Summing up Dirichlet Instantons

Summing up Dirichlet Instantons.

We investigate quantum corrections to the moduli space for hypermultiplets for the type IIA string near a conifold singularity. We find a unique quantum deformation based on symmetry arguments which is consistent with a recent conjecture. The correction can be interpreted as an infinite sum coming from multiple wrappings of the Euclidean Dirichlet branes around the vanishing cycle. [S0031-9007(...

Summing up D-Instantons

We investigate quantum corrections to the moduli space for hypermultiplets for type IIA near a conifold singularity. We find a unique quantum deformation based on symmetry arguments which is consistent with a recent conjecture. The correction can be interpreted as an infinite sum coming from multiple wrappings of the Euclidean D-branes around the vanishing cycle.

Summing up Open String Instantons and N=1 String Amplitudes

We compute the instanton expansions of the holomorphic couplings in the effective action of certain N = 1 supersymmetric four-dimensional open string vacua. These include the superpotential W (φ), the gauge kinetic function f(φ) and a series of other holomorphic couplings which are known to be related to amplitudes of topological open strings at higher world-sheet topologies. The results are in...

Summing up.

Summing Up