Alexander C. Sobotka

Mar 26, 2024 | link.aps.org | Alexander C. Sobotka |Adrienne L. Erickcek |Tristan Smith |Swarthmore College

We derive constraints on the injection of free-streaming dark radiation after big bang nucleosynthesis by considering the decay of a massive hidden sector particle into dark radiation. Such a scenario has the potential to alleviate the Hubble tension by introducing a new energy component to the evolution of the early Universe.