  We consider the Ginzburg-Landau phase transition model with O(n) symmetry
(i.e., the n-vector model) which includes a quenched randomness, i.e., a random
temperature disorder. We have proven rigorously that within the diagrammatic
perturbation theory the quenched randomness does not change the critical
exponents at n tending to 0, which is in contrast to the conventional point of
view based on the perturbative renormalization group theory.
