Speaker
Description
Future weak lensing surveys are poised to deliver unprecedented cosmological constraints, but their statistical power on small scales is fundamentally limited by systematic uncertainties in baryonic feedback. This feedback alters the total matter power spectrum in a way that is degenerate with key cosmological parameters. We introduce a self-consistent halo model that leverages the kinetic Sunyaev-Zel'dovich (kSZ) effect to directly calibrate baryonic physics. kSZ tomography provides a measurement of the galaxy-electron power spectrum, $P_{ge}$, which is a direct probe of the feedback-induced redistribution of the electron distribution in and around halos. We construct a unified framework that combines a stellar mass-based Halo Occupation Distribution (HOD) model for the galaxy-halo connection, a ``baryonification'' scheme for the distribution of gas and dark matter, and a consistent derivation of thermodynamic observables. We forecast how an upcoming measurement of $P_{ge}$ can be used as a prior to break degeneracies within this model. We forecast that this kSZ calibration as well as tSZ cross-correlation statistics significantly improves constraints on baryonic feedback parameters, allowing for the robust inclusion of small-scale weak lensing and galaxy-galaxy lensing data. This, in turn, sharpens cosmological constraints on parameters like $S_8$ and $\Omega_m$, effectively recovering the information that would otherwise be lost to systematic uncertainty.