Compression–Expansion Fixed Point Theorems for Decomposable Maps and Applications to Discontinuous ϕ-Laplacian problems

In this paper, we prove new compression–expansion type fixed point theorems in cones for the so-called decomposable maps, that is, compositions of two upper semicontinuous multivalued maps. As an application, we obtain existence and localization of positive solutions for a differential equation with ϕ-Laplacian and discontinuous nonlinearity subject to multi-point boundary conditions. As far as we are aware, the existence results are new even in the classical case of continuous nonlinearitiesJorge Rodríguez-López was partially supported by Xunta de Galicia ED431C 2019/02S

Topological methods for discontinuous operators and applications

Topological methods are crucial in nonlinear analysis, especially in the study of existence of solutions to diverse boundary value problems. As a well–known fact, continuity is a basic assumption in the classical theory and the clearest limitation of its applicability. That is why most discontinuous differential equations fall outside its scope because the corresponding fixed point operators are not continuous. The main goal of this thesis is to introduce a new definition of topological degree which applies for a wide class of non necessarily continuous operators. This generalization is based on the degree theory for upper semicontinuous multivalued mappings. As a consequence, new fixed point theorems for this class of discontinuous operators are derived. This new theory for discontinuous operators is combined with classical techniques in nonlinear analysis in order to obtain existence, localization and multiplicity results for discontinuous differential equations

Fractional Differential Equations, Inclusions and Inequalities with Applications

During the last decade, there has been an increased interest in fractional differential equations, inclusions, and inequalities, as they play a fundamental role in the modeling of numerous phenomena, in particular, in physics, biomathematics, blood flow phenomena, ecology, environmental issues, viscoelasticity, aerodynamics, electrodynamics of complex medium, electrical circuits, electron-analytical chemistry, control theory, etc. This book presents collective works published in the recent Special Issue (SI) entitled "Fractional Differential Equation, Inclusions and Inequalities with Applications" of the journal Mathematics. This Special Issue presents recent developments in the theory of fractional differential equations and inequalities. Topics include but are not limited to the existence and uniqueness results for boundary value problems for different types of fractional differential equations, a variety of fractional inequalities, impulsive fractional differential equations, and applications in sciences and engineering

A generalization of the Petryshyn-Leggett-Williams fixed point theorem with applications to integral inclusions

10.1016/S0096-3003(00)00077-1Applied Mathematics and Computation1232263-274AMHC