Diffusion wave phenomena and optimal time decay for incompressible viscoelastic flows
Shenghan Li, Yong Wang
TL;DR
This work analyzes diffusion-wave phenomena in three-dimensional incompressible viscoelastic flows near the rest state. It blends a representation-formula approach for the linearized wave equation with stationary-phase techniques and a robust energy framework to derive $L^p$ decay estimates for all $p\ge1$, revealing a hyperbolic-diffusive balance induced by the elastic stress. The results show diffusion waves dominate for $1\le p<2$ while faster decay occurs for $p\ge2$, and they provide sharp decay rates for higher derivatives, along with global well-posedness for small data via negative Sobolev/Besov methods. Overall, the paper advances understanding of the parabolic-hyperbolic coupling in incompressible viscoelastic flows and delivers precise time-decay profiles with potential implications for long-time dynamics and stability analysis.
Abstract
Motivated by the work of D. Hoff and K. Zumbrun (Indiana Univ. Math. J. 44: 603-676, 1995), we investigate the diffusion wave phenomena in three-dimensional incompressible viscoelastic flows. By employing the representation formula of the wave equation and the stationary phase methods on the sphere $\mathbb{S}^{d-1}$, we establish $L^p$ decay estimates for the solution over the whole range $1\leq p \leq \infty$, which reveals the hyperbolic nature of the incompressible viscoelastic flows.
