Emilio Hernández-García

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We study the properties of general Lotka-Volterra models with competitive interactions. The intensity of the competition depends on the position of species in an abstract niche space through an interaction kernel. We show analytically and numerically that the properties of these models change dramatically when the Fourier transform of this kernel is not(More)
A central model in theoretical ecology considers the competition of a range of species for a broad spectrum of resources. Recent studies have shown that essentially two different outcomes are possible. Either the species surviving competition are more or less uniformly distributed over the resource spectrum, or their distribution is “lumped” (or “clumped”),(More)
We present properties of Lotka-Volterra equations describing ecological competition among a large number of interacting species. First we extend previous stability conditions to the case of a non-homogeneous niche space, i.e. that of a carrying capacity depending on the species trait. Second, we discuss mechanisms leading to species clustering and obtain an(More)
We introduce a simple model of population dynamics which considers reproducing individuals or particles with birth and death rates depending on the number of other individuals in their neighborhood. The model shows an inhomogeneous quasistationary pattern with many different clusters of particles arranged periodically in space. We derive the equation for(More)
Motivated by the existence of remarkably ordered cluster arrays of bacteria colonies growing in Petri dishes and related problems, we study the spontaneous emergence of clustering and patterns in a simple nonequilibrium system: the individual-based interacting Brownian bug model. We map this discrete model into a continuous Langevin equation which is the(More)
We investigate the response of an excitable medium to a localized perturbation in the presence of a two-dimensional smooth chaotic flow. Two distinct types of flows are numerically considered: open and closed. For both of them three distinct regimes are found, depending on the relative strengths of the stirring and the rate of the excitable reaction. In(More)
[1] Regular vegetation patterns in semiarid ecosystems are believed to arise from the interplay between long-range competition and facilitation processes acting at smaller distances. We show that, under rather general conditions, longrange competition alone may be enough to shape these patterns. To this end we propose a simple, general model for the(More)
Emilio Hernández-Garcı́a, Cristóbal López, and Zoltán Neufeld 1 Instituto Mediterráneo de Estudios Avanzados (IMEDEA), CSIC-Universitat de les Illes Balears, E-07071 Palma de Mallorca, Spain 2 Dipartimento di Fisica, Università di Roma ‘La Sapienza’, P.le A. Moro 2, I-00185, Roma, Italy Department of Applied Mathematics and Theoretical Physics, University(More)
X iv :n lin /0 20 50 09 v1 [ nl in .C D ] 6 M ay 2 00 2 Spatial Patterns in Chemically and Biologically Reacting Flows Emilio Hernández-Garćıa1∗ , Cristóbal López, and Zoltán Neufeld IMEDEA (CSIC-UIB) Instituto Mediterráneo de Estudios Avanzados, Campus Universitat de les Illes Balears E-07071 Palma de Mallorca, Spain 2 Dipartimento di Fisica, Università di(More)