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J. López-Gómez

Publications and source records attributed to J. López-Gómez.

2 recordsLinked to original sources

Limiting behavior of principal eigenvalues and eigenfunctions for a class of elliptic operators with degenerate large advection

In this paper we study, both numerically and analytically, the asymptotic behavior of the principal eigenfunction of \eqref{1.1}, normalized by \eqref{1.2}, as $s\uparrow +\infty$. Based on the numerical computations of this paper, we can prove that, under condition (Hm) bellow, $φ_s$ approximates $1$ and $φ_s'$ approximates $0$, uniformly in $[-1,1]$, as $s\uparrow +\infty$. As a byproduct of this result, we can derive the asymptotic behavior of the principal eigenvalue in a one-dimensional situation not previously covered by \cite{ChLo} and \cite{PeZh}, as we are working under minimal regularity assumptions on $m(x)$. A recent result of \cite{BWZ} shows that the principal eigenvalue might oscillate as $s\uparrow +\infty$ if $m(x)$ is highly oscillatory. Thus, the oscillatory and regularity properties of $m(x)$ might severely affect the asymptotic behavior of $(λ_s,φ_s)$ as $s\uparrow +\infty$.

math.AP↗

The weighted periodic-parabolic degenerate logistic equation

The main goal of this paper is twofold. First, it characterizes the existence of positive periodic solutions for a general class of weighted periodic-parabolic logistic problems of degenerate type (see (1.1)). This result provides us with is a substantial generalization of Theorem 1.1 of Daners and López-Gómez [12] even for the elliptic counterpart of (1.1), and of some previous findings of the authors in [1] and [2]. Then, it sharpens some results of [19] by enlarging the class of critical degenerate weight functions for which (1.1) admits a positive periodic solution in an unbounded interval of values of the parameter $λ$. The latest findings, not having any previous elliptic counterpart, are utterly new and of great interest in Population Dynamics.

math.AP↗