Misc,
Improved Modeling of the Kinematic Sunyaev-Zel'dovich Projected-Fields signal and its Cosmological Dependence
(2023)cite arxiv:2306.03127Comment: 18 pages, 6 figures, to be submitted to Phys. Rev. D.
Abstract
Over the past decade, the kinematic Sunyaev-Zel'dovich (kSZ) effect has
emerged as an observational probe of the distribution of baryons and velocity
fields in the late Universe. Of the many ways to detect the kSZ, the
`projected-fields kSZ estimator' has the promising feature of not being limited
galaxy samples with accurate redshifts. The current theoretical modeling of
this estimator involves an approximate treatment only applicable at small
scales. As the measurement fidelity rapidly improves, we find it necessary to
move beyond the original treatment and hence derive an improved theoretical
model for this estimator without these previous approximations. We show that
the differences between the predicted signal from the two models are
scale-dependent and will be significant for future measurements from the Simons
Observatory and CMB-S4 in combination with galaxy data from WISE or the Rubin
Observatory, which have high forecasted signal-to-noise ratios ($>100$). Thus,
adopting our improved model in future analyses will be important to avoid
biases. Equipped with our model, we explore the cosmological dependence of this
kSZ signal for future measurements. With a Planck prior, residual uncertainty
on $Łambda$CDM parameters leads to $\sim7\%$ marginalized uncertainties on the
signal amplitude, compared to a sub-percent level forecasted with a fixed
cosmology. To illustrate the potential of this kSZ estimator as a cosmological
probe, we forecast initial constraints on $Łambda$CDM parameters and the sum
of neutrino masses, paving the way for jointly fitting both baryonic
astrophysics and cosmology in future analyses.
