Title: Very-high-energy Gamma-ray Probes of of Cosmology

Abstract:  The observed properties of active galactic nuclei carry the imprint of the magnetic fields and low-energy photon fields encountered by the gamma rays en route to the observer. VERITAS, a ground-based imaging atmospheric-Cherenkov telescope array sensitive to gamma rays above 85 GeV, has collected a large set of observations of blazars for a range of redshifts, the furthest at a redshift of 0.9. These observations can be used to constrain two key cosmological observables: the spectral energy distribution of the extragalactic background light (EBL), and the strength and correlation length of the intergalactic magnetic field (IGMF). We present the latest VERITAS efforts to constrain the EBL and IGMF, together with an overview of future prospects.