BSM

Abstract

I will explain how the wall-crossing behaviour of D-brane instantons in type II Calabi-Yau compactifications is captured by a certain hyperholomorphic line bundle over a hyperkähler manifold. This construction relies on a general duality between 4n-dimensional quaternion-Kähler and hyperkähler spaces with certain continuous isometries. The continuity of the moduli space metric across walls of marginal stability is encoded in non-trivial identities for the Rogers dilogarithm, which are shown to be a consequence of the motivic Kontsevich-Soibelman wall-crossing formula. Finally, I will offer some speculations on how the construction is modified in the presence of NS5-brane effects.