scholarly journals On the existence of dead cores for degenerate Lotka—Volterra models

Author(s):  
M. Delgado ◽  
A. Suárez

In this work we study the existence and qualitative properties of non-negative solutions of the Lotka—Volterra models with nonlinear diffusion under homogeneous Dirichlet boundary conditions. We consider the three typical interactions: prey—predator, competition and symbiosis. Unlike the linear diffusion models, non-trivial non-negative solutions can exist which are not strictly positive. Sufficient conditions in terms of the coefficients involved in the setting of the models are given, assuring that one species (or both) does not survive on a set of its habitat (called ‘dead core’) of positive measure.

1996 ◽  
Vol 19 (3) ◽  
pp. 427-434 ◽  
Author(s):  
Alan V. Lair ◽  
Mark E. Oxley

The authors prove that the nonlinear parabolic partial differential equation∂u∂t=∑i,j=1n∂2∂xi∂xjφij(u)−f(u)with homogeneous Dirichlet boundary conditions and a nonnegative initial condition has a nonnegative generalized solutionu. They also give necessary and sufficient conditions on the constitutive functionsφijandfwhich ensure the existence of a timet0>0for whichuvanishes for allt≥t0.


2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Yuhua Long ◽  
Shaohong Wang ◽  
Jiali Chen

Abstract In the present paper, a class of fourth-order nonlinear difference equations with Dirichlet boundary conditions or periodic boundary conditions are considered. Based on the invariant sets of descending flow in combination with the mountain pass lemma, we establish a series of sufficient conditions on the existence of multiple solutions for these boundary value problems. In addition, some examples are provided to demonstrate the applicability of our results.


2011 ◽  
Vol 141 (6) ◽  
pp. 1279-1294 ◽  
Author(s):  
Marius Ghergu

We study the elliptic system −Δu = δ(x)−avp in Ω, −Δv = δ(x)−buq in Ω, subject to homogeneous Dirichlet boundary conditions. Here, Ω ⊂ ℝN, N ≥ 1, is a smooth and bounded domain, δ(x) = dist(x, ∂Ω), a, b ≥ 0 and p, q ∈ ℝ satisfy pq > −1. The existence, non-existence and uniqueness of solutions are investigated in terms of a, b, p and q.


Author(s):  
César E. Torres Ledesma

AbstractThe purpose of this paper is to study the existence of solutions for equations driven by a non-local regional operator with homogeneous Dirichlet boundary conditions. More precisely, we consider the problemwhere the nonlinear term


2009 ◽  
Vol 11 (01) ◽  
pp. 59-69 ◽  
Author(s):  
PAOLO ROSELLI ◽  
MICHEL WILLEM

We prove the existence of (a pair of) least energy sign changing solutions of [Formula: see text] when Ω is a bounded domain in ℝN, N = 5 and λ is slightly smaller than λ1, the first eigenvalue of -Δ with homogeneous Dirichlet boundary conditions on Ω.


2018 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
A. J. Bissouesse ◽  
Daniel Moukoko ◽  
Franck Langa ◽  
Macaire Batchi

Our aim in this article is to study the existence and the uniqueness of solution for Cahn-Hilliard hyperbolic phase-field system, with initial conditions, homogeneous Dirichlet boundary conditions, polynomial potential in a bounded and smooth domain.


2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Kwangjoong Kim ◽  
Wonhyung Choi ◽  
Inkyung Ahn

<p style='text-indent:20px;'>In this study, we consider a Lotka–Volterra reaction–diffusion–advection model for two competing species under homogeneous Dirichlet boundary conditions, describing a hostile environment at the boundary. In particular, we deal with the case in which one species diffuses at a constant rate, whereas the other species has a constant rate diffusion rate with a directed movement toward a better habitat in a heterogeneous environment with a lethal boundary. By analyzing linearized eigenvalue problems from the system, we conclude that the species dispersion in the advection direction is not always beneficial, and survival may be determined by the convexity of the environment. Further, we obtain the coexistence of steady-states to the system under the instability conditions of two semi-trivial solutions and the uniqueness of the coexistence steady states, implying the global asymptotic stability of the positive steady-state.</p>


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