Neutrino puzzle: Anomalies, interactions, and cosmological tensions

Abstract

Different measurements of the Hubble constant are somewhat in tension. Here, the authors show that a simple effective theory of neutrino self-interactions can lead to a significantly different cosmology. This resolves the Hubble issue while also suggesting an extra neutrino species that could relate to experimental neutrino anomalies. Their results suggest interesting deviations from the standard cosmology may be viable.