2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/172788We consider the well-posedness of models involving age structure and non-linear diffusion. Such problems arise in the study of population dynamics. It is shown how diffusion and age boundary conditions can be treated that depend non-linearly and possibly non-locally on the density itself. The abstract approach is depicted with examples.19 pagesAnalysis of PDEs35M10; 35K90; 92D25text