D-instantons and matter hypermultiplet

We calculate the D-instanton corrections (with all D-instanton numbers) to the quantum moduli space metric of a single matter hypermultiplet with toric isometry, in the effective N=2 supergravity arising in type IIA superstrings compactified on a Calabi–Yau (CY) threefold of Hodge number h2,1=1. The non-perturbative quaternionic hypermultiplet metric is derived by resolution of a complex orbifold singularity, thus generalizing the known (Ooguri–Vafa) solution in flat spacetime to N=2 supergravity.