Global well-posedness and large time behavior of solutions to the compressible Oldroyd-B model without stress diffusion

We consider the Cauchy problem (Rᵈ, d=2, 3) and the initial boundary values problem (Tᵈ, d=2, 3) associated to the compressible Oldroyd-B model which is first derived by Barrett, Lu and S\"uli Existence of large-data finite-energy global weak solutions to a compressible Oldroyd-B model, Commun. Math. Sci. , 15 (2017), 1265--1323 through micro-macro-analysis of the compressible Navier-Stokes-Fokker-Planck system. Due to lack of stress diffusion, the problems considered here are very difficult. Exploiting tools from harmonic analysis, notably the Littlewood Paley theory, we first establish the global well-posedness and time-decay rates for solutions of the model with small initial data in Besov spaces with critical regularity. Then, through deeply exploring and fully utilizing the structure of the perturbation system, we obtain the global well-posedness and exponential decay rates for solutions of the model with small initial data in the Soboles spaces H³ (Tᵈ). Our obtained results improve considerably the recent results by Lu, Pokorn\'y Anal. Theory Appl. , 36 (2020), 348--372, Wang, Wen Math. Models Methods Appl. Sci. , 30 (2020), 139--179, and Liu, Lu, Wen SIAM J. Math. Anal. , 53 (2021), 6216--6242.