Boundedness and exponential stabilization in a degenerate migration-consumption system with logistic damping

Abstract

We study the no-flux problem for a taxis-type migration-consumption system with logistic damping in a bounded planar domain, where the motility function \(ϕ\) vanishes at zero and degenerates algebraically of order \(α\ge1\). We prove uniform boundedness in \(L^\infty(Ω)\times W^{1,\infty}(Ω)\) for every fixed damping coefficient \(b>0\), without any smallness assumption on the initial data, thus improving the previous \(L^2\)-boundedness results. For \(α>1\), we further prove that the solution converges exponentially to the spatially homogeneous state \((a/b,0)\), with an explicit admissible rate. The proof combines a weighted Gagliardo--Nirenberg type inequality adapted to the degeneracy with the dissipative structure of the signal equation. Therefore logistic damping drives the system toward homogeneity, despite the loss of uniform elliptic regularization.