A tomographic test of cosmic anisotropy with the recently-released quasar sample

Abstract

AbstractWe test the cosmic anisotropy in the dipole-modulated $$\Lambda $$ Λ CDM model and Finslerian cosmological model with the recently-released quasar sample. Based on the redshift tomographic method, the quasar sample is divided into two subsets $$z \le z_{cut}$$ z ≤ z cut and $$z > z_{cut}$$ z > z cut by different cutting redshifts. The dipole amplitudes of the two cosmological models from the subsets $$z \le z_{cut}$$ z ≤ z cut are very weak. We find that quasars at a higher redshift range may provide more detailed information about the dipole amplitude $$A_D$$ A D . The dipole directions of each cosmological model from the subsets $$z \le 1.1$$ z ≤ 1.1 and $$z > 1.1$$ z > 1.1 are deviated by $$1\sigma $$ 1 σ level. The Pantheon sample is combined with the two subsets. The dipole amplitude from the two combined datasets is also very weak. In the dipole-modulated $$\Lambda $$ Λ CDM model, the dipole direction from the combined dataset quasar at $$z \le 1.1$$ z ≤ 1.1 and Pantheon sample is far away from the one given by the Pantheon sample. In the Finslerian cosmological model, the dipole directions from the two combined datasets are close to the one in the Pantheon sample.