Percolation process in the presence of velocity fluctuations: One-loop approximation

Critical behaviour of directed bond percolation is studied in presence of an advective velocity field. The velocity field is assumed to be incompressible and generated by the Kraichnan model. The model is studied by means of fieldtheoretic approach. The renormalization group (RG) method is used in order to analyse asymptotic large-scale behaviour of the model near its critical point and to calculate perturbatively all fixed RG points and critical exponents in the framework of double-expansion scheme [1]. We classify possible asymptotic regimes corresponding to infrared stable fixed points of the RG equations which have been calculated up to the one-loop approximation.