Dark Energy from the Thermal Sunyaev Zeldovich Power Spectrum

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 $\hat{I}{\text{c◯}}_{\mathrm{m}}$ and $\ddot{I}{ƒ}_8$). We find that the amplitude of the tSZ power spectrum at $\ell \lesssim 10^3$ depends primarily on $F\equiv \ddot{I}{ƒ}_8(\hat{I}{\text{c◯}}_{\mathrm{m}}/B{)}^{0.40}{h}^{-0.21}$, 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 $w=-1.10\pm 0.12$, $\ddot{I}{ƒ}_8=0.802\pm 0.037$, and $\hat{I}{\text{c◯}}_{\mathrm{m}}=0.265\pm 0.022$ (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 $\hat{I}›$ 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).

Accepted version (MNRAS)