  We show that the Mott metal-insulator transition in the standard one-band
Hubbard model can be understood as a topological phase transition. Our approach
is inspired by the observation that the mid-gap pole in the self-energy of a
Mott insulator resembles the zero-energy spectral pole of the localized surface
state in a topological insulator. We use NRG-DMFT to solve the
infinite-dimensional Hubbard model, and represent the resulting local
self-energy in terms of the boundary Green's function of an auxiliary
tight-binding chain without interactions. The auxiliary system is of
generalized SSH model type; the Mott transition corresponds to a dissociation
of domain walls.
