Scaling, renormalization and statistical conservation laws in the   Kraichnan model of turbulent advection
  We present a systematic way to compute the scaling exponents of the structure functions of the Kraichnan model of turbulent advection in a series of powers of $\xi$, adimensional coupling constant measuring the degree of roughness of the advecting velocity field. We also investigate the relation between standard and renormalization group improved perturbation theory. The aim is to shed light on the relation between renormalization group methods and the statistical conservation laws of the Kraichnan model, also known as zero modes. 
Antti Kupiainen and Paolo Muratore-Ginanneschi