4 papers
Equilibrium points, periodic solutions and the Brouwer fixed point theorem for convex and non-convex domains
Guglielmo Feltrin, Fabio Zanolin
We show the direct applicability of the Brouwer fixed point theorem for the existence of equilibrium points and periodic solutions for differential systems on general domains satis…
Positive subharmonic solutions to superlinear ODEs with indefinite weight
Guglielmo Feltrin
We study the positive subharmonic solutions to the second order nonlinear ordinary differential equation \begin{equation*} u'' + q(t) g(u) = 0, \end{equation*} where has sup…
An application of coincidence degree theory to cyclic feedback type systems associated with nonlinear differential operators
Guglielmo Feltrin, Fabio Zanolin
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…
Multiple positive solutions of a Sturm-Liouville boundary value problem with conflicting nonlinearities
Guglielmo Feltrin
We study the second order nonlinear differential equation \begin{equation*} u"+ \sum_{i=1}^{m} α_{i} a_{i}(x)g_{i}(u) - \sum_{j=0}^{m+1} β_{j} b_{j}(x)k_{j}(u) = 0, \end{equation*}…