Cosmological Tensions and the Transitional Planck Mass Model

Abstract

In this follow-up analysis, we update previous constraints on the transitional Planck mass (TPM) modified gravity model using the latest version of EFTCAMB and provide new constraints using South Pole Telescope (SPT) and Planck anisotropy data along with Planck cosmic microwave background lensing, baryon acoustic oscillations, and Type Ia supernovae data and a Hubble constant, H _0 , prior from local measurements. We find that large shifts in the Planck mass lead to large suppression of power on small scales that is disfavored by both the SPT and Planck data. Using only the SPT temperature-polarization–polarization-polarization (TE-EE) data, this suppression of power can be compensated for by an upward shift of the scalar index to n _s = 1.003 ± 0.016, resulting in ${H}_{0}\,=\,{71.94}_{-0.85}^{+0.86}$ km m ^−1 Mpc ^−1 and a ∼7% shift in the Planck mass. Including the Planck temperature-temperature (TT) ℓ ≤ 650 and Planck TE-EE data restricts the shift to be <5% at 2 σ with H _0 = 70.65 ± 0.66 km m ^−1 Mpc ^−1 . Excluding the H _0 prior, the SPT and Planck data constrain the shift in the Planck mass to be <3% at 2 σ with a best-fit value of 0.04%, consistent with the Λ cold dark matter limit. In this case ${H}_{0}\,=\,{69.09}_{-0.68}^{+0.69}$ km s ^−1 Mpc ^−1 , which is partially elevated by the dynamics of the scalar field in the late Universe. This differs from early dark energy models that prefer higher values of H _0 when the high- ℓ Planck TT data are excluded. We additionally constrain TPM using redshift space distortion data from BOSS DR12 and cosmic shear, galaxy–galaxy lensing, and galaxy clustering data from DES Y1, finding both disfavor transitions close to recombination, but earlier Planck mass transitions are allowed.

Keywords

• Cosmology
• Dark energy
• Cosmological parameters
• Cosmological models