ABSTRACT
Φ , which w ill be called random fields, depend not only on
the impurity configuration (which we denoted by φ before),
but also on all the elim inated modes. They can be regarded
N ON M A GNETIC IM P U R IT IE S 371
as the "dressed impurities, n i. e. , the combined effect of
impurities and the eliminated modes. Qualitatively, the
RG approach w ill concentrate on how the impurities are
ndressedn upon repeated coarse graining. If the effect of
impurities is diminished upon dressing, the critical behav-
ior w ill not be affected qualitatively. If the effect is ampli-
fied, the critical behavior w ill be affected qualitatively.
