The WMAP cold spot
  The WMAP cold spot was found by applying spherical wavelets to the first year
WMAP data. An excess of kurtosis of the wavelet coefficient was observed at
angular scales of around 5 degrees. This excess was shown to be inconsistent
with Gaussian simulations with a p-value of around 1%. A cold spot centered at
(b = -57, l = 209) was shown to be the main cause of this deviation. Several
hypotheses were raised to explain the origin of the cold spot. After performing
a Bayesian template fit a collapsing cosmic texture was found to be the most
probable hypothesis explaining the spot. Here we review the properties of the
cold spot and the possible explanations.
