TY - JOUR T1 - Two Dimensional Interface Problems for Elliptic Equations AU - Lung-an Ying JO - Journal of Partial Differential Equations VL - 1 SP - 37 EP - 48 PY - 2003 DA - 2003/02 SN - 16 DO - http://doi.org/ UR - https://global-sci.org/intro/article_detail/jpde/5404.html KW - Quasilinear elliptic equations KW - interface problems KW - weak solutions KW - singular points AB - We study the structure of solutions to the interface problems for second order quasi-linear elliptic partial differential equations in two dimensional space. We prove that each weak solution can be decomposed into two parts near singular points, a finite sum of functions in the form of cr^α log^m rφ(θ) and a regular one w. The coefficients c and the C^{1,α} norm of w depend on the H¹-norm and the C^{º, α}-norm of the solution, and the equation only.