2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/64403The spectral theorem of the linear 2D Euler operator in Sobolev spaces is presented as a corollary of the spectral theorem in $\ell_2$ space in [Li,00]. Study on the (dashed) line model introduced in [Li,01] is continued. Specifically, invariant manifolds for the line model is established. The corresponding line model for 2D Navier-Stokes equation is also introduced.Analysis of PDEsMathematical PhysicsDynamical SystemsFunctional AnalysisSpectral Theory76, 35text