Neutrino and Dark Radiation properties in light of latest CMB observations

Understand

Recent Cosmic Microwave Background measurements at high multipoles from the South Pole Telescope and from the Atacama Cosmology Telescope seem to disagree in their conclusions for the neutrino and dark radiation properties.

• In this paper we set new bounds on the dark radiation and neutrino properties in different cosmological scenarios combining the ACT and SPT data with the nine year data release of the Wilkinson Microwave Anisotropy Probe (WMAP9), Baryon Acoustic Oscillation data, Hubble Telescope measurements of the Hubble constant, and Supernovae Ia luminosity distance data.
• In the standard three massive neutrino case, the two high multipole probes give similar results if Baryon Acoustic Oscillation data are removed from the analyses and Hubble Telescope measurements are also exploited.
• A similar result is obtained within a standard cosmology with Neff massless neutrinos, although in this case the agreement between these two measurements is also improved when considering simultaneously Baryon Acoustic Oscillation data and Hubble Space Telescope measurements.