Speaker
Dr
Jun-Qian Jiang
(University of Chinese Academy of Sciences)
Description
An exact scale-invariant Harrison-Zeldovich spectrum, i.e. $n_s=1$, has been ruled out at $8.4\sigma$ level according to Planck results. However, the situation changes when we consider the Hubble tension. Extra energy injection in early cosmology (e.g. Early Dark Energy), which is a class of promising solutions of the Hubble tension, seems to call for the return of $n_s=1$. Using recent observational data, we show strong evidence for $n_s=1$ if the Hubble tension is resolved in this way. Furthermore, we show how these solutions can affect the observation constraints on the $r$-$n_s$ plane, bringing unforeseen impacts to the inflation model.
