fun μ _ => Finset.sum_smul.symm)))]
rw [Finset.sum_congr rfl (fun φ _ => Finset.sum_congr rfl (fun ρ _ => Finset.sum_smul.symm))]
trans ∑ φ : Fin 1 ⊕ Fin d, ∑ ρ : Fin 1 ⊕ Fin d,
(((g⁻¹.1.transpose * minkowskiMatrix * g⁻¹.1 : Matrix _ _ _) φ ρ) •
(CovariantLorentzVector.stdBasis φ) ⊗ₜ[] (CovariantLorentzVector.stdBasis ρ))
· refine Finset.sum_congr rfl (fun φ _ => Finset.sum_congr rfl (fun ρ _ => ?_))
apply congrFun
apply congrArg
simp only [Matrix.mul_apply, Matrix.transpose_apply]
rw [Finset.sum_comm]
refine Finset.sum_congr rfl (fun μ _ => ?_)
rw [Finset.sum_mul]
rw [LorentzGroup.transpose_mul_minkowskiMatrix_mul_self]
end minkowskiMatrix
end

View file

@ -6,7 +6,6 @@ Authors: Joseph Tooby-Smith
import HepLean.Meta.Informal
import HepLean.SpaceTime.SL2C.Basic
import Mathlib.RepresentationTheory.Rep
import HepLean.Tensors.Basic
import Mathlib.Logic.Equiv.TransferInstance
/-!