2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/80960The extended Fisher Kolmogorov equation $u_t = u_{xx} - γu_{xxxx} + f(u)$ with arbitrary positive $f(u)$, satisfying $f(0) = f(1) =0$, has monotonic traveling fronts for $γ< 1/12$. We find a simple lower bound on the speed of the fronts which allows to assess the validity of linear marginal stability.3 pages, no figuresPattern Formation and Solitonstext