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Gennaro Infante

Publications and source records attributed to Gennaro Infante.

At least 37 records · Page 2Linked to original sources
arXiv2020

Nonzero positive solutions of fractional Laplacian systems with functional terms

We study the existence of non-zero positive solutions of a class of systems of differential equations driven by fractional powers of the Laplacian. Our approach is based on the notion of fixed point index, and allows us to deal with non-local functional weights and functional boundary conditions. We present two examples to shed light on the type of functionals and growth conditions that can be considered with our approach.

math.AP↗
arXiv2019

Nonzero positive solutions of elliptic systems with gradient dependence and functional BCs

We discuss, by topological methods, the solvability of systems of second-order elliptic differential equations subject to functional boundary conditions under the presence of gradient terms in the nonlinearities. We prove the existence of non-negative solutions and provide a non-existence result. We present some examples to illustrate the applicability of the existence and non-existence results.

math.AP↗
arXiv2019

Positive solutions of systems of perturbed Hammerstein integral equations with arbitrary order dependence

Motivated by the study of systems of higher order boundary value problems with functional boundary conditions, we discuss, by topological methods, the solvability of a fairly general class of systems of perturbed Hammerstein integral equations, where the nonlinearities and the functionals involved depend on some derivatives. We improve and complement earlier results in the literature. We also provide some examples in order to illustrate the applicability of the theoretical results.

math.CA↗
arXiv2017

Nonzero positive solutions of a multi-parameter elliptic system with functional BCs

We prove, by topological methods, new results on the existence of nonzero positive weak solutions for a class of multi-parameter second order elliptic systems subject to functional boundary conditions. The setting is fairly general and covers the case of multi-point, integral and nonlinear boundary conditions. We also present a non-existence result. We provide some examples to illustrate the applicability our theoretical results.

math.AP↗
arXiv2017

Nontrivial solutions of systems of Hammerstein integral equations with first derivative dependence

By means of classical fixed point index, we prove new results on the existence, non-existence, localization and multiplicity of nontrivial solutions for systems of Hammerstein integral equations where the nonlinearities are allowed to depend on the first derivative. As a byproduct of our theory we discuss the existence of positive solutions of a system of third order ODEs subject to nonlocal boundary conditions. Some examples are provided in order to illustrate the applicability of the theoretical results.

math.CA↗
arXiv2017

A short course on positive solutions of systems of ODEs via fixed point index

We shall firstly study the existence of one positive solution of a model problem for one equation via the classical Krasnosel'ski\uı fixed-point theorem. Secondly we investigate how to handle this problem via the fixed point index theory for compact maps. Thirdly we illustrate how this approach can be tailored in order to deal with non-trivial solutions for systems of ODEs subject to local BCs. The case of nonlocal and nonlinear BCs will also be investigated. Finally we present some applications to the existence of radial solutions of some systems of elliptic PDEs.

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arXiv2017

Solvability of Hammerstein integral equations with applications to boundary value problems

In this paper we present some new results regarding the solvability of nonlinear Hammerstein integral equations in a special cone of continuous functions. The proofs are based on a certain fixed point theorem of Leggett and Williams type. We give an application of the abstract result to prove the existence of nontrivial solutions of a periodic boundary value problem. We also investigate, via a version of Krasnosel{\cprime}slki{\uı}'s theorem for the sum of two operators, the solvability of perturbed Hammerstein integral equations in the space of continuous functions of bounded variation in the sense of Jordan. As an application of these results, we study the solvability of a boundary value problem subject to integral boundary conditions of Riemann--Stieltjes type. Some examples are presented in order to illustrate the obtained results.

math.CA↗
arXiv2017

Nonzero radial solutions for elliptic systems with coupled functional BCs in exterior domains

We prove new results on the existence, non-existence, localization and multiplicity of nontrivial radial solutions of a system of elliptic boundary value problems on exterior domains subject to nonlocal, nonlinear, functional boundary conditions. Our approach relies on fixed point index theory. As a by-product of our theory we provide an answer to an open question posed by do {Ó}, Lorca, Sánchez and Ubilla. We include some examples with explicit nonlinearities in order to illustrate our theory.

math.AP↗
arXiv2016

New results for the Liebau phenomenon via fixed point index

We prove new results regarding the existence of positive solutions for a nonlinear periodic boundary value problem related to the Liebau phenomenon. As a consequence we obtain new sufficient conditions for the existence of a pump in a simple model. Our methodology relies on the use of classical fixed point index. Some examples are provided to illustrate our theory. We improve and complement previous results in the literature.

math.CA↗
arXiv2016

Multiple positive solutions of parabolic systems with nonlinear, nonlocal initial conditions

In this paper we study the existence, localization and multiplicity of positive solutions for parabolic systems with nonlocal initial conditions. In order to do this, we extend an abstract theory that was recently developed by the authors jointly with Radu Precup, related to the existence of fixed points of nonlinear operators satisfying some upper and lower bounds. Our main tool is the Granas fixed point index theory. We also provide a non-existence result and an example to illustrate our theory.

math.AP↗
arXiv2016

Solutions of perturbed Hammerstein integral equations with applications

By means of topological methods, we provide new results on the existence, non-existence, localization and multiplicity of nontrivial solutions for systems of perturbed Hammerstein integral equations. In order to illustrate our theoretical results, we study some problems that occur in applied mathematics, namely models of chemical reactors, beams and thermostats. We also apply our theory in order to prove the existence of nontrivial radial solutions of systems of elliptic boundary value problems subject to nonlocal, nonlinear boundary conditions.

math.CA↗
arXiv2016

Non-trivial solutions of local and non-local Neumann boundary-value problems

We prove new results on the existence, non-existence, localization and multiplicity of nontrivial solutions for perturbed Hammerstein integral equations. Our approach is topological and relies on the classical fixed point index. Some of the criteria involve a comparison with the spectral radius of some related linear operators. We apply our results to some boundary value problems with local and nonlocal boundary conditions of Neumann type. We illustrate in some examples the methodologies used.

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