A NEW METHOD FOR DETERMINING THE HUBBLE CONSTANT FROM SUB-TEV GAMMA-RAY OBSERVATIONS

The present uncertainty in the Hubble constant leaves unresolved quest ions regarding the age of the universe and related matters involving t he amount and nature of the dark matter in the universe, consistency w ith the inflationary model of the universe, and the need for a cosmolo gical constant. It is clear that a significantly precise determination of the Hubble constant by as many different methods as possible is cr ucial to our knowledge and understanding of the character of the unive rse. We propose here an entirely new method for determining the Hubble constant, based on measuring the extinction of high-energy gamma-rays emitted by detectable gamma-ray emitting blazars at various redshifts .