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 $T(\hat n)$ and its increment, $\Delta T =T(\hat n_1) - T(\hat n_2)$. Through this method we show that temperature fluctuations in the CMB has fat tails compared to a Gaussian distribution.
Categories: astro-ph cond-mat.stat-mech gr-qc hep-th physics.data-an