Constraints on inflation revisited: an analysis including the latest local measurement of the Hubble constant

• Main Authors: Rui-Yun Guo, Xin Zhang
• Format: Article
• Language: English
• Published: SpringerOpen 2017-12-01
• Series: European Physical Journal C: Particles and Fields
• Online Access: http://link.springer.com/article/10.1140/epjc/s10052-017-5454-9

Abstract We revisit the constraints on inflation models by using the current cosmological observations involving the latest local measurement of the Hubble constant ( $$H_{0} = 73.00\pm 1.75$$ H 0 = 73.00 ± 1.75  km s $$^{-1}$$ - 1  Mpc $$^{-1}$$ - 1 ). We constrain the primordial power spectra of both scalar and tensor perturbations with the observational data including the Planck 2015 CMB full data, the BICEP2 and Keck Array CMB B-mode data, the BAO data, and the direct measurement of $$H_0$$ H 0 . In order to relieve the tension between the local determination of the Hubble constant and the other astrophysical observations, we consider the additional parameter $$N_\mathrm{eff}$$ N eff in the cosmological model. We find that, for the $$\Lambda $$ Λ CDM $$+$$ + $$r$$ r $$+$$ + $$N_\mathrm{eff}$$ N eff model, the scale invariance is only excluded at the 3.3 $$\sigma $$ σ level, and $$\Delta N_\mathrm{eff}>0$$ Δ N eff > 0 is favored at the 1.6 $$\sigma $$ σ level. Comparing the obtained 1 $$\sigma $$ σ and 2 $$\sigma $$ σ contours of $$(n_s,r)$$ ( n s , r ) with the theoretical predictions of selected inflation models, we find that both the convex and the concave potentials are favored at 2 $$\sigma $$ σ level, the natural inflation model is excluded at more than 2 $$\sigma $$ σ level, the Starobinsky $$R^2$$ R 2 inflation model is only favored at around 2 $$\sigma $$ σ level, and the spontaneously broken SUSY inflation model is now the most favored model.