Andrea Trombettoni - CNR-IOM Trieste #
On the properties of two lattice models with long-range couplings #
I will present results on the effects of long-range couplings in two lattice models: 
(i) O\((N)\) models; and (ii) non-interacting fermions. For (i) we study O\((N)\) 
models 
with 
power-law interactions by using functional renormalization group techniques: we show 
that both in the Local Potential Approximation (LPA) and in LPA' all the universality 
classes are the same of the ones of the corresponding short-range O\((N)\) model at an 
effective fractional dimension, so that the critical exponents can be computed for the 
short-range ones. For (ii) we study the effects on the entanglement entropy of the 
long-range-ness of the hoppings for a model of free fermions on a lattice, pointing 
out that deviations from the area law can emerge in presence of a magnetic phase or 
randomness.