Cosmology with Very-High-Energy Gamma-rays

Very-high-energy gamma-ray astronomy is typically concerned with standard astrophysical processes, such as particle acceleration and emission mechanisms in gamma-ray sources. However, gamma-ray observations can also be used to study the magnetic fields and low-energy photon fields encountered by the gamma rays as they travel cosmological distances to reach the observer. Two of these fields, the intergalactic magnetic field (IGMF) and extragalactic background light (EBL), encode information about the early universe and its subsequent evolution. I will present the latest results from VERITAS, a ground-based imaging atmospheric-Cherenkov telescope array sensitive to gamma rays above 85 GeV, on the properties of the EBL and IGMF.

Speaker: Elisa Pueschel (DESY / Zeuthen)