New early dark energy: Solving cosmic tensions with new microphysics in the early universe

by Florian Niedermann (Nordita)

Wednesday 8 Jun 2022, 13:30 → 14:30 Europe/Stockholm

Albano 3: 6228 - Mega (22 seats) (Albano Building 3)

Hybrid talk: Mega (6228, Hus 3, Albano) + https://stockholmuniversity.zoom.us/j/530682073

Differing measurements of the expansion rate of the universe have given rise to an observational dilemma in cosmology commonly referred to as the Hubble tension. A possible solution is provided by the model of new early dark energy (NEDE). Here, a scalar field’s false vacuum energy plays the role of an early dark energy component that leads to a short repulsive boost close to matter-radiation equality before it decays through a triggered first-order phase transition. I will first discuss the phenomenology of NEDE highlighting the role of the trigger mechanism and compare the model to its competitors in the literature. In a second step, I will explore different microscopic realisations of NEDE. I will argue that this program opens the door to a more complete understanding of the dark sector, and, at the same time, provides us with a possible explanation of the active neutrino masses.

Niedermann_2022-Jun-08.mp4