Codimension Two Branes in Einstein-Gauss-Bonnet Gravity
  Codimension two branes play an interesting role in attacking the cosmological constant problem. Recently, in order to handle some problems in codimension two branes in Einstein gravity, Bostock {\it et al.} have proposed using six-dimensional Einstein-Gauss-Bonnet (EGB) gravity instead of six-dimensional Einstein gravity. In this paper, we present the solutions of codimension two branes in six-dimensional EGB gravity. We show that Einstein's equations take a "factorizable" form for a factorized metric tensor ansatz even in the presence of the higher-derivative Gauss-Bonnet term. Especially, a new feature of the solution is that the deficit angle depends on the brane geometry. We discuss the implication of the solution to the cosmological constant problem. We also comment on a possible problem of inflation model building on codimension two branes. 
Peng Wang, Xin-He Meng (Nankai U.)