Rafael Luís

Prof. Dr. Rafael Luís

Faculdade de Ciências Exatas e da Engenharia, Universidade da Madeira, Funchal, Madeira, Portugal
orcid

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 June 2011 in Journal of Biological Dynamics
Verified
Journal Article
Open access
RLRafael Luís
Rafael Luís
SESaber Elaydi
Saber Elaydi
HOHenrique M. sobre a empregabilidade dos licenciados pela Universidade Agostinho Neto. Oliveira
Henrique M. sobre a empregabilidade dos licenciados pela Universidade Agostinho Neto. Oliveira
Our main objective is to study a Ricker-type competition model of two species. We give a complete analysis of stability and bifurcation and determine the centre manifolds, as well as stable and unstable manifolds. It is shown that the autonomous Ricker competition model exhibits subcritical bifurcation, bubbles, period-doubling bifurcation, but no Neimark–Sacker bifurcations. We exhibit the region in the parameter space where the competition exclusion principle applies.

16 September 2010 in Journal of Difference Equations and Applications
Verified
Journal Article
Closed access
RLRafael Luís
Rafael Luís
SESaber Elaydi
Saber Elaydi
HOHenrique M. sobre a empregabilidade dos licenciados pela Universidade Agostinho Neto. Oliveira
Henrique M. sobre a empregabilidade dos licenciados pela Universidade Agostinho Neto. Oliveira
A new class of maps called unimodal Allee maps are introduced. Such maps arise in the study of population dynamics in which the population goes extinct if its size falls below a threshold value. A unimodal Allee map is thus a unimodal map with three fixed points, a zero fixed point, a small positive fixed point, called threshold point, and a bigger positive fixed point, called the carrying capacity. In this paper, the properties and stability of the three fixed points are studied in the setting of non-autonomous periodic dynamical systems or difference equations. Finally, we investigate the bifurcation of periodic systems/difference equations when the system consists of two unimodal Allee maps.

1 January 2014 in Discrete and Continuous Dynamical Systems-Series B
Verified
Journal Article
Open access
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EBE. Cabral Balreira
E. Cabral Balreira
Saber ElaydiSaber Elaydi
Saber Elaydi
RLRafael Luís
Rafael Luís
Under certain analytic and geometric assumptions we show that local stability of the coexistence (positive) fixed point of the planar Ricker competition model implies global stability with respect to the interior of the positive quadrant. This result is a confluence of ideas from Dynamical Systems, Geometry, and Topology that provides a framework to the study of global stability for other planar competition models.

9 October 2017 in Journal of Difference Equations and Applications
Verified
Journal Article
Closed access
EBE. Cabral Balreira
E. Cabral Balreira
SESaber Elaydi
Saber Elaydi
RLRafael Luís
Rafael Luís
We develop a notion of monotonicity for maps defined on Euclidean spaces R+k, of arbitrary dimension k. This is a geometric approach that extends the classical notion of planar monotone maps or planar competitive difference equations. For planar maps, we show that our notion and the classical notion of monotonicity are equivalent. In higher dimensions, we establish certain verifiable conditions under which Kolmogorov monotone maps on R+k have a globally asymptotically stable fixed point. We apply our results to two competition population models, the Leslie–Gower and the Ricker models of two- and three-species. It is shown that these two models have a unique interior fixed point that is globally asymptotically stable.

13 June 2011 in Journal of Difference Equations and Applications
Verified
Journal Article
Closed access
MGMalgorzata Guzowska
Malgorzata Guzowska
RLRafael Luís
Rafael Luís
SESaber Elaydi
Saber Elaydi
In this paper, we study a new logistic competition model. We will investigate stability and bifurcation of the model. In particular, we compute the invariant manifolds, including the important centre manifolds, and study their bifurcation. Saddle-node and period-doubling bifurcation route to chaos are exhibited via numerical simulations.

22 March 2011 in Journal of Difference Equations and Applications
Verified
Journal Article
Closed access
Saber ElaydiSaber Elaydi
Saber Elaydi
RLRafael Luís
Rafael Luís
We present open problems and conjectures for some two-dimensional competition models, namely the logistic competition model and a Ricker-type competition model.