A Good-Vorticity Low-Regularity Integrator for the Inviscid Oldroyd--B System with Stress Diffusion

We establish sharp convergence results for a sequential semi-implicit good-vorticity integrator for the two-dimensional inviscid Oldroyd--B system with stress diffusion on the torus. For exact solutions satisfying $u\in C_tB^{1+α}_{\infty,1}$ and $τ\in C_tB^α_{\infty,1}\cap L^1_tB^{2+α}_{\infty,1}$,