Is the misalignment of the Local Group velocity and the 2MASS Redshift Survey dipole typical in a LambdaCDM model?

TL;DR

This paper predicts the Local Group's acceleration using the 2MASS Redshift Survey within LambdaCDM, showing the observed velocity-dipole misalignment is consistent with standard cosmological models and does not require additional nearby structures.

Contribution

It demonstrates that the observed misalignment can be explained by the halo model's small-scale power, without invoking extra nearby galaxies or distant clusters.

Findings

Misalignment angle of 21 degrees is consistent with LambdaCDM predictions.

Halo model's small-scale power explains the velocity-dipole misalignment.

No need for hypothetical nearby structures to account for the observed misalignment.

Abstract

We predict the acceleration of the Local Group generated by the 2MASS Redshift Survey within the framework of LambdaCDM and the halo model of galaxies. We show that as the galaxy fluctuations derived from the halo model have more power on small scales compared with the mass fluctuations, the misalignment angle between the CMB velocity vector and the 2MRS dipole is in reasonable agreement with the observed 21 degrees. This statistical analysis suggests that it is not necessary to invoke a hypothetical nearby galaxy or a distant cluster to explain this misalignment.