Local energy decay of solutions to the linearized compressible viscoelastic system around motionless state in an exterior domain
Yusuke Ishigaki, Takayuki Kobayashi
TL;DR
This work analyzes the large-time behavior of perturbations for the linearized compressible viscoelastic system around a motionless state in a three-dimensional exterior domain. By conducting a resolvent analysis that combines whole-space and bounded-domain problems via a parametrix, the authors establish a local energy decay of the linearized semigroup with rate $t^{-2-m}$ for time-derivative orders $m$, capturing diffusion from viscous effects and wave propagation from elastic shear and sound modes. A key finding is the low-frequency singularity in the resolvent of the form $\lambda^2\log\lambda$ (distinct from the β=0 case where the singularity is weaker), which underpins the observed diffusion-wave decay and the faster local energy decay relative to classical heat-like behavior. The results extend prior β=0 exterior-domain analyses to the coupled viscoelastic system, providing precise mapping properties of the resolvent operators and a robust analytic framework for the linear evolution in exterior domains.
Abstract
We study the large time behavior of solutions to the system of equations describing motion of compressible viscoelastic fluids. We focus on the linearized system around a motionless state in a three-dimensional exterior domain and derive the local energy decay estimate of its solution to give the diffusion wave phenomena caused by sound wave viscous diffusion and elastic shear wave.
