Recent measurements of the temperature fluctuations of the Cosmic Microwave Background ( CMB ) radiation from the WMAP satellite provide indication of a non-Gaussian behavior .
Although the observed feature is small , it is detectable and analyzable .
Indeed , the temperature distribution P ^ { \mbox { \sc cmb } } ( \Delta T ) of these data can be quite well fitted by the anomalous probability distribution emerging within nonextensive statistical mechanics , based on the entropy S _ { q } \equiv k\ { 1 - \int \upd x [ P ( x ) ] ^ { q } \ } / ( q - 1 ) ( S _ { 1 } = - k \int \upd x P ( x ) \mbox { ln } [ P ( x ) ] ) .
For the CMB frequencies analysed , \nu = 40.7 , 60.8 , and 93.5 GHz , P ^ { \mbox { \sc cmb } } ( \Delta T ) is well described by P _ { q } ( \Delta T ) \propto 1 / [ 1 + ( q - 1 ) B ( \nu ) ( \Delta T ) ^ { 2 } ] ^ { 1 / ( q - 1 ) } , with q = 1.04 \pm 0.01 , the strongest non-Gaussian contribution coming from the South-East sector of the celestial sphere .
Moreover , Monte Carlo simulations exclude , at the 99 % confidence level , P _ { 1 } ( \Delta T ) \propto e ^ { - B ( \nu ) ( \Delta T ) { { } ^ { 2 } } } to fit the three-year data .