A Coulomb branch viewpoint on quiver indices

par Boris Pioline (CERN)

jeudi 8 janv. 2015, 11:00 → 12:00 Europe/Paris

Auditorium (Annecy-le-Vieux)

Quiver quantum mechanics is a useful tool for describing BPS bound states in $N=2$ gauge theories and string vacua. In a recent series of works with J. Manschot and A. Sen, we proposed a formula that expresses the BPS index of quiver quantum mechanics with generic superpotential in terms of a set of invariants associated to ''single-centered'' or ''pure-Higgs'' states. The distinguishing feature of these invariants is that they are insensitive to the Fayet-Iliopoulos parameters, in contrast to the BPS index which is discontinuous across walls of marginal stability. The formula suggests an effective Coulomb branch description in models where the Higgs and Coulomb branches do not decouple.