AI and the World's Hard Problems · Astronomy & space · arXiv · 2026-10-21
Gamma-ray Bursts as Cosmological Probes Calibrated with Strongly Lensed Quasars and Neural Networks
Gamma-ray bursts can probe distances beyond the redshifts routinely covered by Type Ia supernovae, but their cosmological use is limited by calibration circularity and possible redshift-dependent effects. The study uses strongly lensed quasars as external calibrators, reconstructing the luminosity-distance relation with a neural network trained on TDCOSMO strong-lensing distances to calibrate the Amati and Combo GRB relations, and infers cosmological parameters through a hierarchical Bayesian analysis of flat ΛCDM. Amati yields H0 = 78.26 km/s/Mpc and Ωm = 0.670, Combo yields H0 = 78.71 km/s/Mpc and Ωm = 0.635, but the inferred H0 is not an independent GRB measurement since it retains the TDCOSMO distance scale, and precision is limited by GRB scatter and lens-modelling uncertainties.