Target Space Structure of a Chiral Gauged Wess-Zumino-Witten Model
  The background for string propagation is obtained by a chiral gauging of the $SL(2,R)$ Wess-Zumino-Witten model. It is shown explicitly that the resulting background fields satisfy the field equations of the three dimensional string effective action and the target space has curvature singularity. Close connection of our solution with the three dimensional black string is demonstrated. 
Supriya K. Kar and Alok Kumar