This document may be downloaded, read, stored and printed for your own use within the limits of § 53 UrhG but it may not be distributed via the internet or passed on to external parties.Dieses Dokument darf im Rahmen von § 53 UrhG zum eigenen Gebrauch kostenfrei heruntergeladen, gelesen, gespeichert und ausgedruckt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden.Savescu, Simona Blanca2016-03-242019-06-2820100946-8633https://doi.org/10.34657/1907https://oa.tib.eu/renate/handle/123456789/2569The boundary function method for a singularly perturbed time dependent reaction-diffusion problem with Neumann boundary conditions is modified by means of a small parameter (p) featuring in the layer functions, which allows the indication of their exponential decay rates. These functions derived by first order perturbation theory are the ingredients of upper and lower solutions providing existence of solution in the absence of a maximum principle. This solution is also uniqueapplication/pdfeng510Time-dependent semilinear reaction-diffusionsingular perturbationmaximum principle (lack of)upper and lower solutionsboundary functionReport