2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/57412We prove that the essential spectrum of the operator obtained by linearization about a steady state of the Euler equations governing the motion of inviscid ideal fluid in dimension two is a vertical strip whose width is determined by the maximal Lyapunov exponent of the flow induced by the steady state.6 pagesMathematical PhysicsSpectral Theory76E99; 37D25; 47B33; 47D99The Essential Spectrum of the Linearized 2D Euler Operator is a Vertical Bandtext