Powered by Indico
Dark Energy (EDE) models which were proposed to help resolve the Hubble tension have received a lot of attention recently. Interestingly, these models have also been shown to be able to provide an explanation for the observed signal of cosmic birefringence in the Cosmic Microwave Background (CMB) data. In this talk I will briefly review the ultralight axion-like EDE models with n=3 and present our work testing the model against cosmological observations. While previous articles in the literature argue that the n=3 EDE model is not consistent with the observations of cosmic birefringence, we show that it is a consequence of the assumptions made about the dependence of the CMB power spectrum on the model parameters. We relax these assumptions and do an exploration of the full parameter space and find that the model can fit the observations quite well. EDE remains a promising candidate to explain the Hubble tension and cosmic birefringence, hitting two birds with one stone.