BEXCO - Room F(201/202/203/204)
[GA185] Studying cosmological gamma-ray propagation with the Cherenkov Telescope Array
The measurement of gamma rays originating from active galactic nuclei offers the unique opportunity to study the propagation of very-high-energy photons over cosmological distances. Most prominently, gamma rays interact with the extragalactic background light (EBL) to produce electron-positron pairs, imprinting an attenuation signature on gamma-ray spectra. The electron-positron pairs can also induce electromagnetic cascades whose detectability in gamma rays depends on the intergalactic magnetic field (IGMF). Furthermore, physics beyond the Standard Model such as Lorentz invariance violation (LIV) or oscillations between photons and axion-like particles (ALP) could affect the propagation of gamma rays. The future Cherenkov Telescope Array (CTA), with its unprecedented gamma-ray source sensitivity, as well as enhanced energy and spatial resolution at very high energies, is perfectly suited to study cosmological effects on gamma-ray propagation. Here, we present the first results of a study designed to realistically assess the capabilities of CTA to probe the EBL, IGMF, LIV, and ALP.