Stabilization for small mass in a quasilinear parabolic--elliptic--elliptic attraction-repulsion chemotaxis system with density-dependent sensitivity: repulsion-dominant case

TL;DR

This paper proves that solutions to a complex chemotaxis system with density-dependent sensitivity and dominant repulsion effects remain bounded and converge to a uniform equilibrium, extending previous results to nonlinear cases.

Contribution

It establishes the global boundedness and convergence of solutions in a nonlinear chemotaxis system with density-dependent sensitivity, generalizing prior linear results.

Findings

Solutions are globally bounded and stable.

Convergence to the spatially constant equilibrium is proven.

Extends previous linear results to nonlinear systems.

Abstract

This paper deals with the quasilinear attraction-repulsion chemotaxis system \begin{align*} \begin{cases} u_t=\nabla\cdot \big((u+1)^{m-1}\nabla u -\chi u(u+1)^{p-2}\nabla v +\xi u(u+1)^{q-2}\nabla w\big),\\[] 0=\Delta v+\alpha u-\beta v,\\[] 0=\Delta w+\gamma u-\delta w \end{cases} \end{align*} in a bounded domain $\Omega \subset \mathbb{R}^n$ $(n \in \mathbb{N})$ with smooth boundary $\partial \Omega$, where $m, p, q \in \mathbb{R}$, $\chi, \xi, \alpha, \beta, \gamma, \delta>0$ are constants. In the case that $m=1$ and $p=q=2$, when $\chi\alpha-\xi\gamma<0$ and $\beta=\delta$, Tao-Wang (Math. Models Methods Appl. Sci.; 2013; 23; 1-36) proved that global bounded classical solutions toward the spatially constant equilibrium $(\overline{u_0}, \frac{\alpha}{\beta}\overline{u_0}, \frac{\gamma}{\delta}\overline{u_0})$ via the reduction to the Keller-Segel system by using the transformation $z:=\chi v-\xi w$, where $\overline{u_0}$ is the spatial average of the initial data $u_0$. However, since the above system involves nonlinearities, the method is no longer valid. The purpose of this paper is to establish that global bounded classical solutions converge to the spatially constant equilibrium $(\overline{u_0}, \frac{\alpha}{\beta}\overline{u_0}, \frac{\gamma}{\delta}\overline{u_0})$.