Orateur
Prof.
John GRACEY
(University of Liverpool)
Description
We use the large N expansion to compute d-dimensional critical exponents at O(1/N^3) for a generalization of the Gross-Neveu Yukawa universality class that includes a non-abelian symmetry. Specific groups correspond to certain phase transitions in condensed matter physics such as graphene. The effect of the non-abelian symmetry on the exponents is evidenced by the appearance of rank 4 Casimirs in the higher order 1/N analytic corrections. These in effect tag the light-by-light diagrams. The main benefit of the final expressions for the exponents is that one can recover previous results for a variety of universality classes in various limits.
