Regularity of Solutions to Degenerate Non-Doubling Second Order   Equations
  We prove that every weak solution to a certain class of infinitely degenerate quasilinear equations is continuous. An essential feature of the operators we consider is that their Fefferman-Phong associated metric may be non doubling with respect to Lebesgue measure. 
Lyudmila Korobenko and Cristian Rios
math.AP