Fuchsian ODEs as Seiberg dualities

The classical theory of Fuchsian differential equations is largely equivalent to the theory of Seiberg dualities for quiver SUSY gauge theories. In particular: all known integral representations of solutions, and their connection formulae, are immediate consequences of (analytically continued) Seiberg duality in view of the dictionary between linear ODEs and gauge theories with $4$ supersymmetries. The purpose of this divertissement is to explain “physically” this remarkable relation in the spirit of Physical Mathematics. The connection goes through a “mirror-theoretic” identification of irreducible logarithmic connections on $\mathbb{P}^1$ with would-be BPS dyons of 4d $\mathcal{N} = 2 \: SU(2)$ SYM coupled to a certain Argyres–Douglas “matter”. When the underlying bundle is trivial, i.e. the log‑connection is a Fuchs system, the world-line theory of the dyon simplifies and the action of Seiberg duality on the Fuchsian ODEs becomes quite explicit. The duality action is best described in terms of Representation Theory of Kac–Moody Lie algebras (and their affinizations).