On the Cluster Sunyaev-Zel'dovich Effect and Hubble Constant

Abstract

This study shows one important effect of preexistent cosmic microwave background temperature fluctuations on the determination of the Hubble constant through Sunyaev-Zel'dovich effect of clusters of galaxies, especially when coupled with the gravitational lensing effect by the same clusters. The effect results in a broad distribution of the apparent Hubble constant. The combination of this effect with other systematic effects such as the Loeb-Refregier Effect seems to provide an explanation for the observationally derived values of the Hubble constant currently available based on the Sunyaev-Zel'dovich effect, if the true value of the Hubble constant is 60-80 km/s/Mpc. It thus becomes possible that the values of the Hubble constant measured by other techniques which generally give a value around 60-80 km/s/Mpc be reconciled with the SZ effect determined values of the Hubble constant, where are systematically lower than others and have a broad distribution.