Dark Energy from the Thermal Sunyaev Zeldovich Power Spectrum

TL;DR

This paper uses the thermal Sunyaev-Zeldovich power spectrum to constrain dark energy parameters, improving analysis by accounting for trispectrum and marginalizing over various parameters, leading to precise measurements consistent with previous constraints.

Contribution

It introduces an improved analysis of the tSZ power spectrum that includes trispectrum effects and comprehensive marginalization, providing tighter constraints on dark energy and cosmological parameters.

Findings

Measured the amplitude parameter F with 2.6% precision

Constrained the dark energy equation of state to w = -1.10 ± 0.12

Determined the mass bias B = 1.71 ± 0.17

Abstract

We constrain the dark energy equation of state parameter, $w$, using the power spectrum of the thermal Sunyaev-Zeldovich (tSZ) effect. We improve upon previous analyses by taking into account the trispectrum in the covariance matrix and marginalising over the foreground parameters, the correlated noise, the mass bias $B$ in the Planck universal pressure profile, and all the relevant cosmological parameters (i.e., not just $\Omega_{\mathrm{m}}$ and $\sigma_8$). We find that the amplitude of the tSZ power spectrum at $\ell\lesssim 10^3$ depends primarily on $F\equiv \sigma_{8}(\Omega_{{\mathrm{m}}}/B)^{0.40}h^{-0.21}$, where $B$ is related to more commonly used variable $b$ by $B=(1-b)^{-1}$. We measure this parameter with 2.6\% precision, $F=0.460\pm 0.012$ (68% CL). By fixing the bias to $B=1.25$ and adding the local determination of the Hubble constant $H_0$ and the amplitude of the primordial power spectrum constrained by the Planck Cosmic Microwave Background (CMB) data, we find $w=-1.10\pm0.12$, $\sigma_{\mathrm{8}}=0.802\pm0.037$, and $\Omega_{{\mathrm{m}}}=0.265\pm0.022$ (68% CL). Our limit on $w$ is consistent with and is as tight as that from the distance-alone constraint from the CMB and $H_0$. Finally, by combining the tSZ power spectrum and the CMB data we find, in the $\Lambda$ Cold Dark Matter (CDM) model, the mass bias of $B=1.71\pm 0.17$, i.e., $1-b=0.58\pm 0.06$ (68% CL).