Speaker
Description
Dark Acoustic Oscillations (DAO) are characteristic wiggles and cutoffs in the matter power spectrum that probe non-gravitational dark matter (DM) interactions. We synthesize four recent analyses. Inelastic self-scattering in a two-component dark sector generates DAO via exothermic conversion and suppresses small-scale structure. Elastic DM–proton scattering imprints DAO on weak lensing. Our DES Year 3 analysis sets upper limits five times stronger than Planck CMB constraints. In the Mirror Twin Higgs framework, DAO from twin-sector couplings simultaneously alleviate the Hubble and S8 tensions. DM–neutrino interactions yield a nearly 3σ preference when combining early Universe data with DES Y3 cosmic shear, resolving the S8 discrepancy. Critically, China Space Station Telescope (CSST) forecasts project an order-of-magnitude improvement on DM–proton scattering limits and 10% precision on twin baryon abundance. CSST will use these four DAO signals to test dark matter interactions beyond the standard cosmological model.