Percent-level constraints on baryonic feedback with spectral distortion measurements

High-significance measurements of the monopole thermal Sunyaev-Zel'dovich cosmic microwave background spectral distortions have potential to tightly constrain poorly understood baryonic feedback processes. The sky-averaged Compton-$y$ distortion and its relativistic correction are measures total energy in electrons observable universe their mean temperature. We use CAMELS suite hydrodynamic simulations explore possible constraints on parameters describing subgrid implementation from active galactic nuclei supernovae, assuming a PIXIE-like measurement. small $25\text{ }\text{ }{h}^{\ensuremath{-}1}\text{ }\mathrm{Mpc}$ boxes present challenges due significant sample variance. utilize machine learning construct interpolators through noisy simulation data. Using halo model, we translate mass functions into factors reduce variance where required. Our results depend model. In case IllustrisTNG, find that best-determined parameter combination can be measured $\ensuremath{\simeq}2%$ corresponds product (AGN) supernova (SN) feedback. SIMBA, tightest constraint is $\ensuremath{\simeq}0.2%$ ratio between AGN SN A second orthogonal $\ensuremath{\simeq}8%$. demonstrate constraining power measurement late-time monopoles would for models.