D-instantons and twistors: some exact results
D-instantons and twistors: some exact results
We present some results on instanton corrections to the hypermultiplet moduli space in Calabiā€“Yau compactifications of type-II string theories. Previously, using twistor methods, only a class of D-instantons (D2-instantons wrapping A-cycles) was incorporated exactly and the rest was treated only linearly. We go beyond the linear approximation and give a ā€¦