# A New Constraint on Early Dark Energy using the Profile Likelihood

### APA

Herold, L. (2023). A New Constraint on Early Dark Energy using the Profile Likelihood. Perimeter Institute. https://pirsa.org/23010103

### MLA

Herold, Laura. A New Constraint on Early Dark Energy using the Profile Likelihood. Perimeter Institute, Jan. 17, 2023, https://pirsa.org/23010103

### BibTex

@misc{ pirsa_PIRSA:23010103, doi = {10.48660/23010103}, url = {https://pirsa.org/23010103}, author = {Herold, Laura}, keywords = {Particle Physics}, language = {en}, title = {A New Constraint on Early Dark Energy using the Profile Likelihood}, publisher = {Perimeter Institute}, year = {2023}, month = {jan}, note = {PIRSA:23010103 see, \url{https://pirsa.org}} }

Laura Herold Max Planck Institute for Astrophysics (MPA)

## Abstract

A dark energy-like component in the early universe, known as early dark energy (EDE), is a proposed solution to the Hubble tension. In this talk, I will describe how a frequentist profile likelihood yields important complementary information compared to a Bayesian MCMC analysis. While in an MCMC analysis, the EDE model is clearly disfavoured by Cosmic Microwave Background and large-scale structure data, a profile likelihood analysis prefers consistently larger amounts of EDE and with that a Hubble constant consistent with the SH0ES measurement for the same data sets. The difference between MCMC and profile likelihood can be explained by prior volume effects in the MCMC analysis. I will discuss how frequentist and Bayesian methods can give important complementary information in the context of beyond-LCDM models.

Zoom link: https://pitp.zoom.us/j/97257428766?pwd=ckx4ajRsQVRQUnpXaGEvZEtEWW9ldz09