Ultra light axions - new observable signatures and theoretical approaches*

Ultralight axions (ULAs) are a well-motivated dark matter candidate, with well-known experimental signatures on CMB temperature and polarization anisotropies. In this presentation, we explore a number of signatures of ULAs on CMB secondary anistropies (weak lensing of the CMB and the kinetic-Sunyaev Zel'dovich effects), establishing the utility of future CMB experimental, galaxy clustering, and galaxy cluster detection efforts to systematically probe ULA parameter space. We also explore the limits of existing computational methods (based on fluid approximations), and the applicability/utility of novel approaches, like Principal Component Analysis (PCA) with the generalized dark matter (GDM) formalism.