Speaker
Jacob Leedom
(University of California, Berkeley)
Description
A number of proposed and ongoing experiments search for axion dark matter with a mass nearing the limit set by small scale structure. I will discuss the late universe cosmology of these models and show that requiring the axion to have a matter-power spectrum that matches that of cold dark matter constrains the magnitude of the axion couplings to the visible sector. I will also survey mechanisms that can alleviate the bounds, namely, the introduction of large charges, various forms of kinetic mixing, a clockwork structure, and imposing a discrete symmetry. We provide an explicit model for each case and explore their phenomenology and viability to produce detectable ultralight axion dark matter.
Author
Jacob Leedom
(University of California, Berkeley)
Co-author
Jeff Dror
(Lawrence Berkeley National Laboratory)
