Resonant neutrino self-interactions and the $H_0$ tension

Understand

In this work, we study the previously unexplored resonant region of neutrino self-interactions.

• Current disagreement on late and early time observations of the Universe expansion could be solved with new physics acting before the recombination era.
• Nonstandard neutrino self-interactions are among the most appealing candidates to solve this issue since they could be testable in the near (or midterm) future.
• We use linear cosmological datasets to test neutrino self-interactions for a sample of fixed scalar mediator masses in the range $10^{-2}$ eV $\leq m_{\varphi}\leq 10^{2}$ eV.