The standard ΛCDM model is based on the cosmological principle that the universe is homogeneous and isotropic on large scales (greater than 100 Mpc). A crucial test of this principle involves analyzing the Cosmic Microwave Background (CMB), which shows a dipole anisotropy on the order of ΔT/T∼10^−3. This dipole is commonly interpreted as owing to our motion with respect to the CMB rest frame.
A model-independent approach to validate this kinematic hypothesis is to determine the dipole moment in the angular distribution of large-scale structures. Recent observations of dipole anisotropies in the distribution of radio galaxies and quasars, obtained from the NVSS and WISE catalogs, show differences in both direction and magnitude when compared to the CMB dipole. These discrepancies pose a challenge to the predictions of the ΛCDM model.
In this talk, we investigate how considering the clustering dipole affects the cosmic large-scale structure distribution dipole using the NVSS catalog, examine the non-linear regime to calculate the correlation between the clustering dipole and the kinematic dipole, and determine whether these outcomes help reconcile previous measurements of the NVSS dipole with predictions based on the CMB. Additionally, we explore a model in which the distribution of matter on large scales might be intrinsically anisotropic. Using the remnant discrepancy between the observed and predicted dipole, we derive an upper limit for the amplitude of intrinsic anisotropy and calculate the clustering for this model.