English

Boundedness in a chemotaxis system with consumed chemoattractant and produced chemorepellent

Analysis of PDEs 2020-09-25 v1

Abstract

We study this zero-flux attraction-repulsion chemotaxis model, with linear and superlinear production gg for the chemorepellent and sublinear rate ff for the chemoattractant: \begin{equation}\label{problem_abstract} \tag{\Diamond} \begin{cases} u_t= \Delta u - \chi \nabla \cdot (u \nabla v)+\xi \nabla \cdot (u \nabla w) & \text{ in } \Omega \times (0,T_{max}),\\ v_t=\Delta v-f(u)v & \text{ in } \Omega \times (0,T_{max}),\\ 0= \Delta w - \delta w + g(u)& \text{ in } \Omega \times (0,T_{max}). %u(x,0)=u_0(x), \; v(x,0)=v_0(x) & x \in \bar\Omega. \end{cases} \end{equation} In this problem, Ω\Omega is a bounded and smooth domain of Rn\R^n, for n1n\geq 1, χ,ξ,δ>0\chi,\xi,\delta>0, f(u)f(u) and g(u)g(u) reasonably regular functions generalizing the prototypes f(u)=Kuαf(u)=K u^\alpha and g(u)=γulg(u)=\gamma u^l, with K,γ>0K,\gamma>0 and proper α,l>0 \alpha, l>0. Once it is indicated that any sufficiently smooth u(x,0)=u0(x)0u(x,0)=u_0(x)\geq 0 and v(x,0)=v0(x)0v(x,0)=v_0(x)\geq 0 produce a unique classical and nonnegative solution (u,v,w)(u,v,w) to \eqref{problem_abstract}, which is defined in Ω×(0,Tmax)\Omega \times (0,T_{max}), we establish that for any such (u0,v0)(u_0,v_0), the life span \TM=\TM=\infty and u,vu, v and ww are uniformly bounded in Ω×(0,)\Omega\times (0,\infty), (i) for l=1l=1, n{1,2}n\in \{1,2\}, α(0,12+1n)(0,1)\alpha\in (0,\frac{1}{2}+\frac{1}{n})\cap (0,1) and any ξ>0\xi>0, (ii) for l=1l=1, n3n\geq 3, α(0,12+1n)\alpha\in (0,\frac{1}{2}+\frac{1}{n}) and ξ\xi larger than a quantity depending on χv0L(Ω)\chi \lVert v_0 \rVert_{L^\infty(\Omega)}, (iii) for l>1l>1 any ξ>0\xi>0, and in any dimensional settings. Finally, an indicative analysis about the effect by logistic and repulsive actions on chemotactic phenomena is proposed by comparing the results herein derived for the linear production case with those in \cite{LankeitWangConsumptLogistic}.

Keywords

Cite

@article{arxiv.2009.11659,
  title  = {Boundedness in a chemotaxis system with consumed chemoattractant and produced chemorepellent},
  author = {Silvia Frassu and Giuseppe Viglialoro},
  journal= {arXiv preprint arXiv:2009.11659},
  year   = {2020}
}