Scale Invariance in the Causal Approach to Renormalization Theory

The dilation invariance is studied in the framework of Epstein-Glaser approach to renormalization theory. Some analogues of the Callan-Symanzik equations are found and they are applied to the scalar field theory and to Yang-Mills models. We find the interesting result that, if all the fields of the theory have zero masses, then from purely cohomological consideration, one can obtain the anomalous terms of logarithmic type.