Gamma-Ray Bursts and Cosmic Radiation Backgrounds

摘要

If gamma-ray bursts trace the cosmic star formation rate to large redshifts, their prompt and delayed emissions provide new tools for early universe cosmology. In addition to probing the intervening matter via absorption lines in the optical band, GRB continua also contribute to the evolving cosmic radiation background. We discuss the contribution of GRBs to the high-energy background, and the effect parr creation off low-energy background photons has on their observable TeV spectra.