# 2019

## A variational analogue of Krasnoselskii’s cone fixed point theory

AbstractBased on Ekeland’s principle, a variational analogue of Krasnoselskii’s cone compression-expansion fixed point theorem is presented. A general scheme of…

## Positive solutions for discontinuous systems via a multivalued vector version of Krasnosel’skii’s fixed point theorem in cones

AbstractWe establish the existence of positive solutions for systems of second–order differential equations with discontinuous nonlinear terms. To this aim,…

## A four-point boundary value problem with singular φ-Laplacian

Abstract We prove that the four-point boundary value problem \[ -\left[ \phi \left( u^{\prime}\right) \right] ^{\prime}=f\left(t,u,u^{\prime}\right) ,\ u\left( 0\right) =\alpha…

## Existence results for some neutral functional integrodifferential equations with bounded delay

Abstract In this paper, we study a class of neutral functional integrodifferential equations with finite delay in Banach spaces. We…

## Positive solutions for φ-Laplace equations with discontinuous state-dependent forcing terms

AbstractThis paper concerns the existence, localization and multiplicity of positive solutions for a φ-Laplacian problem with a perturbed term that…

## Symmetric positive solutions to a singular φ-Laplace equation

AbstractThe localization of positive symmetric solutions to the Dirichlet problem for second-order ordinary differential equations involving a singular φ-Laplacian is…

## Multiplicity results for operator systems via fixed point index

AbstractWe establish existence, localization and multiplicity results of positive solutions for general operator systems in ordered Banach spaces. Our main…

## Qualitative properties of solutions for mixed type functional-differential equations with maxima

AbstractIn this paper we study some properties of the solutions of a second order system of functional-differential equations with maxima,…

## Inequalities for indices of coincidence and entropies

AbstractWe consider a probability distribution depending on a real parameter x. As functions of x, the Renyi entropy and the…

## Shift λ-Invariant Operators

AbstractThe present note is devoted to a generalization of the notion of shift invariant operators that we call it λ-invariant…