BV solutions to a hyperbolic system of balance laws with logistic growth

TL;DR

This paper establishes the global existence, uniqueness, and asymptotic decay of BV solutions for a modified Keller-Segel hyperbolic system with logistic growth, under small initial variation and amplitude.

Contribution

It introduces a new analysis for BV solutions to a Keller-Segel type system with logistic growth, including decay rates and asymptotic behavior, extending previous hyperbolic balance law results.

Findings

Global BV solutions exist and are unique for small initial data.

Solutions decay over time with quantifiable rates.

The system's flux features new properties compared to classical models.

Abstract

We study BV solutions for a $2\times2$ system of hyperbolic balance laws. We show that when initial data have small total variation on $(-\infty,\infty)$ and small amplitude, and decay sufficiently fast to a constant equilibrium state as $|x|\rightarrow\infty$, a Cauchy problem (with generic data) has a unique admissible BV solution defined globally in time. Here the solution is admissible in the sense that its shock waves satisfy the Lax entropy condition. We also study asymptotic behavior of solutions. In particular, we obtain a time decay rate for the total variation of the solution, and a convergence rate of the solution to its time asymptotic solution. Our system is a modification of a Keller-Segel type chemotaxis model. Its flux function possesses new features when comparing to the well-known model of Euler equations with damping. This may help to shed light on how to extend the study to a general system of hyperbolic balance laws in the future.