Explain the CMB hemispherical power asymmetry

Determine the physical origin of the observed hemispherical asymmetry in CMB power and assess whether it is physically connected to the reported hemispherical overdensity of early-type galaxies.

Background

The paper describes a reported correspondence between warmer, higher-power CMB regions and a sky region containing an excess of early-type galaxies. Although the paper suggests that the correlation could indicate a large-scale matter inhomogeneity, it does not establish the connection and identifies the CMB asymmetry as unresolved.