13 papers
On an affinity principle by Krasnoselskii
Pablo Amster, Julián Epstein
An abstract formulation of a duality principle established by Krasnoselskii is presented. Under appropriate conditions, it shall be shown that, if the solutions of a nonlinear func…
On Landesman-Lazer conditions and the Fundamental Theorem of Algebra
Pablo Amster
We give an elementary proof of a Landesman-Lazer type result for systems by means of a shooting argument and explore its connection with the fundamental theorem of algebra.
On the Solvability of the Periodically Forced Relativistic Pendulum Equation on Time Scales
Pablo Amster, Mariel P. Kuna, Dionicio D. Santos
We study some properties of the range of the relativistic pendulum operator , that is, the set of possible continuous -periodic forcing terms for which the equat…
Multiplicity of Periodic Solutions for Dynamic Liénard Equations with Delay and Singular -laplacian of Relativistic Type
Pablo Amster, Mariel P. Kuna, Dionicio D. Santos
We study the existence and multiplicity of periodic solutions for singular -laplacian equations with delay on time scales. We prove the existence of multiple solutions using top…
Periodic solutions for a nonautonomous mathematical model of hematopoietic stem cell dynamics
Mostafa Adimy, Pablo Amster, Julián Epstein
The main purpose of this paper is to study the existence of periodic solutions for a nonautonomous differential-difference system describing the dynamics of hematopoietic stem cell…
Systems of functional-differential equations periodic solutions for systems of functional-differential semilinear equations at resonance
Pablo Amster, Julián Epstein, Arturo Sanjuán
Motivated by Lazer-Leach type results, we study the existence of periodic solutions for systems of functional-differential equations at resonance with an arbitrary even-dimensional…