ALESSANDRO CODELLO CP3-Origins Odense (Danmark): Functional renormalization group (FRG) methods have proven very useful in the study of universality classes in arbitrary dimension, even fractional. As a result one obtains criticai exponents that are function of d, as well as other parameters, as for example the number of field components N. The question that naturally arises is the interpretation of criticai exponents in non integer dimension and their relation with statistica' models defined directly on fractals. After briefly introducing the FRG I will present some results for Z2 and 0(N) universality in integer and non integer dimension and their connection with statistica' models.

DATA: 13-11-2015