Localizing Gravity on a String-Like Defect in Six Dimensions
  We present a metric solution in six dimensions where gravity is localized on a four-dimensional singular string-like defect. The corrections to four-dimensional gravity from the bulk continuum modes are suppressed by ${\cal O}(1/r^3)$. No tuning of the bulk cosmological constant to the brane tension is required in order to cancel the four-dimensional cosmological constant. 
Tony Gherghetta and Mikhail Shaposhnikov