Constraining H0 in general dark energy models from Sunyaev-Zeldovich/X-ray technique and complementary probes

In accelerating dark energy models, the estimates of the Hubble constant, H0, from Sunyaev-Zel'dovich effect (SZE) and X-ray surface brightness of galaxy clusters may depend on the matter content (ΩM), the curvature (ΩK) and the equation of state parameter (ω). In this article, by using a sample of 25 angular diameter distances of galaxy clusters described by the elliptical β model obtained through the SZE/X-ray technique, we constrain H0 in the framework of a general ΛCDM model (arbitrary curvature) and a flat XCDM model with a constant equation of state parameter ω = px/ρx. In order to avoid the use of priors in the cosmological parameters, we apply a joint analysis involving the baryon acoustic oscillations (BAO) and the CMB Shift Parameter signature. By taking into account the statistical and systematic errors of the SZE/X-ray technique we obtain for nonflat ΛCDM model H0 = 74+5.0−4.0 km s−1 Mpc−1(1σ) whereas for a flat universe with constant equation of state parameter we find H0 = 72+5.5−4.0 km s−1 Mpc−1(1σ). By assuming that galaxy clusters are described by a spherical β model these results change to H0 = 62+8.0−7.0 and H0 = 59+9.0−6.0 km s−1 Mpc−1(1σ), respectively. The results from elliptical description are in good agreement with independent studies from the Hubble Space Telescope key project and recent estimates based on the Wilkinson Microwave Anisotropy Probe, thereby suggesting that the combination of these three independent phenomena provides an interesting method to constrain the Hubble constant. As an extra bonus, the adoption of the elliptical description is revealed to be a quite realistic assumption. Finally, by comparing these results with a recent determination for a flat ΛCDM model using only the SZE/X-ray technique and BAO, we see that the geometry has a very weak influence on H0 estimates for this combination of data.