Optimal time-decay estimates for an Oldroyd-B model with zero viscosity

作者:Huang, Jinrui; Wang, Yinghui; Wen, Huanyao*; Zi, Ruizhao
来源:Journal of Differential Equations, 2022, 306: 456-491.
DOI:10.1016/j.jde.2021.10.046

摘要

In this work, we consider the Cauchy problem for a diffusive Oldroyd-B model in three dimensions. Some optimal time-decay rates of the solutions are derived via analysis of upper and lower time-decay estimates provided that the initial data are small and that the absolute value of Fourier transform of the initial velocity is bounded below away from zero in a low-frequency region. It is worth noticing that the optimal rates are independent of the fluid viscosity or the diffusive coefficient, which is a different phenomenon from that for incompressible Navier-Stokes equations.