Polynomial stability of a coupled wave-heat network
Lassi Paunonen, David Seifert
TL;DR
The paper analyzes a coupled one-dimensional wave-heat network with multiple boundary couplings and proves energy decay to zero. By decomposing the network into a wave subnetwork and a heat subnetwork and applying abstract boundary-node theory (NiPaSe24) and interconnection results, it obtains resolvent bounds and positive transfer-function estimates. For classical solutions, the energy decays at the rate $E(t)=o(t^{-4})$, while all solutions satisfy $E(t)\to0$ as $t\to\infty$. This work provides a robust semigroup-theoretic framework for polynomial stability in complex PDE networks and demonstrates how boundary-node and interconnection techniques yield explicit decay rates.
Abstract
We study the long-time asymptotic behaviour of a topologically non-trivial network of wave and heat equations. By analysing the simpler wave and the heat networks separately, and then applying recent results for abstract coupled systems, we establish energy decay at the rate $t^{-4}$ as $t\to\infty$ for all classical solutions.
