Zusammenfassung
We introduce the notion of generalized hyperpolygon, which arises as a
representation, in the sense of Nakajima, of a comet-shaped quiver. We identify
these representations with rigid geometric figures, namely pairs of polygons:
one in the Lie algebra of a compact group and the other in its
complexification. To such data, we associate an explicit meromorphic Higgs
bundle on a genus-$g$ Riemann surface, where $g$ is the number of loops in the
comet, thereby embedding the Nakajima quiver variety into a Hitchin system on a
punctured genus-$g$ Riemann surface (generally with positive codimension). We
show that, under certain assumptions on flag types, the space of generalized
hyperpolygons admits the structure of a completely integrable Hamiltonian
system of Gelfand-Tsetlin type, inherited from the reduction of partial flag
varieties. In the case where all flags are complete, we present the
Hamiltonians explictly. We also remark upon the discretization of the Hitchin
equations given by hyperpolygons, the construction of triple branes (in the
sense of Kapustin-Witten mirror symmetry), and dualities between tame and wild
Hitchin systems (in the sense of Painlevé transcendents).
Nutzer