A New Measurement of the Hubble Constant and Matter Content of the Universe Using Extragalactic Background Light ?-Ray Attenuation

The Hubble constant H-0 and matter density ?(m) of the universe are measured using the latest ?-ray attenuation results from Fermi-LAT and Cerenkov telescopes. This methodology is based upon the fact that the extragalactic background light supplies opacity for very high energy photons via photon?photon interaction. The amount of ?-ray attenuation along the line of sight depends on the expansion rate and matter content of the universe. This novel strategy results in a value of <CDATA<i km;s(?1);Mpc(?1) and <CDATA<i. These estimates are independent and complementary to those based on the distance ladder, cosmic microwave background (CMB), clustering with weak lensing, and strong lensing data. We also produce a joint likelihood analysis of our results from ?-rays and those from more mature methodologies, excluding the CMB, yielding a combined value of H(0)66.6.+/-.1.6 km.s-1.Mpc-1 and Om.=.0.29.+/-.0.02.