To develop observational tests of quantum gravity, we require lever arms that translate Planck-scale predictions into predictions at observationally accessible scales. In my talk, I will use asymptotically safe quantum gravity as a case study. I will show, how the interplay of quantum gravity with matter (both visible and "dark") shapes the properties of matter fields in and beyond the...
The transparency of the universe to high-energy gamma rays is governed by interactions with low-energy photons from the Cosmic Microwave Background (CMB) and Extragalactic Background Light (EBL) via Breit-Wheeler pair production. New physics models that suppress this process predict increased transparency, offering a testable scenario. This talk explores how such suppression arises within...