Abstract :
We suggest that for singular rotationally invariant closed string backgrounds which need sources for their support at the origin (in particular, for special plane waves and fundamental strings) certain ‘trivial’ α′-corrections (which are usually ignored since in the absence of sources they can be eliminated by a field redefinition) may play an important role leading to the absence of singularities in the exact solutions. These corrections effectively regularize the source delta-function at the scale α′. We demonstrate that similar smearing of the singularity of the leading-order point-charge solution indeed takes place in the open string theory.
