A model for CMB anisotropies on large angular scales

Abstract

We investigate the possibility that a low-temperature, low-frequency anomaly in the black-body spectrum, as it emerges when enlarging the Standard Model's gauge-group factor U(1)$_Y$ to SU(2) (Yang-Mills scale $\sim 10^{-4}$ eV), explains the discrepancy between the Local Group's velocity as directly observed and as inferred by assuming a purely kinematic origin of the CMB dipole. This discrepancy determines the kinetic term for temperature fluctuations in our model action. Upon subtracting the dipole contribution this model can then be used to predict the low multipoles with $l\ge 2$ in the CMB temperature-temperature correlation and to reinvestigate the issue of statistical isotropy.