The CTA Sensitivity to Lorentz-Violating Effects on the Gamma-Ray
  Horizon
  The arrival of TeV-energy photons from distant galaxies is expected to be
affected by their QED interaction with intergalactic radiation fields through
electron-positron pair production. In theories where high-energy photons
violate Lorentz symmetry, the kinematics of the process $\gamma +
\gamma\rightarrow e^+ + e^-$ is altered and the cross-section suppressed.
Consequently, one would expect more of the highest-energy photons to arrive if
QED is modified by Lorentz violation than if it is not. We estimate the
sensitivity of Cherenkov Telescope Array (CTA) to changes in the $\gamma$-ray
horizon of the Universe due to Lorentz violation, and find that it should be
competitive with other leading constraints.
