CMBR dipole from ultra large scale isocurvature perturbations
  The observed CMBR dipole, generally interpreted as the consequence of the peculiar motion of the Sun with respect to the reference frame of the CMBR, can also be explained by the presence of ultra large scale (of the order of $100H_0^{-1}$) isocurvature perturbations. Moreover, the simplest model of inflation with several scalar fields, namely that of double inflation, with appropriate parameters, can produce such perturbations. 
David Langlois (DARC, CNRS UPR 176, Observatoire de Paris-Meudon)