English

Global classical solutions, stability of constant equilibria, and spreading speeds in attraction-repulsion chemotaxis systems with logistic source on $\mathbb{R}^{N}$

Analysis of PDEs 2017-06-23 v3

Abstract

We consider the following chemotaxis systems {ut=Δuχ1(uv1)+χ2(uv2)+u(abu),  xRN,t>0,0=(Δλ1I)v1+μ1u,  xRN,t>0,0=(Δλ2I)v2+μ2u,  in xRN, t>0,u(,0)=u0,  xRN,\begin{cases}u_t=\Delta u-\chi_1\nabla(u\nabla v_1)+\chi_2\nabla(u\nabla v_2)+u(a-bu),\ \ x\in\mathbb R^N,t>0,\\0=(\Delta-\lambda_1I)v_1+\mu_1u,\ \ x\in\mathbb R^N,t>0,\\0=(\Delta-\lambda_2I)v_2+\mu_2u,\ \ \text{in}\ x\in\mathbb R^N,\ t>0,\\u(\cdot,0)=u_0,\ \ x\in\mathbb R^N,\end{cases}where χi, λi, μi, i=1,2\chi_i,\ \lambda_i,\ \mu_i,\ i=1,2 and a, ba,\ b are positive constant real numbers and NN is a positive integer. Under some conditions on the parameters, we prove the global existence and boundedness of classical solutions (u(x,t;u0),v1(x,t;u0),v2(x,t;u0))(u(x,t;u_0),v_1(x,t;u_0),v_2(x,t;u_0)) for nonnegative, bounded, and uniformly continuous initials u0(x)u_0(x). Next, we show that, for every strictly positive initial \,u0(x)u_0(x),limt[u(,t;u0)ab+λ1v1(,t;u0)abμ1+λ2v2(,t;u0)abμ2]=0.\lim_{t\to\infty}\left[\|u(\cdot,t;u_0)-\frac{a}{b}\|_{\infty}+\|\lambda_1v_1(\cdot,t;u_0)-\frac{a}{b}\mu_1\|_{\infty}+\|\lambda_2v_2(\cdot,t;u_0)-\frac{a}{b}\mu_2\|_{\infty}\right]=0. Finally, we explore the spreading properties of the global solutions and prove that there are two positive numbers 0<c(χ1,μ1,λ1,χ2,μ2,λ2)<c+(χ1,μ1,λ1,χ2,μ2,λ2)0<c^*_-(\chi_1,\mu_1,\lambda_1,\chi_2,\mu_2,\lambda_2)<c^*_+(\chi_1,\mu_1,\lambda_1,\chi_2,\mu_2,\lambda_2) such that for every nonegative initial u0(x)u_0(x) with nonempty and compact support, limt[supxctu(x,t;u0)ab+supxctλ1v1(x,t;u0)abμ1+supxctλ2v2(x,t;u0)abμ2]=0\lim_{t\to\infty}\left[\sup_{|x|\leq{ct}}|u(x,t;u_0)-\frac{a}{b}|+\sup_{|x|\leq ct}|\lambda_1v_1(x,t;u_0)-\frac{a}{b}\mu_1|+\sup_{|x|\leq ct}|\lambda_2v_2(x,t;u_0)-\frac{a}{b}\mu_2|\right]=0whenever 0c<c(χ1,μ1,λ1,χ2,μ2,λ2)0\leq c<c^*_-(\chi_1,\mu_1,\lambda_1,\chi_2,\mu_2,\lambda_2),\ andlimt[supxctu(x,t;u0)+supxctv1(x,t;u0)+supxctv2(x,t;u0)]=0\lim_{t\to\infty}\left[\sup_{|x|\geq ct}|u(x,t;u_0)|+\sup_{|x|\geq ct} | v_1(x,t;u_0)|+\sup_{|x|\geq ct}|v_2(x,t;u_0)|\right]=0whenever c>c+(χ1,μ1,λ1,χ2,μ2,λ2)c>c^*_+(\chi_1,\mu_1,\lambda_1,\chi_2,\mu_2,\lambda_2). Furthermore we show thatlim(χ1,χ2)(0,0)c(χ1,μ1,λ1,χ2,μ2,λ2)=lim(χ1,χ2)(0,0)c+(χ1,μ1,λ1,χ2,μ2,λ2)=2a.\lim_{(\chi_1,\chi_2)\to(0,0)}c^*_-(\chi_1,\mu_1,\lambda_1,\chi_2,\mu_2,\lambda_2)=\lim_{(\chi_1,\chi_2)\to(0,0)}c^*_+(\chi_1,\mu_1,\lambda_1,\chi_2,\mu_2,\lambda_2)=2\sqrt{a}.

Keywords

Cite

@article{arxiv.1612.00924,
  title  = {Global classical solutions, stability of constant equilibria, and spreading speeds in attraction-repulsion chemotaxis systems with logistic source on $\mathbb{R}^{N}$},
  author = {Rachidi B. Salako and Wenxian Shen},
  journal= {arXiv preprint arXiv:1612.00924},
  year   = {2017}
}