Constraints on Dark Energy and Distance Duality From Sunyaev–zel'dovich Effect and Chandra X-Ray Measurements

We demonstrate that the recent measurements of the angular diameter distance of 38 clusters of galaxies using Chandra X-ray data and radio observations from the OVRO and BIMA interferometric arrays place new and independent constraints on the dark energy component. In particular, we found that the equation of state is bound to be -1.18 < w < -0.35 at 68% c.l. We also search for deviations in the duality relation between angular and luminosity distances. Using only cluster data, we found that the ratio between the two distances defined as η = D L /D A (1 + z) 2 is bound to be η = 0.97 ± 0.03 at 68% c.l. with no evidence for distance duality violation in the framework of the Λ-CDM model. Comparing the cluster angular diameter distance data with luminosity distance data from type Ia Supernovae, we obtain the model independent constraint η = 1.01 ± 0.07 at 68% c.l. Those results provide a useful check for the cosmological concordance model and for the presence of systematics in SN-Ia and cluster data.