Special Session 104: 

Continuation theorems for the periodic $\phi$-Laplacian equation and applications}

Guglielmo Feltrin
University of Turin
Italy
Co-Author(s):    
Abstract:
Using Mawhin's coincidence degree theory, we obtain some new continuation theorems which are designed to have as a natural application the study of the periodic problem for cyclic feedback type systems. Applications to vector ordinary differential equations with a $\phi$-Laplacian operator will be discussed. In particular, a continuation theorem for the periodic problem associated with $(\phi(u'))' + \lambda f(t,u,u') = 0$, under the only assumption that $\phi$ is a homeomorphism, is the key ingredient to prove multiplicity results for positive periodic solutions to an indefinite Minkowski-curvature equation. This talk is based on a joint works with A. Boscaggin (University of Turin) and F.~Zanolin (University of Udine).