Peculiar Velocity Effects on the CMB

Abstract

The aberration effect due to our peculiar velocity <math xmlns:xlink="http://www.w3.org/1999/xlink"> <mi>β</mi> boldsymbol{β } with respect to the CMB induces mixing among multipoles and off-diagonal correlations at all scales which can be used as a measurement of <math xmlns:xlink="http://www.w3.org/1999/xlink"> <mi>β</mi> boldsymbol{β } , which is independent of the standard measurement using the CMB temperature dipole. Here we review the two techniques that allow this measurement and the forecasts for the achievable precision with which these correlations can be measured in a number of CMB missions. The forecast in the case of Planck was later shown to be very accurate when the collaboration released their first set of data and measured the CMB aberration for the first time. Finally, we show that a proper accounting for the aberration effect solves the mystery of the power asymmetries in the CMB, present since the WMAP era.