Isotherms clustering in cosmic microwave background
  Since the strong clustering of luminous matter in the observable universe is a consequence of an initial non-uniformity of the baryon-photon fluid in the last scattering surface, an investigation of clustering of the isotherms in the cosmic microwave background has been performed. The isotherms clustering has been related to the baryon-photon fluid dynamics and the Taylor-microscale Reynolds number of this motion is estimated to be $10^2$. 3-year WMAP cosmic microwave background map has been used in this investigation. 
A. Bershadskii