Constraints on axion-like polarization oscillations in the CMB with POLARBEAR

Speaker(s) Jacob Spisak (UCSD)

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Very light pseudoscalar fields, often referred to as axions, are compelling dark matter candidates and can potentially be detected through their coupling to the electromagnetic field. Recently a novel detection technique using the cosmic microwave background (CMB) was proposed, which relies on the fact that the axion field oscillates at a frequency equal to its mass in appropriate units, leading to a time-dependent birefringence. For appropriate oscillation periods this allows the axion field at the telescope to be detected via the induced sinusoidal oscillation of the CMB linear polarization. I will discuss how we search for this effect using the POLARBEAR telescope and the constraints we place.