Entropy flow and the g-theorem in quantum critical matter
A recent publication analyzes the fate of the g-theorem in the pseudogap Bose-Fermi Kondo model. This model contains various quantum impurity models as special cases. Contrary to earlier investigations, we reach the conclusion that the g-theorem is not valid for the SU(N) symmetric version of this model. As a result, the boundary entropy may increase along the RG flow. The origin of the inapplicability of the g-theorem is traced back to anomalous contributions of the large-N scaling functions.
