English

New Early Dark Energy as a solution to the $H_0$ and $S_8$ tensions

High Energy Physics - Phenomenology 2024-07-16 v1 Cosmology and Nongalactic Astrophysics High Energy Physics - Theory

Abstract

New Early Dark Energy introduces a new phase of dark energy that decays in a fast-triggered phase transition around matter-radiation equality. The presence of a trigger mechanism sets it apart from other early dark energy models. Here, we will argue that New Early Dark Energy offers a simple and natural framework to extend Λ\LambdaCDM while also providing a pathway to resolving the H0H_0 tension alongside its smaller cousin, the S8S_8 tension. At the microscopic level, we discuss the possibility that the trigger is either given by an ultralight scalar field or a dark sector temperature. In both cases, it prompts the transition of an eV\mathrm{eV}-mass scalar field from its false to its true minimum. Furthermore, we argue that the same phase transition could give rise to a dynamic process for generating neutrino masses.

Keywords

Cite

@article{arxiv.2307.03481,
  title  = {New Early Dark Energy as a solution to the $H_0$ and $S_8$ tensions},
  author = {Florian Niedermann and Martin S. Sloth},
  journal= {arXiv preprint arXiv:2307.03481},
  year   = {2024}
}

Comments

Invited chapter for the edited book Hubble Constant Tension (Eds. E. Di Valentino and D. Brout, Springer Singapore, expected in 2024)