Speaker
Description
The latest Dark Energy Spectroscopic Instrument (DESI) survey results show that dark energy could evolve with time. This is achieved by constraining one of the standard rulers: the sound horizon at the drag epoch, with DESI Baryon Acoustic Oscillation, Cosmic Microwave Background, and supernovae. However, we could also constrain cosmological parameters with the other standard ruler: the particle horizon during the matter-radiation equality. In this talk, I will explain how to constrain the scale of matter-radiation equality with peculiar velocity. I have developed a model-independent method to constrain the scale of matter-radiation equality with the galaxy and velocity power spectra. Our method improves the constraint on the scale of radiation-radiation equality by around 50% compared to the previous method that only uses the galaxy power spectrum. In the future, we can apply this method to the DESI survey to constrain the scale of matter-radiation equality at different redshift bins. Combining this with other datasets can constrain cosmological parameters and potentially provide a complementary test for the time evolution of dark energy.
