Boundary-value problems with non-surjective $\phi$-Laplacian and one-sided bounded nonlinearity
Boundary-value problems with non-surjective $\phi$-Laplacian and one-sided bounded nonlinearity
Using Leray-Schauder degree theory we obtain various existence results for nonlinear boundary-value problems \begin{eqnarray*} (\phi(u'))'=f(t, u, u'),\quad l(u, u')=0 \end{eqnarray*} where $l(u, u')=0$ denotes the periodic, Neumann or Dirichlet boundary conditions on $[0,T],$ $\phi:\mathbb{R}\rightarrow (-a,a)$ is a homeomorphism, $\phi(0)=0.$