Breaking baryon-cosmology degeneracy with the electron density power
  spectrum
  Uncertain feedback processes in galaxies affect the distribution of matter,
currently limiting the power of weak lensing surveys. If we can identify
cosmological statistics that are robust against these uncertainties, or
constrain these effects by other means, then we can enhance the power of
current and upcoming observations from weak lensing surveys such as DES,
Euclid, the Rubin Observatory, and the Roman Space Telescope. In this work, we
investigate the potential of the electron density auto-power spectrum as a
robust probe of cosmology and baryonic feedback. We use a suite of
(magneto-)hydrodynamic simulations from the CAMELS project and perform an
idealized analysis to forecast statistical uncertainties on a limited set of
cosmological and physically-motivated astrophysical parameters. We find that
the electron number density auto-correlation, measurable through either
kinematic Sunyaev-Zel'dovich observations or through Fast Radio Burst
dispersion measures, provides tight constraints on $\Omega_{m}$ and the mean
baryon fraction in intermediate-mass halos, $\bar{f}_{\mathrm{bar}}$. By
obtaining an empirical measure for the associated systematic uncertainties, we
find these constraints to be largely robust to differences in baryonic feedback
models implemented in hydrodynamic simulations. We further discuss the main
caveats associated with our analysis, and point out possible directions for
future work.
