Dynamics of polynomial systems at infinity.
Dynamics of species in a nonautonomous Lotka-Volterra system.
Dynamics of systems with Preisach memory near equilibria
We consider autonomous systems where two scalar differential equations are coupled with the input-output relationship of the Preisach hysteresis operator, which has an infinite-dimensional memory. A prototype system of this type is an LCR electric circuit where the inductive element has a ferromagnetic core with a hysteretic relationship between the magnetic field and the magnetization. Further examples of such systems include lumped hydrological models with two soil layers; they can also appear...
Dynamics of the tumor-immune system competition - the effect of time delay
The model analyzed in this paper is based on the model set forth by V.A. Kuznetsov and M.A. Taylor, which describes a competition between the tumor and immune cells. Kuznetsov and Taylor assumed that tumor-immune interactions can be described by a Michaelis-Menten function. In the present paper a simplified version of the Kuznetsov-Taylor model (where immune reactions are described by a bilinear term) is studied. On the other hand, the effect of time delay is taken into account in order to achieve...
Dynamics of Tuberculosis: The effect of Direct Observation Therapy Strategy (DOTS) in Nigeria
This paper presents mathematical models for tuberculosis and its dynamics under the implementation of the direct observation therapy strategy (DOTS) in Nigeria. The models establish conditions for the eradication of tuberculosis in Nigeria based on the fraction of detected infectious individuals placed under DOTS for treatment. Both numerical and qualitative analysis of the models were carried out and the effect of the fraction of detected cases of active TB on the various epidemiological classes...
Dynamics on Character Varieties and Malgrange irreducibility of Painlevé VI equation
We consider representations of the fundamental group of the four punctured sphere into . The moduli space of representations modulo conjugacy is the character variety. The Mapping Class Group of the punctured sphere acts on this space by symplectic polynomial automorphisms. This dynamical system can be interpreted as the monodromy of the Painlevé VI equation. Infinite bounded orbits are characterized: they come from -representations. We prove the absence of invariant affine structure (and invariant...
Dynamique et formes normales d’équations différentielles implicites
Dans cet article on cherche à comprendre la dynamique locale d’équations différentielles implicites de la forme , où est un germe de fonction sur (où ou ), au voisinage d’un point singulier. Pour cela on utilise la relation intime entre les systèmes implicites et les champs liouvilliens. La classification par transformation de contact des équations implicites provient de la classification symplectique des champs liouvilliens. On utilise alors toute la théorie des formes normales pour les...
Ecuaciiones disipativas, conjuntos absorbentes y atractores
Ecuaciones de evolución con retardo variable.
Este trabajo tiene como objeto presentar resultados de existencia global de soluciones para ciertas ecuaciones diferenciales funcionales asociadas a procesos con retardo variable. El principal argumento será la aplicación de ciertas estimaciones puntuales sobre las soluciones de una ecuación diferencial escalar.
Editorial: Abstract differential and difference equations.
Editors’ preface for the topical issue “Topics in Nonlinear Analysis”
Effect of nonlinear perturbations on second order linear nonoscillatory differential equations.
Effect of randomly fluctuating environment on autotroph-herbivore model system.
Effect of time delay on a detritus-based ecosystem.
Effect on persistence of intra-specific competition in competition models.
Effective Computation of Periodic Orbits and Bifurcation Diagrams in Delay Equations.
Effective computation of the first Lyapunov quantities for a planar differential equation
We take advantage of the complex structure to compute in a short way and without using any computer algebra system the Lyapunov quantities and for a general smooth planar system.
Effective criterion for the transformation of linear functional-differential equations of first order into canonical form with constant coefficients and deviations
Effective estimates for global relations on Euler-type series
Effective finding of the solutions of the form for the differential equations of the finite and infinite order