Characteristic Angular Scales in Cosmic Microwave Background Radiation

We investigate the stochasticity in temperature fluctuations in the cosmic microwave background (CMB) radiation data from {\it Wilkinson Microwave Anisotropy Probe}. We show that the angular fluctuations of the temperature is a Markov process with a {\it Markov angular scale}, $\Theta_{\rm Markov}=1.01^{+0.09}_{-0.07}$. We characterize the complexity of the CMB fluctuations by means of a Fokker-Planck or Langevin equation and measure the associated Kramers-Moyal coefficients for the fluctuating temperature field $T(\widehat{n})$ and its increment, $\mathrm{\Delta }T=T({\widehat{n}}_1)-T({\widehat{n}}_2)$. Through this method we show that temperature fluctuations in the CMB has fat tails compared to a Gaussian distribution.