Friedmann cosmology on codimension 2 brane with time dependent tension
  A solution of codimension 2 brane is found for which 4 dimensional Friedmann cosmology is recovered on the brane with time dependent tension, in the Einstein frame. The effective parameter $p/\rho$ of equation of state on the brane can be quintessence like, de Sitter like or phantom like, depending on integration constants of the solution. 
Hongsheng Zhang, Qi Guo and Rong-Gen Cai