Constraining ALP-photon coupling using galaxy clusters
  We study photon-ALP conversion by resonance effects in the magnetized plasma
of galaxy clusters and compare the predicted distortion of the cosmic microwave
background spectrum in the direction of such objects to measurements of the
thermal Sunyaev-Zeldovich effect. Using galaxy cluster models based on current
knowledge, we obtain upper limits on the photon-ALP coupling constant $g$ of
$\lesssim \mathcal{O}(10^{-11}$ GeV$^{-1}$). The constraints apply to the mass
range of $2\cdot 10^{-14}$ eV $ \lesssim m_\text{ALP} \lesssim 3\cdot 10^{-12}$
eV in which resonant photon-ALP conversions can occur. These limits are
slightly stronger than current limits, and furthermore provide an independent
constraint. We find that a next generation PRISM-like experiment would allow
limits down to $g \approx \mathcal{O} (10^{-14}$ GeV$^{-1})$, two orders of
magnitude stronger than the currently strongest limits in this mass range.
