Single field slow-roll inflation with step uplift to $n_s=1$

Hao-Shi Yuan, Ze-Yu Peng, Yun-Song Piao

The early dark energy resolution of Hubble tension seems to be suggesting a scale-invariant Harrison-Zeldovich spectrum of primordial scalar perturbation, i.e. $n_s=1$ ($|n_s-1|\si…