Imports
/- Copyright (c) 2026 Axiomatic-AI. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Matteo Cipollina, Krystian Nowakowski -/ module public import Physlib.QuantumMechanics.Operators.Unbounded

Eigenvectors of partial linear maps

Main definitions

    LinearPMap.IsEigenvector: a nonzero domain vector satisfying T ψ = μ • ψ.

@[expose] public section

A nonzero vector in the domain of T satisfying T ψ = μ • ψ.

def IsEigenvector (T : H →ₗ.[ℂ] H) (ψ : T.domain) (μ : ℂ) : Prop := T ψ = μ • (ψ : H) ∧ (ψ : H) ≠ 0

The eigenvalue equation for a partial-map eigenvector.

lemma IsEigenvector.apply_eq {T : H →ₗ.[ℂ] H} {ψ : T.domain} {μ : ℂ} (hψ : T.IsEigenvector ψ μ) : T ψ = μ • (ψ : H) := hψ.1

A partial-map eigenvector is nonzero.

lemma IsEigenvector.ne_zero {T : H →ₗ.[ℂ] H} {ψ : T.domain} {μ : ℂ} (hψ : T.IsEigenvector ψ μ) : (ψ : H) ≠ 0 := hψ.2