Global existence and steady states of the density-suppressed motility model with strong Allee effect

• Published in: IMA journal of applied mathematics Vol. 89; no. 2; pp. 387 - 425
• Main Authors: Song, Cui, Wang, Zhi-Cheng, Feng, Zhaosheng
• Format: Journal Article
• Language: English
• Published: Oxford University Press 04.08.2024
• Subjects: steady state; global existence; bifurcation; 92B05; Allee effect; 35A01; 92C17; density-suppressed motility; 35K57; stability
• ISSN: 0272-4960; 1464-3634
• DOI: 10.1093/imamat/hxae013

This paper considers a density-suppressed motility model with a strong Allee effect under the homogeneous Neumman boundary condition. We first establish the global existence of bounded classical solutions to a parabolic–parabolic system over an $N $-dimensional $\mathbf{(N\le 3)}$ bounded domain $\varOmega $, as well as the global existence of bounded classical solutions to a parabolic–elliptic system over the multidimensional bounded domain $\varOmega $ with smooth boundary. We then investigate the linear stability at the positive equilibria for the full parabolic case and parabolic–elliptic case, respectively, and find the influence of Allee effect on the local stability of the equilibria. By treating the Allee effect as a bifurcation parameter, we focus on the one-dimensional stationary problem and obtain the existence of non-constant positive steady states, which corresponds to small perturbations from the constant equilibrium $(1,1)$. Furthermore, we present some properties through theoretical analysis on pitchfork type and turning direction of the local bifurcations. The stability results provide a stable wave mode selection mechanism for the model considered in this paper. Finally, numerical simulations are performed to demonstrate our theoretical results.