I am reading this paper where I am confused about equation 16.
It follows that (one-dimensional) loops can be linked with $K_0$ or, in other words, the space of gapped Floquet evolutions $SU (N )\backslash K_0$ has noncontractible loops, with winding invariant given by $\nu_0 =\frac{1}{i \pi N } Tr \int [F,\Gamma]^{-1} dF$
where $K_0$ is exacctly the space where the integrand diverges.
I undersatnd intuitively how this can be from the winding number where the integral is about an integrand that diverges at a single point. But I can't seem to be able to find the proof or the name of the theorem proving it.
