Fifty years ago Wilson and Fisher published their renowned paper on the epsilon-expansion of the critical $O(N)$ model. Nowadays we may think of the critical $O(N)$ model as a two-parameter family of conformal field theories, labeled by $N$ and spacetime dimension $d$. Advances in both diagrammatic technology and CFT methods have led to a constant supply of new results for the $O(N)$ CFT, both perturbatively and non-perturbatively. In this talk, I will give an introduction to the $O(N)$ CFT from the perspective of conformal field theory, with a focus on the often-implicit assumption of spectrum continuity, which is the conjectural assumption that all conformal data, such as critical exponents and operator scaling dimensions, depend continuously on the parameters $N$ and $d$.

Per partecipare in presenza, prenotarsi seguendo il link https://docs.google.com/document/d/1uaw5DHG0VykTHraDiAqYjbLFXsrOIXaftj_n04sj4PE/edit?usp=sharing
oppure per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271