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Abstract

The Hubble tension refers to a persistent discrepancy between measurements of the Hubble constant obtained from supernovae and the cosmic microwave background. To address this issue, we explore alternative cosmological models and combine various data sources, such as gamma-ray bursts (GRBs), quasars (QSOs), baryon acoustic oscillations, and supernovae.
‍ GRBs are among the most explosive phenomena in the Universe, which have been observed up to redshift 9.4 and thus can be used as cosmological probes. For GRBs, we use a relationship involving three factors, the so-called Dainotti fundamental plane: the peak luminosity, the time at the end of an X-ray plateau, and the X-ray luminosity at that time. For QSOs, we use a relationship between UV and X-ray luminosity. We correct these relationships for any biases using a reliable statistical method. We use two types of likelihoods (ways to infer parameters): traditional Gaussian and a new best-fit method. The new method reduces uncertainties in parameters, especially in the Hubble constant, by up to 35%.