2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/75464Using simple facts from harmonic analysis, namely Bernstein inequality and Plansherel isometry, we prove that the pseudodifferential equation $Δ^αu+Vu=0$ improves the Sobolev regularity of solutions provided the potential $V$ is integrable with the critical power $n/2α>1$.Analysis of PDEsDifferential Geometry35J60; 58J05; 58J40text