A Remark on Smoothing Out Higher Codimension Branes
  We discuss some issues arising in studying (linearized) gravity on non-BPS higher codimension branes in an infinite-volume bulk. In particular, such backgrounds are badly singular for codimension-3 and higher delta-function-like branes with non-zero tension. As we discuss in this note, non-trivial issues arise in smoothing out such singularities. Thus, adding higher curvature terms might be necessary in this context. 
Olindo Corradini, Alberto Iglesias, Zurab Kakushadze and Peter   Langfelder