  Network models for equilibrium integer quantum Hall (IQH) transitions are
described by unitary scattering matrices, that can also be viewed as
representing non-equilibrium Floquet systems. The resulting Floquet bands have
zero Chern number, and are instead characterized by a chiral Floquet (CF)
winding number. This begs the question: How can a model without Chern number
describe IQH systems? We resolve this apparent paradox by showing that non-zero
Chern number is recovered from the network model via the energy dependence of
network model scattering parameters. This relationship shows that, despite
their topologically distinct origins, IQH and CF topology-changing transitions
share identical universal scaling properties.
