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Artículo
Bifurcation from zero of a complete trajectory for non-autonomous logistic PDEs
(World Scientific Publishing, 2005-08)
In this paper we extend the well-known bifurcation theory for autonomous logistic equations to the non-autonomous equation ut − ∆u = λu − b(t)u 2 with b(t) ∈ [b0, B0], 0 < b0 < B0 < 2b0. In particular, we prove the ...
Artículo
On the existence and multiplicity of positive solutions for some indefinite nonlinear eigenvalue problem
(American Mathematical Society, 2004-06)
This paper concerns with the existence, uniqueness and/or multiplicity, and stability of positive solutions of an indefinite weight elliptic problem with concave or convex nonlinearity. We use mainly bifurcation method to ...
Artículo
Cooperative systems with any number of species
(Brown University, 2003-12)
In this paper we study the positive solutions of a cooperative system of any number of equations which considers the case of the slow diffusion and includes the Lotka-Volterra model. We determine conditions of existence of ...
Artículo
Study of the optimal harvesting control for an elliptic problem with slow diffusion
(Sociedade Brasileira de Matemática, 2007)
In this paper our aim is to present a survey of known results of an optimal control problem with concave non-quadratic cost functional and a state equation arising from population dynamics. First, we study in detail the ...
Artículo
Age-dependent diffusive Lotka-Volterra type systems
(Elsevier, 2007-03)
In this paper it is shown that the sub-supersolution method works for age-dependent diffusive nonlinear systems with non-local initial conditions. As application, we prove the existence and uniqueness of positive solution ...
Artículo
Study of an elliptic system arising from angiogenesis with chemotaxis and flux at the boundary
(Elsevier, 2008-06-15)
The main goal of this paper is to study a stationary problem arising from angiogenesis, including terms of chemotaxis and flux at the boundary of the tumor. We give sufficient conditions on terms of the data of the problems ...
Artículo
Analysis of an age-structured predator-prey model with disease in the prey
(Elsevier, 2006-09)
We study a nonlinear predator-prey model in which the prey population is affected by a mild disease, but has an effect on the death-rate and is assumed to have age structure. We assume that the predator population grows ...
Artículo
Study of the optimal harvesting control and the optimality system for an elliptic problem
(Society for Industrial and Applied Mathematics, 2003)
An optimal harvesting problem with concave non-quadratic cost functional and a diffusive degenerate elliptic logistic state equation type is investigated. Under certain assumptions, we prove the existence and uniqueness ...
Artículo
Existence and uniqueness of positive solution of a logistic equation with nonlinear gradient term
(Cambridge University Press, 2007-06)
The main goal of this work is to study the existence and uniqueness of positive solution of a logistic equation including a nonlinear gradient term. In particular, we use local and global bifurcation together with some ...
Artículo
Stability and uniqueness for cooperative degenerate Lotka-Volterra model
(Elsevier, 2002-06)
In this work we deal with the existence, stability and uniqueness of positive solution of the symbiotic Lotka-Volterra degenerate model. We study and characterize the existence of the principal eigenvalue for weakly coupled ...