1304.6399 (Lingfei Wang et al.)

Small non-Gaussianity and dipole asymmetry in the CMB    [PDF]

Lingfei Wang, Anupam Mazumdar

In this paper we provide a prescription for obtaining a small non-Gaussianity and the observed dipole asymmetry in the cosmic microwave background radiation. The observations inevitably lead to multi-field inflationary dynamics, where each field can create positive or negative large non-Gaussianity, resulting a fine cancellation but with an observable imprint on the hemispherical asymmetry. We discuss this possibility within a simple slow-roll scenario and find that it is hard to explain the observed dipole asymmetry. We briefly discuss some speculative scenarios where one can explain dipole asymmetry.

View original: http://arxiv.org/abs/1304.6399