Constraining $H_0$ from Sunyaev-Zel'dovich effect, Galaxy Clusters X-ray   data, and Baryon Oscillations
  Estimates of $H_0$ from Sunyaev-Zel'dovich effect (SZE) and X-ray surface brightness of galaxy clusters depends on the underlying cosmology. In the current $\Lambda$CDM flat cosmology, a possible technique to broke the degenerescency on the mass density parameter ($\Omega_{m}$) is to apply a joint analysis involving the baryon acoustic oscillations (BAO). By adopting this technique to the ($H_0, \Omega_m$) parameter space, we obtain new constraints on the Hubble constant $H_0$ from BAO signature as given by the Sloan Digital Sky Survey (SDSS) catalog. Our analysis based on the SZE/X-ray data for a sample of 25 clusters yields $H_0= 74^{+4}_{-3.5}$ km s$^{-1}$ Mpc$^{-1}$ ($1\sigma$, neglecting systematic uncertainties). This result is in good agreement with independent studies from the {\it{Hubble Space Telescope}} key project and the recent estimates of WMAP, thereby suggesting that the combination of these three independent phenomena provides an interesting method to constrain the Hubble constant. 
J. V. Cunha, L. Marassi, J. A. S. Lima