Exploring the gamma-ray horizon with the next generation of gamma-ray telescopes. Part 2: Extracting cosmological parameters from the observation of gamma-ray sources

The potential of the new generation Cherenkov telescopes to measure the energy spectrum of both, the already established extragalactic very high energy γ-ray emitters and the best very high energy candidates from the EGRET catalogue is discussed. By a realistic simulation of the analysis of the expected extrapolated energy spectra, it is shown that the foreseen capability and precision of these instrument to measure the gamma-ray horizon may open the door to competitive measurements of the cosmological parameters.