Journal of High Energy Physics (Jul 2017)
BPS graphs: from spectral networks to BPS quivers
Abstract
Abstract We define “BPS graphs” on punctured Riemann surfaces associated with A N −1 theories of class S $$ \mathcal{S} $$ . BPS graphs provide a bridge between two powerful frameworks for studying the spectrum of BPS states: spectral networks and BPS quivers. They arise from degenerate spectral networks at maximal intersections of walls of marginal stability on the Coulomb branch. While the BPS spectrum is ill-defined at such intersections, a BPS graph captures a useful basis of elementary BPS states. The topology of a BPS graph encodes a BPS quiver, even for higher-rank theories and for theories with certain partial punctures. BPS graphs lead to a geometric realization of the combinatorics of Fock-Goncharov N - triangulations and generalize them in several ways.
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