Potential of EBL and cosmology studies with the Cherenkov Telescope
  Array
  Very high energy (VHE, E >100 GeV) gamma-rays are absorbed via interaction
with low-energy photons from the extragalactic background light (EBL) if the
involved photon energies are above the threshold for electron-positron pair
creation. The VHE gamma-ray absorption, which is energy dependent and increases
strongly with redshift, distorts the VHE spectra observed from distant objects.
The observed energy spectra of the AGNs carry, therefore, an imprint of the
EBL. The detection of VHE gamma-ray spectra of distant sources (z = 0.11 -
0.54) by current generation Imaging Atmospheric Cherenkov Telescopes (IACTs)
enabled to set strong upper limits on the EBL density, using certain basic
assumptions about blazar physics. In this paper it is studied how the improved
sensitivity of the Cherenkov Telescope Array (CTA) and its enlarged energy
coverage will enlarge our knowledge about the EBL and its sources. CTA will
deliver a large sample of AGN at different redshifts with detailed measured
spectra. In addition, it will provide the exciting opportunity to use gamma ray
bursts (GRBs) as probes for the EBL density at high redshifts.
