Orateur
Nils Schöneberg
(LMU Munich)
Description
Reducing the sound horizon has been shown to be a very efficient way to reconcile the Hubble tension. In this talk I focus on how and why an increased Hubble parameter can follow from such a reduced sound horizon, and what guardrails the CMB provides in this case. The resulting degeneracies with the other cosmological parameters force models like early dark energy and models that shift the recombination redshift in very different phenomenological directions. Focusing on the latter, I show what kind of interesting phenomenological impacts such models can have while also highlighting the theoretical issues such models still face.