https://collaborate.princeton.edu/en/publications/interface-asymptotics-of-eigenspace-wigner-distributions-for-the-/
Interface asymptotics of eigenspace Wigner distributions for the harmonic oscillator - Princeton...
for theharmonic oscillatorinterfaceasymptoticseigenspace
https://leanprover-community.github.io/mathlib4_docs/Mathlib/LinearAlgebra/Eigenspace/Triangularizable.html
Mathlib.LinearAlgebra.Eigenspace.Triangularizable
mathlibeigenspace