Combinatorics

Sublinear function

Physics

Mathematical analysis

Philosophy

Macroeconomics

Economics

Receptor

Topology (electrical circuits)

Chemistry

Production (economics)

Zero (linguistics)

Mathematics

Bounded function

Domain (mathematical analysis)

Linguistics

Chemotaxis

Biochemistry

Nonlinear Analysis

We study this zero-flux attraction–repulsion chemotaxis model, with linear and superlinear production g for the chemorepellent and sublinear rate f for the chemoattractant: (♢)ut=Δu−χ∇⋅(u∇v)+ξ∇⋅(u∇w)in Ω×(0,Tmax),vt=Δv−f(u)vin Ω×(0,Tmax),0=Δw−δw+g(u)in Ω×(0,Tmax).In this problem, Ω is a bounded and smooth domain of Rn, for n≥1, χ,ξ,δ>0, f(u) and g(u) reasonably regular functions generalizing the prototypes f(u)=Kuα and g(u)=γul, with K,γ>0 and proper α,l>0. Once it is indicated that any sufficiently smooth u(x,0)=u0(x)≥0 and v(x,0)=v0(x)≥0 produce a unique classical and nonnegative solution (u,v,w) to (1), which is defined in Ω×(0,Tmax), we establish that for any such (u0,v0), the life span Tmax=∞ and u,v and w are uniformly bounded in Ω×(0,∞), (i) for l=1, n∈{1,2}, α∈(0,12+1n)∩(0,1) and any ξ>0, (ii) for l=1, n≥3, α∈(0,12+1n) and ξ larger than a quantity depending on χ‖v0‖L∞(Ω), (iii) for l>1, α∈(0,12+1n)∩(0,1), any ξ>0, and in any dimensional settings. Finally, an illustrative 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 Lankeit and Wang (2017).

Boundedness in a chemotaxis system with consumed chemoattractant and produced chemorepellent