Hints of new physics for the Hubble tension: violation of cosmological principle

Abstract

Discrepancy between the measurements of Hubble constant $H_{0}$ from the cosmic microwave background (CMB) and the local distance ladder is the most serious challenge to the standard $\Lambda$CDM model. Recent researches point out that it might be related with the violation of cosmological principle. Here, we investigate the impact of dipole-monopole correction on the constraints of $H_{0}$ utilizing the dipole fitting method based on the $\Lambda$CDM model and cosmography method. Our results show that the dipole-monopole correction can reduce the constraints of $H_{0}$ from a larger value consistent with SH0ES results to a smaller value consistent with Planck results. This finding can effectively alleviate the Hubble tension. Through making redshift tomography and model-independent analyses, we confirm that our findings are independent of redshift and cosmological model. In addition, the theoretical prediction of $H(z)/(1+z)$ reconstructed by the constraints of $\Lambda$CDM model with the dipole correction is in agreement with BAOs measurements including 5 DESI BAOs within 1$\sigma$ range except datapoint at z = 0.51. Our research suggests that the Hubble tension originates from new physics beyond the standard $\Lambda$CDM model, which might lead to a violation of the cosmological principle.