RG flows between Gaussian fixed points
Roberto Percacci (SISSA, Trieste)

A scalar theory can have many Gaussian (free) fixed points, corresponding to Lagrangians of the form ‑\phi\box^n\phi. We use the non-perturbative RG to study the flow from the free theory with four derivatives (n = 2) to the free theory with two derivatives (n = 1), in the presence of a shift-invariant interaction. We show that the anomalous dimension changes continuously in such a way that at the endpoints the fields have the correct dimensions of the respective free theories. These results generalize to other values of n, as well as to nonlinear sigma models.