Constraining the anisotropy of the Universe with the X-ray and UV fluxes of quasars

We test the anisotropy in the Finslerian cosmological model with the X-ray and ultraviolet (UV) fluxes of quasars. The 2015 and 2020 compilations of quasars are used in the cosmological constraints. We find that the dipole direction given by the 2015 quasar compilation is not far away from the one provided by the Pantheon sample and the angular differences are around 30 degrees. The Pantheon sample is combined with quasars as the standardized candles to test the cosmic anisotropy. The results from two combined datasets are consistent. They show that the dipole anisotropy is weak in the Finslerian cosmological model. We investigate the Hubble constant H0 in the Finslerian cosmological model. Though the central value of H0 from the combination of six gravitationally lensed quasars, Pantheon sample, and 2020 quasar compilation decreases a little bit, it is consistent with the result from six gravitationally lensed quasars within statistical uncertainties.

Automated summary

In this study, the anisotropy in the Finslerian cosmological model was tested using X-ray and UV fluxes of quasars. The dipole anisotropy was found to be weak, and the Hubble constant H0 showed a slight decrease in the central value but remained consistent within statistical uncertainties with other results.