Conveners
Cosmological tests of ultra-light axions
- Keir Rogers
- (Chair: Andrew Eberhardt)
Description
The fundamental nature of dark matter and dark energy so far eludes direct detection experiments, but it has left its imprint in the cosmic large-scale structure. Ultra-light axions (ULAs; masses m < 10^-17 eV) are motivated by axiverse considerations. Searching for ULAs requires accurate modelling of axion structure formation including wave effects, careful handling of astrophysical uncertainties and consistent observations in independent cosmological probes. I will review a multi-scale, multi-epoch test of ULAs combining state-of-the-art modelling with observations of the cosmic microwave background, galaxy clustering (redshift z < 2), the Lyman-alpha forest (2 < z < 5) and the high-redshift (z > 5) galaxy UV luminosity function from the Hubble and Webb Space Telescopes. I will discuss the extent to which cosmological data are more consistent in the presence of ULAs. I will further discuss prospects for adjudicating the viability of axion models in observations of the galaxy and Milky Way sub-structure distributions in the transformative Vera C. Rubin Observatory.
