Configurations of two D-instantons
  The potential between two separated D-instantons at fixed (super) space-time points is obtained by a simple explicit integration over the `massive' variables of the zero-dimensional reduction of ten-dimensional U(2) super Yang-Mills theory. This potential vanishes for asymptotically large separations, becoming significant at separations of around the ten-dimensional Planck scale with a singularity at the origin, which is resolved by the extra `massless' internal Yang-Mills super-coordinates. 
M.B. Green (DAMTP, University of Cambridge, U.K.) and M. Gutperle   (DAMTP, University of Cambridge, U.K.)