Speaker
Description
The next generation of cosmology surveys will probe the matter distribution of the universe to unparalleled precision. To achieve this level of accuracy in cosmological parameter estimation, we need to use information at small scales of $\sim$ 1 Mpc, which requires an accurate model of baryonic feedback. We use the Dark Matter + Baryon (DMB) model, a flexible halo model with several parameters to describe baryonic feedback that is well fit to a variety of different hydrodynamical simulations. Using a sample of thermal Sunyaev-Zeldovich (tSZ) selected galaxy clusters from the Atacama Cosmology Telescope (ACT) - with masses calibrated via weak lensing from the Dark Energy Survey (DES) - we develop a robust end-to-end pipeline that directly models the calibrated observables. Our analysis demonstrates that the tSZ Y-M relation can constrain several DMB model parameters, providing key insights into baryonic feedback effects on cosmic shear at the several percent level. We find a preference for intermediate to strong levels of feedback, which is both consistent and competitive with several hydrodynamic simulations, as well as with similar analyses performed on complementary probes. Finally, we discuss the implications of our results in the context of current and upcoming cosmic shear surveys.