Title
Ultra-light Axion Dark Matter and CMB B-mode Polarization
Abstract
We propose a new source of anisotropic cosmic birefringence induced by dark matter adiabatic density perturbation. If dark matter is ultralight axions that carry a coupling to photon, its adiabatic density fluctuations will induce anisotropic cosmic birefringence with a blue-tilted rotation power spectrum, thus generating CMB B-mode polarization on sub-degree angular scales. It is shown that the birefringence B modes can dominate over CMB lensing B modes at high l, manifesting as an excess power for l>1500 in future CMB lensing B-mode searches.
Suggested Citation
Ng, Kin-Wang.
(2017).
Ultra-light Axion Dark Matter and CMB B-mode Polarization.
Retrieved from the University of Minnesota Digital Conservancy,
https://hdl.handle.net/11299/188202.