Relating the inhomogeneous power spectrum to the CMB hemispherical anisotropy

Understand

We relate the observed hemispherical anisotropy in the cosmic microwave radiation data to an inhomogeneous power spectrum model.

• The hemispherical anisotropy can be parameterized in terms of the dipole modulation model.
• This model leads to correlations between spherical harmonic coefficients corresponding to multipoles, l and l+1.
• We extract the $l$ dependence of the dipole modulation amplitude, A, by making a fit to the WMAP and PLANCK CMBR data.