Multiple solutions for mixed boundary value problems with phi-Laplacian operators

Abstract

Using Leray-Schauder degree theory and the method of upper and lower solutions we establish existence and multiplicity of solutions for problems of the form $$\displaylines{ (\phi(u'))' = f(t,u,u') \cr u(0)= u(T)=u'(0), }$$ where \(\phi\) is an increasing homeomorphism such that \(\phi(0)=0\), and f is a continuous function. For more information see https://ejde.math.txstate.edu/Volumes/2020/67/abstr.html