ORBIFOLD RESOLUTION BY D-BRANES

We study topological properties of the D-brane resolution of three-dim ensional orbifold singularities, C-3/Gamma, for finite abelian groups Gamma. The D-brane vacuum moduli space is shown to fill out the backgr ound space-time with Fayet-lliopoulos parameters controlling the size of the blow-ups. This D-brane vacuum moduli space can be classically d escribed by a gauged linear sigma model, which is shown to be non-gene ric in a manner that projects out non-geometric regions in its phase d iagram, as anticipated from a number of perspectives. (C) 1997 Publish ed by Elsevier Science B.V.