The evolution of the primordial curvature perturbation in the ultraslow-roll inflation Hao-Ran Zhao, Yi-Chen Liu, Ji-Xiang Zhao and Nan Li Eur. Phys. J. C, 83 9 (2023) 783 Published online: 05 September 2023 DOI: 10.1140/epjc/s10052-023-11959-0