Holographic Wilsonian flows and emergent fermions in extremal charged black holes (Part II)

Recently, a holographic description of field theories with a cutoff
has been proposed by Heemskerk and Polchinski, leading to a
holographic version of the Wilsonian renormalization group. In this
talk, we will describe how to generalize these ideas to fermionic
operators. We will then proceed to apply them to study RG flows in
extremal charged black hole backgrounds. Such backgrounds have a dual
field theory description, which for certain values of the parameters
can have a Fermi surface. The dynamics near the Fermi surface was
captured by Faulkner and Polchinski in an effective semi-holographic
model, containing a strongly coupled sector and an additional fermion
coupled to it. We will show how this effective model can be derived
using the ideas of holographic Wilsonian renormalization group, and in
particular how the additional fermion emerges in the low energy
effective action.