The Atacama Cosmology Telescope: limits on dark matter-baryon interactions from DR4 power spectra

Understand

Diverse astrophysical observations suggest the existence of cold dark matter that interacts only gravitationally with radiation and ordinary baryonic matter.

• Any nonzero coupling between dark matter and baryons would provide a significant step towards understanding the particle nature of dark matter.
• Measurements of the cosmic microwave background (CMB) provide constraints on such a coupling that complement laboratory searches.
• In this work we place upper limits on a variety of models for dark matter elastic scattering with protons and electrons by combining large-scale CMB data from the Planck satellite with small-scale information from Atacama Cosmology Telescope (ACT) DR4 data.