Early Dark Energy: a status update and new constraint using the profile likelihood (Laura Herold, MPA Garching)

Early dark energy (EDE) is a dark energy-like component in the early universe, which was proposed to solve the Hubble tension, a discrepancy between different measurements of the current expansion rate of the universe. Currently, there is no consensus in the literature as to whether EDE can simultaneously solve the Hubble tension and provide an adequate fit to the data from the cosmic microwave background and the large-scale structure of the universe. In this talk, I will give a brief overview on the status of EDE and describe the disagreement about EDE in the literature. To explore the origin of this disagreement, we use a profile likelihood analysis and find evidence that the constraints on EDE from Markov Chain Monte Carlo analyses are influenced by prior volume effects. Using the profile likelihood we construct constraints on the Hubble constant and the fraction of EDE, which are free from these effects, and find that EDE presents a viable solution to the Hubble tension while presenting a good fit to cosmological data sets.