Impact of the latest measurement of Hubble constant on constraining inflation models

Understand

We investigate how the constraint results of inflation models are affected by considering the latest local measurement of $H_0$ in the global fit.

• We use the observational data, including the Planck CMB full data, the BICEP2 and Keck Array CMB B-mode data, the BAO data, and the latest measurement of Hubble constant, to constrain the $\Lambda$CDM+$r$+$N_{\rm eff}$ model, and the obtained 1$\sigma$ and 2$\sigma$ contours of $(n_s, r)$ are compared to the theoretical predictions of selected inflationary models.
• We find that, in this fit, the scale invariance is only excluded at the 3.3$\sigma$ level, and $\Delta N_{\rm eff}>0$ is favored at the 1.6$\sigma$ level.
• The natural inflation model is now excluded at more than 2$\sigma$ level; the Starobinsky $R^2$ model becomes only favored at around 2$\sigma$ level; the most favored model becomes the spontaneously broken SUSY inflation model; and, the brane inflation model is also well consistent with the current data, in this case.