The inflationary origin of the Cold Spot anomaly
  Single-field inflation, arguably the simplest and most compelling paradigm
for the origin of our Universe, is strongly supported by the recent results of
the Planck satellite and the BICEP2 experiment. The results from Planck,
however, also confirm the presence of a number of anomalies in the Cosmic
Microwave Background (CMB), whose origin becomes problematic in single-field
inflation. Among the most prominent and well-tested of these anomalies is the
Cold Spot, which constitutes the only significant deviation from gaussianity in
the CMB. Planck's non-detection of primordial non-gaussianity on smaller scales
thus suggests the existence of a physical mechanism whereby significant
non-gaussianity is generated on large angular scales only. In this letter, we
address this question by developing a localized version of the inhomogeneous
reheating scenario, which postulates the existence of a scalar field able to
modify the decay of the inflaton on localized spatial regions only. We
demonstrate that if the Cold Spot is due to an overdensity in the last
scattering surface, the localization mechanism offers a feasible explanation
for it, thus providing a physical mechanism for the generation of localized
non-gaussianity in the CMB. If, on the contrary, the Cold Spot is caused by a
newly discovered supervoid (as recently claimed), we argue that the
localization mechanism, while managing to enhance underdensities, may well shed
light on the rarity of the discovered supervoid.
