On singularities of spherically symmetric backgrounds in string theory

TL;DR

The paper explores how certain orrections in string theory can regularize singularities in spherically symmetric backgrounds, especially near sources, by effectively smearing out delta-function singularities at the -scale.

Contribution

It shows that trivial orrections, often ignored, can eliminate singularities in string backgrounds with sources, providing a new perspective on regularization.

Findings

orrections can regularize source singularities

Smearing of delta-function singularities occurs at the -scale

Similar effects observed in open string theory

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' \a'-corrections (which are usually ignored since in the absence of sources they can be eliminated by a field redefinition) may play an important role eliminating the singularities in the exact solutions. These corrections effectively regularize the source delta-function at the \a'-scale. We demonstrate that similar smearing of the singularity of the leading-order point-source solution indeed takes place in the open string theory.