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 \pm 0.12 , \sigma _ { \mathrm { 8 } } = 0.802 \pm 0.037 , and \Omega _ { { \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 \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 ) .