Imports
/- Copyright (c) 2026 Joseph Tooby-Smith. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Joseph Tooby-Smith -/ module public import Physlib.Relativity.Fermions.Weyl.LeftHanded public import Physlib.Relativity.Fermions.Weyl.RightHanded public import Physlib.Relativity.Fermions.Weyl.DualLeftHanded public import Physlib.Relativity.Fermions.Weyl.DualRightHanded

Duals for fermions

In this file we give the relationship between Weyl fermions and their duals.

@[expose] public section

Duals of Weyl fermions

The dual of LeftHandedWeyl is DualLeftHandedWeyl, and the dual of RightHandedWeyl is DualRightHandedWeyl.

The morphism between the representation leftHanded and the representation dualLeftHanded defined by multiplying an element of leftHanded by the matrix εᵃ⁰ᵃ¹ = !![0, 1; -1, 0]].

M:SL(2, )ψ:LeftHandedWeyl!![0 * M 0 0 + 1 * M 1 0, 0 * M 0 1 + 1 * M 1 1; -1 * M 0 0 + 0 * M 1 0, -1 * M 0 1 + 0 * M 1 1] = !![!![M 1 1, -M 0 1; -M 1 0, M 0 0] 0 0, !![M 1 1, -M 0 1; -M 1 0, M 0 0] 0 1; !![M 1 1, -M 0 1; -M 1 0, M 0 0] 1 0, !![M 1 1, -M 0 1; -M 1 0, M 0 0] 1 1] * !![0, 1; -1, 0] All goals completed! 🐙
lemma LeftHandedWeyl.dual_hom_apply (ψ : LeftHandedWeyl) : LeftHandedWeyl.dual ψ = DualLeftHandedWeyl.toFin2ℂEquiv.symm (!![0, 1; -1, 0] *ᵥ ψ.toFin2ℂ) := rfl

The morphism from dualLeftHanded to leftHanded defined by multiplying an element of DualLeftHandedWeyl by the matrix εₐ₁ₐ₂ = !![0, -1; 1, 0].

M:SL(2, )ψ:DualLeftHandedWeyl!![0, -1; 1, 0] * !![!![M 1 1, -M 0 1; -M 1 0, M 0 0] 0 0, !![M 1 1, -M 0 1; -M 1 0, M 0 0] 0 1; !![M 1 1, -M 0 1; -M 1 0, M 0 0] 1 0, !![M 1 1, -M 0 1; -M 1 0, M 0 0] 1 1] = !![M 0 0 * 0 + M 0 1 * 1, M 0 0 * -1 + M 0 1 * 0; M 1 0 * 0 + M 1 1 * 1, M 1 0 * -1 + M 1 1 * 0] All goals completed! 🐙
lemma DualLeftHandedWeyl.dual_hom_apply (ψ : DualLeftHandedWeyl) : DualLeftHandedWeyl.dual ψ = LeftHandedWeyl.toFin2ℂEquiv.symm (!![0, -1; 1, 0] *ᵥ ψ.toFin2ℂ) := rfl

The equivalence between the representation leftHanded and the representation dualLeftHanded defined by multiplying an element of leftHanded by the matrix εᵃ⁰ᵃ¹ = !![0, 1; -1, 0]].

ψ:DualLeftHandedWeylDualLeftHandedWeyl.toFin2ℂEquiv.symm ψ.toFin2ℂ = ψ All goals completed! 🐙

leftHandedDualEquiv acting on an element ψ : leftHanded corresponds to multiplying ψ by the matrix !![0, 1; -1, 0].

lemma LeftHandedWeyl.dualEquiv_hom_hom_apply (ψ : LeftHandedWeyl) : LeftHandedWeyl.dualEquiv ψ = DualLeftHandedWeyl.toFin2ℂEquiv.symm (!![0, 1; -1, 0] *ᵥ ψ.toFin2ℂ) := rfl

The inverse of leftHandedDualEquiv acting on an elementψ : dualLeftHanded corresponds to multiplying ψ by the matrix !![0, -1; 1, 0].

lemma LeftHandedWeyl.dualEquiv_inv_hom_apply (ψ : DualLeftHandedWeyl) : LeftHandedWeyl.dualEquiv.symm ψ = LeftHandedWeyl.toFin2ℂEquiv.symm (!![0, -1; 1, 0] *ᵥ ψ.toFin2ℂ) := rfl

The linear equivalence between rightHandedWeyl and DualRightHandedWeyl given by multiplying an element of rightHandedWeyl by the matrix εᵃ⁰ᵃ¹ = !![0, 1; -1, 0]].

informal_definition RightHandedWeyl.dualEquiv where deps := [``RightHandedWeyl, ``DualRightHandedWeyl] tag := "6VZR4"

The linear equivalence rightHandedWeylDualEquiv is equivariant with respect to the action of SL(2,C) on rightHandedWeyl and DualRightHandedWeyl.

informal_lemma RightHandedWeyl.dualEquiv_equivariant where deps := [``RightHandedWeyl.dualEquiv] tag := "6VZSG"