6 papers
Birkhoff-Kellogg type results in product spaces and their application to differential systems
Alessandro Calamai, Gennaro Infante, Jorge RodrÃguez-López
We provide a new version of the well-known Birkhoff-Kellogg invariant-direction Theorem in product spaces. Our results concern operator systems and give the existence of component-…
An existence result in annular regions times conical shells and its application to nonlinear Poisson systems
Gennaro Infante, Giovanni Mascali, Jorge RodrÃguez-López
We provide a new existence result for abstract nonlinear operator systems in normed spaces, by means of topological methods. The solution is located within the product of annular r…
On Krasnosel'skii-Precup fixed point theorem and eigenvalue criteria for existence of positive solutions
Laura M. Fernández-Pardo, Jorge RodrÃguez-López
We provide an alternative approach to Krasnosel'skii-Precup fixed point theorem for operator systems based on the Leray-Schauder fixed point index in cones. Our focus is on the cas…
Component-wise Krasnosel'skii type fixed point theorem in product spaces and applications
Laura M Fernández-Pardo, Jorge RodrÃguez-López
We present a version of Krasnosel'skii fixed point theorem for operators acting on Cartesian products of normed linear spaces, under cone-compression and cone-expansion conditions…
A Birkhoff-Kellogg type theorem for discontinuous operators with applications
Alessandro Calamai, Gennaro Infante, Jorge RodrÃguez-López
By means of fixed point index theory for multi-valued maps, we provide an analogue of the classical Birkhoff--Kellogg Theorem in the context of discontinuous operators acting on af…
A hybrid Krasnosel'skiÄ-Schauder fixed point theorem for systems
Gennaro Infante, Giovanni Mascali, Jorge RodrÃguez-López
We provide new results regarding the localization of the solutions of nonlinear operator systems. We make use of a combination of Krasnosel'ski\uı cone compression-expansion type…