First Cosmological Constraints from the Joint Analysis of Galaxy Clustering and the Kinetic Sunyaev-Zel'dovich Effect

TL;DR

This study combines galaxy clustering and the kinetic Sunyaev-Zel'dovich effect to improve constraints on cosmological parameters using ACT DR6 data and the CMASS galaxy sample, demonstrating the kSZ effect's utility in cosmology.

Contribution

First joint analysis of galaxy clustering and kSZ effect with real data, providing tighter cosmological constraints and demonstrating the kSZ effect's complementary role.

Findings

Tighter constraints on H_0, Ω_m, w_0 compared to galaxy clustering alone.

Detection of pairwise kSZ power spectrum with high S/N (~7).

Improved Figures of Merit for key cosmological parameter pairs.

Abstract

We perform the first joint analysis of galaxy clustering (GC) and the kinetic Sunyaev-Zel'dovich (kSZ) effect to simultaneously constrain cosmological and astrophysical parameters in this work, utilizing a combination of the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) map and the Constant Stellar Mass (CMASS) galaxy sample. As a complementary probe to the galaxy density power spectrum, we incorporate the pairwise kSZ power spectrum detected with a high signal-to-noise ratio (S/N $\sim 7$) to derive constraints on cosmological parameters ($H_0 = 70.82^{+4.94}_{-5.01}$, $\Omega_{\rm m} = 0.290^{+0.092}_{-0.068}$, $w_0 = -1.038^{+0.245}_{-0.437}$) and the average optical depth of the galaxy sample ($\lg\bar{\tau} = -4.24 \pm 0.10$). Compared to the GC-only analysis, the joint analysis yields tighter constraints on these cosmological parameters: the Figures of Merit improve by 20.5\%, 19.7\% and 10.0\% for the $H_0$--$\Omega_{\rm m}$, $H_0$--$w_0$ and $\Omega_{\rm m}$--$w_0$ contours, respectively. For the first time, we demonstrate the complementary applicability of the kSZ effect in constraining cosmological parameters from real observational data.